tag:theconversation.com,2011:/uk/topics/kilauea-53358/articlesKīlauea – The Conversation2022-01-03T13:42:00Ztag:theconversation.com,2011:article/1709192022-01-03T13:42:00Z2022-01-03T13:42:00ZWhy can’t we throw all our trash into a volcano and burn it up?<figure><img src="https://images.theconversation.com/files/435952/original/file-20211206-141213-f6fuq.jpg?ixlib=rb-1.1.0&rect=49%2C0%2C5472%2C3645&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lava flows from a fissure in the aftermath of eruptions from the Kilauea volcano on Hawaii's Big Island, May 22, 2018. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/lava-flows-from-a-fissure-in-the-aftermath-of-eruptions-news-photo/962057980">Andrew Richard Hara/Ena Media Hawaii via Getty Images</a></span></figcaption></figure><figure class="align-left ">
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<p><strong>Why can’t we throw all our trash into a volcano and burn it up? – Georgine T.</strong></p>
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<p>It’s true that lava is hot enough to burn up some of our trash. When Kilauea erupted on the Big island of Hawaii in 2018, the lava flows were <a href="https://www.usgs.gov/media/images/lava-temperatures-were-about-2000-degrees-fahrenheit">hotter than 2,000 degrees Fahrenheit (1,100 Celsius)</a>. That’s hotter than <a href="https://solarsystem.nasa.gov/planets/venus/overview/">the surface of the planet Venus</a>, and hot enough to melt many rocks. It’s also as hot as waste incinerators, which usually burn garbage at <a href="https://www3.epa.gov/ttnchie1/mkb/documents/fthermal.pdf">1,800 to 2,200 F</a> (1,000-1,200 C). </p>
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<p>But not all lavas are the same temperature. The eruptions in Hawaii produce a type of lava called <a href="https://volcanoes.usgs.gov/vsc/glossary/basalt.html">basalt</a>. Basalt is much hotter and more fluid than the lavas that erupt at other volcanoes, like the thicker <a href="https://volcanoes.usgs.gov/vsc/glossary/dacite.html">dacite lava</a> that erupts at Mount St. Helens in Washington state. For example, the 2004-2008 eruption at Mount St. Helens produced a lava dome with surface temperatures less than about 1,300 F (704 C). </p>
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<a href="https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Infographic on number and location of U.S. volcanoes" src="https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/435957/original/file-20211206-21-16nxx9j.jpeg?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">There are 161 volcanoes in 14 U.S. states and territories. Scientists monitor them and warn nearby communities if they see signs that a volcano may erupt.</span>
<span class="attribution"><a class="source" href="https://www.usgs.gov/media/images/us-one-earths-most-volcanically-active-countries">USGS</a></span>
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<p>Beyond temperature, there are other good reasons not to burn our trash in volcanoes. First, although lava at 2,000 degrees F can melt many materials in our trash – including food scraps, paper, plastics, glass and some metals – it’s not hot enough to melt many other common materials, including <a href="https://www.americanelements.com/meltingpoint.html">steel, nickel and iron</a>. </p>
<p>Second, there aren’t many volcanoes on Earth that have lava lakes, or bowl-like craters full of lava, that we could dump trash into. Of all of the thousands of volcanoes on Earth, scientists know of only <a href="https://www.bbc.co.uk/newsround/48856373">eight with active lava lakes</a>. They include <a href="https://www.usgs.gov/media/images/new-usgs-video-about-k-laueas-summit-eruption-now-online">Kilauea</a>, <a href="https://volcano.si.edu/volcano.cfm?vn=390020">Mount Erebus in Antarctica</a> and <a href="https://volcano.si.edu/volcano.cfm?vn=223030">Nyiragongo in the Democratic Republic of the Congo</a>. Most active volcanoes have craters filled with rocks and cooled lava, like <a href="https://www.usgs.gov/volcanoes/mount-st-helens/lava-flows-mount-st-helens">Mount St. Helens</a>, or with water, like <a href="https://www.usgs.gov/media/images/crater-lake-caldera-wizard-island-cinder-cone-and-lava-flows">Crater Lake in Oregon</a>. </p>
<p>The third problem is that dumping trash into those eight active lava lakes would be a very dangerous job. Lava lakes are covered with a crust of cooling lava, but just below that crust they are molten and intensely hot. If rocks or other materials fall onto the surface of a lava lake, they will break the crust, disrupt the underlying lava and cause an explosion. </p>
<p>This happened at Kilauea in 2015: Blocks of rock from the crater rim fell into the lava lake and caused a big explosion that <a href="https://www.usgs.gov/media/videos/rockfall-and-explosion-halemaumau-crater">ejected rocks and lava up and out of the crater</a>. Anyone who threw garbage into a lava lake would have to run away and dodge flaming garbage and lava.</p>
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<figcaption><span class="caption">An eruption from the Cumbre Vieja volcano on the Spanish island of La Palma on Sept. 30, 2021, produced clouds of toxic gas.</span></figcaption>
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<p>Suppose it was possible to dump trash safely into a lava lake: What would happen to the trash? When plastics, garbage and metals burn, they release a lot of toxic gases. Volcanoes already give off tons of toxic gases, including sulfur, chlorine and carbon dioxide. </p>
<p>Sulfur gases can create acidic fog, which we call “vog,” for “volcanic fog.” It can <a href="https://www.usgs.gov/observatories/hawaiian-volcano-observatory/volcanic-gas">kill plants and cause breathing problems for people nearby</a>. Mixing these already-dangerous volcanic gases with other gases from burning our trash would make the resulting fumes even more harmful for <a href="https://www.usgs.gov/media/images/lava-breakouts-access_road">people and plants near the volcano</a>. </p>
<p>Finally, many indigenous communities view nearby volcanoes as sacred places. For example, Halema’uma’u crater at Kilauea is considered the home of Pele, the native Hawaiian goddess of fire, and the area around the crater is <a href="https://www.hawaii.com/discover/culture/pele/">sacred to native Hawaiians</a>. Throwing trash into volcanoes would be a huge insult to those cultures.</p>
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<p class="fine-print"><em><span>Emily Johnson receives funding from the U.S. Geological Survey </span></em></p>Volcanoes might seem like nature’s incinerators, but using them to burn up trash would be dangerous and disrespectful to indigenous people who view them as sacred.Emily Johnson, Research Geologist, US Geological SurveyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1170052019-05-21T19:40:28Z2019-05-21T19:40:28ZThe ‘pulse’ of a volcano can be used to help predict its next eruption<figure><img src="https://images.theconversation.com/files/274836/original/file-20190516-69178-x4wstq.jpg?ixlib=rb-1.1.0&rect=0%2C645%2C4031%2C2372&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The 2018 eruption of Kilauea volcano was preceded by damage of the magma plumbing system at the summit.</span> <span class="attribution"><span class="source">Courtesy of Grace Tobin, 60 Minutes</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Predicting when a volcano will next blow is tricky business, but <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL081609" title="Decrease in Seismic Velocity Observed Prior to the 2018 Eruption of Kīlauea Volcano With Ambient Seismic Noise Interferometry">lessons we learned</a> from one of Hawaii’s recent eruptions may help.</p>
<p><a href="https://theconversation.com/au/topics/kilauea-53358">Kīlauea</a>, on the Big Island of Hawai'i, is probably the best understood volcano on Earth. That’s thanks to monitoring and gathered information that extends back to the formation of the <a href="https://volcanoes.usgs.gov/observatories/hvo/">Hawaiian Volcano Observatory</a> in 1912.</p>
<p>The volcano is also subject to the world’s most technologically advanced geophysical monitoring network.</p>
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Read more:
<a href="https://theconversation.com/from-kilauea-to-fuego-three-things-you-should-know-about-volcano-risk-97775">From Kilauea to Fuego: three things you should know about volcano risk</a>
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<p>From the skies, satellites collect data that show the changing topography of the volcano as magma moves throughout the internal magma plumbing system. Satellites also look at the composition of volcanic gases. </p>
<p>From the ground, volcanologists use a number of highly sensitive chemical and physical tools to further understand the structure of that magma plumbing system. This helps to study the movement of magma within the volcano.</p>
<h2>Earthquakes and vibrations</h2>
<p>A lynch pin of volcano monitoring is seismicity – how often, where and when earthquakes occur. Magma movement within the volcano triggers earthquakes, and putting together the data on their location (a technique known as triangulation) tracks the path of magma underground.</p>
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<a href="https://images.theconversation.com/files/274839/original/file-20190516-69178-wpysqy.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/274839/original/file-20190516-69178-wpysqy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/274839/original/file-20190516-69178-wpysqy.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=215&fit=crop&dpr=1 600w, https://images.theconversation.com/files/274839/original/file-20190516-69178-wpysqy.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=215&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/274839/original/file-20190516-69178-wpysqy.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=215&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/274839/original/file-20190516-69178-wpysqy.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=271&fit=crop&dpr=1 754w, https://images.theconversation.com/files/274839/original/file-20190516-69178-wpysqy.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=271&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/274839/original/file-20190516-69178-wpysqy.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=271&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 schematic of the deep magma plumbind system of Kilauea volcano, Big Island, Hawaii. Magma is transported from deep within the Earth and arrives in a series of summit magma reservoirs.</span>
<span class="attribution"><span class="source">USGS</span></span>
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<p>A newer technique, seismic interferometry, uses vibrations of energy from ocean waves hitting the distant shorelines that then travel through the volcano.</p>
<p>Changes in the speed of these vibrations help us map the 3D footprint of the volcano’s magma plumbing system. We can then detect when, and in some cases how, the magma plumbing system is changing.</p>
<p>This monitoring provides the “pulse” of the volcano during times of inactivity - a baseline from which to detect change during volcanic unrest. This proved invaluable for early warning, and the prediction of where and when, of the eruption of Kīlauea on May 3, 2018.</p>
<p>The “pulse” of Kīlauea includes cycles of <a href="https://volcanoes.usgs.gov/observatories/hvo/hvo_volcano_watch.html?vwid=117">volcano inflation (bulging) and deflation (contraction)</a> as magma moves into and out of the storage region at the summit of the volcano.</p>
<p>The speeds of vibrations travelling through the volcano are predictable during observations of inflation/deflation cycles. When the volcano bulges, the vibrations travel faster through the volcano as rock and magma is compressed. When the volcano contracts these speeds decrease.</p>
<p>We describe this relationship between the two sets of data – the bulging/contraction and the faster/slower speed of vibrations – as coupled.</p>
<h2>Something changed</h2>
<p>Compared to our baseline, we saw the coupled data shift 10 days before the Kīlauea eruption on May 3. That told scientists the magma plumbing system had changed in a significant way.</p>
<p>The volcano was bulging due to the buildup of pressure inside the magma chamber, but the seismic waves were slowing down quite dramatically, instead of speeding up. </p>
<p>Our interpretation of this data was that the summit magma chamber was not able to sustain the pressure from an increasing magma supply – the bulge was too big. Rock material started to break around the summit magma chamber.</p>
<p>Breakage of the rocks perhaps then led to changes of the summit magmatic system so that more magma could more easily arrive at the eruption site about 40km away.</p>
<p>As well as Kīlauea, such coupled data sets are regularly collected, investigated and interpreted in terms of magma transport at other volcanoes globally. Sites include Piton de la Fournaise on Reunion Island, and Etna volcano, Italy. </p>
<p>But our <a href="https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018GL081609">modelling</a> was the first to demonstrate these changes in the coupled data relationship could occur due to weakening of the material inside the volcano before an eruption.</p>
<p>The damage model that we applied can now be used for other volcanoes in a state of unrest. This adds to the toolbox volcanologists need to predict the when and where of an impending eruption. </p>
<h2>So much data, we need help</h2>
<p>When volcanoes are in a heightened state of unrest, the volume of information available from digital data and ground observations is extreme. Scientists tend to rely on observational monitoring first, and other data when time and extra people are available. </p>
<p>But the total amount of incoming data (such as from satellites) is overwhelming, and scientists simply can’t keep up. Machine learning might be able to help us here. </p>
<p><a href="https://www.sciencemag.org/news/2018/12/artificial-intelligence-helps-predict-volcanic-eruptions">Artificial intelligence</a> is the new kid on the block for eruption prediction. Neural networks and other algorithms can use high volumes of complex data and “learn” to distinguish between different signals.</p>
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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>
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<p><a href="https://www.nature.com/articles/d41586-018-07420-y">Automated early alert systems</a> of an impending eruption using sensor arrays exist for some volcanoes today, for example at Etna volcano, Italy. It’s likely that artificial intelligence will make these systems more sophisticated in the future.</p>
<p>Early detection sounds wonderful for authorities charged with public safety, but many volcanologists are wary.</p>
<p>If they lead to multiple false alarms then that could slash trust in scientists for both managers of volcanic crises and the public alike.</p><img src="https://counter.theconversation.com/content/117005/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Rebecca Carey receives funding from the Australian Research Council, US National Science Foundation and New Zealand Marsden Grant.</span></em></p>Scientists say they’ve found a new method to help predict when volcanoes will erupt, based on data crunched from an eruption last year in Hawaii.Rebecca Carey, Senior Lecturer in Earth Sciences, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1040832018-10-12T10:11:28Z2018-10-12T10:11:28Z‘Fake news’ about volcanic eruptions could put lives at risk<figure><img src="https://images.theconversation.com/files/238695/original/file-20181001-195282-17xzigk.jpg?ixlib=rb-1.1.0&rect=4%2C51%2C1414%2C1040&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Katla last erupted in 1918 – but there is no evidence to suggest that it will erupt again soon.</span> <span class="attribution"><span class="source">ICELANDIC GLACIAL LANDSCAPES / wiki</span></span></figcaption></figure><p>The Icelandic volcano Eyjafjallajökull made worldwide headlines in 2010 when it erupted ash that was blown towards Europe, so that air traffic was grounded across the continent. More recently, the volcano’s bigger sister and neighbour, Katla, has also been in the news. First the <a href="https://www.thetimes.co.uk/edition/world/giant-iceland-volcano-katla-about-to-erupt-mw8whrnjc">papers said</a> the “giant volcano” was ready to blow, yet within days articles were appearing to say it was all a mistake and the eruption news was <a href="https://eu.usatoday.com/story/tech/science/2018/09/25/iceland-volcano-eruption-isnt-imminent-despite-wild-headlines/1420060002/">premature</a>. What is going on?</p>
<p>Over the past 1,100 years, <a href="http://earthice.hi.is/katla_volcano">Katla</a> has erupted at least 21 times - an average of around once every 50 years or so. It is exactly a century since the volcano’s last major eruption through the ice, which produced a 14km high column of fragmented volcanic rocks and gas, as well as enormous floods of meltwater, sediment and ice. But this doesn’t mean that another is “due”. Volcanoes don’t erupt to schedule. So why do headlines regularly appear to suggest this is the case?</p>
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<a href="https://images.theconversation.com/files/238699/original/file-20181001-195278-1xkxjsm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238699/original/file-20181001-195278-1xkxjsm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238699/original/file-20181001-195278-1xkxjsm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=373&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238699/original/file-20181001-195278-1xkxjsm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=373&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238699/original/file-20181001-195278-1xkxjsm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=373&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238699/original/file-20181001-195278-1xkxjsm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=469&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238699/original/file-20181001-195278-1xkxjsm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=469&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238699/original/file-20181001-195278-1xkxjsm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=469&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">Katla is in the background…under the ice.</span>
<span class="attribution"><span class="source">danielmoreira02 / shutterstock</span></span>
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<p>This latest news flurry was triggered by the publication of an <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL079096">academic paper</a> by a team of scientists lead by Evgenia Ilyinskaya at the University of Leeds. They had carried out gas-monitoring surveys at Katla in 2016-17, which showed it emitted much more CO₂ than previously estimated. One of the exciting parts of this research was the recommendation that gas monitoring becomes part of the regular observations of volcanoes that are hidden under glaciers or ice sheets. However, many news outlets incorrectly suggested that the observation of these carbon dioxide emissions meant an eruption was imminent, and <a href="https://www.standard.co.uk/news/world/iceland-volcano-eruption-where-is-katla-how-is-a-volcano-formed-a3943756.html">sounded the alarm</a>.</p>
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<p>This sensationalist approach causes more damage beyond merely being incorrect. From a distance, readers and viewers might be interested in the science, the human story, or because even faraway eruptions can have economic or health costs. But for those living in the shadow of the eruption, the immediate impacts are far more pressing, or even life-threatening. Evacuating from a region, moving family and animals, or leaving your house behind all require a degree of certainty that this risk is real and that it should be avoided. To believe a risk is real, information needs to be trusted and thus information providers need to be trustworthy.</p>
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<p>It should therefore be clear that accurate information is essential. Effective risk communication is needed before, during and after a hazardous event, aiming to prevent and mitigate disaster harm, ensure preparedness and aid recovery.</p>
<p>Inaccurate information will of course mean people will have less faith in scientists and news sources next time round. But it can have more immediate effects too. In July 2018, the <a href="https://www.nytimes.com/2018/05/28/travel/hawaii-tourism-kilauea-volcano-eruption.html">New York Times</a> reported how exaggerated coverage of the ongoing Kilauea eruption in <a href="https://volcano.si.edu/volcano.cfm?vn=332010;%20https://www.nps.gov/havo/planyourvisit/lava2.htm">Hawaii</a> lead to a vastly inflated risk perception which saw tourism bookings decrease, which in turn led to loss of income and fears about job losses. In the worst instances, poor information can cause people to ignore evacuation orders.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238679/original/file-20181001-195256-yomuq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238679/original/file-20181001-195256-yomuq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238679/original/file-20181001-195256-yomuq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238679/original/file-20181001-195256-yomuq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238679/original/file-20181001-195256-yomuq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238679/original/file-20181001-195256-yomuq4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238679/original/file-20181001-195256-yomuq4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238679/original/file-20181001-195256-yomuq4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Kilauea lava flows into the ocean. The eruption was impressive – but most people on the island were unaffected.</span>
<span class="attribution"><span class="source">Rachel Blaser/Shutterstock</span></span>
</figcaption>
</figure>
<p>The risks <a href="https://link.springer.com/book/10.1007/978-3-319-44097-2#toc">aren’t easy to communicate</a>. Hazards do not occur in an easy to predict way, they can happen with little warning, and risk assessments virtually always deal in probabilities rather than absolute certainty. Concepts such as <a href="https://water.usgs.gov/edu/100yearflood.html">100-year floods</a> are famously challenging to understand or relate to. In addition, risks to people are influenced by factors such as wealth, age, health, physical ability, whether you own a car, or which floor your apartment is on, so they can vary from person to person, house to house. </p>
<p>Communicating this information therefore comes with responsibilities. By crying wolf too many times, even if the warnings aren’t directly from scientists or the authorities, the media can strongly influence risk perception and create a warning fatigue.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/238709/original/file-20181001-195256-zba4pf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/238709/original/file-20181001-195256-zba4pf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/238709/original/file-20181001-195256-zba4pf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/238709/original/file-20181001-195256-zba4pf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/238709/original/file-20181001-195256-zba4pf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/238709/original/file-20181001-195256-zba4pf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/238709/original/file-20181001-195256-zba4pf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/238709/original/file-20181001-195256-zba4pf.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">Eyjafjallajökull (left) and Katla from above.</span>
<span class="attribution"><span class="source">Kate Smith</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Journalists and editors must consider the ripple effects from an overly sensational news article, and the potential consequences for lives. It doesn’t take long for inaccurate news to spread and multiply across the internet: see, for example, the volcanologist and science writer <a href="https://www.forbes.com/sites/robinandrews/2018/10/04/dont-believe-these-myths-about-indonesias-quake-tsunami-and-eruptions/#727d75184dbc">Robin Andrews</a> having to call out and correct reporting of the recent earthquake and tsunami in Indonesia which often <a href="https://www.express.co.uk/news/world/1026243/indonesia-tsunami-earthquake-volcano-eruption-sulawei-mount-soputan-palu">conflated</a> it with an unrelated volcanic eruption 600 km away on the same island of Sulawesi. The flip side of this is that competent, reliable communications can boost public trust and reduce fear and panic, helping people to take well-informed actions. </p>
<p>The International Journalist’s Network published an article on <a href="http://ijnet.org/en/blog/advice-journalists-covering-natural-disasters">disaster journalism</a> that presents some useful guidelines, much of which emphasises accuracy. I’d also suggest that journalists checks their facts with the scientists doing the work, or with the local organisation responsible for monitoring the hazard. Journalists should also avoid simplifying the forecasting process too much, ensuring that a possible scenario or timeframe is not presented as something of certainty. Readers should always be referred to a reliable source of further information.</p>
<p>These simple measures can be used as a blueprint for strengthening reporting accuracy, and so help regain trust in science communication and the media.</p><img src="https://counter.theconversation.com/content/104083/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kate Smith has received funding from the Natural Environment Research Council, The Leverhulme Trust, the Icelandic Road and Coastal Administration, the National Power Company of Iceland and the University of Iceland.</span></em></p>We can’t say that Katla in Iceland is ‘due’ to erupt, no matter what you have read.Kate Smith, Geoscientist, University of ExeterLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1016752018-08-27T20:10:39Z2018-08-27T20:10:39ZWould an eruption in Melbourne really match Hawaii’s volcanoes? Here’s the evidence<p>Spectacular images of recent volcanic eruptions in Hawaii are a little disheartening – especially given <a href="https://www.9now.com.au/60-minutes/2018/extras/clips/clip-cjkqhcva4001g0rpdqb1uovfw">news reports</a> suggesting there is a sleeping volcano under Melbourne that could <a href="http://www.dailymail.co.uk/news/article-4972456/Volcano-erupt-Melbourne-time.html">awaken and erupt at any moment</a>. </p>
<p>Understanding the geological differences between Melbourne and Hawaii is really helpful in working out how we can keep an eye on future risks in Australia. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australias-volcanic-history-is-a-lot-more-recent-than-you-think-58766">Australia's volcanic history is a lot more recent than you think</a>
</strong>
</em>
</p>
<hr>
<h2>The Newer Volcanics Province</h2>
<p>Victoria and South Australia do host an active volcanic field, called the Newer Volcanics Province (NVP). This is not a single volcano with a large single chamber of molten rock (magma) — the common image of a volcano — but a widespread field of multiple small volcanoes, each with a small volume of magma. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/232435/original/file-20180817-165946-12lw87m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/232435/original/file-20180817-165946-12lw87m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/232435/original/file-20180817-165946-12lw87m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=362&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232435/original/file-20180817-165946-12lw87m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=362&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232435/original/file-20180817-165946-12lw87m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=362&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232435/original/file-20180817-165946-12lw87m.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=455&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232435/original/file-20180817-165946-12lw87m.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=455&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232435/original/file-20180817-165946-12lw87m.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=455&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Location of the Newer Volcanics Province in southeast Australia showing the extent of lava flows and the different types of volcanoes.</span>
<span class="attribution"><a class="source" href="https://www.tandfonline.com/doi/abs/10.1080/08120099.2013.806954">Julie Boyce 2013</a></span>
</figcaption>
</figure>
<p>Melbourne lies at the eastern end of the NVP, and the most recent eruptions in this area occurred over a million years ago. </p>
<p>Mt Gambier in southeastern South Australia represents the western margin of the volcanic field and the most recent eruption — only 5,000 years ago.</p>
<p>Between Melbourne and Mt Gambier there are more than 400 small volcanoes that erupted over a period of 6 million years.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/when-the-bullin-shrieked-aboriginal-memories-of-volcanic-eruptions-thousands-of-years-ago-81986">When the Bullin shrieked: Aboriginal memories of volcanic eruptions thousands of years ago</a>
</strong>
</em>
</p>
<hr>
<p>The NVP was most active between 4.5 million to 5,000 years ago and volcanologists consider the field to still be “<a href="http://volcano.oregonstate.edu/how-volcano-defined-being-active-dormant-or-extinct">active</a>” with the potential for future eruptions.</p>
<p>We do not know when the next eruption will take place.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/232563/original/file-20180819-165940-42j547.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/232563/original/file-20180819-165940-42j547.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/232563/original/file-20180819-165940-42j547.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=800&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232563/original/file-20180819-165940-42j547.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=800&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232563/original/file-20180819-165940-42j547.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=800&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232563/original/file-20180819-165940-42j547.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1005&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232563/original/file-20180819-165940-42j547.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1005&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232563/original/file-20180819-165940-42j547.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1005&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Volcanoes of the Newer Volcanics Province (a) Mt Napier, SE of Hamilton (b) The Noorat complex (c) The Mt Gambier Volcanic Complex, near Mt Gambier (d) The Mt Schank Volcanic Complex, near Mt Gambier (e) Purrumbete volcano, near Camperdown (f ) Tower Hill volcano, near Warrnambool (g) The Red Rock Volcanic Complex, near Colac.</span>
<span class="attribution"><a class="source" href="http://sp.lyellcollection.org/content/early/2016/11/04/SP446.8">Ray Cas and co authors</a></span>
</figcaption>
</figure>
<p>The NVP is located within a tectonic plate – and not along a plate edge like the <a href="https://theconversation.com/five-active-volcanoes-on-my-asia-pacific-ring-of-fire-watch-list-right-now-90618">Ring of Fire volcanoes</a> (for example, Mt Agung on Bali). </p>
<p><a href="https://www.geolsoc.org.uk/Plate-Tectonics/Chap2-What-is-a-Plate">Tectonic plates</a> are large slabs of rock made up of the Earth’s crust and uppermost part of the mantle (<a href="https://www.nationalgeographic.org/encyclopedia/lithosphere/">the lithosphere</a>) which form the outer shell of the Earth, and move around slowly relative to each other.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-volcanoes-erupt-98251">Curious Kids: Why do volcanoes erupt?</a>
</strong>
</em>
</p>
<hr>
<h2>Volcanoes act in different ways</h2>
<p>While Kilauea volcano in <a href="https://volcanoes.usgs.gov/observatories/hvo/hvo_volcanoes.html">Hawaii</a> is also located within a tectonic plate, it has several key differences with the NVP in Southeastern Australia.</p>
<h3>Magma source and volume</h3>
<p>While Hawaii sources large volumes of magma from deep within the Earth, the NVP only receives small amounts of magma from just <a href="https://pubs.geoscienceworld.org/gsa/geology/article-abstract/42/12/1031/131405">below the Earth’s crust</a>. </p>
<p>It’s worth noting here that the makeup of the magma is similar in both locations, with both erupting runny <a href="https://www.britannica.com/science/basalt">basalt</a> – a type of rock low in silica, and high in iron and magnesium.</p>
<p>We suspect that in Australia’s NVP, magma can move very fast from its source to the surface (on a time scale of days). This can bring rock fragments of the mantle (xenoliths) to the surface as the magma moves too fast for them to melt. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/232442/original/file-20180817-165943-x692ck.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/232442/original/file-20180817-165943-x692ck.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=359&fit=crop&dpr=1 600w, https://images.theconversation.com/files/232442/original/file-20180817-165943-x692ck.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=359&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/232442/original/file-20180817-165943-x692ck.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=359&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/232442/original/file-20180817-165943-x692ck.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=451&fit=crop&dpr=1 754w, https://images.theconversation.com/files/232442/original/file-20180817-165943-x692ck.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=451&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/232442/original/file-20180817-165943-x692ck.jpg?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">
<figcaption>
<span class="caption">Fragments of the mantle (xenoliths) in a volcanic bomb erupted at Mt Noorat, brought to the surface by ascending magma.</span>
<span class="attribution"><span class="source">Ray Cas</span></span>
</figcaption>
</figure>
<h3>Eruption frequency</h3>
<p>Hawaiian volcanoes can erupt numerous times, but NVP volcanoes are largely monogenetic — that is, each only erupt once or over a restricted period of time. </p>
<h3>Crust thickness</h3>
<p>Hawaii is located on the oceanic crust of the Pacific Tectonic Plate, which is a thin (around 7 km) layer of material that is dense and rich in iron. The magma can rise through this crust quite easily. </p>
<p>In contrast, the NVP is located on continental crust which is much thicker (about 30km), richer in silica and much less dense. Magma finds it much harder to travel through this kind of material.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/is-there-a-new-volcano-on-hawaii-98784">Is there a new volcano on Hawaii?</a>
</strong>
</em>
</p>
<hr>
<h2>Water adds danger</h2>
<p>The explosivity of a volcanic eruption can depend on availability of water.</p>
<p>“Dry” eruptions – where magma has little-to-no interaction with ground water or water on the Earth’s surface – typically produces mildly explosive eruptions such as <a href="http://www.geology.sdsu.edu/how_volcanoes_work/Hawaiian.html">lava fire fountains</a>, <a href="http://www.geology.sdsu.edu/how_volcanoes_work/Strombolian.html">showers of lava fragments</a> and lava flows.</p>
<p>The most explosive, hazardous eruptions form where rising magma interacts with ground water, surface water or sea water. These “wet”, (<a href="https://volcanoes.usgs.gov/vsc/glossary/phreatomagmatic_eruption.html">phreatomagmatic</a>) eruptions can produce deadly, fast moving, <a href="http://sp.lyellcollection.org/content/145/1/145">ground-hugging currents</a> of gas and volcanic material – called pyroclastic surges, and send abundant fine volcanic ash into the atmosphere.</p>
<p>The Australian Mt Gambier eruption 5,000 years ago was a “wet” eruption, and had a <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/JC087iC02p01231">volcanic explosivity index</a> of 4 on a <a href="https://geology.com/stories/13/volcanic-explosivity-index/">scale of 0-8</a> (where 0 represents a lava eruption, 1 a spectacular lava “fire” fountain as recently witnessed in Hawaii, and 8 represents a catastrophic explosive super-eruption). </p>
<p>The accompanying ash column is estimated to have reached <a href="https://link.springer.com/article/10.1007/s00445-013-0769-3">5km to 10km</a> into the atmosphere.</p>
<p>On Hawaii explosive eruptions are rarer because the magma has a low gas content and groundwater aquifers are not as large as in the NVP. However, when lava flows into the sea there are often <a href="https://volcanoes.usgs.gov/vsc/glossary/phreatic_eruption.html">phreatic</a> or steam explosions which can be hazardous to nearby <a href="http://www.abc.net.au/news/2018-07-17/hawaii-explosion-sends-lava-bomb-into-boat-injuring-tourists/10002228">spectators</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/from-kilauea-to-fuego-three-things-you-should-know-about-volcano-risk-97775">From Kilauea to Fuego: three things you should know about volcano risk</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/233227/original/file-20180823-149481-uc4ob.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/233227/original/file-20180823-149481-uc4ob.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=338&fit=crop&dpr=1 600w, https://images.theconversation.com/files/233227/original/file-20180823-149481-uc4ob.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=338&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/233227/original/file-20180823-149481-uc4ob.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=338&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/233227/original/file-20180823-149481-uc4ob.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=425&fit=crop&dpr=1 754w, https://images.theconversation.com/files/233227/original/file-20180823-149481-uc4ob.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=425&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/233227/original/file-20180823-149481-uc4ob.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">Mt Gambier’s Blue Lake was created by a huge volcanic eruption.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/aerial-view-blue-lake-mount-gambier-1022116594?src=knvUz1BSZTI9YJKDU7dPNA-1-16">from www.shutterstock.com</a></span>
</figcaption>
</figure>
<h2>There’s a lot we don’t know</h2>
<p>Another important factor relates to how we keep an eye on volcano risk at the two sites. Kilauea on Hawaii is extremely well <a href="https://volcanoes.usgs.gov/observatories/hvo/">monitored</a>, and tracking magma moving underground has helped <a href="https://www.wired.com/story/how-volcanologists-predicted-kilaueas-explosive-eruption/">predict</a> eruptions. </p>
<p>In contrast, the NVP is less well monitored, likely because there is no present volcanic activity, and it’s a huge region. </p>
<p>However, warning signs of an eruption are likely to be similar in the NVP to those on Hawaii – small earthquakes, minor uplift and/or subsidence of the ground, changes in ground temperature and gas or steam rising out of the ground.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/ive-always-wondered-why-are-the-volcanoes-on-earth-active-but-the-ones-on-mars-are-not-99831">I've Always Wondered: Why are the volcanoes on Earth active, but the ones on Mars are not?</a>
</strong>
</em>
</p>
<hr>
<p>Also, based on present knowledge of the NVP, there is no clear eruption pattern we can use to try to predict when or where the next eruption will be.</p>
<p>If the NVP were to erupt, significant <a href="http://www.academia.edu/5341698/THE_YOUNG_VOLCANIC_REGIONS_OF_SOUTHEASTERN_AUSTRALIA_EARLY_STUDIES_PHYSICAL_VOLCANOLOGY_AND_ERUPTION_RISK">impacts</a> on our lives would likely occur. These may include:</p>
<ul>
<li>the closure of surrounding <a href="https://www.sciencedirect.com/science/article/pii/S0377027316304127">roads</a> by lava flows and ash fallout </li>
<li>volcanic ash and rocks loading roofs of local buildings </li>
<li><a href="https://volcanoes.usgs.gov/volcanic_ash/water_supply.html">contamination</a> of water reservoirs by ash </li>
<li>damage to machinery and electricity <a href="https://www.sciencedirect.com/science/article/pii/S0377027316304085">infrastructure</a> by infiltrating ash </li>
<li>respiratory problems for people prone to asthma, and </li>
<li>disruption to air traffic across southeastern Australia due to drifting ash clouds driven by prevailing south-westerly winds. </li>
</ul>
<p>Further scientific research is required on active volcanic fields such as the NVP to know how fast magma travels from its source to the surface, how much warning we might have before an eruption, and how long an eruption and its impacts might last.</p><img src="https://counter.theconversation.com/content/101675/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heather Handley receives funding from the Australian Research Council. She is affiliated with the Women in Earth and Environmental Sciences Australasia Network (WOMEESA) and Determining Volcanic Risk in Auckland (DEVORA).</span></em></p><p class="fine-print"><em><span>Jozua van Otterloo is affiliated with the International Association of Volcanology and Chemistry of the Earth's Interior (IAVCEI).</span></em></p><p class="fine-print"><em><span>Ray Cas is affiliated with the University of Tasmania as an Honorary Research Adjunct Professor. </span></em></p>Melbourne lies at the eastern end of a volcanic province, but when’s it going to blow? Understanding the geology of Melbourne and comparing it to Hawaii is really helpful in calculating risk.Heather Handley, Associate Professor in Volcanology and Geochemistry, Macquarie UniversityJozua van Otterloo, Assistant Lecturer in Volcanology, Monash UniversityRay Cas, Professor emeritus, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/977752018-06-06T00:43:13Z2018-06-06T00:43:13ZFrom Kilauea to Fuego: three things you should know about volcano risk<p>Recent photographs and video from the <a href="https://theconversation.com/fuego-volcano-the-deadly-pyroclastic-flows-that-have-killed-dozens-in-guatemala-97707">devastating eruption</a> of Fuego volcano in Guatemala show people stood watching and filming hot, cloud-like flows of gas, ash and volcanic material (known as <a href="https://volcanoes.usgs.gov/vhp/pyroclastic_flows.html">pyroclastic flows</a>) travelling towards them down the slopes of the volcano. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1003414675986567168"}"></div></p>
<p>From this it is clear that some people do not fully understand the risks of the volcanoes they live near. </p>
<p>Although <a href="https://www.britannica.com/science/volcano">each volcano is different</a>, and each presents different risks to the people near to them, there are some generalisations that help us understand what these risks are likely to be.</p>
<p>Three points are clear: location matters, explosiveness can be predicted to an extent, and fast-moving pyroclastic flows of volcanic material are deadly. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/fuego-volcano-the-deadly-pyroclastic-flows-that-have-killed-dozens-in-guatemala-97707">Fuego volcano: the deadly pyroclastic flows that have killed dozens in Guatemala</a>
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<h2>1. Location matters</h2>
<p>The outer layer of the Earth, called the <a href="https://www.nationalgeographic.org/encyclopedia/lithosphere/">lithosphere</a> (crust and upper mantle), is broken up into a number of rigid tectonic plates. <a href="http://geologylearn.blogspot.com/2016/03/relation-of-volcanism-to-plate-tectonics.html">Volcanoes typically occur</a> where the plates move apart from one another, for example at underwater mid-ocean ridges, or collide together at subduction zones. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=423&fit=crop&dpr=1 754w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=423&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/221706/original/file-20180605-175438-d1ydm6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=423&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">Australia sits in the middle of a tectonic plate - whereas New Zealand sits on a boundary between two tectonic plates. <strong>CLICK ON IMAGE TO ZOOM</strong></span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-vector/plate-tectonics-earths-lithosphere-scientific-theory-134705048?src=tTw-S8Bbu7hIuslxFGjmZg-1-4">from www.shutterstock.com</a></span>
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<p>We also find volcanoes in the middle of tectonic plates – these are called “intraplate” volcanoes, such as the Hawaiian and Galápagos oceanic islands. </p>
<p>The magma (molten rock) that feeds volcanoes is generated in different ways in these settings, and different volcanic landforms result. </p>
<p>Hawaii is in the middle of a tectonic plate and volcanic activity there forms relatively low-profile, <a href="https://volcano.si.edu/learn_galleries.cfm?p=2">shield volcanoes</a>. Typically, these volcanoes are built up by many fluid lava flows into broad, gently sloping domes, which resemble a warrior’s shield.</p>
<p>In contrast, Fuego is situated in a subduction zone environment (one plate going under another) where steep-sided, <a href="http://volcano.oregonstate.edu/stratovolcanoes">stratovolcanoes, or composite</a> volcanoes are most common. These often symmetrical, conical volcanoes form from the build up of layers of lava and pyroclastic (fragmented volcanic) rocks.</p>
<h2>2. Magma and gas affect explosiveness</h2>
<p>The volcanic landforms and eruptive styles we see in different settings are largely a <a href="http://www.geology.sdsu.edu/how_volcanoes_work/Controls.html">result of the differences</a> in the composition of the magma (molten rock) erupted, its temperature and its gas content in these contrasting tectonic settings.</p>
<p>Large shield volcanoes in the middle of tectonic plates, such as <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/geo_hist_2008.html">Kilauea volcano in Hawaii</a>, erupts high temperature, low silica lava. This is runnier (less viscous) than magma typically erupted at subduction zone volcanoes (like Fuego). </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/eruptions-and-lava-flows-on-kilauea-but-whats-going-on-beneath-hawaiis-volcano-96919">Eruptions and lava flows on Kilauea: but what's going on beneath Hawai'i's volcano?</a>
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<p>This means that any volatiles (dissolved gases such as water, carbon dioxide and sulphur dioxide) in the Kilauea magma are able to escape more easily compared to in a stickier, higher silica, magma that characterises subduction zone volcanoes.</p>
<p>And so “Hawaiian-style” eruptions are characterised by lava fountaining and flows of hot fluid lava that normally travel slow enough for people to walk away from and evacuate. This is exactly what we have been seeing over the last month in Kilauea’s East Rift Zone.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"998032498259996674"}"></div></p>
<p>In contrast, at subduction zone volcanoes – such as Fuego – the higher water content of the magma and the typically more silica-rich, sticky magmas erupt more explosively. It is harder for gas bubbles formed to escape as magma rises to the surface, which then take up more space and over pressure the system. </p>
<p>Subduction zone volcanoes can produce high columns of gas and ash reaching tens of kilometres into the atmosphere, and scalding hot, fast-moving, cloud-like currents of gas, ash and volcanic material. These pyroclastic flows, or “pyroclastic density currents”, race down the volcano at speeds over 80 km/hr. </p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1004036622604816386"}"></div></p>
<p>Some news reports of eruptions at Fuego have incorrectly termed these pyroclastic flows “rivers of lava”. They are very different to lava flows and much more hazardous. </p>
<p>Clear and accurate communication of volcanic eruptions is crucial if those near the volcano are to understand the real risks.</p>
<h2>3. Pyroclastic flows are deadly</h2>
<p>Pyroclastic flows are extremely hazardous and deadly. They were responsible for deaths in Pompeii and Herculaneum from the AD79 eruption of Vesuvius in Italy. </p>
<p>Even the famous volcanologists <a href="http://volcano.oregonstate.edu/who-were-maurice-and-katia-krafft-how-did-they-die">Katia and Maurice Kraft</a> underestimated the reach of a pyroclastic flow during an eruption at Unzen volcano on June 3, 1991, which killed them along with many others. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-do-most-volcanologists-die-from-getting-too-close-to-volcanoes-82496">Curious Kids: Do most volcanologists die from getting too close to volcanoes?</a>
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<p>Historic subduction zone volcanic eruptions producing devastating pyroclastic flows include: </p>
<ul>
<li>Vesuvius, Italy AD 79</li>
<li>Tambora, Indonesia (1815)</li>
<li>Krakatau (Krakatoa), Indonesia (1883)</li>
<li>Mt Pelée, Caribbean (1902)</li>
<li>Mt St Helens, USA (1980)</li>
<li>Mt Pinatubo, Philippines (1991)</li>
<li>Unzen, Japan (1991).</li>
</ul>
<p>At Fuego, the loose, fragmented volcanic material (known as tephra) lying on the slopes after eruptions may be remobilised by rain to form volcanic mudflows known as lahars. These pose a significant current and future risk for the people surrounding Fuego compared to those living in Hawaii. </p>
<p>Pyroclastic density currents were the <a href="https://www.sciencedirect.com/science/article/pii/S0377027305001563">main cause of death from volcanic activity</a> in the 20th Century, killing around 45,000 people, almost 50% of all volcanic deaths in that time period (total deaths from volcanic activity is estimated to be 91,724).</p>
<p>While eyes are diverted toward eruptions in Central America and the Pacific Ocean, <a href="http://www.thejakartapost.com/travel/2018/06/04/alert-statuses-for-19-volcanoes-raised.html">Indonesia has raised the alert level</a> on some of its volcanoes this week. It now has <a href="https://magma.vsi.esdm.go.id/">21 volcanoes</a> on alert levels 2-4 (yellow, orange and red) on a scale of 1-4. </p>
<p>Local authorities will be vital in managing and communicating the risks of these volcanoes, as well as around Fuego and Kilauea.</p><img src="https://counter.theconversation.com/content/97775/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Heather Handley receives funding from the Australian Research Council. </span></em></p>Important points about volcanoes: location matters, explosiveness can be predicted to an extent, and fast-moving flows of volcanic materials (known as pyroclastic flows) are deadly.Heather Handley, Associate Professor in Volcanology and Geochemistry, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/969192018-05-24T20:04:57Z2018-05-24T20:04:57ZEruptions and lava flows on Kilauea: but what’s going on beneath Hawai'i’s volcano?<p>Over the past few weeks we’ve seen increasingly <a href="https://weather.com/safety/news/2018-05-21-hawaii-kilauea-volcano-aerial-photos">spectacular images</a> reported in the news of the ongoing eruption at Kilauea volcano, on the Pacific island of Hawai'i.</p>
<p>These have been tempered by reports of <a href="http://www.news.com.au/world/north-america/hawaiis-kilauea-volcano-erupts-sending-ash-cloud-into-air-and-forming-gas-glass-as-lava-hits-sea/news-story/0cc553c50cfdfd56a3ba000c91309114">growing destruction</a>, with houses and infrastructure bulldozed, buried or burned by lava flows. </p>
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<strong>
Read more:
<a href="https://theconversation.com/trouble-in-paradise-eruptions-from-kilauea-volcano-place-the-hawaiian-island-on-red-alert-96469">Trouble in paradise: eruptions from Kīlauea volcano place the Hawaiian island on red alert</a>
</strong>
</em>
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<p>Yet Kilauea is one of the world’s most active volcanoes, and has been erupting continually since 1983. So what has triggered this sudden change in activity, threatening homes and livelihoods? The answer relates to what is happening beneath the volcano. </p>
<h2>Kilauea volcano</h2>
<p>Activity at Kilauea is driven by the buoyant upwelling of a plume of hot mantle, which provides the heat to generate magma beneath the volcano. This magma has the potential to erupt from several different locations, or vents, on the volcano.</p>
<iframe src="https://www.google.com/maps/d/embed?mid=1_H52K2m3P5-1awLPjrHY1ySXN7IiXA6N" width="100%" height="480"></iframe>
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<span class="caption">Click on the three blue markers to reveal more.</span>
<span class="attribution"><a class="source" href="https://www.google.com/maps/d/u/0/embed?mid=1_H52K2m3P5-1awLPjrHY1ySXN7IiXA6N">Google Maps/The Conversation</a></span>
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<p>Typically, the crater at the summit of the volcano is where eruptions are expected to occur, but the geology of Kilauea is complex and a rift on the eastern side of the volcano also allows magma to erupt from its flanks. </p>
<p>Over the past decade both the summit crater and a vent on the eastern rift, called Pu’u O’o, have been continually active. The summit crater has hosted a <a href="https://www.youtube.com/watch?v=y0lNb4Hz7ac">lava lake</a> since March 2008.</p>
<p>Lava lakes are relatively rare features seen at only a handful of volcanoes around the world. The fact that they do not cool and solidify tells us that lava lakes are regularly replenished by fresh magma from below.</p>
<p>In contrast, Pu’u O’o, 18km east of the summit crater, has been pouring out <a href="https://pubs.usgs.gov/fs/2012/3127/fs2012-3127.pdf">lava flows since 1983</a>. In the first 20 years of this eruption, 2.1km³ of lava flows were produced, equivalent in volume to 840,000 Olympic swimming pools. All of this tells us that Kilauea volcano regularly receives lots of magma to erupt. </p>
<h2>Current eruptions</h2>
<p>Over the <a href="http://volcano.si.edu/volcano.cfm?vn=332010&vtab=Weekly#May2018">past three weeks</a> activity at Pu’u O’o has stopped, while a series of fissures has opened roughly 20km further east in a subdivision known as Leilani Estates.</p>
<p>This area was previously affected by lava flows in <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/geo_hist_1955.html">1955</a>. </p>
<p>To date, 23 fissures have opened, starting off simply as cracks in the ground, with some developing into highly active vents from which significant lava flows are forming. </p>
<p>At the moment, the longest flows are about 6km long, having <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/multimedia_chronology.html">reached the ocean</a>. This is a further <a href="https://theconversation.com/lava-in-hawaii-is-reaching-the-ocean-creating-new-land-but-also-corrosive-acid-mist-96947">cause for concern</a>, as the lava reacts with seawater to form a corrosive mist.</p>
<p>Meanwhile, at the summit of the volcano, the lava lake has drained from the crater, sparking <a href="https://theconversation.com/trouble-in-paradise-eruptions-from-kilauea-volcano-place-the-hawaiian-island-on-red-alert-96469">fears of more explosive eruptions</a>, as draining magma interacts with groundwater. </p>
<p>Satellite instruments and high-resolution GPS are being used to monitor changes in the shape of the volcano and have found that the <a href="https://www.facebook.com/USGSVolcanoes/photos/a.984262971602264.1073741827.984239038271324/2033888749973009/?type=3&theater">summit region is deflating</a>, while the lower east rift zone, where new fissures have opened in recent days, is inflating.</p>
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<p>The magma reservoirs that feed eruptions on Kilauea can be imagined as balloons, which grow when they are filled and shrink when they are emptied. Deflation at the summit, combined with observations that the lava lake has drained (at a rate of up to 100m over two days!), suggest that the magma reservoir feeding the summit is emptying.</p>
<p>Where is the magma going? Observations of ground inflation around the newly opened fissures to the east indicate that the magma is being diverted down the east rift and accumulating and erupting there instead.</p>
<p>Exactly what has caused this rerouting of the magma is still not clear. A <a href="https://earthquake.usgs.gov/earthquakes/eventpage/us1000dyad#executive">magnitude 6.9 earthquake</a> occurred in the area on May 4 and this may have opened a new pathway for magma to erupt, influencing the geometry of the lower east rift zone.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=580&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=580&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=580&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=729&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=729&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219887/original/file-20180522-51105-1foitu7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=729&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 Landsat8 image (top) of Kilauea volcano taken on March 15, 2018. The relative location of the various vents are marked, and a red, glowing lava flow can just be seen in the north-east of the image. The graphic (bottom) shows an inferred magma pathway below the volcano.</span>
<span class="attribution"><span class="source">NASA/Chris Firth</span>, <span class="license">Author provided</span></span>
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<h2>Lessons for the future</h2>
<p>By combining measurements from Kilauea of ground deformation, earthquake patterns and gas emissions during the current eruption, with observations of the lava that is erupted, volcanologists will be able to piece together a much clearer picture of what triggered this significant change in eruption over the past few weeks.</p>
<p>This knowledge will be crucial in planning for future eruptions, both at Kilauea and at other volcanoes. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/lava-in-hawaii-is-reaching-the-ocean-creating-new-land-but-also-corrosive-acid-mist-96947">Lava in Hawai'i is reaching the ocean, creating new land but also corrosive acid mist</a>
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<hr>
<p>Eruptions from the flanks of a volcano can pose a much more significant hazard for the local population than those from a volcano’s summit, as many more people live in the areas that are directly affected.</p>
<p>This has been amply displayed over the past few weeks on Kilauea by the fissures opening in people’s gardens and lava flows destroying homes and infrastructure.</p>
<p>But Kilauea is not the only volcano to have flank eruptions. For example, lava flows famously emerged from the lower slopes of <a href="https://www.researchgate.net/publication/227129509">Mt Etna in 1669</a>, destroying villages and partially surrounding the regional centre of Catania, on the east coast of Sicily, Italy.</p>
<p>Lessons learned from the current eruption of Kilauea can equally be applied to other volcanoes, like Etna, where more densely populated surroundings mean that the hazards posed by such an eruption would be even greater.</p>
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<figcaption>
<span class="caption">Lava fountains form fissure 22 on the lower east rift zone of Kīlauea volcano, in Hawai'i.</span>
<span class="attribution"><a class="source" href="https://www.usgs.gov/media/images/k-lauea-volcano-lava-fountain-fissure-22">USGS</a></span>
</figcaption>
</figure><img src="https://counter.theconversation.com/content/96919/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chris Firth 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>The current eruption of Kilauea on Hawai'is big island can tell us a lot about what is going on beneath the volcano and may provide lessons for future eruptions.Chris Firth, Lecturer in Geology, Macquarie UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/969472018-05-22T14:43:37Z2018-05-22T14:43:37ZLava in Hawai'i is reaching the ocean, creating new land but also corrosive acid mist<p>There is something special and awe-inspiring about watching new land form. This is what is now happening in Hawai’i as its <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/status.html">Kīlauea volcano erupts</a>. Lava is reaching the ocean and building land while producing spectacular plumes of steam. These eruptions are hugely important for the creation of new land. But they are also dangerous. Where the lava meets the ocean, corrosive acid mist is produced and glass particles are shattered and flung into the air. Volcanic explosions can also hurl lava blocks hundreds of metres and produce waves of scalding hot water. </p>
<p>At Kīlauea, lava is erupting from a line of vents on the volcano’s flanks, and is moving downslope to the edge of the island, where it enters the ocean. This is a process that has been witnessed many times at Hawai’i and other volcanic islands. And it is through many thousands of such eruptions that volcanic islands like Hawai’i form.</p>
<p>The new lava being added to Hawai’i by this latest Kīlauea eruption replaces older land that is being lost by erosion, and so prolongs the island’s lifespan. In contrast, older islands to the north-west have no active volcanoes, so they are being eroded by the ocean and will eventually disappear beneath the waves. The opposite is happening to the south-east of Hawai’i, where an underwater volcano (Lōʻihi Seamount) is building the foundations of what will eventually become the next volcanic island in this area.</p>
<h2>How lava gets to the ocean at Hawai’i</h2>
<p>The lava erupting from the current Kīlauea vents has a temperature of roughly 1150 degrees °C, and has a journey of between 4.5km and 5.5km to reach the ocean. As this lava moves swiftly in channels, it loses little heat and so it can enter the ocean at a temperature of over 1000 degrees°C.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219812/original/file-20180521-14953-hps3d7.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">When lava meets the sea, new land is formed.</span>
<span class="attribution"><a class="source" href="http://www.epa.eu/disasters-photos/volcanic-eruption-photos/fissure-20-flow-reaches-the-ocean-photos-54352112">EPA</a></span>
</figcaption>
</figure>
<h2>What happens when lava meets the ocean?</h2>
<p>We are witnessing one of the most spectacular sights in nature - billowing white plumes of steam (technically water droplets) as hot lava boils seawater. Although these billowing steam clouds appear harmless, they are dangerous because they contain small glass shards (fragmented lava) and acid mist (from seawater). This acid mist known as “laze” (lava haze) can be hot and corrosive. If anyone goes to near it, they can experience breathing difficulties and irritation of their eyes and skin.</p>
<p>Apart from the laze, the entry of lava into the ocean is usually a gentle process, and when steam is free to expand and move away, there are no violent steam-driven explosions.</p>
<p>But a hidden danger lurks beneath the ocean. The lava entering the sea breaks up into blobs (known as pillows), angular blocks, and smaller fragments of glass that form a steep slope beneath the water. This is called a lava delta. </p>
<p>A newly formed lava delta is an unstable beast, and it can collapse without warning. This can trap water within the hot rock, leading to violent steam-driven explosions that can hurl metre-sized blocks up to 250 metres. Explosions occur because when the water turns to steam it suddenly expands to around 1,700 times its original volume. <a href="https://volcanoes.usgs.gov/observatories/hvo/hawaii_ocean_entry.html">Waves of scalding water</a> can also injure people who are too close. People have died and been seriously injured during lava delta collapses </p>
<p>So, the ocean entry points where lava and seawater meet are doubly dangerous, and anyone in the area should pay careful attention to official advice on staying away from them.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/219813/original/file-20180521-14965-kfzbff.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">Pillow Lavas form underneath the ocean.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Nur05028_-_pile_of_pillow_lava.jpg">National Oceanic & Atmospheric Adminstration (NOAA)</a></span>
</figcaption>
</figure>
<h2>What more can we learn from these eruptions?</h2>
<p>Once lava deltas have cooled and become stable they represent new land. <a href="http://sp.lyellcollection.org/content/202/1/91">Studies</a> have revealed that lava deltas have distinctive features, and this has enabled volcanologists to recognise lava deltas in older rocks.</p>
<p>Remarkable examples of lava deltas have been discovered near the top of extinct volcanoes (called tuyas) in Iceland and Antarctica. These deltas can only form in water and the only plausible source of this water in this case is melted ice. This means that these volcanoes had melted water-filled holes up to 1.5km deep in ice sheets, which is an astonishing feat. In fact, these lava deltas are the only remaining evidence of long-vanished ice sheets. </p>
<p>It is a privilege to see these incredible scenes of lava meeting the ocean. The ongoing eruptions form part of the natural process that enables beautiful volcano islands like Hawai'i to exist. But the creation of new land here can also bring danger to those who get too close, whether it be collapsing lava deltas or acid mist.</p><img src="https://counter.theconversation.com/content/96947/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span><a href="mailto:ian.skilling@southwales.ac.uk">ian.skilling@southwales.ac.uk</a> received funding from National Science Foundation in US. </span></em></p><p class="fine-print"><em><span>Dave McGarvie 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>At Kīlauea in Hawai'i, a recent volcanic eruption has created some of the most spectacular sights in nature. But also danger for those around it.Dave McGarvie, School of Physical Sciences, The Open UniversityIan Skilling, Senior Lecturer (Volcanology), University of South WalesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/962602018-05-08T18:43:04Z2018-05-08T18:43:04ZLava, ash flows, mudslides and nasty gases: Good reasons to respect volcanoes<figure><img src="https://images.theconversation.com/files/218151/original/file-20180508-34021-19wgpzp.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Lava flow moves in the Leilani Estates subdivision near Pahoa on the island of Hawaii, May 6, 2018.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Hawaii-Volcano/5f1db96d69c24dcea1d19c0d5e5401d2/12/0">USGS via AP</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Volcanoes are beautiful and awe-inspiring, but the ongoing eruption of Kilauea on Hawaii’s Big Island is showing how dangerous these events can be. So far this event has destroyed dozens of homes and displaced hundreds of people, but no deaths or serious injuries have been reported. Other volcanic eruptions have had deadlier impacts.</p>
<p>As a volcano scientist, I’m very aware of deadly volcanic eruptions can be, even the “nonexplosive” kind we’re seeing in Hawaii now. Since A.D. 1500, volcanic eruptions have killed <a href="https://doi.org/10.1186/s13617-017-0067-4">more than 278,000 people</a>.</p>
<p>Today there are 1,508 active volcanoes around the world. Each year, some 50 to 60 of them <a href="https://volcanoes.usgs.gov/vsc/file_mngr/file-153/FAQs.pdf">erupt</a>. <a href="https://blogs.worldbank.org/voices/inconvenient-apocalyptic-or-somewhere-between-why-we-shouldn-t-be-complacent-about-volcanic">Around 800 million people</a> live within volcanic risk zones. Volcanologists study and monitor volcanoes so that we can try to forecast future eruptions and predict how widely the damage could reach.</p>
<h2>When mountains explode</h2>
<p>Volcanic eruptions can be broadly divided into two types: explosive and nonexplosive. Explosive eruptions occur when magma, which is molten rock in the ground, contains gas. These eruptions are so energetic that the magma is pulverized into small rock particles, called volcanic ash. </p>
<p>Explosive eruptions are responsible for the <a href="http://volcano.oregonstate.edu/deadliest-eruption">highest number of volcanic-related deaths</a>. These events can distribute <a href="https://volcanoes.usgs.gov/vhp/tephra.html">volcanic ash</a> hundreds of miles from the volcano, causing billions of dollars in air travel disruption, water supply pollution and damage to power lines, structures and machinery. Krakatoa in the Pacific (1883) and Mount St. Helens in Washington state (1980) are examples of explosive eruptions. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/xP2dreOI8gI?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">U.S. Geological Survey scientists recount their experiences before, during and after the May 18, 1980 eruption of Mount St. Helens, which killed 57 people, including a USGS researcher.</span></figcaption>
</figure>
<p>The most dangerous features of these events are <a href="https://volcanoes.usgs.gov/vhp/pyroclastic_flows.html">volcanic ash flows</a> – swift, ground-hugging avalanches of searing hot gas, ash and rock that destroy everything in their path. Ash flows produced during the A.D. 79 eruption of Mount Vesuvius in Italy entombed the towns of <a href="http://www.bbc.co.uk/history/ancient/romans/pompeii_portents_01.shtml">Herculaneum and Pompeii</a>. In 1902, ash flows from the eruption of Mount Pelee on the Caribbean island of <a href="https://www.theguardian.com/world/2002/apr/28/physicalsciences.highereducation">Martinique</a> killed more than 29,000 people.</p>
<h2>Lava flows and fountains</h2>
<p>Nonexplosive eruptions occur when little to no gas is contained within the magma. These events produce small fire fountains and lava flows, such as those <a href="https://volcanoes.usgs.gov/volcanoes/kilauea/status.html">currently erupting from Kilauea</a>.</p>
<p>Nonexplosive eruptions tend to be less deadly than explosive eruptions, but can still cause great disruption and destruction. Eruptions at Hawaiian-style volcanoes can occur at the summit or along the flanks. New eruptions typically begin with the opening of a fissure, or long crack, that spews molten lava into the air and sometimes forms <a href="https://volcanoes.usgs.gov/vhp/lava_flows.html">lava flows</a>. </p>
<p>As reports from Hawaii are showing, lava tends to flow rather slowly. Typically it is easy to outrun a lava flow but impossible to stop or divert it. People can escape, but homes and property are vulnerable.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/DNbbNZ5sHIM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Lava flows and fountains consuming homes and property in Leilani Estates on the island of Hawaii.</span></figcaption>
</figure>
<p>Both explosive and nonexplosive eruptions release <a href="https://volcanoes.usgs.gov/vhp/gas.html">volcanic gases</a>, producing a hazardous blend called volcanic fog, or <a href="https://volcanoes.usgs.gov/observatories/hvo/hvo_gas.html">VOG</a>. VOG contains aerosols – fine particles created when sulfur dioxide reacts with moisture in the air. It can cause health problems, damage crops and pollute water supplies. </p>
<p>These particles have global consequences when eruptions eject them into the stratosphere, where they block sunlight, cooling Earth’s climate. This effect can cause widespread crop failure and famine and is responsible for many historic volcanic-related deaths. For example, the 1815 explosive eruption of Tambora in Indonesia caused <a href="http://volcano.oregonstate.edu/vwdocs/volc_images/southeast_asia/indonesia/tambora.html">92,000 starvation-related deaths</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/218154/original/file-20180508-34038-lqdfa6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/218154/original/file-20180508-34038-lqdfa6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/218154/original/file-20180508-34038-lqdfa6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/218154/original/file-20180508-34038-lqdfa6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/218154/original/file-20180508-34038-lqdfa6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/218154/original/file-20180508-34038-lqdfa6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/218154/original/file-20180508-34038-lqdfa6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/218154/original/file-20180508-34038-lqdfa6.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">VOG (volcanic fog), produced by gases from Kilauea, hangs low over the Hawaiian Islands on December 3, 2008, producing unhealthy sulfur dioxide concentrations.</span>
<span class="attribution"><a class="source" href="https://earthobservatory.nasa.gov/NaturalHazards/view.php?id=36089">NASA Earth Observatory</a></span>
</figcaption>
</figure>
<p>Snow-capped volcanoes, such as those in the <a href="https://volcanoes.usgs.gov/observatories/cvo">Cascades</a> and <a href="https://www.avo.alaska.edu/">Alaska</a>, can produce mudflows, or <a href="https://volcanoes.usgs.gov/vhp/lahars.html">lahars</a>. These hazards form when ice and snow melt during an eruption, or ash is washed loose from the surface by heavy rain. </p>
<p>Mudflows have tremendous energy and can travel up to 60 miles per hour down river valleys. They are capable of destroying bridges, structures, and anything else in their path. A mudflow from the 1985 eruption of <a href="https://www.ngdc.noaa.gov/hazard/stratoguide/nevadofeat.html">Nevado del Ruiz</a> in Colombia killed 25,000 people.</p>
<h2>Getting ready for the next eruption</h2>
<p>By studying past and current eruptions, volcanologists constantly refine our ability to predict and mitigate the hazards and risk associated with volcanic activity. But people who live within range of volcanic hazards also can <a href="http://www.redcross.org/get-help/how-to-prepare-for-emergencies#About">minimize their risk</a>. </p>
<p>All residents of these zones should develop household plans for evacuating or sheltering in place and prepare emergency kits with first aid supplies, essential medicines, food and water. Events like the Kilauea eruption are reminders that preparing before natural disasters can make communities more resilient when these events strike.</p><img src="https://counter.theconversation.com/content/96260/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Brittany Brand 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>Fountains of lava from Hawaii’s Kilauea volcano are dramatic, but the most deadly impacts of volcanic eruptions are toxic gases and ash and mud flows.Brittany Brand, Assistant Professor of Geosciences, Boise State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/882222017-11-28T21:12:20Z2017-11-28T21:12:20ZEach volcano has unique warning signs that eruption is imminent<figure><img src="https://images.theconversation.com/files/217781/original/file-20180504-166884-1lbw2x0.jpg?ixlib=rb-1.1.0&rect=507%2C18%2C3458%2C2402&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Where there's smoke, there will be lava?</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Hawaii-Volcano/7dc4c896f8424765a684155576ee5f3f/3/0">U.S. Geological Survey via AP</a></span></figcaption></figure><p>How do volcanologists know what a volcano is going to do?</p>
<p>Each volcano, like each individual person, has its own unique “personality.” You may know, for example, that you can tease your brother mercilessly – up until the point where his eyebrows crease together because that means he’s going to blow his top. But do you know what it means if my eyebrows crease together? (It’s a surefire sign I’m thinking really hard.)</p>
<p>Similarly, one volcano might reveal an imminent eruption by a sudden increase in the frequency and strength of earthquakes located directly below it. A different volcano might not show an increase in earthquake strength but instead display an increase in elevation as magma swells beneath its surface – just as air filling a balloon causes it to increase in size.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/196783/original/file-20171128-28856-1vgj5bf.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/196783/original/file-20171128-28856-1vgj5bf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/196783/original/file-20171128-28856-1vgj5bf.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196783/original/file-20171128-28856-1vgj5bf.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196783/original/file-20171128-28856-1vgj5bf.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196783/original/file-20171128-28856-1vgj5bf.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=471&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196783/original/file-20171128-28856-1vgj5bf.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=471&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196783/original/file-20171128-28856-1vgj5bf.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=471&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Last fall showed a spike in number and magnitude of earthquakes around Agung.</span>
<span class="attribution"><a class="source" href="https://magma.vsi.esdm.go.id/img/eqhist/AGU.png">MAGMA Indonesia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>The best way scientists can determine whether a volcano is about to erupt is to study its past behavior: How did this volcano act before it erupted last time? Our ability to predict eruptions is directly related to the amount of historic data we have for a given volcano.</p>
<p>For most of Earth’s active volcanoes, though, we don’t have detailed information. <a href="https://volcano.si.edu/volcano.cfm?vn=273083#bgvn_199103">Mount Pinatubo, Philippines</a>, for example, erupted catastrophically in 1991; before that, its most recent eruption was around 500 years earlier. <a href="https://pubs.usgs.gov/fs/1997/fs113-97/">Precursors at Mount Pinatubo</a> included ash explosions at the summit, increases in the number of vents spewing hot gas, changes in the volcano’s shape and increases in both the frequency and size of earthquakes. Two months of increasing activity preceded the 1991 paroxysmal eruption.</p>
<p>In contrast, <a href="https://theconversation.com/where-were-you-when-the-mountain-blew-remembering-the-eruption-of-mount-st-helens-41652">Mount St. Helens volcano</a> in the U.S. is probably the most closely watched volcano on the planet. Decades of detailed observations allow geologists to make fairly precise predictions about Mount St. Helens: a specific pattern of earthquakes, for example, means that <a href="https://pubs.usgs.gov/fs/2005/3036/">new lava will erupt</a> within two weeks.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/196780/original/file-20171128-28856-14l96yg.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/196780/original/file-20171128-28856-14l96yg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/196780/original/file-20171128-28856-14l96yg.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=507&fit=crop&dpr=1 600w, https://images.theconversation.com/files/196780/original/file-20171128-28856-14l96yg.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=507&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/196780/original/file-20171128-28856-14l96yg.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=507&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/196780/original/file-20171128-28856-14l96yg.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=638&fit=crop&dpr=1 754w, https://images.theconversation.com/files/196780/original/file-20171128-28856-14l96yg.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=638&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/196780/original/file-20171128-28856-14l96yg.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=638&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">GPS measurements provide models of the direction and rate (length of arrow) of deformation at the summit of Mauna Loa, a potential eruption precursor.</span>
<span class="attribution"><a class="source" href="https://volcanoes.usgs.gov/observatories/hvo/hvo_monitoring_deformation.html">USGS</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Kilauea volcano has been <a href="https://volcano.si.edu/volcano.cfm?vn=332010">erupting since 1983</a>, although there have been temporary pauses in its lava production. In these past 35 years, researchers have gotten familiar with how Kilauea behaves: we have satellite data, instruments that record earthquakes, others that show us how the ground is deforming because of magma pushing at it from below. Data are collected continuously – improving our ability to predict eruptions.</p>
<p>At Kilauea volcano now, lava beneath Kilauea’s summit is traveling underground several kilometers to the east, where it’s coming out of the ground in folks’ back yards. This has happened before: in 1983, <a href="https://earthobservatory.nasa.gov/IOTD/view.php?id=80258">lava from Kilauea destroyed</a> a pleasant neighborhood. And it will happen again.</p>
<p>As technology advances, volcanologists and experts in collecting and interpreting satellite data (including remote-sensing scientists and geodesists) are improving our ability to predict eruptions. Now we can collect important information about volcano shape, temperature and changes in those parameters using satellites that provide the view from space. Satellites give volcanologists a good overall view of the volcano, but can’t supply human-scale details. Satellite orbits typically allow them to pass over a given volcano only once every week or two. We still require seismometers on the ground to detect and report earthquakes caused by magma moving beneath the volcano, but seismometers are too expensive to deploy and maintain everywhere.</p>
<p>Accurate predictions of volcanic eruptions – particularly the size of the eruption and whether the volcano will explode or generate lava flows – are essential for local authorities to make life-and-death decisions about people in the vicinity of an active volcano. If an evacuation is ordered and a volcano explodes, lives are saved. This happened in the 1991 Pinatubo eruption. If an evacuation is ordered and the volcano doesn’t explode, economic losses and human suffering can be catastrophic. This scenario played out <a href="https://pubs.usgs.gov/bul/b2185/">in Mammoth Mountain, California</a>, in 1984, where the local community lost millions of tourist dollars – and there was no eruption.</p>
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<p>To predict eruptions on the scale of hours, days or weeks, we need detailed information about each potentially threatening volcano. Without that, we are forced to make comparisons: will a volcano behave more like Mount St. Helens or Mount Pinatubo, for example? In other words, do creased eyebrows on someone you’ve just met (or, for example, increased seismicity) mean that person is about to blow its top or is just thinking really hard? More data, from more volcanoes, make for better comparisons, but nothing beats really getting to know the behavior of an individual volcano.</p><img src="https://counter.theconversation.com/content/88222/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Tracy Gregg receives funding from NASA.</span></em></p>How do scientists predict volcanic eruptions? To do so with accuracy, they need to know the individual volcano and its history very well.Tracy K.P. Gregg, Associate Professor of Geology, University at BuffaloLicensed as Creative Commons – attribution, no derivatives.