tag:theconversation.com,2011:/us/topics/satellite-imaging-41480/articlesSatellite imaging – The Conversation2024-02-13T15:04:44Ztag:theconversation.com,2011:article/2221072024-02-13T15:04:44Z2024-02-13T15:04:44Z17 million South Africans live on communal land – new study of a rural valley offers insights on how to manage it<figure><img src="https://images.theconversation.com/files/572398/original/file-20240131-19-f7h2o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Tyhume Valley in Eastern Cape, South Africa.</span> <span class="attribution"><span class="source">Wonga Masiza</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The Tyhume River, flowing from the forested Amathole Mountains in South Africa’s Eastern Cape province, gives its name to a valley of 20 villages on communal land. Much of the land is being used to keep livestock, as crop production has declined over the years. This land is <a href="https://www.sciencedirect.com/science/article/abs/pii/S0264837712001998?via%3Dihub">under the custodianship of traditional leaders</a>.</p>
<p>The valley is typical of South Africa’s communal land: affected by <a href="https://doi.org/10.2989/10220119.2022.2138973">soil erosion</a>, <a href="https://www.tandfonline.com/doi/abs/10.1080/00207233.2021.1886557">bush encroachment</a> and <a href="http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0301-603X2022000200005">water scarcity</a>. </p>
<p>About one third (over 17 million) of <a href="https://www.parliament.gov.za/storage/app/media/Pages/2017/october/High_Level_Panel/Commissioned_Report_land/Commisioned_Report_on_Tenure_Reform_LARC.pdf">South Africa’s population lives on communal land</a>, which makes up around <a href="https://sarpn.org/documents/d0002695/index.php">13%</a> of all land in the country. The <a href="https://www.gov.za/sites/default/files/gcis_document/201707/40965gen510.pdf">Communal Land Tenure Bill, 2017</a> defines communal land as “owned, occupied or used by members of a community subject to shared rules or norms and customs”. It can also be owned by the state.</p>
<p>This land can benefit rural communities by providing ecosystem goods and services, such as shelter, water, fuelwood, food and cultural amenities. But natural processes and human activity can transform the land. </p>
<p>Unmonitored and poorly managed land changes can trigger soil erosion, overgrazing, loss of biodiversity and water scarcity. In South Africa, communal land is considered to be <a href="https://doi.org/10.1002/pan3.10260">more degraded than privately owned land</a>. This can negatively affect the livelihoods of people who derive ecosystem services from it.</p>
<p>Common indicators and causes of land degradation are generally understood. But less is known about how people living in communal lands interpret land changes and their impact. It’s unclear what they perceive as land degradation or which kinds of land changes matter most to them. This helps explain the lack of sound policies and practical strategies to rehabilitate land.</p>
<p>Our team of geoinformation scientists at South Africa’s Agricultural Research Council and the University of the Free State carried out <a href="https://www.frontiersin.org/articles/10.3389/fcosc.2023.1205750/full">a study</a> which mapped land use and land cover change in the Tyhume Valley over 30 years. </p>
<p>To understand the extent, causes and impact of communal land change, we analysed a series of historical satellite images from 1989 to 2019 and conducted interviews with locals. Instead of interviewing experts and leaders, the study measured the most common perceptions among community members.</p>
<p>As far as we know, this study is one of the first in South Africa to combine satellite data and local perceptions. This offered a more complete view of communal land change, and valuable insights on its impacts. </p>
<p>We suggested some ways in which this land could be managed better to provide ecosystem services and livelihoods. </p>
<h2>Satellite imagery and community perceptions</h2>
<p>Our study set out to discover whether satellite-measured trends of land use and land cover corresponded with those perceived by the community. We also explored the causes, rate and impact of these trends.</p>
<p>Satellite imagery from 1989 to 2019 revealed increases of the sweet thorn tree (<em>Vachellia karroo</em>) by 25% and the residential area (2.5%). It showed declines of grazing land (18%), cropland (9.6%) and dams (1.1%). </p>
<p>Assisted by 102 long-standing residents, most above 50 years of age, we asked about the causes and impacts of the observed changes. </p>
<p>Most respondents (over 80%) noted the encroachment of the sweet thorn tree on grazing land and abandoned cropland. They said contributing factors were a decrease in fuelwood harvesting due to increased reliance on electricity, the abandonment of cropland (providing habitat for the sweet thorn) and seed dispersal caused by unrestricted movement of animals. Many saw the tree as beneficial because goats like to eat it and it makes good fuel. Others were concerned that this tree was invading productive agricultural land and causing a loss of biodiversity. They mentioned increased scarcity and disappearance of medicinal and culturally significant plants.</p>
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Read more:
<a href="https://theconversation.com/smallholder-crop-farming-is-on-the-decline-in-south-africa-why-it-matters-119333">Smallholder crop farming is on the decline in South Africa. Why it matters</a>
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<p>Most respondents noted a decrease in grazing land, cropland and surface water. As reasons, they cited lack of access control (poor management, allowing bush encroachment), lack of farmer support and equipment, and poor rainfall.</p>
<p>New houses had been erected on grazing land. This was seen as a result of population increase and inward migration. Livestock farmers saw this as a problem because they had to buy fodder or trek their cattle long distances to graze. The population increase also put strain on water resources.</p>
<p>Every village in the area had at least one communal dam that had dried up. Despite 14 years of below-average rainfall and a negative rainfall trend between 1989 and 2019, the trend was not statistically significant. The community perceived that water resources had declined because of overuse and poor maintenance of dams. They said the government no longer desilted community dams, and that the community had abandoned traditional practices such as the maintenance of surface water channels and homestead ponds. </p>
<p>They gave water scarcity as one of the main reasons that croplands had been abandoned.</p>
<p>Most said the communal lands were healthier and offered more resources when areas were fenced off and people had to get permits to use land. Local residents had <a href="https://link.springer.com/article/10.1007/s10745-006-9062-9">cut fences</a> to give their animals unlimited access to grazing and water.</p>
<p>Overall, the changes to the Tyhume Valley environment were not positive. The respondents said the decline in agricultural activity had resulted in increased unemployment and consumption of unhealthy food.</p>
<p>Similar changes have been reported on <a href="https://www.tandfonline.com/doi/abs/10.1080/03057070.2014.943525">many other communal lands</a>.</p>
<h2>Better land management</h2>
<p>The land can be better managed through interventions by village committees, tribal authorities and extension services, and by following spatial planning and land use guidelines.</p>
<p>The sweet thorn can be controlled by stocking more browsing animals. <a href="https://www.tandfonline.com/doi/abs/10.2989/10220119.2016.1178172">Studies</a> have demonstrated that this plant has a high nutritive value.</p>
<p>The community, with help from the government, needs to reinstate water harvesting practices and the regular desilting of dams. Other communal <a href="https://www.drdar.gov.za/restoreddamsreducelivestockmortality/">dam restoration projects</a> in the Eastern Cape have succeeded by dredging and augmentation of stock dams.</p>
<p>This study shows that the combination of <a href="https://theconversation.com/technique-developed-in-kenya-offers-a-refined-way-to-map-tree-cover-76709">satellite imagery</a> and local perceptions provides valuable insights about the extent, causes and impacts of land change in communal areas.</p><img src="https://counter.theconversation.com/content/222107/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wonga Masiza receives funding from Agricultural Research Council.</span></em></p>Satellite images and community perceptions combine to give a fuller picture of land use changes.Wonga Masiza, Researcher, Agricultural Research CouncilLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2143072024-01-04T20:01:53Z2024-01-04T20:01:53ZBecome a beach scientist this summer and help monitor changing coastlines<figure><img src="https://images.theconversation.com/files/565647/original/file-20231213-17-zlgqzp.jpg?ixlib=rb-1.1.0&rect=35%2C11%2C3958%2C2257&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">CoastSnap</span></span></figcaption></figure><p>When you arrive at your favourite beach these summer holidays, you may notice something different about the coast. </p>
<p>With the triple-dip La Niña now <a href="https://media.bom.gov.au/releases/1205/the-bureau-forecasts-an-unusually-warm-summer/">making way for El Niño</a>, our beaches have been through a rollercoaster ride. Some beaches have been completely stripped of sand, while others have grown very wide. </p>
<p>In the past, such changes went mostly unrecorded. However, thanks to a project <a href="https://www.coastsnap.com/">known as CoastSnap</a>, coastal data is now being collected like never before. Using designated camera cradles installed at beach viewpoints, CoastSnap uses community snapshots taken on smartphones to track beach change. </p>
<p>Almost <a href="https://www.spotteron.com/coastsnap/">50,000 photos</a> have been collected so far. They have revealed a varying picture in recent years: from <a href="https://www.abc.net.au/news/2020-02-12/tropical-cyclone-uesi-bring-dangerous-conditions-nsw-coast/11955628">dramatic beach loss during La Niña storms three years ago</a>, to <a href="https://www.smh.com.au/environment/climate-change/the-sydney-beach-that-s-grown-by-59-metres-since-last-summer-20230921-p5e6id.html">60 metres of beach growth in recent months</a>. So with smartphones as commonplace as towels and sunscreen in the beach bag, why not add coastal data collection to your list of holiday activities this summer?</p>
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<a href="https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="CoastSnap stainless steel camera cradle with smartphone placed in it, overlooking Manly beach" src="https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563079/original/file-20231203-29-n4laod.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A CoastSnap community beach monitoring station at Manly Beach in Sydney, Australia.</span>
<span class="attribution"><span class="source">Larry Paice</span></span>
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<h2>Turning beach snaps into scientific data</h2>
<p>Through CoastSnap, we installed a network of stainless-steel camera cradles along coastal trails all around the world. These camera cradles are positioned at a perfect vantage point for tracking changes to the coast – whether it be due to rising sea levels, extreme storms or other factors.</p>
<p>All you need to do is place your camera in the cradle, take a photo and upload it using the QR code at the station. Because the position and angle of the photo is always the same, over time these snaps reveal how the beach is changing.</p>
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Read more:
<a href="https://theconversation.com/millions-of-satellite-images-reveal-how-beaches-around-the-pacific-vanish-or-replenish-in-el-nino-and-la-nina-years-198505">Millions of satellite images reveal how beaches around the Pacific vanish or replenish in El Niño and La Niña years</a>
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<p>As well as being a powerful visual record, <a href="https://www.sciencedirect.com/science/article/pii/S0278434322001492">sophisticated algorithms</a> turn each photo into miniature satellite images that are used to precisely measure shoreline position. This is done using a <a href="https://en.wikipedia.org/wiki/Photogrammetry">process known as photogrammetry</a>, in which pixels in the image are rearranged as though they had been taken from space. </p>
<p>This aerial view enables beach change to be easily measured. Also, since the exact time of photo capture is recorded, the effects of tides as they vary throughout the day can be accounted for.</p>
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<a href="https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="CoastSnap photo of beach (left) and equivalent photo converted to an aerial photo with a red line to mark out the shoreline" src="https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=317&fit=crop&dpr=1 600w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=317&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=317&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=398&fit=crop&dpr=1 754w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=398&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/563240/original/file-20231204-17-8678xw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=398&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">CoastSnap photos are converted to a miniature satellite image using a process known as photogrammetry.</span>
<span class="attribution"><span class="source">Mitchell Harley</span></span>
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<h2>From local to global: a network of community beach monitoring</h2>
<p>From its beginnings on the Northern Beaches of Sydney in 2017, new CoastSnap stations have been rolled out all around the world. We now have more than 350 CoastSnap stations in 31 countries and across five continents. </p>
<p>This makes it the largest coordinated network of coastal monitoring worldwide – and all the data is collected by the community.</p>
<p>In Ghana, West Africa, students from local schools are using CoastSnap to <a href="https://theconversation.com/ghanas-fishing-industry-has-a-golden-seaweed-problem-how-citizen-science-can-help-203007">better understand how the “golden seaweed” sargassum impacts fishing communities</a>.</p>
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Read more:
<a href="https://theconversation.com/like-20-tip-trucks-pouring-sand-on-every-metre-wide-strip-how-extreme-storms-can-replenish-beaches-not-just-erode-them-182039">‘Like 20 tip trucks pouring sand on every metre-wide strip’: how extreme storms can replenish beaches, not just erode them</a>
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<p>On Prince Edward Island in Canada, CoastSnap captured the <a href="https://www.cbc.ca/news/canada/prince-edward-island/pei-fiona-coastal-climate-change-1.6599408">damage done by Hurricane Fiona last year</a>. The same stations are now being used to track the post-hurricane dune recovery.</p>
<p>In Australia, there are currently 125 CoastSnap stations around the country. This enables a big-picture assessment of the coastal consequences of large-scale weather events. For example, during <a href="https://theconversation.com/the-east-coast-rain-seems-endless-where-on-earth-is-all-the-water-coming-from-178316">last year’s record rainfall in eastern Australia</a>, extreme erosion was observed at CoastSnap stations from Queensland to southern New South Wales. The images reveal scouring by floodwaters was the main cause of beach erosion in many locations, rather than wave action as is usually the case.</p>
<p><div data-react-class="TiktokEmbed" data-react-props="{"url":"https://www.tiktok.com/@coastsnap/video/7192798251588898049"}"></div></p>
<h2>Monitoring the present to plan for the future</h2>
<p>Data on coastal change is crucial for managing coastlines into the future. This is particularly important as sea levels continue to rise, storm tracks shift, and beaches come under increasing pressure from overdevelopment.</p>
<p>With several CoastSnap stations already operating for over six years now, this growing record is beginning to observe longer-term changes to the coast. This data is being fed into numerical models that help coastal researchers predict what the coastline will be like in the coming decades – and plan accordingly.</p>
<p>Smart coastal planning will help buffer climate change impacts. This will go some way to ensure future generations can enjoy the coast like we do today. </p>
<p>So as you head out to the beach this summer, look out for your nearest CoastSnap station and help monitor the coastline – it really is a “snap”!</p>
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Read more:
<a href="https://theconversation.com/storms-or-sea-level-rise-what-really-causes-beach-erosion-209213">Storms or sea-level rise – what really causes beach erosion?</a>
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<img src="https://counter.theconversation.com/content/214307/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mitchell Harley receives funding from the Australian Research Council. He is also the New South Wales Chair of the Australian Coastal Society.</span></em></p><p class="fine-print"><em><span>Fred Chaaya works for the University Of New South Wales Water Research Laboratory, which manages the CoastSnap project and network.</span></em></p>With smartphones as commonplace as towels and sunscreen in the beach bag, why not add coastal data collection to your list of holiday activities this summer? Look for the CoastSnap camera cradles.Mitchell Harley, Scientia Senior Lecturer, UNSW SydneyFred Chaaya, Project Engineer, UNSW Water Research LaboratoryLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2193672024-01-03T16:00:11Z2024-01-03T16:00:11ZWe used AI and satellite imagery to map ocean activities that take place out of sight, including fishing, shipping and energy development<figure><img src="https://images.theconversation.com/files/566911/original/file-20231220-19-b20mqb.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4839%2C3265&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many commercial fishing boats do not report their positions at sea or are not required to do so.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/aerial-view-of-small-fishing-boat-in-open-ocean-royalty-free-image/1285320085">Alex Walker via Getty Images</a></span></figcaption></figure><p>Humans are racing to harness the ocean’s vast potential to power global economic growth. Worldwide, ocean-based industries such as fishing, shipping and energy production generate at least <a href="https://doi.org/10.1787/9789264251724-en">US$1.5 trillion</a> in economic activity each year and support <a href="https://doi.org/10.1787/9789264251724-en">31 million jobs</a>. This value has been <a href="https://doi.org/10.1016/j.oneear.2019.12.016">increasing exponentially</a> over the past 50 years and is expected to double by 2030. </p>
<p>Transparency in monitoring this “blue acceleration” is crucial to prevent <a href="http://dx.doi.org/10.5281/zenodo.3553458">environmental degradation</a>, <a href="https://doi.org/10.4060/cc0461en">overexploitation</a> of fisheries and marine resources, and <a href="https://www.newyorker.com/magazine/2023/10/16/the-crimes-behind-the-seafood-you-eat">lawless behavior</a> such as illegal fishing and human trafficking. Open information also will make countries better able to manage vital ocean resources effectively. But the sheer size of the ocean has made tracking industrial activities at a broad scale impractical – until now.</p>
<p>A newly published study in the journal Nature combines satellite images, vessel GPS data and artificial intelligence to <a href="https://dx.doi.org/10.1038/s41586-023-06825-8">reveal human industrial activities across the ocean</a> over a five-year period. Researchers at <a href="https://globalfishingwatch.org/">Global Fishing Watch</a>, a nonprofit organization dedicated to advancing ocean governance through increased transparency of human activity at sea, led this study, in collaboration with <a href="https://scholar.google.com/citations?user=ArWZ7X0AAAAJ&hl=en">me</a> and our colleagues at Duke University, University of California, Santa Barbara and <a href="https://skytruth.org/">SkyTruth</a>.</p>
<p>We found that a remarkable amount of activity occurs outside of public monitoring systems. Our new map and data provide the most comprehensive public picture available of industrial uses of the ocean.</p>
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<a href="https://images.theconversation.com/files/566373/original/file-20231218-27-k4cjbr.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A world map shows large areas where industrial fishing activity is not publicly tracked or recorded." src="https://images.theconversation.com/files/566373/original/file-20231218-27-k4cjbr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566373/original/file-20231218-27-k4cjbr.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=309&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566373/original/file-20231218-27-k4cjbr.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=309&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566373/original/file-20231218-27-k4cjbr.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=309&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566373/original/file-20231218-27-k4cjbr.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=388&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566373/original/file-20231218-27-k4cjbr.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=388&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566373/original/file-20231218-27-k4cjbr.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=388&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Data analysis reveals that about 75% of the world’s industrial fishing vessels are not publicly tracked, with much of that fishing taking place around Africa and South Asia.</span>
<span class="attribution"><span class="source">Global Fishing Watch</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
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<h2>Operating in the dark</h2>
<p>Our research builds on existing technology to provide a much more complete picture than has been available until now. </p>
<p>For example, many vessels carry a device called an automatic identification system, or AIS, that automatically broadcasts the vessel’s identity, position, course and speed. These devices <a href="https://shipping.nato.int/nsc/operations/news/2021/ais-automatic-identification-system-overview">communicate with other AIS devices nearby</a> to improve situational awareness and reduce the chances of vessel collisions at sea. They also transmit to shore-based transponders and satellites, which can be used to <a href="https://globalfishingwatch.org/our-map/">monitor vessel traffic and fishing activity</a>.</p>
<p>However, AIS systems have blind spots. Not all vessels are required to use them, certain regions have poor AIS reception, and vessels engaged in illegal activities may <a href="https://theconversation.com/when-fishing-boats-go-dark-at-sea-theyre-often-committing-crimes-we-mapped-where-it-happens-196694">disable AIS devices</a> or <a href="https://youtu.be/Azm4yKKIlqE?si=vvng8to_Hsa13E1p">tamper with location broadcasts</a>. To avoid these problems, some governments require fishing vessels to use proprietary vessel monitoring systems, but the associated vessel location data is usually confidential.</p>
<p>Some offshore structures, such as oil platforms and wind turbines, <a href="https://www.amsa.gov.au/safety-navigation/navigation-systems/automatic-identification-systems-offshore-structures">also use AIS</a> to guide service vessels, monitor nearby vessel traffic and improve navigational safety. However, location data for offshore structures are often incomplete, outdated or kept confidential for bureaucratic or commercial reasons.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566375/original/file-20231218-23-bd69hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Fishermen wade into the ocean, pulling large nets." src="https://images.theconversation.com/files/566375/original/file-20231218-23-bd69hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566375/original/file-20231218-23-bd69hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566375/original/file-20231218-23-bd69hf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566375/original/file-20231218-23-bd69hf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566375/original/file-20231218-23-bd69hf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566375/original/file-20231218-23-bd69hf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566375/original/file-20231218-23-bd69hf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Fishermen haul their nets by hand from the beach in Muanda, Democratic Republic of Congo. Unregulated fishing by foreign trawlers and other factors have depleted fishing stocks and impoverished local fishermen.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/fishermen-haul-their-nets-by-hand-from-the-beach-in-muanda-news-photo/1237283044">Alexis Huguet/AFP via Getty Images</a></span>
</figcaption>
</figure>
<h2>Shining a light on activity at sea</h2>
<p>We filled these gaps by using artificial intelligence models to identify fishing vessels, nonfishing vessels and fixed infrastructure in 2 million gigabytes of satellite-based <a href="https://sentinels.copernicus.eu/web/sentinel/missions/sentinel-1">radar images</a> and <a href="https://sentinel.esa.int/web/sentinel/missions/sentinel-2">optical images</a> taken across the ocean between 2017 and 2021. We also matched these results to 53 billion AIS vessel position reports to determine which vessels were publicly trackable at the time of the image.</p>
<p>Remarkably, we found that about 75% of the fishing vessels we detected were missing from public AIS monitoring systems, with much of that activity taking place around Africa and South Asia. These previously invisible vessels radically changed our knowledge about the scale, scope and location of fishing activity.</p>
<p>For example, public AIS data wrongly suggests that Asia and Europe have comparable amounts of fishing within their borders. Our mapping reveals that Asia dominates: For every 10 fishing vessels we found on the water, seven were in Asia while only one was in Europe. Similarly, AIS data shows about 10 times more fishing on the European side of the Mediterranean compared with the African side – but our map shows that fishing activity is roughly equal across the two areas.</p>
<p>For other vessels, which are mostly transport- and energy-related, about 25% were missing from public AIS monitoring systems. Many missing vessels were in locations with poor AIS reception, so it is possible that they broadcast their locations but satellites did not pick up the transmission.</p>
<p>We also identified about 28,000 offshore structures – mostly oil platforms and wind turbines, but also piers, bridges, power lines, aquaculture farms and other human-made structures. Offshore oil infrastructure grew modestly over the five-year period, while the number of wind turbines more than doubled globally, with development mostly confined to northern Europe and China. We estimate that the number of wind turbines in the ocean likely surpassed the number of oil structures by the end of 2020.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/566913/original/file-20231220-23-fa89lc.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="World map with locations of wind turbines, oil and gas platforms and other structures highlighted along coastlines." src="https://images.theconversation.com/files/566913/original/file-20231220-23-fa89lc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/566913/original/file-20231220-23-fa89lc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=309&fit=crop&dpr=1 600w, https://images.theconversation.com/files/566913/original/file-20231220-23-fa89lc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=309&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/566913/original/file-20231220-23-fa89lc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=309&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/566913/original/file-20231220-23-fa89lc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=388&fit=crop&dpr=1 754w, https://images.theconversation.com/files/566913/original/file-20231220-23-fa89lc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=388&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/566913/original/file-20231220-23-fa89lc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=388&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Researchers combined machine learning and satellite imagery to create the first global map of offshore infrastructure, spotlighting previously unmapped industrial use of the ocean.</span>
<span class="attribution"><span class="source">Global Fishing Watch</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Supporting real-world efforts</h2>
<p>This data is freely available through the Global Fishing Watch <a href="https://globalfishingwatch.org/datasets-and-code/">data portal</a> and will be maintained, updated and expanded over time there. We anticipate several areas where the information will be most useful for on-the-ground monitoring:</p>
<p>– <strong>Fishing in data-poor regions</strong>: Shipboard monitoring systems are too expensive to deploy widely in many places. Fishery managers in developing countries can use our data to monitor pressure on local stocks. </p>
<p>– <strong>Illegal, unreported and unregulated fishing</strong>: Industrial fishing vessels sometimes operate in places where they should not be, such as <a href="https://hakaimagazine.com/news/the-african-coastline-is-a-battleground-for-foreign-fleets-and-artisanal-fishers/">small-scale and traditional fishing grounds</a> and <a href="https://www.businessinsider.com/fishing-illegal-oceana-going-dark-marine-protected-areas-2018-4">marine protected areas</a>. Our data can help enforcement agencies identify illegal activities and target patrol efforts.</p>
<p>– <strong>Sanction-busting trade</strong>: Our data can shed light on maritime activities that may breach international economic sanctions. For example, <a href="https://www.un.org/securitycouncil/sanctions/1718/resolutions">United Nations sanctions</a> prohibit North Korea from exporting seafood products or selling its fishing rights to other countries. Previous work <a href="https://doi.org/10.1126/sciadv.abb1197">found more than 900 undisclosed fishing vessels</a> of Chinese origin in the eastern waters of North Korea, in violation of U.N. sanctions. </p>
<p>We found that the western waters of North Korea had far more undisclosed fishing, likely also of foreign origin. This previously unmapped activity peaked each year in May, when China bans fishing in its own waters, and abruptly fell in 2020 when North Korea closed its borders because of the COVID-19 pandemic.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ZRLW-3Niseg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Better monitoring may help nations coordinate offshore activities in busy regions like the North Sea.</span></figcaption>
</figure>
<p>– <strong>Climate change mitigation and adaptation</strong>: Our data can help quantify the scale of greenhouse gas emissions from vessel traffic and offshore energy development. This information is important for enforcing climate change mitigation programs, such as the European Union’s <a href="https://climate.ec.europa.eu/eu-action/transport/reducing-emissions-shipping-sector_en">emissions trading scheme</a>. </p>
<p>– <strong>Offshore energy impacts</strong>: Our map shows not only where offshore energy development is happening but also how vessel traffic interacts with wind turbines and oil and gas platforms. This information can shed light on the environmental footprint of building, maintaining and using these structures. It can also help to <a href="https://skytruth.org/cerulean/">pinpoint sources of oil spills</a> and other marine pollution. </p>
<p>Healthy oceans <a href="https://oceanservice.noaa.gov/facts/why-care-about-ocean.html">underpin human well-being</a> in a myriad of ways. We expect that this research will support evidence-based decision-making and help to make ocean management more fair, effective and sustainable.</p>
<p><em>Fernando Paolo, senior machine learning engineer at Global Fishing Watch; David Kroodsma, director of research and innovation at Global Fishing Watch; and Patrick Halpin, Professor of Marine Geospatial Ecology at Duke University, contributed to this article.</em></p><img src="https://counter.theconversation.com/content/219367/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The study described in this article was funded by Oceankind, Bloomberg Philanthropies and National Geographic Pristine Seas. The European Space Agency made radar and optical imagery freely available, and Google provided computing resources and technical support. Jennifer Raynor has worked at National Oceanic and Atmospheric Administration Fisheries, and currently serves on the Board of Trustees for Global Fishing Watch.</span></em></p>A new study reveals that 75% of the world’s industrial fishing vessels are hidden from public view.Jennifer Raynor, Assistant Professor of Natural Resource Economics, University of Wisconsin-MadisonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2175862023-11-27T16:58:05Z2023-11-27T16:58:05ZHow AI ‘sees’ the world – what happened when we trained a deep learning model to identify poverty<figure><img src="https://images.theconversation.com/files/559642/original/file-20231115-23-snwbk5.png?ixlib=rb-1.1.0&rect=29%2C7%2C864%2C524&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Visualising wealth and poverty through AI.</span> <span class="attribution"><span class="source">Authors</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>To most effectively deliver aid to alleviate poverty, you have to know where the people most in need are. In many countries, this is often done with household surveys. But these are usually infrequent and cover limited locations.</p>
<p>Recent advances in artificial intelligence (AI) have created a step change in how to measure poverty and other human development indicators. <a href="https://www.cell.com/patterns/pdf/S2666-3899(22)00225-2.pdf">Our team</a> has used a type of AI known as a deep convolutional neural network (DCNN) to study <a href="https://onlinelibrary.wiley.com/doi/pdf/10.1002/jid.3751">satellite imagery</a> and identify some types of poverty with a level of accuracy close to that of household surveys.</p>
<p>The use of this AI technology could help, for example, in developing countries where there has been a rapid change of land use. The AI could monitor via satellite and potentially spot areas that are in need of aid. This would be much quicker than relying on ground surveys.</p>
<p>Plus, the <a href="https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=10302541">dreamy images</a> our deep learning model has produced give us a unique insight into how AI visualises the world.</p>
<figure class="align-center ">
<img alt="Two satellite images of a villages." src="https://images.theconversation.com/files/559609/original/file-20231115-27-o4k8xg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/559609/original/file-20231115-27-o4k8xg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=301&fit=crop&dpr=1 600w, https://images.theconversation.com/files/559609/original/file-20231115-27-o4k8xg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=301&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/559609/original/file-20231115-27-o4k8xg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=301&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/559609/original/file-20231115-27-o4k8xg.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=378&fit=crop&dpr=1 754w, https://images.theconversation.com/files/559609/original/file-20231115-27-o4k8xg.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=378&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/559609/original/file-20231115-27-o4k8xg.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=378&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Two villages with different wealth ratings as seen from space. The ‘poor’ village is on the left, the ‘wealthy’ on the right.</span>
<span class="attribution"><span class="source">Authors/Google</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>A DCNN is a type of advanced AI algorithm commonly used in processing and analysing visual imagery. The “deep” in its name refers to the multiple layers through which data is processed, making it part of the broader family of deep learning technologies.</p>
<p>Earlier this year our team made an important discovery using the DCNN. This network was initially trained on the vast array of labelled images from the <a href="https://www.image-net.org/about.php">ImageNet</a> repository: a <a href="https://qz.com/1034972/the-data-that-changed-the-direction-of-ai-research-and-possibly-the-world">huge pictorial dataset</a> of objects and living things used to train algorithms. After this initial phase, where the network learned to recognise various objects, we fine-tuned it using daylight satellite images of populated places. </p>
<p><a href="https://arxiv.org/pdf/2210.08785.pdf">Our findings</a> revealed that the DCNN, enhanced by this specialised training, could surpass human performance in accurately assessing poverty levels from satellite imagery. Specifically, the AI system demonstrated an ability to deduce poverty levels from low-resolution daytime satellite images with greater precision than <a href="https://arxiv.org/pdf/2210.08785.pdf">humans analysing</a> high-resolution images.</p>
<p>Such proficiency echoes the superhuman achievements of AI in other realms, such as the <a href="https://www.science.org/doi/pdf/10.1126/science.aar6404?casa_token=1eQBH-8ZrRsAAAAA:4qQXVzp-45bhgMGGNXpEv6uewbihGzDkRzC4pc-k1-u2-lO5sjenv84TArnmw9YPYDlQwWpolndV-DU">Chess and Go</a> engines that consistently outwit human players. </p>
<p>After the training phase was complete, we engaged in an exploration to try to understand what characteristics the DCNN was identifying in the satellite images as being indicative of “high wealth”. This process began with what we referred to as a “blank slate” – an image composed entirely of random noise, devoid of any discernible features.</p>
<p>In a step-by-step manner, the model “adjusts” this noisy image. Each adjustment is a move towards what the model considers a satellite image of a more wealthy place than the previous image. These modifications are driven by the model’s internal understanding and learning from its training data.</p>
<p>As the adjustments continue, the initially random image gradually morphs into one that the model confidently classifies as indicating high wealth. This transformation was revelatory because it unveiled the specific features, patterns, and elements that the model associates with wealth in satellite imagery. </p>
<p>Such features might include (but are not limited to) the density of roads, the layout of urban areas, or other subtle cues that have been learned during the model’s training.</p>
<figure class="align-center ">
<img alt="A block of four images, progressing from a satellite to more abstract AI versions of the original, explainer in paragraph below." src="https://images.theconversation.com/files/559911/original/file-20231116-27-idgukm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/559911/original/file-20231116-27-idgukm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=152&fit=crop&dpr=1 600w, https://images.theconversation.com/files/559911/original/file-20231116-27-idgukm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=152&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/559911/original/file-20231116-27-idgukm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=152&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/559911/original/file-20231116-27-idgukm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=191&fit=crop&dpr=1 754w, https://images.theconversation.com/files/559911/original/file-20231116-27-idgukm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=191&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/559911/original/file-20231116-27-idgukm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=191&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Satellite image (left) of ‘poor’ village, then moves from left to right adding signs of wealth, like roads, progressing towards what the AI ‘sees’ as wealth.</span>
<span class="attribution"><span class="source">Authors/Google</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The sequence of images displayed above serves a crucial purpose in our research. It begins with a baseline satellite image of a village in Tanzania, which our AI model categorises as “poor”, probably due to the sparse presence of roads and buildings.</p>
<p>To test and confirm this hypothesis, we progressively modify each subsequent image in the sequence, methodically enhancing them with additional features such as buildings and roads. These augmentations represent increased wealth and development as perceived by the AI model.</p>
<p>This visual progression shows how the AI is visualising “wealth” as we add things like more roads and houses. The characteristics we deduced from the model’s “ideal” wealth image (such as roads and buildings) are indeed influential in the model’s assessment of wealth.</p>
<p>This step is essential in ensuring that the features we believe to be significant in the AI’s decision-making process do, in fact, correspond to higher wealth predictions.</p>
<p>So by repeatedly adjusting the image, the resulting visualisation gradually evolves into what the network “thinks” wealth looks like. This outcome is often abstract or surreal.</p>
<figure class="align-center ">
<img alt="Abstract image created by AI portraying poverty." src="https://images.theconversation.com/files/559639/original/file-20231115-23-rxgd5r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/559639/original/file-20231115-23-rxgd5r.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/559639/original/file-20231115-23-rxgd5r.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/559639/original/file-20231115-23-rxgd5r.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/559639/original/file-20231115-23-rxgd5r.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/559639/original/file-20231115-23-rxgd5r.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/559639/original/file-20231115-23-rxgd5r.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">What a neural network ‘thinks’ wealth looks like.</span>
<span class="attribution"><span class="source">Authors</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The image above was generated from a blank slate when we asked the DCNN what it associated with “high wealth”. These images have an ethereal quality and don’t closely resemble typical daytime satellite photos. Yet, the presence of “blobs” and “lines” suggests clusters of homes interconnected by roads and streets. The blue hue might even hint at coastal areas.</p>
<h2>Dreamy images</h2>
<p>Inherent in this method is an element of randomness. This randomness ensures that each attempt at visualisation creates a unique image, though all are anchored in the same underlying concept as understood by the network.</p>
<p>However, it is important to note that these visualisations are more a reflection of the network’s “thought process” rather than an objective representation of wealth. They’re constrained by the network’s training and may not accurately align with human interpretations. </p>
<p>It is crucial to understand that while AI feature visualisation offers intriguing insights into neural networks, it also highlights the complexities and limitations of machine learning in mirroring human perception and understanding.</p>
<p>Understanding poverty, particularly in its geographical or regional context, is a complex endeavour. While traditional studies have focused more on individual aspects of poverty, AI, leveraging satellite imagery, has made significant strides in highlighting regional poverty’s geographical patterns.</p>
<p>This is where the real value of AI in poverty assessment lies, in offering a spatially nuanced perspective that complements existing poverty research and aids in formulating more targeted and effective interventions.</p><img src="https://counter.theconversation.com/content/217586/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ola Hall receives funding from Stiftelsen Riksbankens Jubileumsfond, Swedish Research Council and Formas. </span></em></p><p class="fine-print"><em><span>Hamid Sarmadi receives funding from Riksbankens Jubileumsfond.</span></em></p><p class="fine-print"><em><span>Thorsteinn Rögnvaldsson receives funding from the Knowledge Foundation and from Riksbankens Jubileumsfond.</span></em></p>Researchers fed an advanced AI algorithm with satellite photographs to see if it could identify areas of poverty and it interpreted the data through abstract images.Ola Hall, Head of the Department of Human Geography, Lund UniversityHamid Sarmadi, Assistant Professor, School of Information Technology, Halmstad UniversityThorsteinn Rögnvaldsson, Professor, School of Information Technology, Halmstad UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2166432023-11-13T19:46:13Z2023-11-13T19:46:13ZFire is consuming more than ever of the world’s forests, threatening supplies of wood and paper<figure><img src="https://images.theconversation.com/files/558977/original/file-20231112-27-mgtyva.JPG?ixlib=rb-1.1.0&rect=23%2C11%2C3843%2C2573&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">David Lindenmayer</span></span></figcaption></figure><p>A third of the world’s forests are cut for timber. This generates <a href="https://doi.org/10.4060/cb9360en">US$1.5 trillion annually</a>. But
wildfire threatens industries such as timber milling and paper manufacturing, and the threat is far greater than most people realise.</p>
<p><a href="https://www.nature.com/articles/s41561-023-01323-y">Our research</a>, published today in the journal Nature Geoscience, shows that between 2001 and 2021, severe wildfires worldwide destroyed timber-producing forests equivalent to an area the size of Great Britain. Severe fires reach the tree tops and consume the forest canopy.</p>
<p>The amount of timber-producing forest burning each year in severe wildfires has increased significantly in the past decade. The western United States, Canada, Siberia, Brazil and Australia have been most affected.</p>
<p>Timber demand is expected to almost triple by 2050. Supplying demand is clearly going to be challenging. Our research highlights the need to urgently adopt new management strategies and emerging technologies to combat the increasing threat of wildfires.</p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/our-planet-is-burning-in-unexpected-ways-heres-how-we-can-protect-people-and-nature-213215">Our planet is burning in unexpected ways - here’s how we can protect people and nature</a>
</strong>
</em>
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<h2>What we found</h2>
<p>We combined global maps of logging activity and severe wildfires to determine how much timber-producing forest was lost to wildfire this century. Between 2001 and 2021, up to 25 million hectares of timber-producing forest was severely burned. The extent of fire has jumped markedly in the past decade, from an average of less than one million hectares a year up to 2015 to triple that since then. </p>
<p>At a national scale, the three countries with the largest absolute wildfire-induced losses of timber-producing forest were Russia, the US and Canada. When it comes to proportion of their forestry land lost, the nations with the highest percentages burnt were Portugal, followed by Australia. </p>
<h2>Why are more forests burning?</h2>
<p>Climate change is a <a href="https://doi.org/10.1038/s41467-021-27225-40">major driver of fire weather and fire behaviour</a>. The increased risk of high-severity wildfire is an entirely expected outcome of warmer temperatures and, in some places, reduced rainfall. </p>
<p>However, it remains unclear why so much wood-production forest is being lost, and why the increase in burnt area has been so marked in the past decade. </p>
<p>One possible reason is <a href="https://doi.org/10.1111/conl.12122">logging makes forests more flammable</a>. This has been documented in parts of southeastern Australia, where intact forest always <a href="https://www.nature.com/articles/s41559-022-01717-y">burnt at lower severity than harvested forest</a> across the entire footprint of the Black Summer fires. Forests that have been subject to thinning also are <a href="http://doi.org/10.1111/aec.13096">at risk of high-severity wildfire</a>. </p>
<h2>What does this mean for us?</h2>
<p>Whatever the reason, it is clear these fires in wood-production forests will have profound impacts on global timber supplies and all the industries associated with them. This is a huge problem for society and the environment, because timber demand is expected to triple by 2050, in part to facilitate the transition away from carbon-intensive cement in construction. </p>
<p>In many parts of the world, it typically takes 80–100 years or even longer to grow a tree to a size at which it can be a sawlog for products like furniture and floorboards. So the increased frequency of high-severity wildfire means fewer areas of forest <a href="https://doi.org/10.1071/WF20129">will escape fire for long enough</a> to reach timber harvesting age. </p>
<p>This is especially problematic where logging makes forests more prone to burning in a high-severity wildfire.</p>
<p>Furthermore, given the long-term nature of timber production, typically on cutting cycles ranging from 40 years to more than a century, future timber crops will face a very different climate as they mature. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/558979/original/file-20231112-17-1qsmgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Photo of a timber production forest that has been burnt" src="https://images.theconversation.com/files/558979/original/file-20231112-17-1qsmgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/558979/original/file-20231112-17-1qsmgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=402&fit=crop&dpr=1 600w, https://images.theconversation.com/files/558979/original/file-20231112-17-1qsmgm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=402&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/558979/original/file-20231112-17-1qsmgm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=402&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/558979/original/file-20231112-17-1qsmgm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=505&fit=crop&dpr=1 754w, https://images.theconversation.com/files/558979/original/file-20231112-17-1qsmgm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=505&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/558979/original/file-20231112-17-1qsmgm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=505&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Timber production forests such as this, near Marysville in Victoria, are burning before they reach maturity.</span>
<span class="attribution"><span class="source">David Lindenmayer</span></span>
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Read more:
<a href="https://theconversation.com/why-tasmania-and-victoria-dominate-the-list-of-australias-largest-trees-and-why-these-majestic-giants-are-under-threat-200276">Why Tasmania and Victoria dominate the list of Australia's largest trees – and why these majestic giants are under threat</a>
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<h2>Responding to the challenge</h2>
<p>If wood production from forests becomes increasing costly and timber is increasingly hard to source, there may be more pressure from industry and government to log other places, such as tropical forests, with high biodiversity and conservation value. </p>
<p>One way to tackle the problem is to grow more timber in plantations. Plantations already produce <a href="https://www.sciencedirect.com/science/article/abs/pii/S0378112722006351">a third of the main forms of wood-producing timber</a> – called industrial roundwood. They do this from just 3% of the area of natural forests. </p>
<p>Well managed plantations can grow a successful timber crop within a couple of decades. This is a lot shorter than the many decades and sometimes even centuries required to grow sawlogs in native forests. Having a <a href="https://doi.org/10.1016/j.foreco.2022.120641">shorter growing time in plantations</a> increases the chances of harvesting trees before they are destroyed in a wildfire. </p>
<p>But plantations, like some logged and regenerated native forests, can be highly flammable. Fire risks need to be carefully managed. That includes planning, to avoid putting neighbouring areas and human communities at <a href="https://doi.org/10.1016/j.foreco.2022.120641">greater risk of being burnt</a>. </p>
<p>Another key strategy to better protect timber resources will be to adopt new technologies to more quickly <a href="https://doi.org/10.1126/science.ade4721">detect and then rapidly suppress ignitions</a> such as those originating from lightning strikes. </p>
<p>Big fires start as small fires. The <a href="https://doi.org/10.5849/forsci.10-096">best time to suppress fires is when they are small</a>, and as soon as ignition occurs. We have been involved in the development of drone fleets and unmanned aerial water and fire suppressant dispensing craft to more quickly <a href="https://doi.org/10.1126/science.ade4721">detect and extinguish wildfires</a>. </p>
<p>New technologies, as well as more, better planned and managed plantations will be crucial in not only protecting forests, but also <a href="https://doi.org/10.1126/science.ade4721">safeguarding the flow of marketable timber</a> and the industries dependent upon them. </p>
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<strong>
Read more:
<a href="https://theconversation.com/yes-climate-change-is-bringing-bushfires-more-often-but-some-ecosystems-in-australia-are-suffering-the-most-211683">Yes, climate change is bringing bushfires more often. But some ecosystems in Australia are suffering the most</a>
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<img src="https://counter.theconversation.com/content/216643/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Lindenmayer receives funding from the Australian Government and the Victorian Government. He is a Councillor in the Biodiversity Council. </span></em></p><p class="fine-print"><em><span>Chris Bousfield received funding for this research from the Natural Environment Research Council, UK.</span></em></p><p class="fine-print"><em><span>David Edwards does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Satellite data shows wildfires are destroying large areas of timber-producing forests around the world. These fires are becoming more destructive with each passing year.David Lindenmayer, Professor, The Fenner School of Environment and Society, Australian National UniversityChris Bousfield, Postdoctoral Research Associate, University of CambridgeDavid Edwards, Professor, University of CambridgeLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2051132023-05-21T20:00:24Z2023-05-21T20:00:24Z‘Painting with fire’: how northern Australia developed one of the world’s best bushfire management programs<figure><img src="https://images.theconversation.com/files/526716/original/file-20230517-28-mjxdxc.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1824%2C1643&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Satellite imagery shows how burnt areas in central Arnhem Land are lines carefully 'painted' across the landscape.</span> <span class="attribution"><a class="source" href="https://apps.sentinel-hub.com/eo-browser/">Sentinel Hub EO Browser</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Right now, hundreds of bushfires are burning across northern Australia. But this is not a wildfire catastrophe – in fact, these burns are making things safer in one of the most fire-prone landscapes in the world.</p>
<p>From April to June each year, fire managers – such as Traditional Owners, park rangers and pastoralists – aim to create small, “cool” fires with care and precision to reduce fuel loads before conditions get severe later in the dry season. This work, “painting” landscapes with fire, is constantly informed by satellite data.</p>
<p>The combination of space technology with Indigenous knowledge and the know-how of pastoralists and park rangers has been everyday practice across northern Australia for the past 20 years. Not only does this work produce some of the best fire management outcomes in the world, it also demonstrates how cutting-edge technology can inform local and traditional knowledge for environmental management.</p>
<h2>The satellite view</h2>
<p>In the early 2000s, researchers and land managers brought together by the <a href="https://www.eoas.info/biogs/A001949b.htm">Cooperative Research Centre for the Sustainable Development of Tropical Savannahs</a> realised satellite imagery could be of great help for fire management across Australia’s vast tropical savannas. </p>
<p>These landscapes have always been prone to fire. After First Nations people moved away (or were forced) from these areas over the course of the 20th century, savanna fires <a href="https://esajournals.onlinelibrary.wiley.com/doi/full/10.1890/120251">became more frequent and intense</a>.</p>
<p>Satellite imagery had long been used to understand the extent and severity of fires and other landscape-altering events. But researchers realised it could also be used to manage those fires – if up-to-date imagery could be provided to the public on a daily basis. </p>
<p>The result was regularly updated maps of recently burnt areas distributed via a website launched in 2003, hosted by Charles Darwin University – <a href="https://firenorth.org.au/">North Australian Fire Information</a> (NAFI).</p>
<p>Twenty years on, NAFI’s maps of active fires and burnt areas underpin fire management across northern Australia. The maps are used for planning, response, implementation, and reporting. </p>
<h2>Carbon credits and international attention</h2>
<p>NAFI’s fire information also informs the federal government’s calculations for <a href="https://www.abc.net.au/news/rural/2012-11-02/indigenous-fire-project-to-earn-carbon-credits/6123622">carbon credits related to reduced savanna burning</a>, which many people across Australia’s north are using to generate income. Some of this income is then put back into work to reduce the extent and severity of fires. </p>
<p>NAFI fire data also inform the national <a href="https://afdrs.com.au/">Australian Fire Danger Rating System</a> so it can be more effectively applied by bushfire agencies in remote areas.</p>
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Read more:
<a href="https://theconversation.com/the-worlds-best-fire-management-system-is-in-northern-australia-and-its-led-by-indigenous-land-managers-133071">The world's best fire management system is in northern Australia, and it's led by Indigenous land managers</a>
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<p>The same data have provided evidence showing north Australia has had <a href="https://theconversation.com/the-worlds-best-fire-management-system-is-in-northern-australia-and-its-led-by-indigenous-land-managers-133071">one of the most significant declines in fire</a> across any large landscape globally. </p>
<p>The successes of the NAFI service are drawing <a href="https://theconversation.com/fighting-fire-with-fire-botswana-adopts-indigenous-australians-ancient-burning-tradition-135363">international interest</a> as a model for fire information in other fire-susceptible regions around the world.</p>
<h2>Painting with fire</h2>
<p>Most Australians have a poor understanding of the history of fire on this continent. Fire has been a key human–ecological force that shaped landscapes over tens of thousands of years. </p>
<p>Over the past 20 years, <a href="https://theconversation.com/we-are-professional-fire-watchers-and-were-astounded-by-the-scale-of-fires-in-remote-australia-right-now-172773">proactive use of fire for landscape management</a> has been revived in northern Australia. </p>
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Read more:
<a href="https://theconversation.com/we-are-professional-fire-watchers-and-were-astounded-by-the-scale-of-fires-in-remote-australia-right-now-172773">We are professional fire watchers, and we're astounded by the scale of fires in remote Australia right now</a>
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<p>The scale of the work undertaken by Northern fire managers, particularly at this time of year when fuel load reduction burns are underway, is easy to see on NAFI. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/526703/original/file-20230517-21-qpi2sc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526703/original/file-20230517-21-qpi2sc.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=320&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526703/original/file-20230517-21-qpi2sc.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=320&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526703/original/file-20230517-21-qpi2sc.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=320&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526703/original/file-20230517-21-qpi2sc.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=402&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526703/original/file-20230517-21-qpi2sc.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=402&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526703/original/file-20230517-21-qpi2sc.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=402&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">A snapshot from NAFI from 15 May 2023. Each coloured dot represents an active fire.</span>
<span class="attribution"><a class="source" href="https://firenorth.org.au">NAFI</a></span>
</figcaption>
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<p>Landscape-scale fire management, as applied in Northern Australia, is a sophisticated endeavour where science, technology and engineering support local knowledge. </p>
<h2>Beyond science and technology</h2>
<p>In a world rapidly being <a href="https://www.abc.net.au/news/2022-11-04/east-kimberley-fire-forum-climate-change-impacts/101609248">transformed by climate change</a>, the skills required to make our societies sustainable and resilient involve more than just science and technology. Good environmental management will also require diverse, locally based skills and capacity to act.</p>
<p>Good fire management, as a case in point, requires an ability to blend skills and ways of thinking across multiple knowledge systems as well as a huge amount of hard work on the land.</p>
<p>Enabling easy, appropriately curated <a href="https://savannafiremapping.com/">access</a> to satellite-derived land information – and training to understand it – is critical. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/526707/original/file-20230517-28-1bru81.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/526707/original/file-20230517-28-1bru81.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/526707/original/file-20230517-28-1bru81.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=471&fit=crop&dpr=1 600w, https://images.theconversation.com/files/526707/original/file-20230517-28-1bru81.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=471&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/526707/original/file-20230517-28-1bru81.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=471&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/526707/original/file-20230517-28-1bru81.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=591&fit=crop&dpr=1 754w, https://images.theconversation.com/files/526707/original/file-20230517-28-1bru81.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=591&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/526707/original/file-20230517-28-1bru81.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=591&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Tiwi Rangers at a training session on using satellite data and digital mapping for fire management.</span>
<span class="attribution"><span class="source">Rohan Fisher</span>, <span class="license">Author provided</span></span>
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<p>NAFI also develops and delivers training for land managers. Through workshops delivered across regional Australia, from remote Indigenous communities in the Kimberley and the top end to pastoralists in northern Queensland and central Australia, we are building high-tech capacity among those with the vital on-ground knowledge.</p>
<p>The journey of NAFI and fire management in northern Australia over the past 20 years illustrates how innovation is not just about technology, no matter how advanced. Innovation produces results when it is combined with other knowledge and put into the hands of the right people in the right way.</p><img src="https://counter.theconversation.com/content/205113/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rohan Fisher works for Charles Darwin University and has received federal funding to support the NAFI service. </span></em></p><p class="fine-print"><em><span>Peter Jacklyn works for Charles Darwin University and has received federal funding to support the NAFI service.</span></em></p>Satellite data and traditional know-how combined have drastically reduced fires across northern Australia over the past 20 years.Rohan Fisher, Information Technology for Development Researcher, Charles Darwin UniversityPeter Jacklyn, NAFI Service Manager and Knowledge and Adoption Coordinator, Charles Darwin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2027292023-04-17T20:03:55Z2023-04-17T20:03:55ZAntarctica’s heart of ice has skipped a beat. Time to take our medicine<figure><img src="https://images.theconversation.com/files/521207/original/file-20230417-22-oeal0p.jpg?ixlib=rb-1.1.0&rect=4%2C4%2C2998%2C1949&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Australian Antarctic Program Partnership</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The rhythmic expansion and contraction of Antarctic sea ice is like a heartbeat. </p>
<p>But lately, there’s been a skip in the beat. During each of the last two summers, the ice around Antarctica has retreated farther than ever before.</p>
<p>And just as a change in our heartbeat affects our whole body, a change to sea ice around Antarctica affects the whole world.</p>
<p>Today, researchers at the Australian Antarctic Program Partnership (AAPP) and the Australian Centre for Excellence in Antarctic Science (ACEAS) have joined forces to release a science briefing for policy makers, <a href="https://aapp.shorthandstories.com/on-thin-ice/index.html">On Thin Ice</a>. </p>
<p>Together we call for rapid cuts to greenhouse gas emissions, to slow the rate of global heating. We also need to step up research in the field, to get a grip on sea-ice science before it’s too late. </p>
<iframe width="100%" height="1057" src="https://www.youtube.com/embed/UPXLWa6CHlk?autoplay=1&loop=1&playlist=UPXLWa6CHlk" title="Seasonal cycle, Antarctic sea ice (animation by NASA/GSFC Science Visualisation Studio)" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" allowfullscreen=""></iframe>
<p><a href="https://cdn.theconversation.com/static_files/files/2640/antarctic.gif?1681696019">The seasonal expansion and contraction of Antarctic sea ice (Animation by NASA/GSFC Science Visualisation Studio)</a></p>
<h2>The shrinking white cap on our blue planet</h2>
<p>One of the largest seasonal cycles on Earth happens in the ocean around Antarctica. During autumn and winter the surface of the ocean freezes as sea ice advances northwards, and then in the spring the ice melts as the sunlight returns. </p>
<p>We’ve been able to measure sea ice from satellites since the late 1970s. In that time we’ve seen a regular cycle of freezing and melting. At the winter maximum, sea ice covers an area more than twice the size of Australia (roughly 20 million square kilometres), and during summer it retreats to cover less than a fifth of that area (about 3 million square km).</p>
<p>In 2022 the summer minimum was less than 2 million square km for the first time since satellite records began. This summer, the minimum was even lower – just 1.7 million square km.</p>
<iframe src="https://flo.uri.sh/visualisation/13437160/embed" title="Interactive or visual content" class="flourish-embed-iframe" frameborder="0" scrolling="no" style="width:100%;height:600px;" sandbox="allow-same-origin allow-forms allow-scripts allow-downloads allow-popups allow-popups-to-escape-sandbox allow-top-navigation-by-user-activation" width="100%" height="400"></iframe>
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<p>The annual freeze pumps cold salty water down into the deep ocean abyss. The water then flows northwards. About <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2007JC004477">40% of the global ocean</a> can be traced back to <a href="https://blog.csiro.au/antarctic-bottom-water/">the Antarctic coastline</a>. </p>
<p>By exchanging water between the surface ocean and the abyss, sea ice formation helps to sequester heat and carbon dioxide in <a href="https://www.pnas.org/doi/abs/10.1073/pnas.1323922111">the deep ocean</a>. It also helps to bring long-lost nutrients back up to the surface, supporting ocean life around the world.</p>
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Read more:
<a href="https://theconversation.com/torrents-of-antarctic-meltwater-are-slowing-the-currents-that-drive-our-vital-ocean-overturning-and-threaten-its-collapse-202108">Torrents of Antarctic meltwater are slowing the currents that drive our vital ocean 'overturning' – and threaten its collapse</a>
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<p>Not only does sea ice play a crucial role in pumping seawater across the planet, it insulates the ocean underneath. During the long days of the Antarctic summer, sunlight usually hits the bright white surface of the sea ice and is <a href="https://svs.gsfc.nasa.gov/20022">reflected back into space</a>.</p>
<p>This year, there is less sea ice than normal and so the ocean, which is dark by comparison, is absorbing much more solar energy than normal. This will accelerate ocean warming and will likely impede the wintertime growth of sea ice.</p>
<h2>Headed for stormy seas</h2>
<p>The Southern Ocean is a stormy place; the epithets “Roaring Forties” and “Furious Fifties” are well deserved. When there is less ice, the coastline is more exposed to storms. Waves pound on coastlines and ice shelves that are normally sheltered behind a broad expanse of sea ice. This battering can lead to <a href="https://earthobservatory.nasa.gov/images/149640/ice-shelf-collapse-in-east-antarctica">the collapse of ice shelves</a> and an increase in the rate of sea level rise as ice sheets slide off the land <a href="https://www.antarcticglaciers.org/glaciers-and-climate/changing-antarctica/shrinking-ice-shelves/ice-shelves/#SECTION_4">into the ocean more rapidly</a>.</p>
<iframe src="https://flo.uri.sh/visualisation/13424226/embed" title="Interactive or visual content" class="flourish-embed-iframe" frameborder="0" scrolling="no" style="width:100%;height:600px;" sandbox="allow-same-origin allow-forms allow-scripts allow-downloads allow-popups allow-popups-to-escape-sandbox allow-top-navigation-by-user-activation" width="100%" height="400"></iframe>
<div style="width:100%!;margin-top:4px!important;text-align:right!important;"><a class="flourish-credit" href="https://public.flourish.studio/visualisation/13424226/?utm_source=embed&utm_campaign=visualisation/13424226" target="_top"><img alt="Made with Flourish" src="https://public.flourish.studio/resources/made_with_flourish.svg"> </a></div>
<p>Sea ice supports many levels of the food web. When sea ice melts it releases iron, which <a href="https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/GB004i001p00005">promotes phytoplankton growth</a>. In the spring we see phytoplankton blooms that follow the retreating sea ice edge. If less ice forms, there will be less iron released in the spring, and less phytoplankton growth.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/smoke-from-the-black-summer-fires-created-an-algal-bloom-bigger-than-australia-in-the-southern-ocean-164564">Smoke from the Black Summer fires created an algal bloom bigger than Australia in the Southern Ocean</a>
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</p>
<hr>
<p>Krill, the small crustaceans that provide food to whales, seals, and penguins, <a href="https://link.springer.com/article/10.1007/s00300-021-02868-7">need sea ice</a>. Many larger species such as penguins and seals rely on sea ice to breed. The impact of changes to the sea ice on these larger animals varies dramatically between species, but they are all intimately tied to the rhythm of ice formation and melt. Changes to the sea-ice heartbeat will disrupt the finely balanced ecosystems of the Southern Ocean.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/521208/original/file-20230417-16-w9r1p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Three Adelie penguins and a leopard seal on the sea ice" src="https://images.theconversation.com/files/521208/original/file-20230417-16-w9r1p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521208/original/file-20230417-16-w9r1p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521208/original/file-20230417-16-w9r1p8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521208/original/file-20230417-16-w9r1p8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521208/original/file-20230417-16-w9r1p8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521208/original/file-20230417-16-w9r1p8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521208/original/file-20230417-16-w9r1p8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sea ice provides habitat for marine life, ranging in size from microbes to the largest animals on the planet. Here Adelie penguins approach a leopard seal.</span>
<span class="attribution"><span class="source">Wendy Pyper AAD</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>A diagnosis for policy makers</h2>
<p>Long term measurements show the subsurface Southern Ocean is <a href="https://www.nature.com/articles/s41467-020-20781-1">getting warmer</a>. This warming is caused by <a href="https://journals.ametsoc.org/view/journals/clim/34/1/jcliD200454.xml">our greenhouse gas emissions</a>. We don’t yet know if this ocean warming directly caused the record lows seen in recent summers, but it is a likely culprit.</p>
<p>As scientists in Australia and around the world work to understand these recent events, new evidence will come to light for a clearer understanding of what is causing the sea ice around Antarctica to melt.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/521220/original/file-20230417-28-eydi6e.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A chart of monthly sea ice extent showing the difference between the long-term average sea ice and the observed sea ice in each month" src="https://images.theconversation.com/files/521220/original/file-20230417-28-eydi6e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/521220/original/file-20230417-28-eydi6e.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=345&fit=crop&dpr=1 600w, https://images.theconversation.com/files/521220/original/file-20230417-28-eydi6e.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=345&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/521220/original/file-20230417-28-eydi6e.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=345&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/521220/original/file-20230417-28-eydi6e.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=434&fit=crop&dpr=1 754w, https://images.theconversation.com/files/521220/original/file-20230417-28-eydi6e.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=434&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/521220/original/file-20230417-28-eydi6e.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=434&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Antarctic sea ice is highly variable, but there has been less ice than normal for almost all of the last seven years. This chart of monthly sea ice extent anomaly shows the difference between the long-term average sea ice and the observed sea ice in each month. By removing the annual cycle due to sea ice formation and melt, we can see the longer term variability underneath, and the extreme low sea ice events in recent years.</span>
<span class="attribution"><span class="source">Dr Phil Reid, BoM</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>If you noticed a change in your heartbeat, you’d likely see a doctor. Just as doctors run tests and gather information, climate scientists undertake fieldwork, gather observations, and run simulations to better understand the health of our planet. </p>
<p>This crucial work requires specialised icebreakers with sophisticated observational equipment, powerful computers, and high-tech satellites. International cooperation, data sharing, and government support are the only ways to provide the resources required.</p>
<p>After noticing the first signs of heart trouble, a doctor might recommend more exercise or switching to a low-fat diet. Maintaining the health of our planet requires the same sort of intervention – we must rapidly cut our consumption of fossil fuels and improve our scientific capabilities.</p><img src="https://counter.theconversation.com/content/202729/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Edward Doddridge receives funding from the Australian Research Council and the Australian Government.</span></em></p>The rhythmic expansion and contraction of Antarctic sea ice is like a heartbeat. But there’s been a skip in the beat. Deeply concerned scientists have released a diagnosis for policy-makers.Edward Doddridge, Research Associate in Physical Oceanography, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1993572023-02-06T17:01:03Z2023-02-06T17:01:03ZEarthquake in Turkey and Syria: how satellites can help rescue efforts<p>In disasters like the <a href="https://www.lemonde.fr/international/article/2023/02/06/le-sud-de-la-turquie-frappe-par-un-seisme-de-magnitude-7-8_6160659_3210.html">7.8 magnitude earthquake</a> and <a href="https://earthquake.usgs.gov/earthquakes/map/?currentFeatureId=us6000jlqa&extent=30.41078,25.37842&extent=42.90816,49.98779">7.5-magnitude aftershock</a> that struck Syria and Turkey on February 6, 2023, international cooperation on satellite imaging plays a crucial role in the rescue and recovery efforts.</p>
<p>Such data enables humanitarian aid to better deliver water and food by mapping the condition of roads, bridges, buildings, and – most crucially – identifying populations trying to escape potential aftershocks by gathering in stadiums or other open spaces.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/508350/original/file-20230206-31-phy2vy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="satellite photo and location of multiple earthquakes that have struck Turkey and Syria" src="https://images.theconversation.com/files/508350/original/file-20230206-31-phy2vy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/508350/original/file-20230206-31-phy2vy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=301&fit=crop&dpr=1 600w, https://images.theconversation.com/files/508350/original/file-20230206-31-phy2vy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=301&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/508350/original/file-20230206-31-phy2vy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=301&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/508350/original/file-20230206-31-phy2vy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=378&fit=crop&dpr=1 754w, https://images.theconversation.com/files/508350/original/file-20230206-31-phy2vy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=378&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/508350/original/file-20230206-31-phy2vy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=378&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Earthquakes that have occurred since Sunday afternoon, February 5, in the region. In blue, the 7.8 magnitude earthquake. In orange, the numerous aftershocks: the size of the disc indicates the magnitude.</span>
<span class="attribution"><a class="source" href="https://earthquake.usgs.gov/earthquakes/map/?currentFeatureId=us6000jllz&extent=23.68477,12.74414&extent=48.54571,61.96289&baseLayer=satellite">USGS</a></span>
</figcaption>
</figure>
<p>To quickly turn the eyes of satellites toward the affected areas, the Turkish Disaster and Emergency Management Authority (<a href="https://en.afad.gov.tr/">AFAD</a>) requested the activation of the international charter on <a href="https://disasterscharter.org/web/guest/home">“Space and Major Disasters”</a> at 7:04 a.m. local time. The United Nations did so for Syria at 11:29 local time.</p>
<p>In the meantime, 11 space agencies got ready to operate the most appropriate optical and radar satellites. For France, these are the optical satellites <a href="https://spot.cnes.fr/fr">Spot</a>, <a href="https://pleiades.cnes.fr/en/PLEIADES/index.htm">Pléaides</a> and <a href="https://earth.esa.int/eogateway/missions/pleiades-neo">Pléiades Neo</a> (medium, high and very high resolution), which will provide the first images as they pass over the area. Radar satellites will complement the optical information, as they also operate at night and through clouds, and can image landslides and even very small changes in altitude.</p>
<p>Every year, millions of people around the world are affected by disasters, whether natural (cyclone, tornado, typhoon, earthquake, landslide, volcanic eruption, tsunami, flood, forest fire, etc.) or man-made (oil pollution, industrial explosions, and more). Unfortunately, the intensity and frequency of these disasters are increasing with climate change, creating more and more victims, damaged homes, and devastated landscapes.</p>
<h2>Anatomy of a disaster</h2>
<p>The international charter on <a href="https://disasterscharter.org/web/guest/home">“Space and Major Disasters”</a> defines a disaster as a large-scale, sudden, unique and uncontrolled event, resulting in loss of life or damage to property and the environment, and requiring urgent action to acquire and provide data.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/466030/original/file-20220530-20-a1wa4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/466030/original/file-20220530-20-a1wa4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466030/original/file-20220530-20-a1wa4d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466030/original/file-20220530-20-a1wa4d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466030/original/file-20220530-20-a1wa4d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466030/original/file-20220530-20-a1wa4d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466030/original/file-20220530-20-a1wa4d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Landslide in Munnar, India. Access to affected areas is often difficult.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/rakesh/1933161414/">Rakesh Pai/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>The charter was created by the National Space Research Centre and the European Space Agency in 1999, soon joined by the Canadian Space Agency. Today, <a href="https://disasterscharter.org/web/guest/home">17 member space agencies</a> have joined forces to provide free satellite imagery as quickly as possible over the disaster area. Since 2000, the charter has been activated 797 times in more than 154 countries. It has since been complemented by similar initiatives from Europe (<a href="https://emergency.copernicus.eu/">Copernicus Emergency</a>) and Asia (<a href="https://sentinel-asia.org/">Sentinel Asia</a>).</p>
<p>Almost three quarters of the activations of the charter are due to weather phenomena: storms, hurricanes and especially floods, which alone account for half of the activations. In these sometimes unforeseen crisis situations, when the ground is damaged or flooded and roads are impassable, land-based resources are not always able to analyse the extent of the disaster and organise relief and humanitarian aid in the best possible way. By capturing the situation from space, with very high resolution, satellites provide crucial information quickly.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/466035/original/file-20220530-20-mecx69.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/466035/original/file-20220530-20-mecx69.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=289&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466035/original/file-20220530-20-mecx69.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=289&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466035/original/file-20220530-20-mecx69.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=289&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466035/original/file-20220530-20-mecx69.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=363&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466035/original/file-20220530-20-mecx69.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=363&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466035/original/file-20220530-20-mecx69.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=363&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hurricane Harvey caused flooding in Texas in 2018, displacing 30,000 people, and requiring the rescue of 17,000.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/sentinelhub/46200452394/in/album-72157704784948961/">Sentinel Hub/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>In some cases, the charter cannot be activated. This can be because the subject matter is outside the scope of the charter (wars and armed conflicts) or because space imagery is sometimes of little interest (in the case of heat waves and epidemics), or because the phenomenon evolves slowly and over a long time span (droughts).</p>
<h2>Satellite data in response to crises around the world</h2>
<p>As soon as a disaster occurs, satellites are programmed to quickly acquire images over the affected areas. More than 60 satellites, optical or radar, can be mobilised at any given time.</p>
<p>Depending on the type of disaster, different satellites will be mobilised, based on pre-established crisis plans – among them: <a href="https://en.wikipedia.org/wiki/TanDEM-X">TerraSAR-X/Tandem-X</a>, <a href="https://en.wikipedia.org/wiki/QuickBird">QuickBird-2</a>, <a href="https://www.asc-csa.gc.ca/fra/satellites/radarsat/default.asp">Radarsat</a>, <a href="https://en.wikipedia.org/wiki/Programme_Landsat">Landsat-7/8</a>, <a href="https://en.wikipedia.org/wiki/SPOT_(satellite)">SPOT</a>, <a href="https://en.wikipedia.org/wiki/Pl%C3%A9iades_(satellite)">Pleiades</a>, <a href="https://en.wikipedia.org/wiki/Sentinel-2">Sentinel-2</a> among others.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/466033/original/file-20220530-16-b4snga.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/466033/original/file-20220530-16-b4snga.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=289&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466033/original/file-20220530-16-b4snga.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=289&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466033/original/file-20220530-16-b4snga.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=289&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466033/original/file-20220530-16-b4snga.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=363&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466033/original/file-20220530-16-b4snga.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=363&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466033/original/file-20220530-16-b4snga.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=363&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Russian forest fires in the Irkutsk region in 2017, caused by lightning.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/sentinelhub/46200453044/in/photostream/">Sentinel Hub/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Optical images are similar to photos seen from space, but <a href="https://theconversation.com/sismo-citoyens-et-chercheurs-du-monde-entier-sallient-pour-comprendre-le-recent-seisme-dha-ti-166787">radar images</a> can be more difficult to interpret by non-experts. So following the disaster, satellite information is reworked to make it easier to understand. For example, the images are transformed into impact or change maps for rescue workers, flood alert maps for the public, and mapping of burnt or flooded areas with damage estimates for decision-makers.</p>
<p>Collaborative work between field users and satellite operators is essential. Progress has been made thanks to innovations in Earth observation technologies (notably the performance of optical resolutions – from 50 to 20 metres and now 30 centimetres) and 3D data processing software, but also thanks to the development of digital tools that can couple satellite and in situ data. The needs of the field have also contributed to the evolution of the charter’s intervention processes in terms of delivery time and quality of the products delivered.</p>
<h2>Reconstruction after disasters</h2>
<p>Emergency management is of course essential, but it is equally vital for all affected countries to consider reconstruction and the future. Indeed, the <a href="https://centredecrise.be/fr/que-font-les-autorites/le-cycle-du-risque">“risk cycle”</a> posits that reconstruction, resilience and risk prevention all play an important role in the return to normality. While disasters cannot be predicted, they can be better prepared for, especially in countries where they are recurrent. For example, residents could benefit from earthquake-resistant construction, the creation of safe gathering places or relocating to living areas to safe locations. Learning survival skills is also crucial.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/466034/original/file-20220530-14-np1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/466034/original/file-20220530-14-np1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466034/original/file-20220530-14-np1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466034/original/file-20220530-14-np1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466034/original/file-20220530-14-np1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466034/original/file-20220530-14-np1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466034/original/file-20220530-14-np1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Floods in Gan in Béarn in 2018.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/pezon64/42709789225/">Bernard Pez/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc-nd/4.0/">CC BY-NC-ND</a></span>
</figcaption>
</figure>
<p>Several initiatives, called <a href="https://www.recovery-observatory.org/drupal/en/node/811">“reconstruction observatories”</a>, have been carried out after major disasters – two examples are Haiti in 2021 and in Beirut after the 2019 port explosion. The aim is to coordinate satellite images to enable a detailed and dynamic assessment of damage to buildings, roads, farms, forests and more in the most affected areas, to monitor reconstruction planning, to reduce risks and to monitor changes over a three- to four-year time horizon.</p><img src="https://counter.theconversation.com/content/199357/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emilie Bronner ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>Using space imagery can help guide relief efforts to critical areas during a natural disaster.Emilie Bronner, Représentante CNES au Secrétariat Exécutif de la Charte Internationale Espace et Catastrophes Majeures, Centre national d’études spatiales (CNES)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1976182023-01-25T20:22:54Z2023-01-25T20:22:54ZThese 5 spectacular impact craters on Earth highlight our planet’s wild history<figure><img src="https://images.theconversation.com/files/505989/original/file-20230123-19-t7bakx.jpg?ixlib=rb-1.1.0&rect=513%2C163%2C3030%2C2130&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Image of Gosses Bluff taken from the ISS.</span> <span class="attribution"><span class="source">NASA</span></span></figcaption></figure><p>I think all craters are cool, I’m just going to start with that. I am very biased.</p>
<p>Impact craters occur on every planetary body <a href="https://solarsystem.nasa.gov/solar-system/our-solar-system/overview/">in our Solar System</a>, no matter the size. By studying impact craters and the meteorites that cause them, we can learn about the processes and the geology that shape our entire Solar System.</p>
<p>This list contains some of my favourite impact craters down here on Earth.</p>
<h2>1. Meteor Crater, AZ, US</h2>
<p><em><strong>The one that started it all.</strong></em></p>
<p>Barringer Crater (often called Meteor Crater), is located near the city of Winslow on Route 66 in Arizona, US, and was the first crater confirmed to have been caused by an extraterrestrial impact. </p>
<p>Meteor Crater is about 1km in diameter and roughly 50,000 years old, making it relatively “young”. We’ve known about the crater since the late 19th century, but there was debate as to whether it was from an impact, or associated with the nearby volcanic province.</p>
<p>It wasn’t until the 1960s when <a href="https://en.wikipedia.org/wiki/Coesite">high-pressure forms of quartz</a> were identified in the rocks, together with meteorite fragments found nearby, that scientists could <a href="https://www.science.org/doi/10.1126/science.132.3421.220">conclusively say it was a meteorite impact</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/505988/original/file-20230123-20-8xxitc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A light brown landscape viewed directly from above, with a round pockmark in the middle" src="https://images.theconversation.com/files/505988/original/file-20230123-20-8xxitc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505988/original/file-20230123-20-8xxitc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505988/original/file-20230123-20-8xxitc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505988/original/file-20230123-20-8xxitc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505988/original/file-20230123-20-8xxitc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505988/original/file-20230123-20-8xxitc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505988/original/file-20230123-20-8xxitc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Barringer Crater is unusually well preserved in the arid climate of the Colorado Plateau.</span>
<span class="attribution"><span class="source">USGS National Map Data Download and Visualization Services.</span></span>
</figcaption>
</figure>
<p>The crater is a site of active research. It is very well preserved, making it an excellent place to learn about the process of impact cratering. Since the early Apollo days, Meteor Crater has also been used to train astronauts. The practice continues to this day, with <a href="https://www.space.com/meteor-crater-hole-from-space-lunar-surface">Artemis astronauts learning</a> how to navigate terrains like those they will encounter on the lunar surface, as well as a bit of geology. </p>
<p>Today you can visit the crater (the gift shop is excellent!) and take a tour around the rim. It is a great addition to any trip to the Grand Canyon.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506050/original/file-20230124-15-mrdiel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A rocky sand-coloured landscape with a bowl-shaped depression in the middle and a blue sky above it" src="https://images.theconversation.com/files/506050/original/file-20230124-15-mrdiel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506050/original/file-20230124-15-mrdiel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=304&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506050/original/file-20230124-15-mrdiel.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=304&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506050/original/file-20230124-15-mrdiel.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=304&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506050/original/file-20230124-15-mrdiel.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=382&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506050/original/file-20230124-15-mrdiel.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=382&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506050/original/file-20230124-15-mrdiel.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=382&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A view of the entire Meteor Crater from the side. Note the tiny people on the viewing platform on the right-hand edge.</span>
<span class="attribution"><span class="source">IrinaK/Shutterstock</span></span>
</figcaption>
</figure>
<h2>2. Chicxulub, Yucatán, Mexico</h2>
<p><em><strong>The dinosaur killer!</strong></em></p>
<p>Possibly the best-known meteorite impact on Earth is the one that left the largely buried Chicxulub impact structure on the Yucatán peninsula in Mexico. This 180km diameter crater is the second largest on Earth and has been dated to <a href="https://eps.harvard.edu/files/eps/files/renne.kt_.science.2013.pdf">66 million years ago</a> – coincidental with the extinction of the dinosaurs. </p>
<p>For years geologists had searched for a mass extinction recorded in rocks around the world. It wasn’t until the discovery of <a href="https://en.wikipedia.org/wiki/Iridium">iridium</a>, an element much more abundant in meteorites than on Earth, that the pieces fell into place.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506211/original/file-20230124-12-4kbxzc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A green landscape seen from above with a cemicircle labelled as a trough" src="https://images.theconversation.com/files/506211/original/file-20230124-12-4kbxzc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506211/original/file-20230124-12-4kbxzc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=340&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506211/original/file-20230124-12-4kbxzc.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=340&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506211/original/file-20230124-12-4kbxzc.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=340&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506211/original/file-20230124-12-4kbxzc.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=428&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506211/original/file-20230124-12-4kbxzc.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=428&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506211/original/file-20230124-12-4kbxzc.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=428&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The subtle impression of the impact crater is still visible on the Yucatán peninsula today.</span>
<span class="attribution"><a class="source" href="https://photojournal.jpl.nasa.gov/catalog/PIA03379">NASA/JPL</a></span>
</figcaption>
</figure>
<p>The object that impacted Earth is estimated to have been 10km in diameter, travelling at 20km/s. That’s about 5 minutes to travel from Sydney to Los Angeles. </p>
<p>It wasn’t just the dinosaurs that became extinct though – it is estimated that 75% of the plant and animal species on Earth became extinct as a result of this event. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-the-dinosaurs-went-extinct-asteroid-collision-triggered-potentially-deadly-volcanic-eruptions-112134">How the dinosaurs went extinct: asteroid collision triggered potentially deadly volcanic eruptions</a>
</strong>
</em>
</p>
<hr>
<p>The impact would have been immediately catastrophic, with aftereffects felt for decades. There were large tsunamis, and forests burned around the world. Sunlight would have been obliterated by ash and gases, possibly for years, triggering a global winter where many more species perished. </p>
<p>Eventually, though, the crater system became a <a href="https://ui.adsabs.harvard.edu/abs/2022NRvEE...3..338M/abstract">flourishing deep biosphere</a> as the planet repopulated at the end of that long winter.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/dsQuEOVGYFE?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
</figure>
<h2>3. Vredefort, South Africa</h2>
<p><em><strong>The big one.</strong></em></p>
<p>Impact craters can be a source of economic resources. For example, the impact can concentrate pre-existing metals when a crater is formed, or it can expose buried sediments that otherwise wouldn’t have been near the surface.</p>
<p>The latter is the case at the Vredefort structure in South Africa. It is estimated that more than a third of the world’s gold has been mined from here. </p>
<p>The Vredefort impact structure is the biggest confirmed crater on Earth and <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022JE007186">is roughly 2 billion years old</a>. The original crater was thought to be up to 300km in diameter, but has largely eroded away. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/504599/original/file-20230116-18-e6877u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A highly detailed overhead view of a rocky orange-yellow landscape with a circular structure in it" src="https://images.theconversation.com/files/504599/original/file-20230116-18-e6877u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/504599/original/file-20230116-18-e6877u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=604&fit=crop&dpr=1 600w, https://images.theconversation.com/files/504599/original/file-20230116-18-e6877u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=604&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/504599/original/file-20230116-18-e6877u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=604&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/504599/original/file-20230116-18-e6877u.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=759&fit=crop&dpr=1 754w, https://images.theconversation.com/files/504599/original/file-20230116-18-e6877u.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=759&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/504599/original/file-20230116-18-e6877u.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=759&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Vredefort Dome imaged from NASA’s space shuttle in 1985.</span>
<span class="attribution"><span class="source">NASA</span></span>
</figcaption>
</figure>
<p>The impact exposed some of the oldest rocks on the planet. It is one of very few places where you can see a complete geological record of a whopping third of Earth’s history, with rocks ranging from 2.1 to 3.5 billion years in age.</p>
<p>When most people think of an impact crater, they think of a roughly circular depression, like Meteor Crater. But craters can have different shapes and features – Vredefort has a complex shape and is known as a multi-ring impact basin. These basins form in very large impacts and can also be seen on other planetary bodies; Mare Orientale on the Moon is one example.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506212/original/file-20230125-18580-x1935e.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A concentric circle on a grey background with a darker patch in the middle" src="https://images.theconversation.com/files/506212/original/file-20230125-18580-x1935e.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506212/original/file-20230125-18580-x1935e.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506212/original/file-20230125-18580-x1935e.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506212/original/file-20230125-18580-x1935e.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506212/original/file-20230125-18580-x1935e.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506212/original/file-20230125-18580-x1935e.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506212/original/file-20230125-18580-x1935e.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">One of the more spectacular features on our Moon, Mare Orientale is located on the boundary of the near and the far side.</span>
<span class="attribution"><a class="source" href="https://apod.nasa.gov/apod/ap110312.html">NASA/GSFC/Arizona State Univ./Lunar Reconnaissance Orbiter</a></span>
</figcaption>
</figure>
<h2><strong>4. Tnorala (Gosses Bluff) crater, NT, Australia</strong></h2>
<p><em><strong>Dreamtime stories.</strong></em></p>
<p>Australia is home to the oldest continuous living culture in the world, with evidence of people living on the continent for at least <a href="https://www.researchgate.net/publication/318562213_Human_occupation_of_northern_Australia_by_65000_years_ago">65,000 years</a>. It is also home to 30 impact craters, and these imposing geological structures are often considered sacred places by the local Indigenous communities. </p>
<p>Gosse’s Bluff impact crater is known as Tnorala by the Western Arrernte people. Their <a href="https://northernterritory.com/alice-springs-and-surrounds/see-and-do/tnorala--conservation-reserve">dreamtime stories of the creation time</a> say the crater formed</p>
<blockquote>
<p>when a group of women danced across the sky as the Milky Way. During this dance a mother put her baby aside in its wooden baby carrier. The carrier toppled over the edge of the dancing area and crashed to earth where it was transformed into the circular rock formation of Tnorala.</p>
</blockquote>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506214/original/file-20230125-18584-x1935e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A large red rocky feature on the horizon, with ruddy brown earth in the foreground" src="https://images.theconversation.com/files/506214/original/file-20230125-18584-x1935e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506214/original/file-20230125-18584-x1935e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506214/original/file-20230125-18584-x1935e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506214/original/file-20230125-18584-x1935e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506214/original/file-20230125-18584-x1935e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506214/original/file-20230125-18584-x1935e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506214/original/file-20230125-18584-x1935e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A distant view of Tnorala.</span>
<span class="attribution"><span class="source">sabine_lj/Shutterstock</span></span>
</figcaption>
</figure>
<p>Today Tnorala is 4.5km in diameter and sits 150m above the surrounding desert, but when it was first formed 142 million years ago, it was probably closer to 24km in diameter and has eroded over time.</p>
<p>Several other craters in Australia have songlines and Dreamtime stories associated with them, such as the <a href="https://nt.gov.au/parks/find-a-park/henbury-meteorites-conservation-reserve">Henbury crater field</a> which is 120km south east of Gosses Bluff, and is one of the few impact events to have been witnessed by humans. That meteorite crashed into what is now central Australia 4,700 years ago.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506217/original/file-20230125-23-9v8sqo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A large rocky circle on a red landscape seen from above" src="https://images.theconversation.com/files/506217/original/file-20230125-23-9v8sqo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506217/original/file-20230125-23-9v8sqo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=363&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506217/original/file-20230125-23-9v8sqo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=363&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506217/original/file-20230125-23-9v8sqo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=363&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506217/original/file-20230125-23-9v8sqo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=456&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506217/original/file-20230125-23-9v8sqo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=456&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506217/original/file-20230125-23-9v8sqo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=456&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Tnorala as seen on Google Earth.</span>
<span class="attribution"><a class="source" href="https://earth.google.com/web/@-23.83883539,132.31364704,732.86571228a,13201.20111175d,35y,-6.78107894h,59.97982337t,0r">Google Earth/CNES/Airbus</a></span>
</figcaption>
</figure>
<h2>5. Nördlinger Ries, Germany</h2>
<p><em><strong>Diamonds and gemstones.</strong></em></p>
<p>Nördlinger Ries, also just known as Ries crater, is one I’ve been lucky enough to visit. It formed around 14 million years ago and is roughly <a href="https://www.researchgate.net/publication/319963163_A_high-precision_40Ar39Ar_age_for_the_Nordlinger_Ries_impact_crater_Germany_and_implications_for_the_accurate_dating_of_terrestrial_impact_events">24km in diameter</a>. The town of Nördlingen is inside the crater, just south of the centre. If you climb the church steeple, you can see the ridge of the rim of the crater.</p>
<p>This was the second crater proved to be of impact origin by the <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/JZ066i010p03371">same team</a> that investigated Meteor Crater.</p>
<p>Again, the identification of a very high pressure form of quartz – coesite – held the key. This mineral had previously only been found naturally in rocks thought to have formed deep within Earth, or in nuclear test explosions. There was no evidence of either in Nördlingen, meaning the coesite must have formed in an impact. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/506219/original/file-20230125-20-m9zcbj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A patchwork image of green white and dark emerald showing a satellite view of Germany" src="https://images.theconversation.com/files/506219/original/file-20230125-20-m9zcbj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/506219/original/file-20230125-20-m9zcbj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506219/original/file-20230125-20-m9zcbj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506219/original/file-20230125-20-m9zcbj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506219/original/file-20230125-20-m9zcbj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506219/original/file-20230125-20-m9zcbj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506219/original/file-20230125-20-m9zcbj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A satellite image showing the outline of the crater delineated by dark forests. In the middle, the town of Nördlingen is visible with its red rooftops.</span>
<span class="attribution"><a class="source" href="https://www.esa.int/ESA_Multimedia/Images/2019/05/Ries_crater_Germany">ESA</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Lots of buildings in the city, including the church, were built using rocks formed in the impact. This includes a brecciated (literally - broken into angular fragments) rock called suevite. This particular suevite is special because the pre-impact rocks in this part of Bavaria included a layer of graphite.</p>
<p>During the impact, the graphite was subjected to very high pressures and temperatures. This transformed the graphite into millions of micro-diamonds which are spread through the buildings of the city. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/506220/original/file-20230125-20126-sgrnby.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A wrinkly, spiky green mineral held within a person's fingertips" src="https://images.theconversation.com/files/506220/original/file-20230125-20126-sgrnby.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/506220/original/file-20230125-20126-sgrnby.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/506220/original/file-20230125-20126-sgrnby.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/506220/original/file-20230125-20126-sgrnby.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/506220/original/file-20230125-20126-sgrnby.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/506220/original/file-20230125-20126-sgrnby.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/506220/original/file-20230125-20126-sgrnby.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A piece of moldavite found in Czechia.</span>
<span class="attribution"><span class="source">KPixMining/Shutterstock</span></span>
</figcaption>
</figure>
<p>The impact also hit a sandy layer of material near the surface, creating glassy green tektites. Tektites are impact melt glasses formed from material that’s thrown high into the atmosphere. They can often be found hundreds or thousands of kilometres from the original impact site.</p>
<p>In this case, they were found in Czechia near the River Moldau and are thus named moldavites. Unlike the diamonds at Ries, moldavite occurs in large-enough specimens to be used in jewellery as a semiprecious stone.</p>
<h2>Still more craters to be found</h2>
<p>The five impact craters above are diverse, and could all be considered unique. None of them have exhausted all the scientific questions we could ask. </p>
<p>Excitingly, there are still more craters we could find on Earth. As satellite imaging datasets become readily available at even higher resolutions, we are able to identify more potential impact structures in remote areas. Field geologists could explore these and search for the structures and chemical signals of an impact.</p>
<p>Each crater – no matter how old or how obscured – is ready to teach us something new about our planet, our Solar System, and the geological processes that shape it.</p><img src="https://counter.theconversation.com/content/197618/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Helen Brand does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Meteor impacts are an inevitable part of being a rocky planet in space. The craters they leave behind are a window into the tumultuous history of Earth.Helen Brand, Senior Beamline Scientist - Powder Diffraction, Australian Nuclear Science and Technology OrganisationLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1949972022-11-22T02:39:29Z2022-11-22T02:39:29ZHow satellites, radar and drones are tracking meteorites and aiding Earth’s asteroid defence<figure><img src="https://images.theconversation.com/files/496382/original/file-20221121-18-he3p7h.jpeg?ixlib=rb-1.1.0&rect=3%2C0%2C2166%2C1506&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.nasa.gov/image-feature/watching-meteors-from-the-space-stationrces/3361/">NASA</a></span></figcaption></figure><p>On July 31 2013 a <a href="https://cneos.jpl.nasa.gov/fireballs/">constellation of US defence satellites</a> saw a streak of light over South Australia as a rock from outer space burned through Earth’s atmosphere on its way to crash into the ground below. </p>
<p>The impact created an explosion equivalent to about 220 tonnes of TNT. More than 1,500km away, in Tasmania, the bang was heard by detectors normally used to listen for <a href="https://www.dfat.gov.au/international-relations/security/asno/Pages/australian-ims-stations">extremely low-frequency sounds</a> from illegal tests of nuclear weapons.</p>
<p>These were two excellent indications that there should be a patch of ground covered in meteorites somewhere north of Port Augusta. But how could we track them down?</p>
<p>My colleagues and I who work on the <a href="https://dfn.gfo.rocks/">Desert Fireball Network (DFN)</a>, which tracks incoming asteroids and <a href="https://dfn.gfo.rocks/meteorites.html">the resulting meteorites</a>, had a couple of ideas: weather radar and drones.</p>
<h2>Eyes in space</h2>
<p>Finding meteorites is not an easy task. There is a network of high-quality ground-based sensors called the <a href="https://gfo.rocks/">Global Fireball Observatory</a>, but it only covers about 1% of the planet.</p>
<p>The <a href="https://cneos.jpl.nasa.gov/fireballs/">US satellite data</a> published by NASA covers a much larger area than ground-based detectors, but it only picks up the biggest fireballs. What’s more, they <a href="https://academic.oup.com/mnras/article/483/4/5166/5256650">don’t always give an accurate idea of the meteor’s trajectory</a>.</p>
<p>So, to have any chance to find a meteorite from these data, you need a little outside help.</p>
<h2>Weather radars</h2>
<p>In 2019, Australia’s Bureau of Meteorology started making its weather radar data <a href="https://www.openradar.io/">openly available</a> to researchers and the public. I saw this as an opportunity to complete the puzzle.</p>
<p>I combed through the record of events from the Desert Fireball Network and NASA, and cross-matched them with nearby weather radars. Then I looked for unusual radar signatures that could indicate the presence of falling meteorites.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/496384/original/file-20221121-22-iwtkve.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An annoyed aerial photo showing the locations of the Woomera radar station and the falling meteorites." src="https://images.theconversation.com/files/496384/original/file-20221121-22-iwtkve.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/496384/original/file-20221121-22-iwtkve.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=334&fit=crop&dpr=1 600w, https://images.theconversation.com/files/496384/original/file-20221121-22-iwtkve.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=334&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/496384/original/file-20221121-22-iwtkve.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=334&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/496384/original/file-20221121-22-iwtkve.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=420&fit=crop&dpr=1 754w, https://images.theconversation.com/files/496384/original/file-20221121-22-iwtkve.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=420&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/496384/original/file-20221121-22-iwtkve.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=420&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Woomera weather radar station captured reflections from the falling meteorites.</span>
<span class="attribution"><span class="source">Curtin University</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>And bingo, the 2013 event was not too far from the Woomera radar station. The weather was clear, and the radar record showed some small reflections at about the right place and time.</p>
<p>Next, I had to use the weather data to figure out how the wind would have pushed the meteorites around on their way down to Earth. </p>
<p>If I got the calculations right, I would have a treasure map showing the location of a rich haul of meteorites. If I got them wrong, I would end up sending my team to wander around in the desert for two weeks for nothing.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-weather-radar-can-keep-tabs-on-the-elusive-magpie-goose-126278">How weather radar can keep tabs on the elusive magpie goose</a>
</strong>
</em>
</p>
<hr>
<h2>The search</h2>
<p>I gave what I hoped was an accurate treasure map to my colleague Andy Tomkins from Monash University. In September this year, he happened to be driving past the site on his way back from an expedition in the Nullarbor.</p>
<p>Thankfully, Andy found the first meteorite within 10 minutes of looking. In the following two hours, his team found nine more.</p>
<figure class="align-center ">
<img alt="Photo of several people walking through a desert field looking at the ground." src="https://images.theconversation.com/files/496385/original/file-20221121-16-he3p7h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/496385/original/file-20221121-16-he3p7h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/496385/original/file-20221121-16-he3p7h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/496385/original/file-20221121-16-he3p7h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/496385/original/file-20221121-16-he3p7h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/496385/original/file-20221121-16-he3p7h.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/496385/original/file-20221121-16-he3p7h.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A field team from Monash University searched for meteorites in the strewn field.</span>
<span class="attribution"><span class="source">Monash University</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The technique of finding meteorites with weather radars <a href="https://ares.jsc.nasa.gov/meteorite-falls/how-to-find-meteorites/">was pioneered</a> by my colleague Marc Fries in the US. However, this is the first time it has been done outside the US NEXRAD radar network. (When it comes to monitoring airspace, the US has more powerful and more densely packed tech than anyone else.)</p>
<p>This first search confirmed there were lots of meteorites on the ground. But how were we going to find them all?</p>
<p>That’s where the drones come in. We used a method developed by my colleague Seamus Anderson to <a href="https://gfo.rocks/blog/2022/03/14/First_Meteorite_Found_with_Drone.html">automatically detect meteorites from drone images</a>.</p>
<p>In the end we collected 44 meteorites, weighing a bit over 4kg in total. Together they form what we call a “strewn field”.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/496386/original/file-20221121-13-qssltc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="An aerial view of a desert field with a black dot (a meteorite) highlighted by a yellow square." src="https://images.theconversation.com/files/496386/original/file-20221121-13-qssltc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/496386/original/file-20221121-13-qssltc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/496386/original/file-20221121-13-qssltc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/496386/original/file-20221121-13-qssltc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/496386/original/file-20221121-13-qssltc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/496386/original/file-20221121-13-qssltc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/496386/original/file-20221121-13-qssltc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A machine-learning algorithm identified meteorites from drone photos.</span>
<span class="attribution"><span class="source">Curtin Uni</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Strewn fields <a href="https://onlinelibrary.wiley.com/doi/10.1111/maps.13892">tell us a lot</a> about how an asteroid fragments in our atmosphere.</p>
<p>That’s quite important to know, because the energy of these things is comparable to that of nuclear weapons. For example, the 17-metre asteroid that exploded over Chelyabinsk in Russia in 2013 produced an explosion 30 times the size of the bomb dropped on Hiroshima in 1945. </p>
<p>So when the next big one is about to hit, it may be useful to predict how it will deposit its energy in our atmosphere.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/astronomers-have-detected-another-planet-killer-asteroid-could-we-miss-one-coming-our-way-193709">Astronomers have detected another 'planet killer' asteroid. Could we miss one coming our way?</a>
</strong>
</em>
</p>
<hr>
<p>With new telescopes and better technology, we are starting to see some asteroids <a href="https://skymapper.anu.edu.au/news/great-balls-fire/">before they hit Earth</a>. We will see even more when projects such as the <a href="https://www.lsst.org">Vera Rubin Observatory</a> and the <a href="https://atlas.fallingstar.com">Asteroid Terrestrial-impact Last Alert System (ATLAS)</a> are up and running.</p>
<p>These systems might give us as much as a few days’ notice that an asteroid is heading for Earth. This would be too late to make any effort to deflect it – but plenty of time for preparation and damage control on the ground.</p>
<h2>The value of open data</h2>
<p>This find was only made possible by the free availability of crucial data – and the people who made it available.</p>
<p>The US satellites that detected the fireball are presumably there to detect missile and rocket launches. However, somebody (I don’t know who) must have figured out how to publish some of the satellite data without giving away too much about their capabilities, and then lobbied hard to get the data released. </p>
<p>Likewise, the find would not have happened without the work of Joshua Soderholm at Australia’s Bureau of Meteorology, who worked to make low-level weather radar data openly accessible for other uses. Soderholm went to the trouble to make the radar data <a href="https://www.go-fair.org/fair-principles/">readily available and easy to use</a>, which goes well beyond the vague formulations you can read at the bottom of scientific papers like “data available upon reasonable request”.</p>
<p>There is no shortage of fireballs to track down. Right now, we’re on the hunt for a meteorite that was spotted in space last weekend before <a href="https://www.nytimes.com/2022/11/19/science/fireball-asteroid-toronto-new-york.html?">blazing through the sky over Ontario, Canada</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/a-pristine-chunk-of-space-rock-found-within-hours-of-hitting-earth-can-tell-us-about-the-birth-of-the-solar-system-194725">A pristine chunk of space rock found within hours of hitting Earth can tell us about the birth of the Solar System</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/194997/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Hadrien Devillepoix does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>From space to the outback, meteorite-tracking tools are building the knowledge we need to prepare for a future asteroid impact.Hadrien Devillepoix, Researcher in Planetary Astronomy, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1719502022-10-12T19:02:08Z2022-10-12T19:02:08ZThese stunning satellite images look like abstract art – and they reveal much about our planet<figure><img src="https://images.theconversation.com/files/487986/original/file-20221004-12-13cupg.jpg?ixlib=rb-1.1.0&rect=14%2C14%2C4977%2C4977&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">This is an enhanced satellite image of Western Australia's Great Sandy Desert. Yellow sand dunes cover the upper right, red splotches indicate burned areas, and other colours show different types of surface geology.
</span> <span class="attribution"><span class="source">USGS/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p><em>Environmental scientists see flora, fauna and phenomena the rest of us rarely do. In this series, we’ve invited them to share their unique <a href="https://theconversation.com/au/topics/photos-from-the-field-92499">photos from the field</a>.</em></p>
<hr>
<p>There’s something to be said for a job that pays you to stroll over the Scottish Highlands, scoot around a Greek Island, or go on an expedition to Antarctica – all in the name of geoscience, the study of the Earth. </p>
<p>But during COVID travel restrictions, many geologists had to mine the collection of samples and data they already had. Other geologists used satellite and other images to make geological interpretations.</p>
<p>This field of geology is called remote sensing, which is the process of using, for instance, satellites or aeroplanes to observe the physical features of an area at a distance. It’s often easier to see how geology shapes our landscapes by taking this birds-eye view.</p>
<p>In terrific news for remote sensing geologists, armchair geology enthusiasts and lovers of stunning landscapes, the United States Geological Survey (USGS) has a <a href="https://unsplash.com/@usgs">vast collection</a> of satellite images of the Earth’s surface, capturing breathtaking geological features from space. </p>
<p>Remote sensing geologists use many techniques which make features of interest more distinct. This enhances or alters colours, which you can see in a few of my picks of USGS’s eight most fascinating images. Here’s what they reveal about the planet.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/5-rocks-any-great-australian-rock-collection-should-have-and-where-to-find-them-163578">5 rocks any great Australian rock collection should have, and where to find them</a>
</strong>
</em>
</p>
<hr>
<h2>Volcanoes from space</h2>
<p>Volcanoes are usually pretty distinctive when you see them from the ground, whether it’s the iconic Mount Fuji, the lava fields of Iceland, or the <a href="https://www.tandfonline.com/doi/figure/10.1080/08120099.2013.806954?scroll=top&needAccess=true">hundreds of volcanoes</a> that pockmark the fields of western Victoria in Australia. </p>
<p>From above, they can look a little different. In the first image below of Mount Elgon on the border of Uganda and Kenya, you can spot the “caldera” – a bowl-shaped depression in the centre of the volcano where the rock has collapsed after the magma chamber empties. </p>
<p>In the second image of New Zealand’s Mount Taranaki, you can spot the crater, which is also a depression, but forms when the volcano explodes and rocks are ejected.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480226/original/file-20220822-54174-bc8uno.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mount Elgon, Uganda and Kenya.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="Volcano crater from above surrounded by a dark green circle of forest" src="https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480244/original/file-20220822-13569-89k1oy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mount Taranaki in Egmont National Park, New Zealand.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<p>The products of volcanoes may also be obvious in satellite images. You can see the lava flow from the Haruj volcano in Libya in the third image below. It is a black stain of basalt on the surrounding white and yellow sand, to envy even the finest <a href="https://www.rorschach.org">Rorschach inkblots</a>.</p>
<p>This field of lava is about 185 kilometres wide, a huge distance that’s possible because the <a href="https://www.scirp.org/journal/paperinformation.aspx?paperid=53675">chemical composition</a> of the lava made it runny and able to flow a long distance from the eruption site. </p>
<figure class="align-center ">
<img alt="A black splatter of lava in surrounding sandy desert landscape" src="https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480246/original/file-20220822-64771-9t0pw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Haruj Volcanic Field, Libya.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<p>Some magma-related features have stumped geologists for years. Only by combining remote sensing with observations on the ground have they been able to solve these geological puzzles. The Richat Structure in Mauritania’s Maur Adrar Desert, shown below, is one such feature. </p>
<p>It looks like a meteorite impact crater or, perhaps, a bullseye for intergalactic visitors. But in recent years, researchers determined – after much debate – that it formed when a series of magmas from deep below the surface <a href="https://link.springer.com/article/10.1007/s12517-021-08734-4">intruded into the existing sediments</a>.</p>
<figure class="align-center ">
<img alt="Grey concentric rings of rock surrounded by green landscape from above" src="https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480247/original/file-20220822-64736-uxhp2j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Richat Structure, Mauritania.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<p>Some of these magmas formed concentric circles, known as ring dikes, which is the main feature we see in satellite imagery. These ring dike magmas never reached the surface and are only exposed now because the overlying rocks eroded away over time. </p>
<p>But other magmas in the series <a href="https://www.sciencedirect.com/science/article/abs/pii/S1464343X14000971?via%3Dihub">did make it to the surface to erupt as lava</a>. You can see the small volcano formed by these surface eruptions on the USGS image where it appears as a white-grey smudge interrupting the southwestern part of the innermost ring dike. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/photos-from-the-field-the-stunning-crystals-revealing-deep-secrets-about-australian-volcanoes-161176">Photos from the field: the stunning crystals revealing deep secrets about Australian volcanoes</a>
</strong>
</em>
</p>
<hr>
<h2>When rocks collide</h2>
<p>The landscapes of Iran’s Zagros Mountains and China’s Keping Shan thrust range have two major things in common. </p>
<p>First, they both look spectacular from above. Second, they were both <a href="https://pubs.geoscienceworld.org/books/book/1510/chapter-abstract/107191433/The-Evolution-of-the-Tethys-Region-throughout-the?redirectedFrom=fulltext">formed at the bottom of oceans</a> and were then <a href="https://www.lyellcollection.org/doi/10.1144/SP348.5">uplifted and deformed</a> by geological forces to form the ridges and valleys which dominate these two regions today. </p>
<figure class="align-center ">
<img alt="View from above of domes of rock between valleys" src="https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480251/original/file-20220822-14060-fxzpze.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Zagros Mountains, Iran.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<figure class="align-center ">
<img alt="A landscape from above showing multi-coloured layers of rock that have been folded and broken apart" src="https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/480249/original/file-20220822-64444-rh5qzj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Keping Shan thrust belt, China.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span></span>
</figcaption>
</figure>
<p>Both mountain belts were created when land masses collided, and the pressure from these collisions caused the rocks to fold over themselves. In some places, the rocks broke apart completely. </p>
<p>These breaks, known as faults, brought up deeper, older rocks to sit on top of younger rocks. These <a href="https://earthobservatory.nasa.gov/images/82853/faults-in-xinjiang">faults form the layered ridges</a> seen in the satellite image of Keping Shan.</p>
<p>Unlike Keping Shan, the ridges in the Zagros Mountains were formed when softer rocks, such as silt and mudstone, <a href="https://www.geolsoc.org.uk/Policy-and-Media/Outreach/Plate-Tectonic-Stories/Hartland-Quay/Zagros-Range#:%7E:text=The%20Zagros%20Mountains%20formed%20as,increase%20in%20height%20each%20year.">were eroded away over time</a>. This erosion formed valleys beside the more resistant rocks of limestone and dolomite, which comprise the arch-shaped folded domes. </p>
<h2>Unravelling rivers</h2>
<p>Rivers make huge changes to our landscapes. Over many years they can find and exploit weaknesses in rocks to carve their way through any terrain. Rivers look and behave differently depending on <a href="https://geo.libretexts.org/Courses/University_of_California_Davis/GEL_109%3A_Sediments_and_Strata_(Sumner)/08%3A_Old_or_Lost_Pages/8.06%3A_Rivers">factors</a> such as flow rate, how much sediment they carry, and the gradient of the slope they’re on. </p>
<p>Rivers can consist of one narrow and winding stream (called a meandering river) such as the Beni River in Bolivia, or a wide channel made up of many branches braided together between bars of sediment (called a braided river), such as the portion of Brazil’s Rio Negro in the last image below. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A blue sinuous river cuts through bright green forest" src="https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488664/original/file-20221006-24-ru6ftz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Beni River, Bolivia.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="View from above of the blue Rio Negro (black river) with a mosaic of rivers surrounded by green plains." src="https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/488665/original/file-20221006-20453-jjy784.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rio Negro, Brazil.</span>
<span class="attribution"><span class="source">United States Geological Survey/Unsplash</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Looking at the meandering Beni River from above, you can see how the twists and turns of the river have evolved over time. The u-shaped lakes scattered along the edges of the river are called <a href="https://www.tandfonline.com/doi/abs/10.1080/00049188208702813?journalCode=cage20">oxbow lakes</a>. </p>
<p>These oxbow lakes are the former channel of the river which have since been cut off when the river eroded a new, more direct channel to follow. In Australia, oxbow lakes are also known as billabongs.</p>
<p>Unlike the slowly meandering Beni River, the wide channel of the Rio Negro is created by fast flows and the deposition of coarse sediment. These characteristics form the mosaic of small islands between the branching flow of water. The islands become submerged during Brazil’s wet season when the volume and flow of the water is higher. </p>
<p>Armed with this new knowledge, book a window seat next time you fly and see what geological wonders you can spy from above.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-dingo-fence-from-space-satellite-images-show-how-these-top-predators-alter-the-desert-155642">The dingo fence from space: satellite images show how these top predators alter the desert</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/171950/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Emily Finch has previously received funding from an Australian Postgraduate Award and a Society of Economic Geologists Graduate Student Fellowship.</span></em></p>The United States Geological Survey has a vast collection of satellite images capturing breathtaking geological features of our planet. As a geologist, I’ve picked eight of the most fascinating.Emily Finch, Research Affiliate, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1884252022-08-15T12:39:00Z2022-08-15T12:39:00ZWar in Ukraine highlights the growing strategic importance of private satellite companies – especially in times of conflict<figure><img src="https://images.theconversation.com/files/478830/original/file-20220811-24-60by8c.jpg?ixlib=rb-1.1.0&rect=70%2C50%2C4115%2C2452&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Private companies have launched dozens of imaging satellites – like the two small boxes in the middle of the photo – into orbit in recent years.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/nasa2explore/12468114213/in/set-72157629601396498">NASA/Steve Jurvetson</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>Satellites owned by private companies have played an unexpectedly important role in the war in Ukraine. For example, in early August 2022, images from the private satellite company Planet Labs <a href="https://www.nytimes.com/live/2022/08/10/world/ukraine-russia-news-war">showed that</a> a recent attack on a Russian military base in Crimea caused more damage than Russia had suggested in public reports. Ukrainian President Volodymyr Zelenskyy <a href="https://www.president.gov.ua/en/news/sho-bilshe-bude-vtrat-v-okupantiv-shvidshe-mi-zmozhemo-zviln-76997">highlighted the losses</a> as evidence of Ukraine’s progress in the war. </p>
<p>Soon after the war began, <a href="https://www.cnet.com/science/space/ukraine-asks-commercial-satellite-operators-for-help-tracking-russian-troops/">Ukraine requested data</a> from private satellite companies around the world. By the end of April, Ukraine was getting imagery from U.S. companies <a href="https://www.satellitetoday.com/government-military/2022/04/26/intelligence-community-is-rapidly-delivering-commercial-satellite-imagery-to-ukraine-nga-official-says/">mere minutes</a> after the data was collected.</p>
<p>My research focuses on <a href="https://mitpress.mit.edu/9780262037181/">international cooperation in satellite Earth observations</a>, including the role of the private sector. While experts have long known that satellite imagery is useful during a conflict, the war in Ukraine has shown that commercial satellite data can make a decisive difference – informing both military planning as well as the public view of a war. Based on the strategic value commercial satellite imagery has held during this war, I believe it is likely that more nations will be investing in private satellite companies.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/479089/original/file-20220815-704-uvsojl.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/479089/original/file-20220815-704-uvsojl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/479089/original/file-20220815-704-uvsojl.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=406&fit=crop&dpr=1 600w, https://images.theconversation.com/files/479089/original/file-20220815-704-uvsojl.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=406&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/479089/original/file-20220815-704-uvsojl.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=406&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/479089/original/file-20220815-704-uvsojl.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=511&fit=crop&dpr=1 754w, https://images.theconversation.com/files/479089/original/file-20220815-704-uvsojl.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=511&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/479089/original/file-20220815-704-uvsojl.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=511&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption"></span>
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<h2>Growth of the commercial satellite sector</h2>
<p>Remote-sensing satellites circle the Earth collecting imagery, radio signals and many other types of data. The technology was originally developed by governments for military reconnaissance, weather forecasting and environmental monitoring. But over the past two decades, commercial activity in this area has grown rapidly – particularly in the U.S. The number of commercial Earth observation satellites has increased <a href="https://www.ucsusa.org/resources/satellite-database">from 11 in 2006 to more than 500 in 2022</a>, about 350 of which belong to U.S. companies.</p>
<p>The earliest commercial satellite remote-sensing companies worked closely with the military from the beginning, but many of the newer entrants were not developed with national security applications in mind. Planet Labs, the U.S.-based company that has played a big role in the Ukrainian conflict, <a href="https://www.planet.com/faqs/">describes its customers</a> as those in “agriculture, government, and commercial mapping,” and it hopes to expand to “insurance, commodities, and finance.” Spire, another U.S. company, was originally focused on <a href="https://spacenews.com/lofty-aspirations-for-spires-weather-watching-cubesats/">monitoring weather and tracking commercial maritime activity</a>. However, when the U.S. government <a href="https://www.satellitetoday.com/innovation/2016/09/28/nga-growing-acceptance-satellite-imagery-startups/">set up pilot programs</a> in 2016 to evaluate the value of data from these companies, many of the companies welcomed this new source of revenue.</p>
<h2>Value of commercial data for national security</h2>
<p>The U.S. government has its own highly capable network of spy satellites, so partnerships with private companies may come as a surprise, but there are clear reasons the U.S. government benefits from these arrangements.</p>
<p>First is the simple fact that purchasing commercial data allows the government to see more locations on the Earth more frequently. In some cases, data is now available quickly enough to <a href="https://www.ifri.org/sites/default/files/atoms/files/m._borowitz_military_use_small_satellites_in_orbit_03.2022.pdf">enable real-time decision-making</a> on the battlefield.</p>
<p>The second reason has to do with data sharing practices. Sharing data from spy satellites requires officials to go through a complex declassification process. It also risks revealing information about classified satellite capabilities. Neither of these is a concern with data from private companies. This aspect makes it <a href="https://mitpress.mit.edu/books/open-space">easier for the military to share satellite information</a> within the U.S. government as well as with U.S. allies. This advantage has proved to be a <a href="https://www.satellitetoday.com/government-military/2022/04/26/intelligence-community-is-rapidly-delivering-commercial-satellite-imagery-to-ukraine-nga-official-says/">key factor</a> for the war in Ukraine.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/478833/original/file-20220811-5086-wca263.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A satellite photo of an air base with blast marks." src="https://images.theconversation.com/files/478833/original/file-20220811-5086-wca263.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/478833/original/file-20220811-5086-wca263.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/478833/original/file-20220811-5086-wca263.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/478833/original/file-20220811-5086-wca263.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/478833/original/file-20220811-5086-wca263.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/478833/original/file-20220811-5086-wca263.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/478833/original/file-20220811-5086-wca263.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This photo was taken by a Planet Labs satellite on Aug. 10, 2022, and shows damage to planes from a Ukrainian attack that took place only one day before, on Aug. 9, 2022.</span>
<span class="attribution"><span class="source">Imagery courtesy of Planet Labs PBC</span></span>
</figcaption>
</figure>
<h2>Use of satellite data in Ukraine</h2>
<p>Commercial satellite imagery has proved to be critical to this war in two ways. First, it’s a media tool that allows the public to watch as the war progresses in incredible detail, and second, it’s a source of important information that helps the Ukrainian military plan day-to-day operations.</p>
<p>Even before the war began in February 2022, the U.S government was <a href="https://www.politico.com/news/2022/04/06/satellite-russian-war-crimes-00023386">actively encouraging</a> commercial satellite companies to share their imagery and raise awareness of Russian activity. Commercial companies <a href="https://www.nato.int/cps/en/natohq/opinions_191839.htm?selectedLocale=en">released images</a> showing <a href="https://www.marketwatch.com/story/how-fears-of-russian-invasion-of-ukraine-put-open-source-intelligence-in-spotlight-11645033603">Russian troops amassing near the Ukrainian border</a>, directly contradicting statements by Russia.</p>
<p>In early March 2022, Ukraine’s Vice Prime Minister, Mykhailo Fedorov, asked eight commercial satellite companies for access to their data. In his request, he said that this could be the first major war in which <a href="https://www.cnet.com/science/space/ukraine-asks-commercial-satellite-operators-for-help-tracking-russian-troops/">commercial satellite imagery played a significant role</a>. Some companies obliged, and within the first two weeks of the conflict the Ukrainian government <a href="https://www.satellitetoday.com/government-military/2022/04/26/intelligence-community-is-rapidly-delivering-commercial-satellite-imagery-to-ukraine-nga-official-says/">received data covering</a> more than 15 million square miles (40 million square km) of the war zone.</p>
<p>The U.S. government significantly <a href="https://www.defensenews.com/battlefield-tech/space/2022/04/06/intelligence-agencies-accelerate-use-of-commercial-space-imagery-to-support-ukraine/">increased its purchases of imagery</a> that could be provided to Ukraine. The U.S. government has also actively fostered connections directly between <a href="https://www.defensenews.com/battlefield-tech/space/2022/04/06/intelligence-agencies-accelerate-use-of-commercial-space-imagery-to-support-ukraine/">U.S. companies and Ukrainian intelligence analysts</a>, helping promote the flow of information.</p>
<p>A recent example of the value of these images comes again from Planet Labs. Over the past few weeks, the company has been releasing images showing the conflict drawing dangerously <a href="https://www.npr.org/2022/08/10/1116461260/ukraine-zaporizhzhia-nuclear-plant-russia-war-satellite-images">near the Zaporizhzhia nuclear power plant</a>. In recent days, U.N. officials have said the situation poses a “<a href="https://www.iaea.org/newscenter/pressreleases/director-general-grossi-alarmed-by-shelling-at-ukraine-npp-says-iaea-mission-vital-for-nuclear-safety-and-security">very real risk of a nuclear disaster</a>” and pushed for U.N. experts to be allowed to visit the site.</p>
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<p>Before the war, Ukrainian officials thought money was better spent on “down-to-earth” security needs, rather than expensive satellites. But now these officials view <a href="https://www.defenseone.com/technology/2022/07/five-space-lessons-russias-invasion-taught-ukraine/374101/">satellite imagery as critical</a> – both to battlefield awareness and for documenting atrocities allegedly carried out by Russian troops. </p>
<h2>Looking forward</h2>
<p>Some space experts have called the war in Ukraine the first “<a href="https://spacenews.com/on-national-security-drawing-lessons-from-the-first-commercial-space-war/">commercial space war</a>.” The conflict has clearly shown the national security value of commercial satellite imagery, the ability of commercial satellite images to <a href="https://doi.org/10.1177/0022002720987285">promote transparency</a> and the importance of not only national space power, but also <a href="https://doi.org/10.5038/1944-0472.12.1.1729">the space capabilities of allies</a>.</p>
<p>I believe the fact that the U.S. commercial sector had such a significant effect on military operations and public opinion will lead to increased government investment in the private satellite sector globally. Leaders in Ukraine intend to <a href="https://www.defenseone.com/technology/2022/07/five-space-lessons-russias-invasion-taught-ukraine/374101/">invest in domestic satellite imaging capabilities</a>, and the U.S. has <a href="https://www.satellitetoday.com/government-military/2022/04/26/intelligence-community-is-rapidly-delivering-commercial-satellite-imagery-to-ukraine-nga-official-says/">expanded its commercial purchases</a>. This expansion may raise new challenges if abundant satellite imagery is available to actors on both sides of a conflict in the future.</p>
<p>Some Earth-observing satellite companies have expressed hope that the lessons learned will extend <a href="https://qz.com/2159831/vcs-invest-97-million-in-capellas-space-radar/">beyond war and national security</a>. The ability to rapidly produce images and analysis could be used to <a href="https://gisgeography.com/remote-sensing-applications/">monitor agricultural trends</a> or <a href="https://gisgeography.com/remote-sensing-applications/">provide insight into illegal mining operations</a>. </p>
<p>The war in Ukraine may well prove to be a key turning point for both global transparency in conflict and the commercial Earth-observing sector as a whole.</p><img src="https://counter.theconversation.com/content/188425/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mariel Borowitz receives funding from the National Science Foundation, the National Aeronautics and Space Administration, and the European Union. She has done consulting work for the Space Foundation, the North Atlantic Treaty Organization, and the Institut Français des Relations Internationales.</span></em></p>Private satellite companies have boomed in recent years, and many experts have wondered what role they would play in a conflict. They have proved to be invaluable to Ukraine in recent months.Mariel Borowitz, Associate Professor of International Affairs, Georgia Institute of TechnologyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1727732021-12-06T19:06:11Z2021-12-06T19:06:11ZWe are professional fire watchers, and we’re astounded by the scale of fires in remote Australia right now<figure><img src="https://images.theconversation.com/files/435752/original/file-20211206-21-bgeg21.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5391%2C3581&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>While southern Australia experienced a wet winter and a soggy spring, northern Australia has seen the opposite. Extreme fire weather in October and November led to bushfires across <a href="https://firenorth.org.au/">120,000 square kilometres</a> of southern savanna regions.</p>
<p>Significant fires continue to burn in the Kimberley, the Top End, Cape York and the northern deserts. And while recent rain across the central deserts has reduced the current fire risk, it will significantly increase fuel loads which creates the potential for large wildfires in summer.</p>
<p>We are professional fire watchers. The lead author of this article, Rohan Fisher, <a href="https://firenorth.org.au/">maps and monitors</a> fires across the tropical savannas and rangelands that comprise 70% of the Australian continent. The scale of burning we’re now seeing astounds us – almost as much as the lack of interest they generate.</p>
<p>This continent’s fire ecology is poorly understood by most Australians, despite recent significant bushfire events close to big cities. But as we enter the Pyrocene age under worsening climate change, good fire knowledge is vitally important. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/australia-you-have-unfinished-business-its-time-to-let-our-fire-people-care-for-this-land-135196">Australia, you have unfinished business. It's time to let our 'fire people' care for this land</a>
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</em>
</p>
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<figure class="align-center ">
<img alt="Indigenous man and child walk on burnt landscape" src="https://images.theconversation.com/files/435758/original/file-20211206-15-1szo1gh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435758/original/file-20211206-15-1szo1gh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435758/original/file-20211206-15-1szo1gh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435758/original/file-20211206-15-1szo1gh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435758/original/file-20211206-15-1szo1gh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435758/original/file-20211206-15-1szo1gh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435758/original/file-20211206-15-1szo1gh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">On the Mitchell Plateau in Western Australia, a Kandiwal man and his child walk through country burnt by traditional fires. Such ancient methods must be expanded to help Australia survive the Pyrocene.</span>
<span class="attribution"><span class="source">Philip Schubert/Shutterstock</span></span>
</figcaption>
</figure>
<h2>In the desert, fire and water are linked</h2>
<p>Fires in arid Australia are extensive, largely unmanaged, often destructive and significantly under-reported. Improving their management involvement is crucial to both Traditional Owners and the ecological health of our continent. </p>
<p>To improve pyro-literacy, we developed a <a href="https://savannafiremapping.com/nafi-mobile-app/">mobile app</a> to map fires across most of Australia in real-time. </p>
<p>This year, <a href="https://www.abc.net.au/news/2021-11-30/extreme-heatwave-to-hit-kimberley-and-the-pilbara/100658568">Western Australia</a> and the <a href="https://www.abc.net.au/news/2021-10-19/nt-heatwave-conditions-peak-record-temperatures-bom/100549312">Northern Territory</a> experienced serious heatwaves late in the year and a late start to the wet season. This provided the perfect bushfire conditions.</p>
<p>In contrast, central Australia has experienced rare flooding rains, including at Alice Springs which recorded the <a href="https://www.abc.net.au/news/2021-11-13/alice-springs-wettest-november-on-record/100616212">wettest November</a> on record. This creates dangerous fuel loads heading into summer.</p>
<p>In the desert, water and fire is coupled in both space and time. Fire burns where water flows, because that’s where fuel – in the form of vegetation – is heaviest. </p>
<p>The below satellite image from the Pilbara illustrates this point. It shows the path of an arid-zone fire flowing like water along dry creeks and drainage lines. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/434382/original/file-20211129-15-q3vm4s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/434382/original/file-20211129-15-q3vm4s.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=403&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434382/original/file-20211129-15-q3vm4s.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=403&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434382/original/file-20211129-15-q3vm4s.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=403&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434382/original/file-20211129-15-q3vm4s.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=506&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434382/original/file-20211129-15-q3vm4s.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=506&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434382/original/file-20211129-15-q3vm4s.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=506&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Arid-zone fire travelling along dry creeks and drainage lines.</span>
</figcaption>
</figure>
<p>Where country is not managed for fire, it can lead to catastrophic outcomes. </p>
<p>The incidence of previous fire also influences fire spread. Without the regular application of fire, large tracts of desert can accumulate heavy fuel loads, primed for ignition. </p>
<p>Over a few months in 2011, our data show more than 400,000 square kilometres in central Australia burned – almost twice the size of Victoria. It was one of the <a href="https://austrangesoc.com.au/range-management-newsletter-12-2/#article_166">largest</a> single fire events in recent Australian history and coincided with the wet La Nina period in 2010-12. </p>
<p>Watching from satellites in space, we mapped the spread of the fires in near-real time, as this video shows:</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/yJJPm0cUTJ4?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A hot spot animation of the 2011 fire season in central Australia.</span></figcaption>
</figure>
<h2>Fire management through time</h2>
<p>For many thousands of years, Australia’s Indigenous people have skilfully burned landscapes to manage country. <a href="https://www.dpaw.wa.gov.au/management/fire/fire-and-the-environment/41-traditional-aboriginal-burning">Most fires</a> are relatively low-intensity or “cool” and do not burn large areas. This results in a <a href="https://theconversation.com/australia-you-have-unfinished-business-its-time-to-let-our-fire-people-care-for-this-land-135196">fine-scale mosaic</a> of different vegetation types and fuel ages, reducing the chance of large fires.</p>
<p>Researchers have <a href="https://www.cabdirect.org/cabdirect/abstract/20063159465">looked back in time</a> to provide insight into fire management as it once was. This was done using aerial photography taken in the 1940s and 1950s in preparation for missile testing at Woomera in South Australia. </p>
<p>The below aerial photo from 1953 reveals a complex mosaic of burn patterns and burn ages – a result of fine-scale land management by Traditional Owners. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/434607/original/file-20211130-18-1x8y4pf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/434607/original/file-20211130-18-1x8y4pf.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=427&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434607/original/file-20211130-18-1x8y4pf.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=427&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434607/original/file-20211130-18-1x8y4pf.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=427&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434607/original/file-20211130-18-1x8y4pf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=537&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434607/original/file-20211130-18-1x8y4pf.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=537&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434607/original/file-20211130-18-1x8y4pf.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=537&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A 1953 aerial photo of the Western Desert showing a complex fine scale fire mosaic resulting from Indigenous burning.</span>
</figcaption>
</figure>
<p>But following the displacement of Indigenous people and the decline of traditional burning practices, fire regimes changed dramatically. The average fire size today is many orders of magnitude <a href="https://www.researchgate.net/profile/Andrew-Burbidge/publication/284776990_Evidence_of_altered_fire_regimes_in_the_Western_Desert_regime_of_Australia/links/565bca3508aeafc2aac62299/Evidence-of-altered-fire-regimes-in-the-Western-Desert-regime-of-Australia.pdf">greater</a> than those set under Aboriginal management. </p>
<p>The change has been <a href="https://www.publish.csiro.au/wr/wr05032">implicated</a> in the decline and extinction of some mammals and plant species. One massive and fast-moving October fire in the Tanami desert – home to endangered bilbies – burned nearly 7,000 square kilometres over a few days, our data show.</p>
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Read more:
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<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/434379/original/file-20211129-25-ilvsxy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/434379/original/file-20211129-25-ilvsxy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=409&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434379/original/file-20211129-25-ilvsxy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=409&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434379/original/file-20211129-25-ilvsxy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=409&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434379/original/file-20211129-25-ilvsxy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=514&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434379/original/file-20211129-25-ilvsxy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=514&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434379/original/file-20211129-25-ilvsxy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=514&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The massive and fast-moving Tanami desert fire burnt nearly 7,000 km2 over a few days.</span>
</figcaption>
</figure>
<h2>Back to desert burning</h2>
<p>Like everywhere on this continent, fire in our vast deserts must be well-managed. Getting people back on desert country to reintroduce complex fire mosaics is difficult work but will have <a href="https://www.publish.csiro.au/wf/wf20057">significant</a> benefits for both nature and Indigenous people.</p>
<p>Challenges include building capacity amongst ranger groups and communities, overcoming legal and insurance hurdles and employing novel techniques to apply “cool” fires at a near-continental scale. </p>
<p>The role of Indigenous ranger groups is critical here. Organisations such as <a href="https://10deserts.org/">10 Deserts</a> – a partnership between Indigenous and conservation organisations – are supporting desert fire work. </p>
<p><a href="https://10deserts.org/committee/peter_murray/">Peter Murray</a> is chair of the 10 Deserts project and a Ngurrara Traditional Owner from the Great Sandy Desert. On the importance of this work, he says:</p>
<blockquote>
<p>Right now, we’re working on Indigenous “right way” cultural burning as a means of preventing wildfires. We’re developing dedicated male and female ranger teams to look after the land and develop tourism. And we’re encouraging traditional owners to return to the desert to share and exchange knowledge as well as collecting and storing that knowledge to pass onto younger generations.</p>
</blockquote>
<figure class="align-center ">
<img alt="Indigenous man burning country" src="https://images.theconversation.com/files/434611/original/file-20211130-27-1i2yotw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/434611/original/file-20211130-27-1i2yotw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/434611/original/file-20211130-27-1i2yotw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/434611/original/file-20211130-27-1i2yotw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/434611/original/file-20211130-27-1i2yotw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/434611/original/file-20211130-27-1i2yotw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/434611/original/file-20211130-27-1i2yotw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Indigenous rangers are crucial when caring for fire-prone landscapes.</span>
<span class="attribution"><span class="source">Kanyirninpa Jukurrpa/Gareth Catt</span></span>
</figcaption>
</figure>
<h2>Living in the Pyrocene</h2>
<p>As climate change worsens, we’re now living in a global fire age dubbed <a href="https://www.stephenpyne.com/disc.htm">the Pyrocene</a>. This will bring challenges across the Australian continent. </p>
<p>Throughout remote Australia, increasing extreme fire weather will see more severe bushfires. Good fire management in these landscapes is urgently needed. In the northern tropical savannas, Indigenous-led fire management at the landscape scale is already <a href="https://theconversation.com/the-worlds-best-fire-management-system-is-in-northern-australia-and-its-led-by-indigenous-land-managers-133071">producing</a> some of the worlds best fire management outcomes.</p>
<p>The challenge is to introduce similar scales of fire management across our vast deserts. These regions are rich with nature and culture, and they deserve far more attention than they’ve received to date. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/5-big-ideas-how-australia-can-tackle-climate-change-while-restoring-nature-culture-and-communities-172156">5 big ideas: how Australia can tackle climate change while restoring nature, culture and communities</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/172773/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rohan Fisher receives funding from the federal Department of Agriculture, Water and the Environment and the Department of Industry, Science, Energy and Resources. </span></em></p><p class="fine-print"><em><span>Neil Burrows is affiliated with the Liberal party </span></em></p>Fires in arid Australia are extensive, largely unmanaged, often destructive and significantly under-reported.Rohan Fisher, Information Technology for Development Researcher, Charles Darwin UniversityNeil Burrows, Adjunct professor, The University of Western AustraliaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1707472021-10-29T17:30:20Z2021-10-29T17:30:20ZWe mapped every large solar plant on the planet using satellites and machine learning<figure><img src="https://images.theconversation.com/files/429115/original/file-20211028-20-d1jxmg.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C2991%2C1423&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Jenson / shutterstock</span></span></figcaption></figure><p>An astonishing <a href="https://www.nrel.gov/news/program/2021/documenting-a-decade-of-cost-declines-for-pv-systems.html">82% decrease</a> in the cost of solar photovoltaic (PV) energy since 2010 has given the world a fighting chance to build a zero-emissions energy system <a href="https://www.inet.ox.ac.uk/publications/no-2021-01-empirically-grounded-technology-forecasts-and-the-energy-transition/">which might be less costly</a> than the fossil-fuelled system it replaces. The <a href="https://iea.blob.core.windows.net/assets/77ecf96c-5f4b-4d0d-9d93-d81b938217cb/World_Energy_Outlook_2018.pdf">International Energy Agency</a> projects that PV solar generating capacity must grow ten-fold by 2040 if we are to meet the dual tasks of alleviating global poverty and constraining warming to well below 2°C. </p>
<p>Critical challenges remain. Solar is “intermittent”, since sunshine varies during the day and across seasons, so energy must be stored for when the sun doesn’t shine. Policy must also be designed to ensure solar energy reaches the furthest corners of the world and places where it is most needed. And there will be inevitable trade-offs between solar energy and other uses for the same land, including conservation and biodiversity, agriculture and food systems, and community and indigenous uses.</p>
<p>Colleagues and I have now published in the journal Nature the first <a href="https://www.nature.com/articles/s41586-021-03957-7">global inventory</a> of large solar energy generating facilities. “Large” in this case refers to facilities that generate at least 10 kilowatts when the sun is at its peak. (A typical small residential rooftop installation has a capacity of around 5 kilowatts). </p>
<p>We built a machine learning system to detect these facilities in satellite imagery and then deployed the system on over 550 terabytes of imagery using several human lifetimes of computing.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429144/original/file-20211028-27-1w50gcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="World map with dots" src="https://images.theconversation.com/files/429144/original/file-20211028-27-1w50gcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429144/original/file-20211028-27-1w50gcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=366&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429144/original/file-20211028-27-1w50gcw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=366&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429144/original/file-20211028-27-1w50gcw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=366&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429144/original/file-20211028-27-1w50gcw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=459&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429144/original/file-20211028-27-1w50gcw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=459&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429144/original/file-20211028-27-1w50gcw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=459&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A map of all the large solar facilities detected up to 2018 (lighter colours = more recent)</span>
<span class="attribution"><span class="source">Kruitwagen et al, Nature</span></span>
</figcaption>
</figure>
<p>We searched almost half of Earth’s land surface area, filtering out remote areas far from human populations. In total we detected 68,661 solar facilities. Using the area of these facilities, and controlling for the uncertainty in our machine learning system, we obtain a global estimate of 423 gigawatts of installed generating capacity at the end of 2018. This is very close to the International Renewable Energy Agency’s (IRENA) <a href="https://www.irena.org/publications/2019/Jul/Renewable-energy-statistics-2019">estimate</a> of 420 GW for the same period. </p>
<h2>Tracking the growth of solar energy</h2>
<p>Our study shows solar PV generating capacity grew by a remarkable 81% between 2016 and 2018, the period for which we had timestamped imagery. Growth was led particularly by increases in India (184%), Turkey (143%), China (120%) and Japan (119%).</p>
<p>Facilities ranged in size from sprawling gigawatt-scale desert installations in Chile, South Africa, India and north-west China, through to commercial and industrial rooftop installations in California and Germany, rural patchwork installations in North Carolina and England, and urban patchwork installations in South Korea and Japan. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429116/original/file-20211028-21-1wplvee.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Aerial photo of rice fields and solar farms" src="https://images.theconversation.com/files/429116/original/file-20211028-21-1wplvee.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429116/original/file-20211028-21-1wplvee.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=379&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429116/original/file-20211028-21-1wplvee.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=379&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429116/original/file-20211028-21-1wplvee.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=379&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429116/original/file-20211028-21-1wplvee.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=476&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429116/original/file-20211028-21-1wplvee.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=476&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429116/original/file-20211028-21-1wplvee.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=476&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Solar mixed with rice fields on reclaimed land in South Korea.</span>
<span class="attribution"><span class="source">Stock for you / shutterstock</span></span>
</figcaption>
</figure>
<h2>The advantages of facility-level data</h2>
<p>Country-level aggregates of our dataset are very close to IRENA’s <a href="https://www.irena.org/publications/2019/Jul/Renewable-energy-statistics-2019">country-level statistics</a>, which are collected from questionnaires, country officials, and industry associations. Compared to other facility-level datasets, we address some critical coverage gaps, particularly in developing countries, where the diffusion of solar PV is critical for expanding electricity access while reducing greenhouse gas emissions. In developed and developing countries alike, our data provides a common benchmark unbiased by reporting from companies or governments.</p>
<p>Geospatially-localised data is of critical importance to the energy transition. Grid operators and electricity market participants need to know precisely where solar facilities are in order to know accurately the amount of energy they are generating or will generate. Emerging <a href="https://www.turing.ac.uk/research/research-projects/solar-nowcasting-machine-vision">in-situ or remote systems</a> are able to use location data to predict increased or decreased generation caused by, for example, passing clouds or changes in the weather. </p>
<p>This increased predictability allows solar to reach <a href="https://www.sciencedirect.com/science/article/abs/pii/S0960148115302901">higher proportions of the energy mix</a>. As solar becomes more predictable, grid operators will need to keep fewer fossil fuel power plants in reserve, and fewer penalties for over- or under-generation will mean more marginal projects will be unlocked.</p>
<p>Using the back catalogue of satellite imagery, we were able to estimate installation dates for 30% of the facilities. Data like this allows us to study the precise conditions which are leading to the diffusion of solar energy, and will help governments better design subsidies to encourage faster growth. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/429135/original/file-20211028-13-rtdsf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="World map showing solar facilities and previous land use" src="https://images.theconversation.com/files/429135/original/file-20211028-13-rtdsf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/429135/original/file-20211028-13-rtdsf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=356&fit=crop&dpr=1 600w, https://images.theconversation.com/files/429135/original/file-20211028-13-rtdsf6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=356&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/429135/original/file-20211028-13-rtdsf6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=356&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/429135/original/file-20211028-13-rtdsf6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=448&fit=crop&dpr=1 754w, https://images.theconversation.com/files/429135/original/file-20211028-13-rtdsf6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=448&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/429135/original/file-20211028-13-rtdsf6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=448&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The authors compared the locations of the solar facilities to data on land use, to find out what was there before. Cropland (light brown) was easily the most common.</span>
<span class="attribution"><span class="source">Kruitwagen et al, Nature</span></span>
</figcaption>
</figure>
<p>Knowing where a facility is also allows us to study the unintended consequences of the growth of solar energy generation. In our study, we found that solar power plants are most often in agricultural areas, followed by grasslands and deserts. </p>
<p>This highlights the need to carefully consider the impact that a ten-fold expansion of solar PV generating capacity will have in the coming decades on food systems, biodiversity, and lands used by vulnerable populations. Policymakers can provide incentives to instead install solar generation on rooftops which cause less land-use competition, or other renewable energy options.</p>
<hr>
<p><em>The <a href="https://github.com/Lkruitwagen/solar-pv-global-inventory">github</a>, <a href="https://zenodo.org/record/5045001">code</a>, and <a href="https://zenodo.org/record/5005868">data</a> repositories from this research have been made available to facilitate more research of this type and to kickstart the creation of a complete, open, and current dataset of the planet’s solar energy facilities.</em></p><img src="https://counter.theconversation.com/content/170747/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The work was supported by Descartes Labs <a href="https://descarteslabs.com/">https://descarteslabs.com/</a>, who provided the cloud computation infrastructure, and World Resources Institute, who provided the cross-validation data.</span></em></p>Our data provides a common benchmark unbiased by reporting from companies or governments.Lucas Kruitwagen, Climate Change and Artificial Intelligence Researcher, University of OxfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1620732021-08-03T12:34:16Z2021-08-03T12:34:16ZSunny with a chance of sneezing – I’m building a tool to forecast pollen levels that will help allergy sufferers know when it’s safe to go outside<figure><img src="https://images.theconversation.com/files/414210/original/file-20210802-26-1mcpjqh.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5539%2C3820&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Advance warning of high pollen levels could help people plan their activities to avoid allergies.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/car-driver-using-asthma-inhaler-royalty-free-image/1304794626">Dobrila Vignjevic/E+ via Getty Images</a></span></figcaption></figure><p>Do flowers blossoming in spring make you miserable? Are you sworn enemies with fall bloomers like ragweed? If you suffer from pollen allergies, imagine the usefulness of a reliable pollen forecast that could help you manage your symptoms by providing an early warning when pollen conditions are bad.</p>
<p>We’re working on it! <a href="https://scholar.google.com/citations?user=sUwveOEAAAAJ&hl=en&oi=ao">As an atmospheric scientist, I study</a> the weather, climate and anything in our Earth’s atmosphere, including pollen. One in three people in the U.S. <a href="https://doi.org/10.1056/NEJMcp1412282">suffer from allergic rhinitis</a>, otherwise known as “allergies,” and pollen is the most common cause.</p>
<p>While allergic rhinitis is not curable, its symptoms can be successfully treated. Two main methods are medication and pollen avoidance. They both rely on knowing when, where and how much pollen is, and is expected to be, in the air. Many medications work best if taken before symptoms occur. Advance knowledge of pollen allows allergy sufferers to change plans in order to minimize their exposure to pollen. </p>
<p>My colleagues and I are pulling together what we know about how plant biology and meteorology affect the amount of pollen in the air, along with pollen count numbers, to build a reliable pollen forecast. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/414211/original/file-20210802-24-1jmlm3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="magnified view of pollen grains" src="https://images.theconversation.com/files/414211/original/file-20210802-24-1jmlm3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/414211/original/file-20210802-24-1jmlm3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=445&fit=crop&dpr=1 600w, https://images.theconversation.com/files/414211/original/file-20210802-24-1jmlm3j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=445&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/414211/original/file-20210802-24-1jmlm3j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=445&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/414211/original/file-20210802-24-1jmlm3j.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=559&fit=crop&dpr=1 754w, https://images.theconversation.com/files/414211/original/file-20210802-24-1jmlm3j.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=559&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/414211/original/file-20210802-24-1jmlm3j.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=559&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A view of pollen from various plants, magnified 586 times under the microscope.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/pollen-high-powered-photomicrographic-magnification-are-news-photo/179796938">BSIP/Universal Images Group via Getty Images</a></span>
</figcaption>
</figure>
<h2>Counting pollen grain by grain</h2>
<p>Allergic symptoms tend to be more severe the higher the concentration of airborne pollen. The amount of pollen in the air is constantly changing, so it would be ideal to monitor pollen in populated areas at regular frequent intervals. In the U.S., <a href="https://pollen.aaaai.org/#/">the National Allergy Bureau</a> collects, processes and distributes daily pollen concentrations from stations around the country. </p>
<p>Unfortunately, there are fewer than 90 active stations. Of these, many do not count on weekends or outside of the main pollen season. Part of the reason is that these are volunteer-run stations, and pollen monitoring requires significant time and resources.</p>
<p>Pollen is collected using a machine that sucks in air and traps pollen on sticky tape. A trained technician then processes, identifies and counts the tiny pollen grains under a microscope. During the height of pollen season, it may take a few hours for a technician to count the day’s pollen. Automated pollen monitoring systems do exist and would greatly reduce the need for human resources. But for now, these systems are either extremely expensive or have not been evaluated for accuracy.</p>
<h2>Building a forecasting model</h2>
<p>Pollen that causes allergic reactions is from <a href="http://sweetgum.nybg.org/science/glossary/glossary-details/?irn=2953">anemophilous or wind-pollinated plants</a>. Pollen grains contain the <a href="http://pollen.utulsa.edu/whatispollen.html">male sperm from the plant</a>, an essential component of plant reproduction. Anemophilous plants produce a lot of pollen because they rely on the whims of the wind to carry it to reach the female counterparts of their species to reproduce and grow new plants. The amount of pollen in the air has been rising because <a href="https://doi.org/10.1073/pnas.2013284118">climate change is lengthening the pollen season</a> and increasing how much pollen gets produced. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/414212/original/file-20210802-26-18kit17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="backlit pollen wafts in the air around a flowering tree branch" src="https://images.theconversation.com/files/414212/original/file-20210802-26-18kit17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/414212/original/file-20210802-26-18kit17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/414212/original/file-20210802-26-18kit17.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/414212/original/file-20210802-26-18kit17.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/414212/original/file-20210802-26-18kit17.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/414212/original/file-20210802-26-18kit17.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/414212/original/file-20210802-26-18kit17.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Certain weather conditions make it more likely to be a heavy pollen day.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/pollen-like-snow-royalty-free-image/91821142">Alkimson/iStock via Getty Images Plus</a></span>
</figcaption>
</figure>
<p>Since we have access to only a limited amount of pollen count data, my colleagues and I leverage what we know about the environment to estimate the amount of pollen in the air. Generally warm, sunny, dry and windy days are correlated with high airborne pollen concentrations, and rainy and humid days with low concentrations. </p>
<p>Plants depend on water and sunlight to grow. The timing of precipitation, temperature and solar radiation can affect a plant’s development and its readiness to flower. Once the plant is ready to flower, environmental variables can determine when pollen is released, how far it travels and how long it remains in the air. </p>
<p>The <a href="https://doi.org/10.1016/j.scitotenv.2021.145590">pollen model my colleagues and I have developed</a> uses these known relationships between meteorology and pollen to estimate airborne pollen. We also include satellite images of vegetation in the model because satellites can detect greening and provide an estimate of the beginning of spring.</p>
<p>Our model can forecast pollen 1 to 14 days in advance for locations where there are pollen stations. But due to the sparsity of pollen stations, we are working on extending the model to forecast in locations with no pollen counts. In those places we use nearby pollen station data, along with localized meteorology, to estimate the pollen. </p>
<p>Although pollen reporting and forecasts do exist in the popular media, <a href="https://doi.org/10.1186/1710-1492-8-S1-A11">their pollen reports differ from observations</a>, and their forecasts are limited only to categories of trees, grasses and weeds. Our forecast can predict for specific pollen types because our model includes information about how each plant type interacts differently with the environment.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/414213/original/file-20210802-18-11a1ai0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="woman checks her phone against backdrop of windows at night" src="https://images.theconversation.com/files/414213/original/file-20210802-18-11a1ai0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/414213/original/file-20210802-18-11a1ai0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/414213/original/file-20210802-18-11a1ai0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/414213/original/file-20210802-18-11a1ai0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/414213/original/file-20210802-18-11a1ai0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/414213/original/file-20210802-18-11a1ai0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/414213/original/file-20210802-18-11a1ai0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Checking the pollen forecast could help you plan when to take allergy medication and how much time you’d spend outside.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-businesswoman-checking-smartphone-in-the-royalty-free-image/969436696">Klaus Vedfelt/DigitalVision via Getty Images</a></span>
</figcaption>
</figure>
<h2>A fine-tuned forecast in your pocket</h2>
<p>We are collaborating with medical professionals and health scientists to understand the pollen levels associated with increasing severity of allergic symptoms. Our plan is to tailor the forecast to allow patients to better manage their symptoms.</p>
<p>So far, we can accurately forecast for four of the most abundant pollen types in the U.S. only in locations with pollen stations. We are seeking funding to expand to other pollen types and other locations, and we are working on creating a platform to automate the data processing and run the forecast.</p>
<p>Ultimately, we want to provide a forecast every day during pollen season to give allergy sufferers the information they need to manage their symptoms. <a href="https://doi.org/10.1016/j.rmed.2005.05.012">Allergies are often undertreated</a> and <a href="https://doi.org/10.1111/crj.12015">knowledge about self-care is limited</a>, so a reliable pollen forecast that is easy to access – for example via an app on your phone – along with education on allergy management, could really help allergy sufferers.</p>
<p>[<em>You’re smart and curious about the world. So are The Conversation’s authors and editors.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=youresmart">You can read us daily by subscribing to our newsletter</a>.]</p><img src="https://counter.theconversation.com/content/162073/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fiona Lo does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Scientists are building a pollen forecasting model using meteorology, botany, pollen count numbers and satellite imagery to help people plan ahead.Fiona Lo, Postdoctoral Researcher in Environmental and Occupational Health Sciences, University of WashingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1578262021-04-11T16:54:32Z2021-04-11T16:54:32ZHow we mapped billions of trees in West Africa using satellites, supercomputers and AI<figure><img src="https://images.theconversation.com/files/391657/original/file-20210325-23-vh42gj.JPG?ixlib=rb-1.1.0&rect=12%2C18%2C4007%2C2661&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Modern computing allows to spot isolated trees and shrubs in semi-arid areas, facilitating research on the evolution of vegetation cover.</span> <span class="attribution"><span class="source">Martin Brandt</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The possibility that vegetation cover in semi-arid and arid areas was retreating has long been an issue of international concern. In the 1930s it was first theorized that the Sahara was expanding and woody vegetation was on the retreat. In the 1970s, spurred by the <a href="https://www.gfdl.noaa.gov/sahel-drought/">“Sahel drought”</a>, focus was on the threat of “desertification”, caused by human overuse and/or climate change. In recent decades, the potential impact of climate change on the vegetation has been the main concern, along with the feedback of vegetation on the climate, associated with the role of the vegetation in the global carbon cycle.</p>
<p>Using high-resolution satellite data and machine-learning techniques at supercomputing facilities, we have now been able to map billions of individual trees and shrubs in West Africa. The goal is to better understand the real state of vegetation coverage and evolution in arid and semi-arid areas.</p>
<h2>Finding a shrub in the desert – from space</h2>
<p>Since the 1970s, satellite data have been used extensively to map and monitor vegetation in semi-arid areas worldwide. Images are available in “high” spatial resolution (with NASA’s satellites <a href="https://landsat.gsfc.nasa.gov/multispectral-scanner-system">Landsat MSS</a> and <a href="https://www.usgs.gov/centers/eros/science/usgs-eros-archive-landsat-archives-landsat-4-5-thematic-mapper-tm-level-1-data">TM</a>, and ESA’s satellites <a href="https://earth.esa.int/eogateway/missions/spot">Spot</a> and <a href="https://sentinels.copernicus.eu/web/sentinel/home">Sentinel</a>) and “medium or low” spatial resolution (<a href="https://earth.esa.int/eogateway/missions/noaa">NOAA AVHRR</a> and <a href="https://modis.gsfc.nasa.gov/about/">MODIS</a>).</p>
<p>To accurately analyse vegetation cover at continental or global scale, it is necessary to use the highest-resolution images available – with a resolution of 1 metre or less – and up until now the costs of acquiring and analysing the data have been prohibitive. Consequently, most studies have relied on moderate- to low-resolution data. This has not allowed for the identification of individual trees, and therefore these studies only yield aggregate estimates of vegetation cover and productivity, mixing herbaceous and woody vegetation.</p>
<p>In a new study covering a large part of the semi-arid Sahara-Sahel-Sudanian zone of West Africa, <a href="https://www.nature.com/articles/s41586-020-2824-5">published in <em>Nature</em></a> in October 2020, an international group of researchers was able to overcome these limitations. By combining an immense amount of high-resolution satellite data, advanced computing capacities, machine-learning techniques and extensive field data gathered over decades, we were able to identify individual trees and shrubs with a crown area of more than 3 m<sup>2</sup> with great accuracy. The result is a database of 1.8 billion trees in the region studied, available to all interested.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/391659/original/file-20210325-21-1nbg76x.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/391659/original/file-20210325-21-1nbg76x.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=556&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391659/original/file-20210325-21-1nbg76x.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=556&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391659/original/file-20210325-21-1nbg76x.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=556&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391659/original/file-20210325-21-1nbg76x.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=699&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391659/original/file-20210325-21-1nbg76x.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=699&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391659/original/file-20210325-21-1nbg76x.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=699&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Supercomputing, machine learning, satellite data and field assessments allow to map billions of individual trees in West Africa.</span>
<span class="attribution"><span class="source">Martin Brandt</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Presently, this work is expanded to cover the semi-arid belt south of the Sahara across the African continent to the Red Sea. The current count of trees is 13 billion, and further refinements of the methodology are being made. It is expected that the geographical coverage will be widened, first to the rest of the semi-arid zones of Africa and then to other continents.</p>
<p>To cover Africa’s entire Sahelian zone, from the Atlantic to the Red Sea, we used approximately 100,000 satellite images – for a total data volume of hundreds of terabytes. Using NASA and <a href="https://en.wikipedia.org/wiki/Blue_Waters">Blue Waters</a> supercomputers, the images were stitched together to create a continuous mosaic. The trees were then identified using <a href="https://theconversation.com/deep-learning-and-neural-networks-77259">deep learning</a>, an artificial-intelligence technique in which the computer is trained to recognize individual trees. During the training, tens of thousands of trees were “shown” to the computer by an operator, using field knowledge in combination with image-interpretation skills. Subsequently, the results of the machine-based identification were checked. Overall, the accuracy has proven to be highly correlated with field measurements.</p>
<h2>Unexpected information on individual trees</h2>
<p>Our database of trees and shrubs contains information on each tree, its exact location (typically with an uncertainty of few meters), its crown size, the date of acquisition of the satellite image in which it was identified, and its estimated above-ground woody mass and carbon content. In the future, other information, e.g. its height and phenological characteristics may be added.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/391660/original/file-20210325-21-rsnscr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/391660/original/file-20210325-21-rsnscr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391660/original/file-20210325-21-rsnscr.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391660/original/file-20210325-21-rsnscr.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391660/original/file-20210325-21-rsnscr.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391660/original/file-20210325-21-rsnscr.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391660/original/file-20210325-21-rsnscr.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The relationship between humans and trees cannot always be related with losses in tree cover, as people in the semi-arid Sahel safeguard and promote trees within settlements and farmlands.</span>
<span class="attribution"><span class="source">Martin Brandt</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Already at this early stage of the project, important implications are evident. In the West-African study we found many more trees than we would have expected. Other data-sources actually report that trees are virtually absent in the Sahara and North-Sahelian zone, yet we found hundreds of millions of trees. The carbon stock associated with these trees is larger – and more stable – than carbon stocks in the herbaceous vegetation. Moreover, we found that trees in farmlands are generally larger than in pristine savannas, and the overall tree cover in populated and managed places is high. This exemplifies that high density of human population cannot always be related to losses in tree cover, as people in the semi-arid Sahel safeguard and promote trees within settlements and farmlands.</p>
<h2>What will the database be used for?</h2>
<p>This database is expected to be useful for a range of different purposes. In particular, it will constitute a baseline, allowing for future studies of the temporal evolution of woody vegetation at large scale, possibly even at a continental or global scale.</p>
<p>The database will allow analysis of which factors control the occurence of trees in drylands, for example human pressure, or environmental factors such as rainfall, soils or geomorphology. The information will feed into the modeling of ecosystems and “full Earth System”, since trees are of great significance in the interaction between the atmosphere and the land surface, controlling both carbon exchange, evapotranspiration and aerodynamic roughness.</p>
<p>Finally, the information could be used to inform and support environmental policies at national and international levels.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=121&fit=crop&dpr=1 600w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=121&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=121&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=152&fit=crop&dpr=1 754w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=152&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/202296/original/file-20180117-53314-hzk3rx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=152&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
</figcaption>
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<p><em>Created in 2007 to help accelerate and share scientific knowledge on key societal issues, the Axa Research Fund has been supporting nearly 600 projects around the world conducted by researchers from 54 countries. To learn more, visit the site of the <a href="https://www.axa-research.org/en/">Axa Research Fund</a>.</em></p><img src="https://counter.theconversation.com/content/157826/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Martin Brandt a reçu des financements de AXA post doctoral research fund. </span></em></p><p class="fine-print"><em><span>Kjeld Rasmussen ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>Advanced techniques allowed our research team to build an open database of billions of individual trees and challenge some common perceptions about vegetation in arid and semi-arid zones.Martin Brandt, Assistant professor of geography, University of CopenhagenKjeld Rasmussen, Associate professor emeritus, University of CopenhagenLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1576302021-03-29T11:12:26Z2021-03-29T11:12:26ZWhy we need to get better at predicting space weather<figure><img src="https://images.theconversation.com/files/391681/original/file-20210325-19-cp881k.jpg?ixlib=rb-1.1.0&rect=155%2C116%2C6334%2C3327&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A solar flare.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/sun-solar-flare-particles-coronal-mass-752393257">Shutterstock/Color4260</a></span></figcaption></figure><p>The Sun is the most important source of energy for sustaining life on Earth, but it gives us a lot more than just light and heat. It also gives us solar storms. </p>
<p>Disturbances on the Sun, such as coronal mass ejections produced by solar flares that emanate from active sunspot regions, can cause solar storms. Solar flares and coronal mass ejections emit vast quantities of radiation and charged particles into space. </p>
<p>These events can damage the Earth’s <a href="https://theconversation.com/solar-storms-could-lead-to-a-global-techno-meltdown-16678">communication and power infrastructures</a>, resulting in power outages and reduced system functionality. Satellites, space stations and astronauts, aviation, GPS, power grids and more can be affected.</p>
<p>As our civilisation becomes more advanced, we become more vulnerable to the effects of solar storms. Now, as the Sun’s activity <a href="https://www.esa.int/Safety_Security/Solar_cycle_25_the_Sun_wakes_up">is on the increase</a>, we need to get better at predicting solar weather.</p>
<p>Many people still remember the collapse of Canada’s Quebec electrical grid on <a href="https://www.nasa.gov/topics/earth/features/sun_darkness.html">13 March 1989</a>, which lasted for nine hours and affected six million people. It caused hundreds of millions of dollars in damages and lost revenues. This blackout was caused by solar storms. </p>
<p><a href="https://www.swsc-journal.org/articles/swsc/pdf/2013/01/swsc130015.pdf">The Carrington Event</a>, named for the amateur astronomer who recorded it, was another powerful solar storm which happened in September 1859. Cutting edge technology in 1859 was limited to electrical telegraphs, and most of those failed all over Europe and North America, in some cases giving their operators electric shocks. </p>
<p>These days, we’re much more reliant on technology, which is in turn increasingly vulnerable to the effects of space and its unique natural disasters.</p>
<h2>Space radiation</h2>
<p>Space is vast, cold, dark and awash with radiation. Radiation in space comes mainly from galactic cosmic radiation – high energy particles thrown out from other galaxies – and solar particle events – high energy particles from our own Sun.</p>
<p>In space radiation, atoms are accelerated in interstellar space to speeds close to the speed of light. Eventually, the electrons are stripped out and only the positively charged nucleus remains.</p>
<p>Humans have been observing and counting sunspots for more than 400 years, making this the <a href="https://www.nature.com/news/long-term-research-slow-science-1.12623#:%7E:text=The%20world's%20longest%2Drunning%20experiments,a%20marathon%2C%20not%20a%20sprint.&text=Although%20science%20is%20a%20long,length%20of%20a%20funding%20cycle.">longest running experiment</a> in the world. The sun has an 11-year sunspot cycle, and at the moment, we are in the middle of that cycle. Now it’s approaching “solar maximum”, where the greatest solar activity occurs. The next solar maximum is expected to begin in 2025.</p>
<figure class="align-center ">
<img alt="The northern lights over a lake." src="https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/391688/original/file-20210325-19-1i3lp77.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The northern lights are caused by solar flares.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/icelandic-spiral-northern-lights-autumn-time-528933889">Shutterstock/Mike-Hubert.com</a></span>
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<p>People are familiar with the northern lights, which is one visible effect of solar radiation. Earth’s magnetic field, which protects us from most of the dangers of space radiation, directs the charged particles to the poles, where they enter our atmosphere and cause beautiful light displays.</p>
<p>But the radiation can also impact technology and people. During strong solar radiation storms, energetic protons can damage electronic circuits inside satellites and the biological DNA of astronauts. Passengers and crew flying over the north pole would be exposed to increased radiation. </p>
<p>These radiation storms can create errors that make navigation operations extremely difficult. Energetic protons can also ionise the atoms and molecules in the atmosphere, creating a layer of free electrons. This layer can absorb high-frequency radio waves, causing a blackout of high-frequency communications, also known as shortwave radio.</p>
<p>With our increasing reliance on technology, predicting the weather in space is crucial. However, accurately predicting space weather has long been a challenging problem for experts.</p>
<h2>Predicting space weather</h2>
<p>Understanding the complexity of sunspots will help us predict whether significant solar flares may happen. My colleagues and I developed a real-time automated computer system which uses image processing and artificial intelligence technologies to monitor and analyse solar satellite data. This helps predict the likelihood of solar flares in the coming 24 hours. </p>
<p>We pioneered new techniques for automatic processing, detection and feature extraction of solar features – like active regions and sunspots – captured by Nasa’s solar dynamics observatory satellite. We also introduced the first automated and real-time system <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2008SW000401">to classify sunspots</a>. Before this, the classification of sunspots was a manual process painstakingly carried out by experts. </p>
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Read more:
<a href="https://theconversation.com/four-graphs-that-suggest-we-cant-blame-climate-change-on-solar-activity-130154">Four graphs that suggest we can't blame climate change on solar activity</a>
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<p>Space missions and astronauts are much more likely to be affected by radiation, because they aren’t protected by Earth’s magnetic field. The effects on humans could include radiation sickness, increased risk for cancer, degenerative diseases and central nervous system effects. </p>
<p>Despite these risks, human and robotic activities are increasing in space and Nasa is working to land humans on Mars by the 2030s. There are two rovers – <a href="https://theconversation.com/curiosity-catches-a-whiff-of-methane-on-mars-and-a-possibility-of-past-life-35595">Curiosity</a> and <a href="https://theconversation.com/mars-perseverance-rover-set-for-nail-biting-landing-heres-the-rocket-science-154886">Perseverance</a> – and <a href="https://theconversation.com/mars-insight-why-well-be-listening-to-the-landing-of-the-perseverance-rover-153672">one lander</a> currently operational on Mars, with <a href="https://theconversation.com/how-the-exomars-mission-could-sniff-out-life-on-mars-and-what-to-do-next-56182">another rover planned</a> for launch in 2022. </p>
<p>Our space weather prediction system is <a href="http://spaceweather.inf.brad.ac.uk/">publicly available</a>, and is now used as one of the decision-making tools for Nasa’s robotic missions and to manage radiation effects on Nasa’s Chandra X-ray observatory orbit.</p>
<p>As we continue venturing further into space, we’ll need to strengthen our current space weather prediction capabilities to build a greater picture of solar activity and mitigate its effects around the solar system. </p>
<p>This task is incredibly challenging, as most solar observations are taken for Earth’s field of view. Better modelling and investigation of the evolution of solar features is necessary to accommodate for the drastically different celestial orbits around the Sun.</p><img src="https://counter.theconversation.com/content/157630/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rami Qahwaji received funding from The Engineering and Physical Sciences Research Council (EPSRC), European Commission, and the European Space Agency.</span></em></p>Satellites, space stations and astronauts, aviation, GPS, power grids and more can be affected.Rami Qahwaji, Professor of Visual Computing, University of BradfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1560402021-03-17T18:57:28Z2021-03-17T18:57:28ZMangroves from space: 30 years of satellite images are helping us understand how climate change threatens these valuable forests<figure><img src="https://images.theconversation.com/files/389708/original/file-20210315-15-1m49nid.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C1920%2C1276&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Travel Sourced, Pixabay</span> <span class="attribution"><a class="source" href="https://pixabay.com/photos/trees-plants-bridge-pathway-5775331/">Travel Sourced, Pixabay</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Australia is home to around 2% of the world’s mangrove forests and is the <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/geb.12449">fifth</a> most mangrove-forested country on Earth. Mangroves play a crucial role in the ecosystem thanks to the dizzying array of plants, animals and birds they feed, house and protect.</p>
<p>Mangrove forests help <a href="https://theconversation.com/how-mangroves-protect-people-from-increasingly-frequent-and-powerful-tropical-storms-118200">protect coastal communities from cyclones and storms</a> by absorbing the brunt of a storm’s energy. They help our fight against climate change by <a href="https://theconversation.com/our-home-is-girt-by-sea-our-land-abounds-in-natures-carbon-sinks-2026">storing vast amounts of carbon</a> that would otherwise be released as greenhouse gases.</p>
<p>In other words, mangroves are some of our <a href="https://theconversation.com/ecocheck-australias-wet-tropics-are-worth-billions-if-we-can-keep-out-the-invading-ants-56815">most precious ecosystems</a>. Despite their importance, there is much we don’t know about these complex wetland forests. For example, when does their growing season start? And, how long does it last? </p>
<p>Usually, answering these types of questions requires frequent data collection in the field, but that can be costly and time-consuming. An alternative is to use satellite images. In the future, this will allow us to track the impacts of climate change on mangroves and other forests.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/389968/original/file-20210316-13-xgrq97.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Mangroves flowering and fruiting in Townsville, QLD." src="https://images.theconversation.com/files/389968/original/file-20210316-13-xgrq97.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389968/original/file-20210316-13-xgrq97.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389968/original/file-20210316-13-xgrq97.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389968/original/file-20210316-13-xgrq97.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389968/original/file-20210316-13-xgrq97.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389968/original/file-20210316-13-xgrq97.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389968/original/file-20210316-13-xgrq97.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mangroves play a crucial role in the ecosystem thanks to the dizzying array of plants, animals and birds they feed, house and protect.</span>
<span class="attribution"><span class="source">Nicolas Younes</span></span>
</figcaption>
</figure>
<h2>What is phenology?</h2>
<p><a href="https://www.mdpi.com/2072-4292/12/24/4008">Our research</a> used satellite images to study the life cycles of mangrove forests in the Northern Territory, Queensland, and New South Wales. We compared the satellite images with field data collected in the 1980s, 1990s and 2000s, and found a surprising degree of variation in mangrove life cycles. </p>
<p>We’re using the phrase life cycle, but the scientific term is “phenology”. Phenology is the study of periodic events in the life cycles of plants and animals. For example, some plants flower and fruit during the spring and summer, and some lose their leaves in autumn and winter. </p>
<p>Phenology is important because when plants are growing, they absorb carbon from the atmosphere and store it in their leaves, trunks, roots, and in the soil. As phenology is often affected by environmental conditions, studying phenology helps us understand how climate change is affecting Australian ecosystems such as mangrove forests.</p>
<p>So how can we learn a lot in a short amount of time about mangrove phenology? That’s where satellite imagery comes in.</p>
<h2>How we use satellites to study mangrove phenology</h2>
<p>Satellites are an excellent tool to study changes in forest health, area, and phenology. Some satellites have been taking images of Earth for decades, giving us the chance to look back at the state of mangrove forests from 30 years ago or more.</p>
<p>You can think of satellite images much like the photo gallery in your smartphone: you can see many of your family members in a single image, and you can see how everyone grows and “blooms” over time. In the case of mangroves, we can see different regions and species in a single satellite image, and we can use past images to study the life cycles of mangrove forests.</p>
<p>For example, satellite images depicted below, which use <a href="https://nationalmap.gov.au/#share=s-8tz2d8PICqz45GBXIRgNRR8wdL7">data from the Australian government’s National Maps website</a>, show how mangroves forests have changed in the Kimberley region of Western Australia between 1990 and 2019. You can see how the mangrove forest has reduced in some areas, but expanded in others. Overall, this mangrove forest seems to be doing pretty well thanks in large part to the fact this area has a reasonably small human population.</p>
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<p><a href="https://www.mdpi.com/2072-4292/12/24/4008">Our study</a> of satellite images of mangrove forests in the Northern Territory, Queensland, and New South Wales - and how they compared with data collected on the ground - found not all mangroves have the same life cycles. </p>
<p>For instance, many mangrove species grow new leaves only once per year, while other species grow new leaves twice a year. These subtle, but important differences will allow us to track the impacts of climate change on mangroves and other forests.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/389969/original/file-20210316-21-1by4mkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Mangroves at different growth stages in Bushland Beach, QLD" src="https://images.theconversation.com/files/389969/original/file-20210316-21-1by4mkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389969/original/file-20210316-21-1by4mkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389969/original/file-20210316-21-1by4mkd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389969/original/file-20210316-21-1by4mkd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389969/original/file-20210316-21-1by4mkd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389969/original/file-20210316-21-1by4mkd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389969/original/file-20210316-21-1by4mkd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Satellite images of mangrove forests reveal not all mangroves have the same life cycles. Here we see mangroves at different growth stages.</span>
<span class="attribution"><span class="source">Nicolas Younes</span></span>
</figcaption>
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<h2>How climate change affects mangrove phenology</h2>
<p>Climate change is <a href="https://science.sciencemag.org/content/370/6520/1066.full">changing the phenology of many forests</a>, causing them to flower and fruit earlier than expected.</p>
<p>Science cannot yet tell us exactly how mangrove phenology will be affected by climate change but the results could be catastrophic. If mangroves flower or fruit earlier than expected, pollinators such as bats, bees and birds may starve or move to a different forests. Without pollinators, mangroves may not reproduce and can die.</p>
<p>The next step in our research is to figure out how climate change is affecting the life cycles of mangroves. To do this, we will use satellite images of mangroves across Australia and factor in data on temperature and rainfall. </p>
<p>We think rising temperatures are causing longer periods of leaf growth, a theory we plan to test by studying data from now with satellite images from the 80s and 90s. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/389727/original/file-20210316-13-n0zjqd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A mangrove forest." src="https://images.theconversation.com/files/389727/original/file-20210316-13-n0zjqd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389727/original/file-20210316-13-n0zjqd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389727/original/file-20210316-13-n0zjqd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389727/original/file-20210316-13-n0zjqd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389727/original/file-20210316-13-n0zjqd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389727/original/file-20210316-13-n0zjqd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389727/original/file-20210316-13-n0zjqd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The next step in our research is to figure out how climate change is affecting the life cycles of mangroves.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>Satellite monitoring can’t do it all</h2>
<p>Satellites can tell us a lot about how a mangrove forest is faring. For example, satellite images captured a dieback event (depicted below, using <a href="https://nationalmap.gov.au/#share=s-8tsixRnPv65x7yRlLU5Z2kXLzqw">data from the Australian government’s National Maps website</a>) that happened between 2015 and 2016, when around 7,400 hectares of mangroves died <a href="https://theconversation.com/extreme-weather-likely-behind-worst-recorded-mangrove-dieback-in-northern-australia-71880">in the Gulf of Carpentaria</a> due to drought and unusually high air and sea temperatures. </p>
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<figcaption>Images: NationalMap/Data61</figcaption>
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<p>But satellite monitoring is not enough on its own and cannot capture the detail you can get on the ground. For example, satellites cannot capture the flowering or fruiting of mangroves because flowers are often too small and fruits are often camouflaged. Also, satellites cannot capture what happens under the canopy.</p>
<p>It is also important to recognise the work of researchers on the ground. Ground data allows us to validate or confirm the information we see in satellite images. When we noted some mangrove forests were growing leaves twice per year, we validated this observation with field data, and confirmed with experts in mangrove ecosystems. Field data is crucial to understand the life cycles of ecosystems worldwide and how forests are responding to changes in the climate.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/389729/original/file-20210316-21-16qt65o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A bird in a wetlands." src="https://images.theconversation.com/files/389729/original/file-20210316-21-16qt65o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/389729/original/file-20210316-21-16qt65o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=499&fit=crop&dpr=1 600w, https://images.theconversation.com/files/389729/original/file-20210316-21-16qt65o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=499&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/389729/original/file-20210316-21-16qt65o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=499&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/389729/original/file-20210316-21-16qt65o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=627&fit=crop&dpr=1 754w, https://images.theconversation.com/files/389729/original/file-20210316-21-16qt65o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=627&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/389729/original/file-20210316-21-16qt65o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=627&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Wetlands, including mangroves, are some of our most precious ecosystems.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/156040/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Nicolás Younes Cárdenas received Student Research Grants from the Wet Tropics Management Authority, the National Environment Science Program (NESP) Tropical Water Quality (TWQ) Hub, and the Centre for Tropical Water & Aquatic Ecosystem Research (TropWater). </span></em></p><p class="fine-print"><em><span>Karen Joyce and Stefan W Maier do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>We used satellite images to study the life cycles of mangrove forests in the Northern Territory, Queensland, and New South Wales — and found a surprising degree of variation.Nicolas Younes, Postdoctoral research fellow, James Cook UniversityKaren Joyce, Senior Lecturer - Remote sensing and spatial information, James Cook UniversityStefan W Maier, Adjunct Research Fellow, James Cook UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1556422021-02-23T19:10:42Z2021-02-23T19:10:42ZThe dingo fence from space: satellite images show how these top predators alter the desert<figure><img src="https://images.theconversation.com/files/385681/original/file-20210222-19-r4r2ax.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3488%2C2616&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The dingo fence in the Strzelecki Desert.</span> <span class="attribution"><span class="source">Mike Letnic</span></span></figcaption></figure><p>As one of the longest structures in the world, the dingo fence is an icon of Australia. It stretches more than 5,600 kilometres across three states, including 150 kilometres that traverses the red sand dunes of the Strzelecki Desert.</p>
<p>Since it was established in the early 20th century, the fence has had one job: to keep dingoes out. The effect of this on the environment has been enormous — in fact, you can see it from outer space.</p>
<p>Our <a href="https://link.springer.com/article/10.1007/s10980-021-01206-w">research</a> has, for the first time, used satellite imagery to show the effects of predators on vegetation at a vast scale. </p>
<p>Dingoes eat kangaroos, and kangaroos eat grass. So on the side of the fence where dingoes are rare, there are more kangaroos, and less grass cover between sand dunes. This has important flow-on effects for the ecosystem in the region. </p>
<p>Similar changes to vegetation may have occurred throughout the world, where other large predators, such as wolves or big cats, have been removed. But these aren’t visible without the stark contrast boundaries like the dingo fence provide.</p>
<h2>Reshaping the landscape</h2>
<p>The fence was built to stop dingoes moving into sheep grazing land in southeastern Australia. As Australia’s largest terrestrial predator, dingoes pose a big threat to livestock. </p>
<p>Today, dingoes “inside” the fence continue to be killed by various means (not all <a href="https://www.abc.net.au/news/2018-09-21/farm-operator-guilty-over-motorbike-death-on-remote-nsw-property/10287564">of them humane</a>), including <a href="https://www.dpi.nsw.gov.au/biosecurity/vertebrate-pests/pest-animals-in-nsw/wild-dogs/wild-dog-control">poison baits, trapping and shooting</a>. </p>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/385207/original/file-20210219-12-fenk28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/385207/original/file-20210219-12-fenk28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385207/original/file-20210219-12-fenk28.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385207/original/file-20210219-12-fenk28.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385207/original/file-20210219-12-fenk28.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385207/original/file-20210219-12-fenk28.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385207/original/file-20210219-12-fenk28.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Where dingoes are removed, increasing populations of kangaroos can lead to overgrazing.</span>
<span class="attribution"><span class="source">Nick Chu</span></span>
</figcaption>
</figure>
<p>It has long been understood that removing large predators can drive changes in ecosystems across large areas. A well-known example is the <a href="https://doi.org/10.1016/j.foreco.2015.06.007">removal of wolves</a> in Yellowstone National Park in the 1920s, which saw an elk grazing increase, limiting the growth of tree and shrub seedlings.</p>
<p>Where dingoes are removed, increasing populations of kangaroos can lead to overgrazing. This, in turn, damages the quality of the soil, making the landscape more vulnerable to erosion. </p>
<p>Less vegetation can also leave small animals, such as the vulnerable dusky hopping mouse, exposed to other threats like cat predation. Indeed, <a href="https://theconversation.com/like-cats-and-dogs-dingoes-can-keep-feral-cats-in-check-114748">2019 research showed</a> dingoes “outside” the fence keep cat and fox populations down in the Strzelecki Desert. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/like-cats-and-dogs-dingoes-can-keep-feral-cats-in-check-114748">Like cats and dogs: dingoes can keep feral cats in check</a>
</strong>
</em>
</p>
<hr>
<p>And <a href="https://newsroom.unsw.edu.au/news/science-tech/how-dingoes-sculpt-shape-sand-dunes-australian-desert">research from 2018</a> showed dingo removal could even reshape the desert landscape, as changes to vegetation alter wind flow and sand movement.</p>
<h2>Changes this large can’t be seen from the ground</h2>
<p>Often, however, the effects of removing predators have gone unnoticed. There are two main reasons why. </p>
<p>First, many large predators were removed before scientists monitored ecosystems. <a href="https://doi.org/10.1111/j.1365-2907.2004.00038.x">For example</a>, wolves were hunted to extinction in Britain during the 17th or 18th century (although there are now <a href="https://www.bbc.com/news/uk-scotland-33533035">proposals to reintroduce them</a>). </p>
<p>Second, changes occur over such large areas, so it’s difficult to spot any differences when researching from the ground.</p>
<p>So to gauge the impact of the fence, we used images captured by sensors on the NASA Landsat satellites, which have been regularly observing the Earth since 1972.</p>
<p>We looked at a section of the fence that follows the state border of New South Wales through the Strzelecki Desert, and used this to analyse the effects of removing a top predator.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/ivmQk5EsScw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">32-year time lapse of dead vegetation cover for the Strzelecki Desert.</span></figcaption>
</figure>
<h2>Capturing the impact</h2>
<p>We used images processed for Australia by the <a href="https://www.jrsrp.org.au/">Joint Remote Sensing Research Program</a>, which are <a href="https://portal.tern.org.au/">publicly available</a>. </p>
<p>Using thousands of field measurements, each satellite image was converted into an image of “fractional cover”. This splits the landscape into three core components: bare soil, green vegetation and dead or dry vegetation. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/kangaroos-and-other-herbivores-are-eating-away-at-national-parks-across-australia-122953">Kangaroos (and other herbivores) are eating away at national parks across Australia</a>
</strong>
</em>
</p>
<hr>
<p>The dead vegetation fraction, which includes all non-photosynthetic material such as dry leaves and twigs, is particularly useful in the desert. It’s a more reliable indicator of vegetation cover, as green vegetation only sticks around for three months or so <a href="https://onlinelibrary.wiley.com/doi/10.1002/esp.4721">after rain</a>.</p>
<p>Viewing “natural colour” satellite images of the Strzelecki Desert, as our eyes see the world, doesn’t show the differences across the dingo fence very well. But when we view images of dead vegetation cover a few months after rainfall, we can see the stark effect kangaroo grazing has on the landscape, where dingoes are rare. </p>
<p>You can see these effects in the images below.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/385221/original/file-20210219-16-16iwswj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385221/original/file-20210219-16-16iwswj.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=355&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385221/original/file-20210219-16-16iwswj.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=355&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385221/original/file-20210219-16-16iwswj.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=355&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385221/original/file-20210219-16-16iwswj.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=446&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385221/original/file-20210219-16-16iwswj.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=446&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385221/original/file-20210219-16-16iwswj.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=446&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A natural colour Landsat image from winter in 2011 after a large rainfall event (left) does not show the dingo fence, though it does when converted to dead vegetation cover (right).</span>
<span class="attribution"><span class="source">Adrian Fisher</span></span>
</figcaption>
</figure>
<p>When we analysed dead vegetation cover images for each season between 1988 and 2020, we found obvious differences between the maximum dead vegetation cover and the variability of dead vegetation cover through time, as the images below show. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/385211/original/file-20210219-14-ycd1fm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385211/original/file-20210219-14-ycd1fm.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=331&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385211/original/file-20210219-14-ycd1fm.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=331&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385211/original/file-20210219-14-ycd1fm.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=331&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385211/original/file-20210219-14-ycd1fm.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=416&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385211/original/file-20210219-14-ycd1fm.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=416&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385211/original/file-20210219-14-ycd1fm.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=416&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The differences in vegetation cover across the dingo fence become most apparent after satellite images are converted to dead vegetation cover and analysed over time.</span>
<span class="attribution"><span class="source">Adrian Fisher</span></span>
</figcaption>
</figure>
<p>The results from satellite images were supported by ground surveys. This included repeated nighttime counts of kangaroos and dingoes seen with powerful spotlights. </p>
<p>We also fenced off plots and observed how the vegetation changed. After five years, the kangaroo-free plots in the dingo-free areas looked like islands of grass in an otherwise bare desert.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/385212/original/file-20210219-22-1vym2x3.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/385212/original/file-20210219-22-1vym2x3.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/385212/original/file-20210219-22-1vym2x3.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/385212/original/file-20210219-22-1vym2x3.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/385212/original/file-20210219-22-1vym2x3.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/385212/original/file-20210219-22-1vym2x3.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/385212/original/file-20210219-22-1vym2x3.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">One of the fenced plots excluding kangaroos in Sturt National Park, western NSW, showing a clear difference in vegetation cover due to grazing pressure where dingoes are rare.</span>
<span class="attribution"><span class="source">Mike Letnic</span></span>
</figcaption>
</figure>
<h2>What do we do about dingoes?</h2>
<p>So, should we tear down the fence to reintroduce dingoes back into landscapes for the biodiversity benefits, like wolves in Yellowstone?</p>
<p><a href="https://www.theage.com.au/national/victoria/animal-rights-group-raise-concerns-over-grampians-dingo-plan-20210127-p56x7z.html">There are no simple answers</a> to this question. Allowing dingoes to return to the landscape inside the fence will reduce kangaroo numbers and increase grass growth — but will also devastate sheep farming. </p>
<p>Conservationists, farmers and other land managers need to start discussing where and how we can safely return dingoes to landscapes, finding a balance between restoring ecosystems and protecting farms.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/living-blanket-water-diviner-wild-pet-a-cultural-history-of-the-dingo-80189">Living blanket, water diviner, wild pet: a cultural history of the dingo</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/155642/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Mike Letnic receives funding from the Australian Research Council </span></em></p><p class="fine-print"><em><span>Mitchell Lyons receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Will Cornwell receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Adrian G. Fisher and Charlotte Mills do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The dingo fence is the longest fence in the world. The environment looks almost identical on either side — until you view it from space.Adrian G. Fisher, Lecturer in Remote Sensing, UNSW SydneyCharlotte Mills, Visiting Fellow, UNSW SydneyMike Letnic, Professor, Evolution and Ecology Research Centre, UNSW SydneyMitchell Lyons, Senior research fellow, The University of QueenslandWill Cornwell, Associate Professor in Ecology and Evolution, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1547602021-02-08T14:44:38Z2021-02-08T14:44:38ZSix ways satellites make the world a better place<figure><img src="https://images.theconversation.com/files/383032/original/file-20210208-21-1ucbyp7.jpg?ixlib=rb-1.1.0&rect=58%2C44%2C4744%2C3212&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Satellites affect your life every day.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/space-satellite-orbiting-earth-elements-this-363654452">Shutterstock</a></span></figcaption></figure><p><a href="http://www.ucsusa.org/satellite_database">Almost 3,000</a> operational spacecraft orbit our Earth. This number is <a href="https://theconversation.com/thousands-more-satellites-will-soon-orbit-earth-we-need-better-rules-to-prevent-space-crashes-154014">growing constantly</a>, thanks to cheaper materials and smaller satellites.</p>
<p>Having this many satellites in orbit can create problems, including <a href="https://theconversation.com/uk/search?q=space+junk">space junk</a> and the way they change our view of <a href="https://theconversation.com/spacexs-starlink-satellites-are-about-to-ruin-stargazing-for-everyone-149516">the night sky.</a> But satellites provide a vital service.</p>
<p>Many people are familiar with GPS, which helps us navigate. Some may know satellites provide crucial data for our weather forecasts. But satellites affect our lives in many different ways – and some of these may surprise you. </p>
<p><strong>1. Spending money</strong></p>
<p>Whether you pay for your morning coffee using a contactless payment, Google Pay, or even with cash withdrawn from an ATM, none of it would be possible without satellites. In fact, all financial transactions – from multimillion pound stock market transactions, to your monthly Netflix subscription – <a href="https://ieeexplore.ieee.org/document/8579173">rely on satellite location and timing services for security</a>. </p>
<p><a href="https://www.ptb.de/cms/fileadmin/internet/fachabteilungen/abteilung_4/4.4_zeit_und_frequenz/pdf/2017_Reliable_time_from_GNSS_InsideGNSS_Bauch_Whibberley.pdf">Global navigation satellite systems</a> orbit about 20,000km above the surface of the Earth and continually communicate with phones and computers to tell them precisely where they are and what time it is. GPS, a US system, is the most well-known of these but Europe’s Galileo and the Russian GLONASS systems provide similar services. </p>
<figure class="align-center ">
<img alt="Galileo satellite in orbit, Earth in the background." src="https://images.theconversation.com/files/383036/original/file-20210208-23-vfx2cy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/383036/original/file-20210208-23-vfx2cy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/383036/original/file-20210208-23-vfx2cy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/383036/original/file-20210208-23-vfx2cy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/383036/original/file-20210208-23-vfx2cy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/383036/original/file-20210208-23-vfx2cy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/383036/original/file-20210208-23-vfx2cy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Europe’s Galileo satellites.</span>
<span class="attribution"><a class="source" href="https://www.esa.int/Applications/Navigation/Galileo/Facts_and_figures">ESA-P. Carril</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span>
</figcaption>
</figure>
<p>We rely on this precise timing to ensure financial transactions take place in sync. If we got our timings wrong, money could appear to arrive in one person’s account before it has left the other. This is particularly problematic for stock market trading in which prices can fluctuate dramatically in a matter of seconds, but it’s also a security requirement for financial institutions worldwide.</p>
<p><strong>2. Saving lives</strong></p>
<p>Many people will have heard natural disasters such as forest fires and tropical storms are becoming <a href="https://www.ipcc.ch/report/managing-the-risks-of-extreme-events-and-disasters-to-advance-climate-change-adaptation/">more frequent and more devastating</a> due to climate change. Fortunately, satellites provide a way to monitor these disasters, study their behaviour, and even support our response and relief efforts. </p>
<p><a href="https://ororatech.com/">OroraTech</a>, a German company, is using data from a range of spacecraft to detect outbreaks of fire as soon as they occur. They use infrared images to identify hot spots as they appear, wind measurements to predict the fire’s path, and terrain and vegetation maps to help firefighters plan their response. </p>
<p>Data from satellites has been also been used to <a href="https://www.sciencedirect.com/science/article/abs/pii/S2212420916304794">monitor tropical storms</a>, predict their path and help communities prepare for the expected impact. </p>
<p>While all of these efforts are admirable, for such a drastic global challenge, we need a coordinated global response. In 2000, 17 countries agreed to freely share satellite data in emergencies. To date, there have been <a href="https://www.sciencedirect.com/science/article/abs/pii/S0094576502002977">almost 700 uses</a> of this charter to support disaster response efforts in 126 countries, drawing on data from more than 60 satellites.</p>
<p><strong>3. Standing up for what’s right</strong></p>
<p>Satellites operate in a “no-man’s land”, with no country or entity able to claim a region of space <a href="https://www.unoosa.org/oosa/en/ourwork/spacelaw/treaties/introouterspacetreaty.html">as their own</a>. Because of this, satellites can image anywhere on Earth, unlike aircraft or drones, which may need permission to enter another country’s airspace. </p>
<p>Most satellites operate close to the Earth, just 300km to 1000km above our heads, and take just 90 minutes to complete a full orbit around the Earth. As the Earth rotates beneath the spacecraft, each orbit brings new areas of the Earth into view. </p>
<p>With almost 3000 satellites overhead, it’s very hard to hide from all the eyes in the sky. For this reason, satellite data has become a vital source for activists, journalists and investigators. It has empowered local communities to address <a href="https://www.nature.com/news/satellite-alerts-track-deforestation-in-real-time-1.19427">illegal deforestation</a>, enabled the <a href="https://doi.org/10.1007/978-3-030-35426-8_3">prosecution of war criminals</a>, and <a href="http://journals.ehu.lt/index.php/perekrestki/article/view/977/870">uncovered government fabrications</a> such as the shooting down of Malaysia Airlines MH17.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mh17-crash-report-establishes-the-cause-but-only-criminal-investigation-can-find-those-responsible-49178">MH17 crash report establishes the cause, but only criminal investigation can find those responsible</a>
</strong>
</em>
</p>
<hr>
<p><strong>4. Stopping pirates</strong></p>
<p>All ships above a certain size are required to broadcast their position every minute or so. Close to shore, these signals can be detected by land-based antennae, but when ships are at sea these signals can only be received by satellites and, of course, other nearby vessels. </p>
<p>Pirates, illegal fishers, and others up to no good, will often not carry a beacon, or will turn it off to avoid detection. Fortunately, high resolution satellite imagery <a href="https://ieeexplore.ieee.org/document/5278254?arnumber=5278254">can pick out boats</a> against the dark surrounding sea using a technique called synthetic aperture radar. </p>
<p>By comparing the locations of the ships seen with the location of the detected beacons, we can <a href="https://ieeexplore.ieee.org/document/6048939">identify those ships</a> that have “gone dark” and alert authorities that something suspicious is afoot.</p>
<p><strong>5. Spotting endangered species</strong></p>
<p>As you may imagine, counting animals is a tricky business, made even harder by animals that live in remote, hard to reach locations. To tackle this challenge, satellite imagery has been used to estimate the <a href="https://www.sciencedirect.com/science/article/pii/S0034425713002678">size of penguin colonies</a> by measuring the amount of guano (bird poo) on the ice. </p>
<figure class="align-center ">
<img alt="Three penguins walking along a beach, rocks in the background." src="https://images.theconversation.com/files/383033/original/file-20210208-23-1l6804d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/383033/original/file-20210208-23-1l6804d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=318&fit=crop&dpr=1 600w, https://images.theconversation.com/files/383033/original/file-20210208-23-1l6804d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=318&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/383033/original/file-20210208-23-1l6804d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=318&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/383033/original/file-20210208-23-1l6804d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=399&fit=crop&dpr=1 754w, https://images.theconversation.com/files/383033/original/file-20210208-23-1l6804d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=399&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/383033/original/file-20210208-23-1l6804d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=399&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Satellites study penguin poo.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/african-penguin-on-sandy-beach-spheniscus-536896912">Shutterstock</a></span>
</figcaption>
</figure>
<p>Very recently, using extremely high resolution satellite data, scientists have even been able to identify and count individual animals, such as <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/mms.12544">whales</a> and <a href="https://zslpublications.onlinelibrary.wiley.com/doi/pdfdirect/10.1002/rse2.195">elephants</a>, in images taken from space. It’s a far cry from being able to track down a lost dog, but it’s an incredible tool for conservationists trying to protect endangered animal species from extinction through poaching, human encroachment and habitat destruction.</p>
<p><strong>6. Searching for life</strong></p>
<p>Not all satellites orbiting our Earth are looking down – some of them look off into deep space. There are lots of telescopes on Earth used to study our skies, but by sending these telescopes into orbit we can avoid looking through the Earth’s atmosphere, giving us a clearer view of the cosmos beyond. </p>
<p>This clear view is particularly important in our search for exoplanets – planets orbiting other stars beyond our solar system. Unlike stars, planets don’t give off their own light source, so we detect them by measuring the tiny dip in starlight that occurs as the planet passes in front of the star it is orbiting. </p>
<p>The hope is that some of these planets might be like our own Earth and capable of hosting extra-terrestrial life. <a href="https://www.esa.int/Science_Exploration/Space_Science/Cheops/ESA_s_exoplanet_watcher_Cheops_reveals_unique_planetary_system">Cheops, a European Space Agency mission</a> launched in 2019, has just started sending back information about its <a href="https://doi.org/10.1007/s10686-020-09679-4">first detected distant worlds</a>. It may seem like a long shot, but one day these missions could answer the age old question of whether anyone is out there.</p><img src="https://counter.theconversation.com/content/154760/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ciara McGrath receives funding from the UK Space Agency, the European Space Agency, and the Scottish Funding Council, and has previously received funding from the Engineering and Physical Sciences Research Council (EPSRC) and the Air Force Office of Scientific Research (AFOSR).</span></em></p>Satellites impact our lives in many different ways, and some of these may surprise you.Ciara McGrath, Research Fellow, Electronic And Electrical Engineering, University of Strathclyde Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1536642021-01-25T14:32:13Z2021-01-25T14:32:13ZFive ways artificial intelligence can help space exploration<figure><img src="https://images.theconversation.com/files/379734/original/file-20210120-15-ni8svg.jpg?ixlib=rb-1.1.0&rect=152%2C970%2C5766%2C4967&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Various types of astronaut assistant are in development.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/astronaut-robot-artificial-intelligence-handshake-on-1424259551">Michal Bednarek/shutterstock.com</a></span></figcaption></figure><p>Artificial intelligence has been making waves in recent years, enabling us to solve problems faster than traditional computing could ever allow. Recently, for example, Google’s artificial intelligence subsidiary <a href="https://deepmind.com/blog/alphafold/">DeepMind developed AlphaFold2</a>, a program which solved the <a href="https://theconversation.com/ai-makes-huge-progress-predicting-how-proteins-fold-one-of-biologys-greatest-challenges-promising-rapid-drug-development-151181">protein-folding problem</a>. This is a problem which has had baffled scientists for 50 years.</p>
<p>Advances in AI have allowed us to make progress in all kinds of disciplines – and these are not limited to applications on this planet. From designing missions to clearing Earth’s orbit of junk, here are a few ways artificial intelligence can help us venture further in space.</p>
<h2>Astronaut assistants</h2>
<figure class="align-right ">
<img alt="The AI system CIMON." src="https://images.theconversation.com/files/379739/original/file-20210120-19-13dov3s.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/379739/original/file-20210120-19-13dov3s.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/379739/original/file-20210120-19-13dov3s.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/379739/original/file-20210120-19-13dov3s.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/379739/original/file-20210120-19-13dov3s.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1131&fit=crop&dpr=1 754w, https://images.theconversation.com/files/379739/original/file-20210120-19-13dov3s.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1131&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/379739/original/file-20210120-19-13dov3s.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1131&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">CIMON will assist astronauts on the International Space Station.</span>
<span class="attribution"><a class="source" href="https://images.nasa.gov/details-KSC-20180628-PH_KLS01_0008">NASA/Kim Shiflett</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Do you remember Tars and Case, the assistant robots from the film Interstellar? While these robots don’t exist yet for real space missions, researchers are working towards something similar, creating intelligent assistants to help astronauts. These AI-based assistants, even though they may not look as fancy as those in the movies, could be incredibly useful to space exploration.</p>
<p>A <a href="https://arc.aiaa.org/doi/abs/10.2514/6.2020-2255">recently developed</a> virtual assistant can potentially detect any dangers in lengthy space missions such as changes in the spacecraft atmosphere – for example increased carbon dioxide – or a sensor malfunction that could be potentially harmful. It would then alert the crew with suggestions for inspection. </p>
<p>An <a href="https://www.dlr.de/content/en/articles/news/2020/02/20200415_cimon-2-makes-its-debut-on-the-iss.html">AI assistant called Cimon</a> was flown to the international space station (ISS) in December 2019, where it is being tested for three years. Eventually, Cimon will be used to reduce astronauts’ stress by performing tasks they ask it to do. NASA is also developing a companion for astronauts aboard the ISS, <a href="https://robonaut.jsc.nasa.gov/R2/">called Robonaut</a>, which will work alongside the astronauts or take on tasks that are too risky for them.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/astronauts-are-experts-in-isolation-heres-what-they-can-teach-us-153334">Astronauts are experts in isolation, here's what they can teach us </a>
</strong>
</em>
</p>
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<h2>Mission design and planning</h2>
<p>Planning a mission to Mars is not an easy task, but artificial intelligence can make it easier. New space missions traditionally rely on knowledge gathered by previous studies. However, this information can often be limited or not fully accessible.</p>
<p>This means the technical information flow is constrained by who can access and share it among other mission design engineers. But what if all the information from practically all previous space missions were available to anyone with authority in just a few clicks. One day there may be a smarter system – similar to Wikipedia, but with artificial intelligence that can answer complex queries with reliable and relevant information – to help with early design and planning of new space missions. </p>
<p>Researchers are working on the idea of a <a href="https://ieeexplore.ieee.org/abstract/document/8742082">design engineering assistant</a> to reduce the time required for initial mission design which otherwise takes many human work hours. <a href="https://arc.aiaa.org/doi/10.2514/6.2018-1366">“Daphne” is another example</a> of an intelligent assistant for designing Earth observation satellite systems. Daphne is used by systems engineers in satellite design teams. It makes their job easier by providing access to relevant information including feedback as well as answers to specific queries.</p>
<h2>Satellite data processing</h2>
<p>Earth observation satellites generate tremendous amounts of data. This is received by ground stations in chunks over a large period of time, and has to be pieced together before it can be analysed. While there have been some crowdsourcing projects to do basic satellite imagery analysis on a very small scale, artificial intelligence can come to our rescue for detailed satellite data analysis.</p>
<p>For the sheer volume of data received, AI has been very effective in processing it smartly. It’s been used to estimate <a href="https://www.sciencedirect.com/science/article/abs/pii/S0034425720304983">heat storage in urban areas</a> and to combine <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/er.6055">meteorological data with satellite imagery</a> for wind speed estimation. AI has also helped with <a href="https://www.sciencedirect.com/science/article/abs/pii/S0038092X19303068">solar radiation estimation</a> using geostationary satellite data, among many other applications.</p>
<p>AI for data processing can also be used for the satellites themselves. In recent research, scientists tested various AI techniques for a remote <a href="https://link.springer.com/article/10.1007/s10462-019-09760-1">satellite health monitoring system</a>. This is capable of analysing data received from satellites to detect any problems, predict satellite health performance and present a visualisation for informed decision making.</p>
<figure class="align-center ">
<img alt="A computer-generated image of space debris around Earth." src="https://images.theconversation.com/files/379740/original/file-20210120-21-1v0fhm3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/379740/original/file-20210120-21-1v0fhm3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=480&fit=crop&dpr=1 600w, https://images.theconversation.com/files/379740/original/file-20210120-21-1v0fhm3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=480&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/379740/original/file-20210120-21-1v0fhm3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=480&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/379740/original/file-20210120-21-1v0fhm3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=603&fit=crop&dpr=1 754w, https://images.theconversation.com/files/379740/original/file-20210120-21-1v0fhm3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=603&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/379740/original/file-20210120-21-1v0fhm3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=603&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">AI has also been harnessed to address the problem of space junk.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Space_debris#/media/File:Debris-GEO1280.jpg">NASA Orbital Debris Program Office</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Space debris</h2>
<p>One of the biggest space challenges of the 21st century is how to tackle <a href="https://theconversation.com/uk/topics/space-junk-844">space debris</a>. <a href="https://www.esa.int/Safety_Security/Space_Debris/Space_debris_by_the_numbers">According to ESA</a>, there are nearly 34,000 objects bigger than 10cm which pose serious threats to existing space infrastructure. There are some innovative approaches to deal with the menace, such as designing satellites to re-enter Earth’s atmosphere if they are deployed within the low Earth orbit region making them disintegrate completely in a controlled way.</p>
<p>Another approach is to avoid any possible collisions in space, preventing the creation of any debris. In a recent study, researchers developed a method to <a href="https://arc.aiaa.org/doi/full/10.2514/1.G005398">design collision avoidance manoeuvres</a> using machine-learning (ML) techniques.</p>
<p><a href="https://ieeexplore.ieee.org/abstract/document/9250908">Another novel approach</a> is to use the enormous computing power available on Earth to train ML models, transmit those models to the spacecraft already in orbit or on their way, and use them on board for various decisions. One way to ensure safety of space flights has <a href="https://www.sciencedirect.com/science/article/abs/pii/S0094576520303921">recently been proposed</a> using already trained networks on board the spacecraft. This allows more flexibility in satellite design while keeping the danger of in orbit collision at a minimum.</p>
<h2>Navigation systems</h2>
<p>On Earth, we are used to tools such as Google Maps which use GPS or other navigation systems. But there is no such a system for other extraterrestrial bodies, for now.</p>
<p>We do not have any navigation satellites around the Moon or Mars but we could use the millions of images we have from observation satellites such as the Lunar Reconnaissance Orbiter (LRO). In 2018, a team of researchers from NASA in collaboration with Intel developed <a href="https://moon.nasa.gov/resources/168/tour-of-the-moon-4k/">an intelligent navigation system</a> using AI to explore the planets. They trained the model on the millions of photographs available from various missions and created a virtual Moon map.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/nr5Pj6GQL2o?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Virtual tour of the Moon.</span></figcaption>
</figure>
<p>As we carry on to explore the universe, we will continue to plan ambitious missions to satisfy our inherent curiosity as well as to improve the human lives on Earth. In our endeavours, artificial intelligence will help us both on Earth and in space make this exploration possible.</p><img src="https://counter.theconversation.com/content/153664/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Audrey Berquand receives funding from ESA and the University of Strathclyde. </span></em></p><p class="fine-print"><em><span>Deep Bandivadekar does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Artificial intelligence can help us venture further in space.Deep Bandivadekar, PhD candidate at the Aerospace Centre of Excellence, University of Strathclyde Audrey Berquand, PhD candidate in Mechanical and Aerospace Engineering, University of Strathclyde Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1514582021-01-14T21:59:46Z2021-01-14T21:59:46ZNew mangrove forest mapping tool puts conservation in reach of coastal communities<figure><img src="https://images.theconversation.com/files/378676/original/file-20210113-17-1rltit9.jpg?ixlib=rb-1.1.0&rect=98%2C57%2C5259%2C3517&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Mangroves, like these in Madagascar, provide a range of benefits, including protection from storms and the prevention of coastal erosion.</span> <span class="attribution"><span class="source">(Louise Jasper/Blue Ventures)</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Mangroves are salt-tolerant plants found in intertidal areas throughout much of the world’s <a href="https://data.unep-wcmc.org/datasets/4">tropical and subtropical coastlines</a>. Mangrove ecosystems are highly variable, ranging from sparse, stunted shrubs to dense stands of thick-stemmed tall trees. </p>
<p>These ecosystems provide habitat for an incredibly diverse <a href="https://doi.org/10.1016/j.aquabot.2007.12.007">range of species</a> including fish (from snapper to shark), invertebrates (such as shrimp and crab), reptiles (from snakes to crocodiles), birds (from kingfishers to hawks), primates (such as macaques and lemurs) and even Bengal tigers. </p>
<p>Mangroves also provide <a href="https://www.unep-wcmc.org/resources-and-data/the-importance-of-mangroves-to-people--a-call-to-action">essential goods and services</a> to millions living in coastal communities — they prevent shoreline erosion, provide protection from storms, supply food, cooking and building materials, and contain places of cultural and spiritual significance. They are also <a href="https://doi.org/10.1038/ngeo1123">incredibly carbon dense</a> storing as much or more carbon than their terrestrial forest peers — the majority of this carbon is stored in incredibly deep soils. </p>
<figure class="align-center ">
<img alt="Two women holding a GPS unit aloft near a mangrove" src="https://images.theconversation.com/files/378724/original/file-20210114-14-6h591c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378724/original/file-20210114-14-6h591c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378724/original/file-20210114-14-6h591c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378724/original/file-20210114-14-6h591c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378724/original/file-20210114-14-6h591c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378724/original/file-20210114-14-6h591c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378724/original/file-20210114-14-6h591c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Community members using GPS to map mangrove forest in Lamboara, Madagascar.</span>
<span class="attribution"><span class="source">(Garth Cripps/Blue Ventures)</span></span>
</figcaption>
</figure>
<p>Despite their obvious value, aquaculture, agriculture, urban development and unmanaged harvest are converting mangrove ecosystems across much of the tropics. Approximately <a href="https://doi.org/10.1641/0006-3568(2001)051%5B0807:MFOOTW%5D2.0.CO;2">35 per cent of global mangrove cover was lost</a> in the 1980s and ‘90s. While the rate of loss slowed in the past two decades — to an estimated <a href="https://doi.org/10.1038/s41467-020-18118-z">four per cent between 1996 and 2016</a> — many regions remain hotspots for mangrove loss, <a href="https://www.mdpi.com/2072-4292/11/6/728">including Myanmar</a>.</p>
<hr>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=504&fit=crop&dpr=1 754w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=504&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/369797/original/file-20201117-13-180ibt9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=504&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><strong><em>This story is part of <a href="https://theconversation.com/uk/topics/oceans-21-96784">Oceans 21</a></em></strong>
<br><em>Our series on the global ocean opened with <a href="https://oceans21.netlify.app/">five in depth profiles</a>. Look out for new articles on the state of our oceans in the lead up to the UN’s next climate conference, COP26. The series is brought to you by The Conversation’s international network.</em></p>
<hr>
<p>My colleagues and I use satellite imagery and field measurements to study mangrove ecosystems in several countries. We’ve developed an accessible and intuitive tool that provides coastal managers with the accurate, reliable, up-to-date and locally relevant information they need for effective community-based conservation of these critical <a href="https://discover.blueventures.org/blue-forests/">blue (marine) forests</a>. </p>
<h2>New mangrove mapping tool</h2>
<p>Until now, information from satellite imagery on mangrove extent and change was either global in coverage and not intended for the smaller areas typically covered by community-based conservation efforts, or — if focused on a local scale — required substantial and costly technical expertise. </p>
<p>As a result, local resource managers often lacked the detail they need to effectively plan for the conservation, restoration and managed-use of mangrove forests, and tap into <a href="https://www.cifor.org/publications/pdf_files/Books/BFripp1401.pdf">payments for ecosystem services (PES)</a> programs, and the wealth of climate finance available for forest and <a href="https://doi.org/10.1016/j.marpol.2015.12.020">blue carbon initiatives</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/378679/original/file-20210113-13-hq7tjy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378679/original/file-20210113-13-hq7tjy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378679/original/file-20210113-13-hq7tjy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378679/original/file-20210113-13-hq7tjy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378679/original/file-20210113-13-hq7tjy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378679/original/file-20210113-13-hq7tjy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378679/original/file-20210113-13-hq7tjy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Community mangrove mapping in Lamboara, Madagascar.</span>
<span class="attribution"><span class="source">(Garth Cripps/Blue Ventures)</span></span>
</figcaption>
</figure>
<p>Our new tool — the Google Earth Engine Mangrove Mapping Methodology (<a href="https://www.mdpi.com/2072-4292/12/22/3758">GEEMMM</a>) makes this information freely available to coastal managers and covers the smaller areas they’re concerned with. </p>
<p>The need for a tool like this is enormous. Global products like the <a href="https://www.globalmangrovewatch.org/">Global Mangrove Watch</a> are not intended for local use. And the conventional methods required for local mapping involve a range of technical hurdles including data availability, data processing techniques, computing power and specialized software. All of this remains well beyond the scope of most locally led conservation project budgets. </p>
<p>Our new tool bypasses these barriers and offers an accessible approach to non-specialists including a comprehensive, step-by-step workflow. It requires no specialized expertise with satellite imagery, data processing or coding. The tool only requires basic computer skills, a relatively stable internet connection, and an understanding of the key steps for mapping mangroves. </p>
<h2>Piloting the new tool</h2>
<p>To pilot our new mangrove mapping tool, we used Myanmar — a <a href="https://www.mdpi.com/2072-4292/11/6/728">global loss hotspot</a> — as a case study. This loss is mostly happening due to widespread conversion for agriculture, such as rice, oil palm and rubber, and for aquaculture, primarily shrimp. </p>
<p>The tool produces current and historic maps of mangrove extent, assesses the quantitative and qualitative accuracy of these maps, and calculates the amount of change that has occurred within a given area of concern. Our results show an alarming 35 per cent loss of mangroves throughout coastal Myanmar since 2004.</p>
<figure class="align-center ">
<img alt="Satellite images showing mangrove deforestation." src="https://images.theconversation.com/files/378720/original/file-20210114-24-150ul7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378720/original/file-20210114-24-150ul7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=626&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378720/original/file-20210114-24-150ul7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=626&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378720/original/file-20210114-24-150ul7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=626&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378720/original/file-20210114-24-150ul7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=787&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378720/original/file-20210114-24-150ul7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=787&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378720/original/file-20210114-24-150ul7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=787&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Mangrove loss in Rakhine State, Myanmar, along the SE coast of Ramree Island and W coast of Taungup Township. The left panels (1) show historic Landsat satellite imagery, ca. 2004-08, and the right panels (2) show contemporary imagery, ca. 2014-18. The top panels (a) show landscape features appear as they would in a regular colour photograph, while the bottom panels (b) show a false colour composite, which provides additional contrast. The mangroves are most easily identifiable in the false colour composite as the dark red regions close to the water. In this 10-year window, large swaths of mangroves have clearly been deforested.</span>
<span class="attribution"><span class="source">(Trevor Gareth Jones)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>My colleagues in Madagascar are further testing the new tool along the country’s west coast where <a href="https://blueventures.org/new-research-mapping-madagascars-mangroves/">21 per cent of the island’s mangroves — an area equivalent in size to 80,000 soccer fields — were lost between 1990 and 2010</a>. </p>
<p>Mangroves are a threatened ecosystem in Madagascar, and understanding where they are — and how they’re being used — is crucial for coastal communities. “These communities need to be supported with the use of a simple monitoring tool that is adaptable to the local context,” said Cicelin Rakotomahazo, the coordinator for Blue Forests in Andavadoaka, Madagascar.</p>
<p>Our new mangrove mapping tool is <a href="https://github.com/Blue-Ventures-Conservation/GEEMMM">freely accessible online</a> to non-profit users and runs in Google Earth Engine with detailed instructions. The tool offers locally relevant information and removes key technical barriers for use, providing a ready-to-go approach through which coastal managers can use their local knowledge to map mangrove ecosystems anywhere they are found. Those using the tool also play a role in testing and shaping its development. </p>
<p>Healthy mangroves protect people from waves and storms, prevent coastal erosion, and serve as a nursery for fish and invertebrates. They provide shelter for local and migratory birds, and hunting grounds for primates and reptiles. They store significant amounts of carbon, making serious contributions towards global climate change mitigation. </p>
<p>The communities that live in and around mangrove ecosystems are their biggest advocates, and this new mangrove mapping tool (GEEMMM) offers a tangible contribution towards local mangrove conservation, restoration and managed use.</p><img src="https://counter.theconversation.com/content/151458/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Trevor Gareth Jones works for Blue Ventures Conservation, the conservation NGO in charge of this project. </span></em></p>Despite their enormous value, mangroves are being removed at an alarming rate. A new tool aims to help communities reverse mangrove loss and tap into conservation programs and funding.Trevor Gareth Jones, Adjunct Professor of Forest Resources Management and MGEM Program Advisor, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1516222021-01-01T10:24:31Z2021-01-01T10:24:31ZSix space missions to look forward to in 2021<figure><img src="https://images.theconversation.com/files/373359/original/file-20201207-19-18k1dtp.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C2100%2C1480&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">NASA's James Webb telescope mirror undergoing cryogenic testing.</span> <span class="attribution"><span class="source"> Ball Aerospace/Flickr</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Space exploration achieved several notable firsts in 2020 despite the COVID-19 pandemic, including <a href="https://theconversation.com/spacex-astronaut-launch-heres-the-rocket-science-139398">commercial human spaceflight</a> and returning <a href="https://theconversation.com/hayabusa-2-returning-asteroid-sample-could-help-uncover-the-origins-of-life-and-the-solar-system-151415">samples of an asteroid</a> to Earth. </p>
<p>The coming year is shaping up to be just as interesting. Here are some of the missions to keep an eye out for.</p>
<h2>Artemis 1</h2>
<p>Artemis 1 is the first flight of the Nasa-led, international <a href="https://www.nasa.gov/what-is-artemis">Artemis program</a> to return astronauts to the Moon by 2024. This will consist of an uncrewed Orion spacecraft which will be sent on a three-week flight around the Moon. IT will reach a maximum distance from Earth of 450,000km – the farthest into space that any spacecraft that can transport humans will have ever flown.</p>
<p>Artemis 1 will be launched into Earth orbit on the first Nasa <a href="https://www.nasa.gov/exploration/systems/sls/index.html">Space Launch System</a>, which will be the most powerful rocket in operation. From Earth orbit, the Orion will be propelled onto a different path towards the Moon by the rocket’s <a href="https://www.nasa.gov/sls/interim_cryogenic_propulsion_stage_141030.html">interim cryogenic propulsion stage</a>. The Orion capsule will then travel to the Moon under the power provided by a <a href="https://www.esa.int/ESA_Multimedia/Images/2020/11/Bye_bye_European_Service_Module_see_you_in_space">service module</a> supplied by the European Space Agency (Esa).</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/XcPtQYalkcs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
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<p>The mission will provide engineers back on Earth with a chance to evaluate how the spacecraft performs in deep space and serve as a prelude to <a href="https://www.nasa.gov/feature/nasa-s-first-flight-with-crew-important-step-on-long-term-return-to-the-moon-missions-to">later crewed</a> lunar missions. The launch of Artemis 1 is currently scheduled for late in 2021.</p>
<h2>Mars missions</h2>
<p>In February, Mars will receive a flotilla of terrestrial robotic guests from several countries. The United Arab Emirates’ <a href="https://spaceflightnow.com/2020/07/19/united-arab-emirates-successfully-sends-its-first-mission-toward-mars/">Al Amal (Hope)</a> spacecraft is the Arab world’s first interplanetary mission. It is scheduled to arrive in Mars orbit on February 9, where it will spend two years monitoring the Martian weather and disappearing atmosphere. </p>
<p>Arriving within a couple of weeks after Al Amal will be the China National Space Administration’s <a href="https://www.planetary.org/space-missions/tianwen-1">Tianwen-1</a>, consisting of an orbiter and a surface rover. The spacecraft will enter Martian orbit for several months before deploying the rover to the surface. If it succeeds, China will become the third country to land anything on Mars. The mission has several objectives including mapping the mineral composition of the surface and searching for sub-surface water deposits. </p>
<p>Nasa’s Perseverance rover will land at <a href="https://mars.nasa.gov/mars2020/mission/science/landing-site/">Jezero Crater</a> on February 18 and search for any signs of ancient life which may have been preserved in the clay deposits there. Critically, it will also store a cache of Martian surface samples on board as the first part in a <a href="https://theconversation.com/life-on-mars-europe-commits-to-groundbreaking-mission-to-bring-back-rocks-to-earth-128328">highly ambitious</a> international program to return samples of Mars to Earth. </p>
<h2>Chandrayaan-3</h2>
<p>In March 2021, the Indian Space Research Organisation (ISRO) is planning to launch its third lunar mission: Chandrayaan-3. Chandrayaan-1 launched in 2008 and was one of the first <a href="https://www.indiatoday.in/science/story/chandrayaan-1-12-years-from-discovering-water-molecules-to-boosting-india-space-prowess-1734091-2020-10-22">major missions in the Indian space programme</a>. Comprising an orbiter and a surface penetrator probe, the mission was one of the first to confirm <a href="https://solarsystem.nasa.gov/missions/chandrayaan-1/in-depth/">evidence of lunar water</a>. </p>
<p>Unfortunately, contact with the satellite was <a href="https://www.newscientist.com/article/dn17715-indias-first-lunar-probe-fails-after-less-than-a-year/">lost less than a year later</a>. Sadly, there was a similar mishap with its successor, Chandrayaan-2, which consisted of an orbiter, a lander (Vikram) and a lunar rover (Pragyan).</p>
<figure class="align-center ">
<img alt="Computer image of a satellite above the Moon." src="https://images.theconversation.com/files/373358/original/file-20201207-23-w5nwov.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/373358/original/file-20201207-23-w5nwov.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=600&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373358/original/file-20201207-23-w5nwov.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=600&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373358/original/file-20201207-23-w5nwov.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=600&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373358/original/file-20201207-23-w5nwov.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=754&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373358/original/file-20201207-23-w5nwov.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=754&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373358/original/file-20201207-23-w5nwov.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=754&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Artist depiction of the the Chandrayaan-2 lunar mission from India.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/artist-depiction-chandrayaan-2-lunar-mission-1485515831">Raymond Cassel/Shuttestock</a></span>
</figcaption>
</figure>
<p>Chandrayaan-3 was <a href="https://www.space.com/india-confirms-moon-landing-mission-chandrayaan-3.html">announced a few months later</a>. It will consist of <a href="https://www.indiatoday.in/science/story/chandrayaan-3-to-be-launched-in-2021-sans-orbiter-images-suggest-moon-rusting-along-poles-1719277-2020-09-07">only a lander and rover</a>, as the previous mission’s orbiter is still functioning and providing data. </p>
<p>If all goes well the Chandrayaan-3 rover will touch down in the lunar south pole’s Aitken basin. It’s of particular interest as it is thought to host numerous deposits of subsurface water ice – a vital component for any future <a href="https://theconversation.com/how-to-build-a-moon-base-120259">sustainable lunar habitation</a>.</p>
<h2>James Webb Space Telescope</h2>
<p>The James Webb Space Telescope <a href="https://theconversation.com/how-hubbles-successor-will-give-us-a-glimpse-into-the-very-first-galaxies-45970">is the successor</a> to the Hubble Space Telescope, but has had a rocky path to being launched. Initially planned for a 2007 launch, the Webb telescope is almost 14 years late and has cost roughly <a href="https://www.theverge.com/2018/8/1/17627560/james-webb-space-telescope-cost-estimate-nasa-northrop-grumman">US$10 billion</a> (£7.4 billion) after apparent underestimates and overruns similar to those experienced by Hubble.</p>
<p>Whereas Hubble has provided some amazing views of the universe in visible and ultraviolet region of light, Webb is planning to <a href="https://www.jwst.nasa.gov/content/about/comparisonWebbVsHubble.html">focus observations in the infrared wavelength band</a>. The reason for this is that when observing really distant objects there will probably be gas clouds in the way. </p>
<figure class="align-center ">
<img alt="Computer enhanced image of a swirling galaxy with bright light at centre." src="https://images.theconversation.com/files/373364/original/file-20201207-17-2pd60z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/373364/original/file-20201207-17-2pd60z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=513&fit=crop&dpr=1 600w, https://images.theconversation.com/files/373364/original/file-20201207-17-2pd60z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=513&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/373364/original/file-20201207-17-2pd60z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=513&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/373364/original/file-20201207-17-2pd60z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=645&fit=crop&dpr=1 754w, https://images.theconversation.com/files/373364/original/file-20201207-17-2pd60z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=645&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/373364/original/file-20201207-17-2pd60z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=645&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The galaxy NGC 2275 seen by Hubble.</span>
<span class="attribution"><span class="source">Esa/Hubble & Nasa, J. Lee and the PHANGS-HST Team;</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>These gas clouds block really small wavelengths of light, such as X-rays and ultra violet light, while longer wavelengths like infra-red, microwave and radio can get through more easily. So by observing in these longer wavelengths we should see more of the universe.</p>
<p>Webb also has a much bigger mirror of 6.5-metre diameter compared to Hubble’s 2.4-metre diameter mirror – essential for improving image resolution and seeing finer detail.</p>
<p>The primary mission of Webb is look at light from galaxies at the edge of the universe which can tell us about how the first stars, galaxies and planetary systems formed. Potentially this could include some information about the origin of life as well, as Webb is planning on imaging exoplanet atmospheres in high detail, searching for the building blocks of life. Do they exist on other planets, and if so, how did they get there? </p>
<p>We are also likely to be treated to some <a href="https://www.discovermagazine.com/the-sciences/happy-birthday-hubble-the-telescopes-most-underrated-images">stunning images</a> similar to those produced by Hubble. Webb is currently scheduled to launch on an Ariane 5 rocket on October 31.</p><img src="https://counter.theconversation.com/content/151622/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>India may land on the Moon this coming year, while Nasa will launch its new, powerful rocket farther into space than any other human rated spacecraft.Ian Whittaker, Senior Lecturer in Physics, Nottingham Trent UniversityGareth Dorrian, Post Doctoral Research Fellow in Space Science, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1517962020-12-17T18:55:07Z2020-12-17T18:55:07ZEurope’s natural waterways: death by a million cuts<figure><img src="https://images.theconversation.com/files/375118/original/file-20201215-19-gjiwt8.jpg?ixlib=rb-1.1.0&rect=30%2C12%2C3995%2C2251&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The Caban Coch dam, in Wales' Elan Valley, is just one of the estimated 1.2 million river barriers in Europe.</span> <span class="attribution"><span class="source">Sara Barrento/Nature</span>, <span class="license">Author provided</span></span></figcaption></figure><p>The <a href="https://www.theguardian.com/books/2011/dec/22/franz-kafka-winter-reads">works of Franz Kafka</a> often describe people trying to reach a goal but never arriving – all ways are blocked, any possible detours turn out to be impassable. Migratory fish and invertebrates in European rivers today are in a similarly Kafkaesque situation. <a href="https://doi.org/10.1038/s41586-020-3005-2">New research in the journal <em>Nature</em></a>, published December 17, reveal that on average, there are at least 0.74 barriers per kilometre of European waterway. This means that an organism can hardly travel more than 1,000 meters without being stopped by a dam, weir, culvert, sluice or ramp.</p>
<p>The movement of flowing water is the essential nature of all running water systems, from small rivulets to large rivers. But this natural movement, and especially its pulsing nature, with flood events and droughts, is too dynamic for human beings who have sought to become “master and possessor of nature” (Descartes, <a href="https://fr.wikipedia.org/wiki/Ma%C3%AEtres_et_possesseurs_de_la_nature"><em>Discours de la methode</em></a>) since their earliest days. Building bridges to cross waterways, controlling river flow to ease navigation, mastering floods, diverting water for irrigation – all of this is the high art of engineering, and a part of human culture since prehistory.</p>
<h2>At first, limited impacts</h2>
<p>Until the industrial age, humans only had local or regional influence on the environment, and these impacts were relatively limited (<a href="https://www.sciencedirect.com/science/article/abs/pii/S1642359315000762">Wantzen et al. 2016</a>). Still, studies indicate that even in the Middle Ages, mills constructed in tributaries of the Rhine interfered with salmon attempting to reach their spawning grounds and cut their population in half (<a href="https://pubmed.ncbi.nlm.nih.gov/27623373/">Lenders 2017</a>, <a href="https://www.elsevier.com/books/rivers-of-europe/tockner/978-0-08-102612-0">Wantzen et al. 2020</a>). Half of “very much” may still be “enough”, but for how long?</p>
<p>Today, only a few very remote rivers can flow freely (<a href="https://www.nature.com/articles/s41586-019-1111-9">Grill et al. 2019</a>), their waters inundating and fertilising natural floodplains full of fish and with flourishing vegetation, their sediments are transported downstream, build islands and even deltas in the sea. In Europe, it is hard to find such exceptions like the Vjosa River (<a href="https://link.springer.com/article/10.1007/s10980-020-00993-y">Schiemer et al. 2020</a>), which flows from Greece through Albania to the Adriatic. Most of the rivers in the industrialised Global North as well as those in developing countries of the Global South have been fragmented into pieces that hardly flow any more, and in which sediments are blocked above dams, and their bed becomes incised by erosion.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/eVm7K4Chujk?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Adaptive management of barriers in European rivers (AMBER).</span></figcaption>
</figure>
<p>The river deltas of the Ebro, Nile and Mekong are vanishing, receiving only a small percentage of the natural sediment yield from their headwaters (<a href="https://doi.org/10.1016/j.scitotenv.2017.11.361">Kondolf et al. 2018</a>). Fish searching for their spawning sites are blocked or become weakened by a series of fish passes that only few of them survive. And even if they arrive, their offspring migrating downstream struggle to survive the return trip.</p>
<p>As if there had been an invisible plan for their eradication, clandestinely executed in the past two centuries, almost all large migratory fish species worldwide have been brought to the brink of extinction (<a href="https://science.sciencemag.org/content/351/6269/128.full">Winemiller et al. 2016</a>). Fascinating, living fossils like the million-year old sturgeon species can still be visited in zoos, but are rarely found in nature.</p>
<p>Other species that depend on migratory fish, such as river mussels that use them for transporting their larvae, are in peril. One example is the freshwater pearl mussel in Europe (<a href="https://doi.org/10.1007/s10750-017-3456-0">Prié et al. 2017</a>. Also under threat are the guardians of the fish, the traditional fishermen (<a href="https://www.sciencedirect.com/science/article/pii/S0301479716306636">Dugan et al. 2010</a> whose livelihoods depend on them. Awareness of the scale and severity of this problem has arrived only slowly in the society.</p>
<h2>Understanding the scale of the problem</h2>
<p>International treaties such as the European Water Framework Directive (<a href="https://www.sciencedirect.com/science/article/pii/S004896971835126X">Carvalho et al. 2019</a>), have given rise to efforts that may tackle the problem, by removing selected dams, creating detours or by releasing water according to natural flows.</p>
<p>The first step is to understand the dimension of the problem. How the many dams are there? Large ones, higher than 15 meters, can be seen on satellite images. In most countries, they also require construction permits, so that information can be obtained worldwide with high precision. However, smaller barriers such as low-profile dams and culverts can be (and are) built without detailed formalities, and can hardly be seen from space. Moreover, there is a dizzying confusion about expressions to name these constructions, even within a single country.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/375122/original/file-20201215-13-mf077.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Europe's main rivers, with each basins indicated by a different colour" src="https://images.theconversation.com/files/375122/original/file-20201215-13-mf077.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/375122/original/file-20201215-13-mf077.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=495&fit=crop&dpr=1 600w, https://images.theconversation.com/files/375122/original/file-20201215-13-mf077.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=495&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/375122/original/file-20201215-13-mf077.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=495&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/375122/original/file-20201215-13-mf077.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=622&fit=crop&dpr=1 754w, https://images.theconversation.com/files/375122/original/file-20201215-13-mf077.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=622&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/375122/original/file-20201215-13-mf077.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=622&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Europe’s main rivers, with each basins indicated by a different color. Thickness is proportional to stream order.</span>
<span class="attribution"><span class="source">Author provided based on ECRINS data, EEA, Copenhagen</span></span>
</figcaption>
</figure>
<p>The Horizon 2020 project named <a href="https://amber.international">AMBER</a>, coordinated by Carlos Garcia de Leaniz of Swansea University in Wales, has gathered scientists from all over Europe to develop an atlas showing these barriers. In the framework of my work as the UNESCO Chair <a href="http://www.unesco-chair-river-culture.eu/">“Fleuves et Patrimoine – River Culture”</a> and as coordinator of the <a href="http://www.lestudium-ias.com/consortium/ecohydraulics-and-dam-removal">LeStudium Consortium on Ecohydraulics and Dam Removal</a>, I was able to contribute to the AMBER team of more than 50 scientists who jointly assembled the highly heterogeneous data into a unified databank for all of Europe.</p>
<p>While France has for long established a public data bank for flow obstacles, <a href="https://www.data.gouv.fr/fr/datasets/les-referentiels-des-obstacles-a-lecoulement-sur-les-cours-deau-roe/">ROE</a>, the situation in other countries is more complicated. In Italy, dozens of expressions for very similar types of barriers exist, and in Spain, less than 50% of the obstacles were known. In Germany, with its federal structure, each <em>Bundesland</em> (county) has a different way of recording data. However, the <em>Länder</em> collaborate in a joint working group, the <a href="https://www.lawa.de/English-About-LAWA.html">LAWA</a>.</p>
<h2>An atlas showing all flow obstacles in Europe</h2>
<p>Once in hand, all these data were brought together into a single format with a consistent terminology, so that they were applicable to the <a href="https://amber.international/european-barrier-atlas/"><em>Barrier Atlas</em></a>, which can be freely downloaded from the AMBER website. During the time-intensive process of gathering and processing the data, we learned how the European collaboration for sustainable environmental management can be improved – the French word <em>millefeuille</em> (a thousand leaves) describes the current situation well. We also have to overcome the institutional barriers at so many levels, within and between the countries.</p>
<p>Two of the findings for our paper were particularly shocking:</p>
<ul>
<li><p>The number of barriers in Europe is far higher than we had expected, more than 1.2 million.</p></li>
<li><p>Approximately 10% of those barriers are obsolete and could be removed.</p></li>
</ul>
<p>These findings raise important questions, including how to remove the most disturbing of the 120,000 obsolete barriers, what to consider during their removal, and how to slow the ever-growing damming trend in the Global South. Scientists all over the world, including our consortium, are currently working these issues, and advances are being made.</p>
<p>Still, what’s most needed is the political will by the society to switch from a single-sided view of rivers as a mere resource to be exploited to an acknowledgement of their role as cradles of humanity, as essential life-support systems, and as biological and cultural entities to be preserved for their own nature – as part of a “River Culture” (<a href="https://www.sciencedirect.com/science/article/abs/pii/S1642359315000762">Wantzen et al. 2016</a>).</p>
<hr>
<figure class="align-center ">
<img alt="The Vjosa river flows from Greece through Albania" src="https://images.theconversation.com/files/375185/original/file-20201215-17-yf4iaj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/375185/original/file-20201215-17-yf4iaj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/375185/original/file-20201215-17-yf4iaj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/375185/original/file-20201215-17-yf4iaj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/375185/original/file-20201215-17-yf4iaj.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/375185/original/file-20201215-17-yf4iaj.JPG?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/375185/original/file-20201215-17-yf4iaj.JPG?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=425&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Vjosa river extends more than 270 km from its sources in Greece through Albania and then the Adriatic Sea. While relatively wild, its lower reaches are threatened by several large-scale dam projects.</span>
<span class="attribution"><a class="source" href="https://link.springer.com/article/10.1007/s10980-020-00993-y">Gregor Subic</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/151796/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Karl M. Wantzen ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'a déclaré aucune autre affiliation que son organisme de recherche.</span></em></p>New research published in the journal Nature reveals that more than 1.2 million flow barriers exist on European rivers and that approximately 10% are obsolete.Karl M. Wantzen, UNESCO Chair River Culture/Fleuves et Patrimoine, Université de ToursLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1399562020-07-29T12:18:47Z2020-07-29T12:18:47ZRoutine gas flaring is wasteful, polluting and undermeasured<figure><img src="https://images.theconversation.com/files/346237/original/file-20200708-3983-1gpw9fy.jpg?ixlib=rb-1.1.0&rect=0%2C4%2C3000%2C1989&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Flaring gas at an oil production site outside Williston, North Dakota.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/gas-flare-is-seen-at-an-oil-well-site-on-july-26-2013-news-photo/174480635?adppopup=true">Andrew Burton/Getty Images</a></span></figcaption></figure><p>If you’ve driven through an area where companies extract oil and gas from shale formations, you’ve probably seen flames dancing at the tops of vertical pipes. That’s flaring – the mostly uncontrolled practice of burning off a byproduct of oil and gas production. Over the past 10 years, the U.S. shale oil and gas boom has made this country one of the <a href="http://pubdocs.worldbank.org/en/645771560185594790/pdf/New-ranking-Top-30-flaring-countries-2014-2018.pdf">world’s top five flaring nations</a>, just behind <a href="https://asiatimes.com/2019/12/russias-gas-flare-up-but-less-than-before/">Russia</a>, Iran and <a href="https://www.nytimes.com/2020/07/16/world/middleeast/iraq-gas-flaring-cancer-environment.html">Iraq</a>. </p>
<p>It’s a dubious distinction. Routine flaring gives the industry a <a href="https://www.bloomberg.com/news/articles/2019-04-10/permian-basin-is-flaring-more-gas-than-texas-residents-use-daily">black eye</a>. </p>
<p>I am an <a href="https://scholar.google.com/citations?user=qL3H2OwAAAAJ&hl=en">atmospheric scientist</a> studying <a href="http://www.enviropedia.org.uk/Atmosphere/Trace_Gases.php">trace gases</a> – chemicals that make up a small fraction of Earth’s atmosphere, but can have significant effects on the environment and human health. In several recent studies with graduate and undergraduate students, I have shown how routine flaring is inaccurately assessed and creates a sizable source of air pollution. </p>
<p>Due to a rapid <a href="https://www.eia.gov/outlooks/steo/report/prices.php">oil price drop</a> in the spring of 2020, new oil exploration has plummeted and production is running at reduced levels. But the industry can <a href="https://uk.reuters.com/article/us-global-oil-usa-production-graphics/u-s-shale-companies-to-boost-oil-output-by-500000-bpd-by-month-end-idUKKBN23O2OQ">rapidly resume activities</a> as demand and prices recover. And so will flaring. </p>
<p><a href="https://www.rrc.state.tx.us/about-us/commissioners/christian/news/061620a-christian-flaring-report/">Regulatory agencies</a>, under pressure from environmental groups and parts of the industry, are finally considering rules to curb flaring. But can this wasteful and polluting practice be stopped?</p>
<h2>Economic expediency</h2>
<p>Each operating shale oil well produces variable amounts of “<a href="https://www.eia.gov/dnav/ng/TblDefs/ng_prod_off_tbldef2.asp">associated” or “casinghead” gas</a>, a raw gas mixture of highly volatile hydrocarbons, mostly methane. Producers often don’t want this gas unless it can be collected through an existing network of pipelines. </p>
<p>Even when that’s possible, they may decide to dispose of the gas anyway because the cost of collecting and moving it can initially be higher than the value of the gas. This is where flaring comes in.</p>
<p>Routine flaring is common in the Bakken shale formation in North Dakota, the Eagle Ford shale in south-central Texas and the Permian Basin in northwest Texas and New Mexico. Texas has flared <a href="http://blogs.edf.org/energyexchange/files/2018/06/Permian-Flaring-Report-2017-3.pdf">about as much gas annually</a> as <a href="https://www.eia.gov/dnav/ng/ng_cons_sum_dcu_STX_a.htm">all of its residential users consume</a>. In the Permian Basin alone, <a href="https://www.houstonchronicle.com/business/energy/article/Report-Flaring-wasted-750-million-of-natural-15335793.php">about US$750 million worth of gas</a> was wasted in 2018, without any public benefit. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/y4eDlG9U25c?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">In the Permian Basin region of west Texas, residents say gas flaring is polluting the air and making them sick.</span></figcaption>
</figure>
<p>At the same time, gas flaring <a href="http://folk.uio.no/roberan/img/GCB2019/PNG/s21_2019_CO2growthbars_category.png">contributes approximately 1% of man-made atmospheric carbon dioxide emissions globally</a>. That is when flares combust hydrocarbons efficiently, converting them to carbon dioxide. In contrast, when flares burn poorly or go out, they pollute the air with more harmful gases. </p>
<p>Our studies in <a href="http://doi.org/10.1525/elementa.289">two</a> <a href="http://doi.org/10.1525/elementa.414">regions</a> of the Eagle Ford shale in Texas showed that flares may be the dominant source of <a href="https://www.atsdr.cdc.gov/toxfaqs/tf.asp?id=396&tid=69">nitrogen oxides, or NOx</a> in these rural areas. NOx emissions contribute to acid rain, ozone and smog formation, and can irritate the eyes, nose, throat and lungs. </p>
<p>We found that at the sites we studied, industrial combustion sources such as flares produced about 10 times more NOx than cars in the area. Although a single flare may be a relatively small source, the large number of flares and <a href="http://doi.org/10.1525/elementa.414">high variability of NOx production per flare</a> can cause large-scale atmospheric impacts <a href="https://advances.sciencemag.org/content/6/17/eaaz5120/F3.large.jpg">visible from space</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/348185/original/file-20200717-35-1sw2huk.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/348185/original/file-20200717-35-1sw2huk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/348185/original/file-20200717-35-1sw2huk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=359&fit=crop&dpr=1 600w, https://images.theconversation.com/files/348185/original/file-20200717-35-1sw2huk.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=359&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/348185/original/file-20200717-35-1sw2huk.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=359&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/348185/original/file-20200717-35-1sw2huk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=451&fit=crop&dpr=1 754w, https://images.theconversation.com/files/348185/original/file-20200717-35-1sw2huk.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=451&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/348185/original/file-20200717-35-1sw2huk.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=451&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The nonprofit Skytruth posts time series views of gas flares seen from space, from 2012 to the present. Above, how flares looked in mid-July 2020.</span>
<span class="attribution"><a class="source" href="https://viirs.skytruth.org/apps/heatmap/flaringmap.html#lat=38.95911&lon=-93.20723&zoom=4&offset=15">Skytruth.org</a></span>
</figcaption>
</figure>
<h2>Unauthorized venting may explain high flaring volumes</h2>
<p>Almost all flares are open combustion sources. They can be detected from space as bright, fixed-location heat radiation sources. Scientists have developed algorithms to <a href="https://eogdata.mines.edu/download_viirs_fire.html">catalog this radiant heat</a> and relate it to the <a href="https://eogdata.mines.edu/images/Cedigaz_calibration_2012-14_20160120.png">reported volume of gas flared globally</a>.</p>
<p>With the help of undergraduate students, sociologist <a href="http://www.katewillyard.com/">Kate Willyard</a> and I evaluated data from the satellite-based Visible Infrared Imaging Radiometer, or <a href="https://ncc.nesdis.noaa.gov/VIIRS/aboutVIIRS.php">VIIRS</a>. We calculated flaring volumes in the two Texas shale oil production regions, both on a per-wellpad and per-county basis. We then compared it to a database from the <a href="https://www.rrc.state.tx.us/oil-gas/">Texas Railroad Commission</a>, which regulates oil and gas production, for the years 2012-2015, and found large discrepancies between the two datasets. </p>
<p>In total, the volumes reported in the state database were <a href="https://doi.org/10.1016/j.scitotenv.2019.06.465">only around half of what the satellite observed</a>. Another, less detailed <a href="https://www.spglobal.com/en/research-insights/articles/are-some-shale-producers-under-reporting-gas-flaring-to-keep-oil-flowing">bulk analysis</a> by the research firm S&P Global found similar discrepancies for shale regions in New Mexico and North Dakota. </p>
<p>These large differences may be explained by reporting errors and by several flare operations that are simply exempted from volume reporting. But we suspect that there is an even more systemic, mundane explanation: venting – the direct release of raw gas to the atmosphere. </p>
<p>Venting gas is allowed only for a small set of operations in the industry if it can be done safely. It is usually prohibited because it emits hydrocarbons, including air toxics such as benzene that can cause <a href="https://www.lung.org/clean-air/outdoors/what-makes-air-unhealthy/toxic-air-pollutants">cancer, birth defects or other serious health problems</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/346452/original/file-20200708-3974-1t74vtd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/346452/original/file-20200708-3974-1t74vtd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/346452/original/file-20200708-3974-1t74vtd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/346452/original/file-20200708-3974-1t74vtd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/346452/original/file-20200708-3974-1t74vtd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/346452/original/file-20200708-3974-1t74vtd.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/346452/original/file-20200708-3974-1t74vtd.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/346452/original/file-20200708-3974-1t74vtd.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A natural gas flare burns at dusk in the Permian Basin in Texas.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/gas-flaring-in-the-permian-basin-royalty-free-image/1178074562?adppopup=true">Bronte Wittpenn/Bloomberg via Getty Images</a></span>
</figcaption>
</figure>
<p>But venting mainly emits <a href="https://www.epa.gov/ghgemissions/overview-greenhouse-gases#methane">methane</a>, which contributes to global warming and <a href="https://phys.org/news/2018-10-methane-emissions-key-role-ozone.html">atmospheric ozone formation</a>. Venting from flare stacks is illegal, since the flare is considered a waste treatment facility, but the practice apparently <a href="https://www.permianmap.org/flaring-emissions">has increased over time</a>. </p>
<p>Recent, higher-resolution satellite measurements of atmospheric methane over the Permian basin reveal that its emissions must be <a href="https://phys.org/news/2020-04-satellite-highest-emissions-oil-gas.html">significantly higher than what is routinely reported to the Environmental Protection Agency</a>, exceeding 3% of production instead of the more typically assumed 1-2%. Extra methane illegally vented through flare stacks would end up in the Texas Railroad Commission’s database, but satellites looking for heat radiation from combustion would not detect it. </p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>That heat radiation is converted into flaring volumes, using total reported volumes to agencies nationwide. But if a much smaller volume is actually flared, with some of the gas not combusted but vented, the satellite data would overestimate flaring. This is a problem because scientists and the <a href="https://www.worldbank.org/en/programs/zero-routine-flaring-by-2030">World Bank’s zero flaring initiative</a> employ these satellite-based flaring estimates.</p>
<h2>Investors say flaring can be avoided</h2>
<p>For a decade conservation groups such as the <a href="https://www.edf.org/climate/methane-research-series-16-studies">Environmental Defense Fund</a> have called on regulators to address the shale industry’s methane emissions and the rapid increase in flaring. The Obama administration <a href="https://www.doi.gov/sites/doi.gov/files/uploads/methane_waste_prevention_rule_factsheet_final.pdf">adopted a new rule in 2016</a> to curb methane leaks and reduce flaring on public and Indian lands. Now the Trump administration is <a href="https://www.blm.gov/programs/energy-and-minerals/oil-and-gas/operations-and-production/methane-and-waste-prevention-rule">trying to undo</a> this action, albeit with <a href="https://www.reuters.com/article/us-usa-methane-judge/federal-judge-blocks-trump-administrations-easing-of-rule-on-methane-emissions-idUSKCN24H1YG">limited success</a>. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1286719825616740354"}"></div></p>
<p>Meanwhile, a <a href="https://business.edf.org/insights/tackling-flaring-learnings-from-leading-permian-operators/">new study</a> commissioned by the Environmental Defense Fund and involving investors concludes that there are feasible and cost-effective ways for oil and gas companies to minimize flaring even without much regulation. Nevertheless, given that much of the industry has already spent a decade without widely employing such best-practice measures, I expect that oil and gas companies are likely to keep wasting and polluting for the foreseeable future unless government agencies impose tighter regulations.</p><img src="https://counter.theconversation.com/content/139956/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Gunnar W. Schade received funding from a crowd-funding activity to evaluate Permian basin air quality, and private funding from a rancher to measure air quality in southwest Texas. </span></em></p>Flaring, or burning, waste gas from energy production has sharply increased over the past decade. It wastes usable fuel, pollutes the air, and helps drive climate change.Gunnar W. Schade, Associate Professor of Atmospheric Sciences, Texas A&M UniversityLicensed as Creative Commons – attribution, no derivatives.