tag:theconversation.com,2011:/nz/topics/antarctic-peninsula-40415/articlesAntarctic Peninsula – The Conversation2020-11-13T14:00:17Ztag:theconversation.com,2011:article/1470692020-11-13T14:00:17Z2020-11-13T14:00:17Z200 years ago, people discovered Antarctica – and promptly began profiting by slaughtering some of its animals to near extinction<figure><img src="https://images.theconversation.com/files/363986/original/file-20201016-23-n65p2x.png?ixlib=rb-1.1.0&rect=0%2C9%2C3072%2C1945&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Workmen dissecting a whale carcass in Antarctica, circa 1935</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/workmen-dissecting-a-whale-carcass-in-antarctica-news-photo/3310716">Hulton Archive via Getty Images</a></span></figcaption></figure><p>Two hundred years ago, on Nov. 17, Connecticut ship captain <a href="https://doi.org/10.2307/210532">Nathaniel Palmer spotted the Antarctic continent</a>, one of three parties to do so in 1820. Unlike explorers Edward Bransfield and Fabian von Bellingshausen, Palmer was a sealer who quickly saw economic opportunity in the rich sealing grounds on the Antarctic Peninsula.</p>
<p>In the two centuries since, Antarctica has seen a range of commercial, scientific and diplomatic developments. While <a href="https://global.oup.com/academic/product/frozen-empires-9780190249144?cc=us&lang=en&">some countries attempted to claim territory on the continent</a> in the first half of the 20th century, today the region is governed through the international <a href="https://www.ats.aq/index_e.html">Antarctic Treaty System</a>. </p>
<p>Although the treaty claims to govern Antarctica in the interests of all “mankind,” some countries have gained greater benefits from the region than others. While mining is currently banned under the Antarctic Treaty and the days of sealing and whaling are over, Antarctica’s marine living resources are still being exploited to this day.</p>
<h2>Fur and blubber</h2>
<p>Palmer was followed by a rush of other sealing ships, mostly from the United States and Britain, that methodically killed fur seals along Antarctic beaches, <a href="https://catalog.hathitrust.org/Record/000684110">swiftly taking populations to the brink of extinction</a>. Seal fur was used for clothing in the 18th and 19th centuries in many parts of the world and was an important part of <a href="https://www.sup.org/books/title/?id=27054">U.S. and European trade with China</a> in the 19th century.</p>
<p>Fur sealing had a real boom-and-bust quality. Once a region was picked over, the sealers would move to more fruitful grounds. Before 1833, at least <a href="https://books.google.com/books/about/Sealing_in_the_Southern_Oceans_1788_1833.html?id=kkyfuAAACAAJ">7 million fur seals were killed in the Antarctic and sub-Antarctic</a>. As early as 1829, British naturalist James Eights lamented the loss of the fur seal on the Antarctic peninsula: “<a href="https://catalog.hathitrust.org/Record/000684110">This beautiful little animal was once most numerous here</a>.” </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/363782/original/file-20201015-17-1fdyso8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Watercolor painting depicting an Antarctic landscape with a man in the foreground swinging an ax into the bloody carcass of a seal." src="https://images.theconversation.com/files/363782/original/file-20201015-17-1fdyso8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363782/original/file-20201015-17-1fdyso8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=446&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363782/original/file-20201015-17-1fdyso8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=446&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363782/original/file-20201015-17-1fdyso8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=446&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363782/original/file-20201015-17-1fdyso8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=560&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363782/original/file-20201015-17-1fdyso8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=560&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363782/original/file-20201015-17-1fdyso8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=560&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">‘The Antarctic Butcher’ painted by Standish Backus, 1956.</span>
<span class="attribution"><a class="source" href="https://www.history.navy.mil/our-collections/art/exhibits/exploration-and-technology/antarctica-operation-deep-freeze-i-1955-56/life-in-camp/the-antarctic-butcher.html">U.S. Naval Art Collection</a></span>
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<p>Elephant seals were also hunted, but for their blubber, which could be converted into oil. It was not difficult for hunters to drive them to the beaches, lance them through the heart (or, later, shoot them in the skull), drain their blood and remove their blubber. “We left the dead things, raw and meaty, lying on the beach,” <a href="https://books.google.com/books/about/South_Latitude.html?id=a-Nzlo95OrsC">according to one sealer</a>. The <a href="https://www.google.com/books/edition/Sealing_in_the_Southern_Oceans_1788_1833/kkyfuAAACAAJ?hl=en">birds would pick the skeletons clean within days</a>. </p>
<p>Sealing rapidly declined in the 1960s, owing to a mix of evolving cultural sentiments and changing availability of other materials, such as plastics, that could be made into warm synthetic clothing and petroleum-based lubricants. </p>
<p>The broadcast of <a href="https://www.cbc.ca/archives/entry/new-rules-to-protect-seals">footage showing Canadian sealing in the early 1960s</a> scandalized North American and European citizens and <a href="https://books.google.com.au/books?id=oCSQDwAAQBAJ&source=gbs_navlinks_s">prompted a quick shift in attitudes toward sealing</a>. The Convention for the Conservation of Antarctic Seals was signed in 1972, regulating the large-scale slaughter of seals for all nations in the region. Today, the population of <a href="https://www.iucnredlist.org/species/2058/66993062">fur seals has rebounded</a>, with a <a href="https://www.iucnredlist.org/species/2058/66993062#population">colony of over 5 million</a> on South Georgia alone, though numbers have declined since 2000. Elephant seals, too, have largely rebounded, with an <a href="https://www.iucnredlist.org/species/13583/45227247">estimated stable population of 650,000</a> since the mid-1990s. </p>
<h2>Blood-red water</h2>
<p>The whaling grounds off Antarctica were so rich they drew fleets from many nations. First came Norwegian and British companies, later to be joined by others from Germany, Russia, the Netherlands and Japan. Whaling had occurred in the Southern Ocean in the 19th century, but it wasn’t until the first half of the 20th century that <a href="https://books.google.com/books/about/The_History_of_Modern_Whaling.html?id=-miE3r5DgPUC">whales were hunted to near extinction there</a>. </p>
<p>In the 19th century, whale oil was used primarily for lamp fuel. But after 1910, <a href="https://books.google.com/books/about/The_History_of_Modern_Whaling.html?id=-miE3r5DgPUC">new uses were found for the oil</a>, including <a href="https://books.google.com/books/about/The_History_of_Modern_Whaling.html?id=-miE3r5DgPUC">as industrial lubricants and edible fats</a>. </p>
<p>Whaling became extremely lucrative for a small group of companies, including <a href="https://www.atlasobscura.com/articles/what-is-margarine-made-of">Unilever, whose early fortunes were built from margarine made with whale oil</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/363989/original/file-20201016-13-1hrvkq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Three whale carcasses in various stages of dismemberment are on the deck of a large ship with men working on them." src="https://images.theconversation.com/files/363989/original/file-20201016-13-1hrvkq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363989/original/file-20201016-13-1hrvkq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=735&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363989/original/file-20201016-13-1hrvkq1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=735&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363989/original/file-20201016-13-1hrvkq1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=735&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363989/original/file-20201016-13-1hrvkq1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=924&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363989/original/file-20201016-13-1hrvkq1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=924&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363989/original/file-20201016-13-1hrvkq1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=924&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">Aboard a Japanese whaling ship near Antarctica, 1962.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/south-pole-a-japanese-whaling-1962-news-photo/1182685696">Marka/Universal Images Group via Getty Images</a></span>
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<p>At first, whales killed at sea had to be brought to a shore station to be processed. <a href="https://books.google.com/books/about/Great_Waters.html?id=lyMGwgEACAAJ">In 1925, an observer wrote</a>, “What an appalling stench it is…The water in which the whales float, and on which we too are riding, is blood red.” From the late 1920s on, these <a href="https://press.uchicago.edu/ucp/books/book/chicago/S/bo9845648.html">shore stations were replaced by pelagic whaling stations</a>, where whales were processed more efficiently on factory ships at sea.</p>
<p>In 1946, some international efforts were made to protect whales. The goal of the <a href="https://archive.iwc.int/pages/view.php?ref=3607&k=">International Whaling Commission</a> created that year was “to provide for the proper conservation of whale stocks and thus make possible the orderly development of the whaling industry.” </p>
<p>But, again in the 1960s, public attitudes toward whales, like seals, began to change when environmentalists revealed they were highly intelligent, sociable creatures that <a href="https://www.npr.org/2014/12/26/373303726/recordings-that-made-waves-the-songs-that-saved-the-whales">sang in the ocean depths</a>. Most nations ceased whale hunting in the Antarctic by the end of the 1960s – because of this consciousness and also because there were inexpensive alternatives to whale products. </p>
<h2>Fishing</h2>
<p>Antarctica’s rich marine life continues to be exploited today. <a href="https://www.ccamlr.org/en/organisation/fishing-ccamlr">Krill and toothfish began to be fished in the 1970s</a>. </p>
<p>Krill, <a href="https://www.nationalgeographic.com/animals/invertebrates/group/krill/">a small shrimp-like crustacean</a>, is used in nutritional supplements and pet foods. <a href="https://www.ccamlr.org/en/fisheries/krill-%E2%80%93-biology-ecology-and-fishing">Norway, China, South Korea and Chile are its biggest harvesters</a>. Toothfish, which has been marketed as Chilean sea bass, is on menus worldwide. </p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/us/newsletters/the-daily-3?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p>
<p>Since 1982, the Commission for the Conservation of Antarctic Marine Living Resources has managed these fisheries with the overriding goal of maintaining the whole ecosystem. Whales, seals, birds and other fish rely on krill, making them essential to the Antarctic marine ecosystem. </p>
<p>While krill and toothfish are currently both plentiful in the Antarctic, it is unclear how much the <a href="https://doi.org/10.1038/d41586-018-05372-x">reduction of sea ice and the changing migration patterns of predators</a> who feed on these species are affecting their populations.</p>
<p>Historically and currently, only a small number of people have profited from Antarctica’s living resources, at the great expense of animal populations. Even if sustainable harvesting is possible now, climate change is rapidly undermining Antarctic’s ecological stability. </p>
<p>While major <a href="https://www.greenpeace.org/usa/victories/creating-the-world-park-antarctica/">environmental campaigns try to raise awareness</a> of Antarctica’s fragility, most consumers of its products likely do not even know their provenance. Whale and seal populations continue to recover from past overexploitation, but the future impacts of current fishing practices and climate change are uncertain.</p><img src="https://counter.theconversation.com/content/147069/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alessandro Antonello receives funding from the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Daniella McCahey 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>For 200 years, a small number of countries have exploited the marine wildlife of Antarctica, often with devastating impact on their populations.Daniella McCahey, Assistant Professor of History, Texas Tech UniversityAlessandro Antonello, Senior Research Fellow in History, Flinders UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1476712020-10-18T19:09:23Z2020-10-18T19:09:23ZHumans threaten the Antarctic Peninsula’s fragile ecosystem. A marine protected area is long overdue<figure><img src="https://images.theconversation.com/files/363815/original/file-20201015-17-4vc7qz.jpg?ixlib=rb-1.1.0&rect=5%2C29%2C3876%2C2555&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Antarctica, the world’s <a href="https://media.nature.com/original/magazine-assets/d41586-018-07183-6/d41586-018-07183-6.pdf">last true wilderness</a>, has been protected by an <a href="https://www.ats.aq/e/antarctictreaty.html">international treaty</a> for the last 60 years. But the same isn’t true for most of the ocean surrounding it. </p>
<p><a href="https://www.asoc.org/advocacy/marine-protected-areas">Just 5%</a> of the Southern Ocean is protected, leaving biodiversity hotspots exposed to threats from human activity. </p>
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Read more:
<a href="https://theconversation.com/antarctica-has-lost-3-trillion-tonnes-of-ice-in-25-years-time-is-running-out-for-the-frozen-continent-98176">Antarctica has lost 3 trillion tonnes of ice in 25 years. Time is running out for the frozen continent</a>
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<p>The Western Antarctic Peninsula, the northernmost part of the continent and one of its <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0011683">most biodiverse regions</a>, is particularly vulnerable. It faces the cumulative threats of commercial krill fishing, tourism, research infrastructure expansion and climate change. </p>
<p>In an <a href="https://www.nature.com/articles/d41586-020-02939-5">article</a> published in Nature today, we join more than <a href="https://homewardboundprojects.com.au/about/">280 women in STEMM</a> (science, technology, engineering, maths and medicine) from the global leadership initiative Homeward Bound to call for the immediate protection of the peninsula’s marine environment, through the designation of a <a href="https://www.antarcticanow.org/">marine protected area</a>.</p>
<p>Our call comes ahead of a meeting, due in the next fortnight, of the <a href="https://www.ccamlr.org/en">international group</a> responsible for establishing marine protected areas in the Southern Ocean. We urge the group to protect the region, because delays could be disastrous.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/E7XcImKxvEg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Why we must establish a marine protected area around the peninsula, right now. Video: LUMA.</span></figcaption>
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<h2>Threats on the peninsula</h2>
<p>The Southern Ocean <a href="https://theconversation.com/explainer-how-the-antarctic-circumpolar-current-helps-keep-antarctica-frozen-106164">plays a vital role</a> in global food availability and security, regulates the planet’s climate and drives global ocean currents. Ice covering the continent stores 70% of the earth’s freshwater. </p>
<p>Climate change threatens to unravel the Southern Ocean ecosystem as species superbly adapted to the cold struggle to adapt to warmer temperatures. The impacts of climate change are especially insidious on the Western Antarctic Peninsula, one of the fastest-warming places on Earth. In February, temperatures reached a record high: <a href="https://theconversation.com/anatomy-of-a-heatwave-how-antarctica-recorded-a-20-75-c-day-last-month-134550">a balmy 20.75°C</a>. </p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/anatomy-of-a-heatwave-how-antarctica-recorded-a-20-75-c-day-last-month-134550">Anatomy of a heatwave: how Antarctica recorded a 20.75°C day last month</a>
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<p>The peninsula is also the <a href="https://theconversation.com/humans-are-encroaching-on-antarcticas-last-wild-places-threatening-its-fragile-biodiversity-142648">most-visited part of Antarctica</a>, thanks to its easy access, dramatic beauty, awe-inspiring wildlife and rich marine ecosystems. </p>
<p>Tourist numbers have doubled in the past decade, increasing the risk of introducing invasive species that hitch a ride on the toursts’ gear. More than <a href="https://www.scribd.com/document/470576496/Polar-Perspectives-No-1-Is-it-time-for-a-paradigm-shift-in-how-Antarctic-tourism-is-controlled#download&from_embed">74,000 cruise ship passengers</a> visited last year, up from 33,000 in the 2009-10 season.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/363812/original/file-20201015-19-1wtkdxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Six tourists standing on ice with their backs to the camera" src="https://images.theconversation.com/files/363812/original/file-20201015-19-1wtkdxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363812/original/file-20201015-19-1wtkdxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363812/original/file-20201015-19-1wtkdxv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363812/original/file-20201015-19-1wtkdxv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363812/original/file-20201015-19-1wtkdxv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363812/original/file-20201015-19-1wtkdxv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363812/original/file-20201015-19-1wtkdxv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&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">The peninsula is the most visited region in Antarctica.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p><a href="https://theconversation.com/australia-wants-to-build-a-huge-concrete-runway-in-antarctica-heres-why-thats-a-bad-idea-139596">The expansion of infrastructure</a> to accommodate scientists and research, such as buildings, roads, fuel storage and runways, can also pose a threat, as it displaces local Antarctic biodiversity. </p>
<p>Eighteen nations have science facilities on the Antarctic Peninsula, the highest concentration of research stations anywhere on the continent. There are 19 permanent and 30 seasonal research bases there. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australia-wants-to-build-a-huge-concrete-runway-in-antarctica-heres-why-thats-a-bad-idea-139596">Australia wants to build a huge concrete runway in Antarctica. Here's why that's a bad idea</a>
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<p>Another big threat to biodiversity in the peninsula is the commercial fishing of Antarctic krill, a small, shrimp-like crustacean which is the <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2017.2015">cornerstone of life</a> in this region.</p>
<h2>A cornerstone of life</h2>
<p>Krill is a foundation of the food chain in Antarctica, with whales, fish, squid, seals and Adélie and gentoo penguins all feeding on it.</p>
<p>But as sea ice cover diminishes, more industrial fishing vessels can encroach on penguin, seal and whale foraging grounds, effectively acting as a competing super-predator for krill. </p>
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Read more:
<a href="https://theconversation.com/climate-change-threatens-antarctic-krill-and-the-sea-life-that-depends-on-it-138436">Climate change threatens Antarctic krill and the sea life that depends on it</a>
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<p>In the past 30 years, colonies of Adélie and Chinstrap penguins on the Antarctic Peninsula have <a href="https://www.jstor.org/stable/41242231?seq=1">declined by more than 50%</a> due to reduced sea ice and krill harvesting.</p>
<p>Commercial Antarctic krill fishing is largely for omega-3 dietary supplements and fish-meal. The fishery in the waters of the Western Antarctic Peninsula is the largest in the <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-2979.2011.00406.x">Southern Ocean</a>. </p>
<figure class="align-center ">
<img alt="Close-up of krill" src="https://images.theconversation.com/files/363814/original/file-20201015-21-wwwqb7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363814/original/file-20201015-21-wwwqb7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=406&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363814/original/file-20201015-21-wwwqb7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=406&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363814/original/file-20201015-21-wwwqb7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=406&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363814/original/file-20201015-21-wwwqb7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=510&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363814/original/file-20201015-21-wwwqb7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=510&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363814/original/file-20201015-21-wwwqb7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=510&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Krill is a vital part of the food web in Antarctica.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>The krill catch here has <a href="https://www.ccamlr.org/en/fisheries/krill">more than tripled</a> from 88,800 tonnes in 2000 to almost 400,000 tonnes in 2019 — the third-largest krill catch in history and a volume not seen since the 1980s. </p>
<h2>How do we save it?</h2>
<p>To save the Antarctic Peninsula, one of critical steps is to protect its waters and its source of life: those tiny, but crucially important, Antarctic krill. </p>
<p>This can be done by establishing a marine protected area (MPA) in the region, which would limit or prohibit human activities such as commercial fishing.</p>
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<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/why-marine-protected-areas-are-often-not-where-they-should-be-133076">Why marine protected areas are often not where they should be</a>
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<p>An MPA around the peninsula was first proposed <a href="https://www.researchgate.net/publication/336888437_Protecting_Antarctica_through_Co-production_of_actionable_science_Lessons_from_the_CCAMLR_marine_protected_area_process">in 2018</a>, <a href="https://www.ccamlr.org/en/science/mpa-planning-domains">covering</a> 670,000 square kilometres. But the Commission for the Conservation of Antarctic Marine Living Resources (the organisation responsible for establishing MPAs in the Southern Ocean) has yet to reach agreement on it.</p>
<p>The proposed MPA is an excellent example of balancing environmental protection with <a href="https://theconversation.com/no-take-marine-areas-help-fishers-and-fish-far-more-than-we-thought-119659">commercial interests</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/364044/original/file-20201017-23-dnx5as.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/364044/original/file-20201017-23-dnx5as.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/364044/original/file-20201017-23-dnx5as.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=1142&fit=crop&dpr=1 600w, https://images.theconversation.com/files/364044/original/file-20201017-23-dnx5as.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=1142&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/364044/original/file-20201017-23-dnx5as.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=1142&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/364044/original/file-20201017-23-dnx5as.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1435&fit=crop&dpr=1 754w, https://images.theconversation.com/files/364044/original/file-20201017-23-dnx5as.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1435&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/364044/original/file-20201017-23-dnx5as.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1435&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.nature.com/articles/d41586-020-02939-5">Nature 586: 496-499 22 October 2020</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The area would be split into two zones. The first is a general protection zone covering 60% of the MPA, designed to protect different habitats and key wildlife and mitigate specific ecosystem threats from fishing. </p>
<p>The second is a krill fishery zone, allowing for a precautionary management approach to commercial fishing and keeping some fishing areas open for access. </p>
<p>The proposed MPA would stand for 70 years, with a review every decade so zones can be adjusted to preserve ecosystems.</p>
<h2>No more disastrous delays</h2>
<p>The commission is made up of 25 countries and the European Union. In its upcoming meeting, the proposed MPA will once again be considered. Two other important MPA proposals are also on the table in the East Antarctic and Weddell Sea.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/363871/original/file-20201016-19-nqs3y2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map of the current and proposed Marine Protected Areas under consideration." src="https://images.theconversation.com/files/363871/original/file-20201016-19-nqs3y2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/363871/original/file-20201016-19-nqs3y2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=598&fit=crop&dpr=1 600w, https://images.theconversation.com/files/363871/original/file-20201016-19-nqs3y2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=598&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/363871/original/file-20201016-19-nqs3y2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=598&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/363871/original/file-20201016-19-nqs3y2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=751&fit=crop&dpr=1 754w, https://images.theconversation.com/files/363871/original/file-20201016-19-nqs3y2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=751&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/363871/original/file-20201016-19-nqs3y2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=751&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A map of the current and proposed marine protected areas under consideration.</span>
<span class="attribution"><span class="source">Cassandra Brooks</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In fact, for <a href="https://www.theguardian.com/environment/2019/nov/02/antarctic-marine-park-conservationists-frustrated-after-protection-bid-fails-for-eight-time">eight consecutive years</a>, the proposal for a marine park in Eastern Antarctica has failed. Delays like this are potentially disastrous for the fragile ecosystem.</p>
<p>Protecting the peninsula is the most pressing priority due to rising threats, but the commission should adopt all three to fulfil their <a href="https://www.researchgate.net/publication/269874896_Competing_values_on_the_Antarctic_high_seas_CCAMLR_and_the_challenge_of_marine-protected_areas">2002 commitment</a> to establishing an MPA network in Antarctica. </p>
<p>If all three were established, then more than 3.2 million square kilometres of the Southern Ocean would be protected, giving biodiversity a fighting chance against the compounding threats of human activity in the region. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/protecting-ocean-habitats-isnt-easy-when-industries-are-booming-but-can-they-be-part-of-the-solution-145422">Protecting ocean habitats isn't easy when industries are booming – but can they be part of the solution?</a>
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<img src="https://counter.theconversation.com/content/147671/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marissa Parrott works for Zoos Victoria, a not-for-profit zoo-based conservation organisation, and is a founding member of AntarcticaNOW an organisation of women in STEMM championing Marine Protected Areas for Antarctica. She was a participant in Homeward Bound, a global leadership initiative for women in STEMM, travelling to the Antarctic Peninsula in late 2019 with the largest ever all-woman expedition to Antarctica.</span></em></p><p class="fine-print"><em><span>Carolyn Hogg is the Science-Lead for the Threatened Species Initiative, funded by BioPlatforms Australia; and was a participant in the women in STEMM global leadership program, Homeward Bound, travelling to the Antarctica Peninsula in late 2019 with the largest ever all-woman expedition to Antarctica. She currently receives funding from the University of Sydney and the Australian Research Council.</span></em></p><p class="fine-print"><em><span>Cassandra Brooks is an Assistant Professor at the University of Colorado at Boulder. She was a participant in the women in STEMM global leadership program, Homeward Bound, traveling to the Antarctica Peninsula in late 2019 with the largest ever all-woman expedition to Antarctica. She currently receives funding from the Pew Charitable Trusts. She is currently Deputy Chief Officer of the Scientific Committee on Antarctic Research's (SCAR) Standing Committee on the Antarctic Treaty System and in this role participates on the SCAR delegation to CCAMLR. </span></em></p><p class="fine-print"><em><span>Justine Shaw is a Senior Research Fellow at The University of Queensland. She is a co-founder of the women in STEMM global leadership program, Homeward Bound. Justine receives funding from the National Environmental Science Program and the Australian Antarctic Science Program. She is affiliated with Australian Academy of Science EMCR Forum Executive Committee. She is a board director of Homeward Bound Projects Ltd. </span></em></p><p class="fine-print"><em><span>Melissa Cristina Márquez was a participant of Homeward Bound's cohort 4, traveling to the Antarctica Peninsula in late 2019 with the largest ever all-woman expedition. Homeward Bound is a global leadership initiative for women in STEMM.</span></em></p>More than 280 women in STEMM call for a marine protected area to be established in the waters of the Western Antarctic Peninsula.Marissa Parrott, Reproductive Biologist, Wildlife Conservation & Science, Zoos Victoria, and Honorary Research Associate, BioSciences, The University of MelbourneCarolyn Hogg, Senior Research Manager, University of SydneyCassandra Brooks, Assistant Professor Environmental Studies, University of Colorado BoulderJustine Shaw, Conservation Biologist, The University of QueenslandMelissa Cristina Márquez, PhD Candidate, Curtin UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1415362020-06-29T20:05:50Z2020-06-29T20:05:50ZNew research shows the South Pole is warming faster than the rest of the world<figure><img src="https://images.theconversation.com/files/344471/original/file-20200629-155334-1k3ni1c.jpg?ixlib=rb-1.1.0&rect=18%2C180%2C5986%2C3583&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Elaine Hood/NSF</span></span></figcaption></figure><p>Climate scientists long thought Antarctica’s interior may not be very sensitive to warming, but our <a href="https://www.nature.com/articles/s41558-020-0815-z">research</a>, published today, shows a dramatic change. </p>
<p>Over the past 30 years, the South Pole has been one of the fastest changing places on Earth, warming more than three times more rapidly than the rest of the world.</p>
<p>My colleagues and I argue these warming trends are unlikely the result of natural climate variability alone. The effects of human-made climate change appear to have worked in tandem with the significant <a href="https://www.nature.com/articles/ngeo1129">influence natural variability in the tropics has on Antarctica’s climate</a>. Together they make the South Pole warming one of the strongest warming trends on Earth.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/antarctica-has-lost-3-trillion-tonnes-of-ice-in-25-years-time-is-running-out-for-the-frozen-continent-98176">Antarctica has lost 3 trillion tonnes of ice in 25 years. Time is running out for the frozen continent</a>
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<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/344227/original/file-20200626-104494-1d54xjc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/344227/original/file-20200626-104494-1d54xjc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/344227/original/file-20200626-104494-1d54xjc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/344227/original/file-20200626-104494-1d54xjc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/344227/original/file-20200626-104494-1d54xjc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/344227/original/file-20200626-104494-1d54xjc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/344227/original/file-20200626-104494-1d54xjc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Amundsen-Scott South Pole station is the Earth’s southern-most weather observatory.</span>
<span class="attribution"><span class="source">Craig Knott/NSF</span></span>
</figcaption>
</figure>
<h2>The South Pole is not immune to warming</h2>
<p>The South Pole lies within the coldest region on Earth: the Antarctic plateau. Average temperatures here range from -60°C during winter to just -20°C during summer. </p>
<p>Antarctica’s climate generally has a huge range in temperature over the course of a year, with strong regional contrasts. Most of West Antarctica and the Antarctic Peninsula were <a href="https://www.nature.com/articles/nature07669">warming during the late 20th century</a>. But the South Pole — in the remote and high-altitude continental interior — <a href="https://science.sciencemag.org/content/296/5569/895">cooled until the 1980s</a>.</p>
<p>Scientists have been tracking temperature at the Amundsen-Scott South Pole Station, Earth’s southernmost weather observatory, since 1957. It is one of the longest-running complete temperature records on the Antarctic continent. </p>
<p>Our analysis of weather station data from the South Pole shows it has warmed by 1.8°C between 1989 and 2018, changing more rapidly since the start of the 2000s. Over the same period, the warming in West Antarctica suddenly stopped and the Antarctic Peninsula began cooling.</p>
<p>One of the reasons for the South Pole warming was stronger low-pressure systems and stormier weather east of the Antarctic Peninsula in the Weddell Sea. With clockwise flow around the low-pressure systems, this has been transporting warm, moist air onto the Antarctic plateau. </p>
<iframe title="Annual mean surface temperature anomalies" aria-label="Interactive line chart" id="datawrapper-chart-IWBdY" src="https://datawrapper.dwcdn.net/IWBdY/1/" scrolling="no" frameborder="0" style="border: none;" width="100%" height="400"></iframe>
<h2>South Pole warming linked to the tropics</h2>
<p>Our <a href="https://www.nature.com/articles/s41558-020-0815-z">study</a> also shows the ocean in the western tropical Pacific started warming rapidly at the same time as the South Pole. We found nearly 20% of the year-to-year temperature variations at the South Pole were linked to ocean temperatures in the tropical Pacific, and several of the warmest years at the South Pole in the past two decades happened when the western tropical Pacific ocean was also unusually warm. </p>
<p>To investigate this possible mechanism, we performed a climate model experiment and found this ocean warming produces an atmospheric wave pattern that extends across the South Pacific to Antarctica. This results in a stronger low-pressure system in the Weddell Sea. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/344468/original/file-20200629-155339-1wlw4v5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/344468/original/file-20200629-155339-1wlw4v5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=505&fit=crop&dpr=1 600w, https://images.theconversation.com/files/344468/original/file-20200629-155339-1wlw4v5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=505&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/344468/original/file-20200629-155339-1wlw4v5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=505&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/344468/original/file-20200629-155339-1wlw4v5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=635&fit=crop&dpr=1 754w, https://images.theconversation.com/files/344468/original/file-20200629-155339-1wlw4v5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=635&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/344468/original/file-20200629-155339-1wlw4v5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=635&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Map of the Antarctic continent.</span>
<span class="attribution"><span class="source">National Science Foundation</span></span>
</figcaption>
</figure>
<p>We know from <a href="https://journals.ametsoc.org/jas/article/46/22/3401/22569/Topographic-Effects-on-the-Mean-Tropospheric-Flow">earlier studies</a> that strong regional variations in temperature trends are partly due to Antarctica’s shape. </p>
<p>The <a href="http://www.antarcticglaciers.org/antarctica-2/east-antarctic-ice-sheet/">East Antarctic Ice Sheet</a>, bordered by the South Atlantic and Indian oceans, extends further north than the West Antarctic Ice Sheet, in the South Pacific. This causes two distinctly different weather patterns with different climate impacts. </p>
<p>More steady, westerly winds around East Antarctica keep the local climate relatively stable, while frequent intense storms in the high-latitude South Pacific transport warm, moist air to parts of West Antarctica. </p>
<p>Scientists have suggested these two different weather patterns, and the mechanisms driving their variability, are the likely reason for strong regional variability in Antarctica’s temperature trends.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-solar-heat-drives-rapid-melting-of-parts-of-antarcticas-largest-ice-shelf-118835">How solar heat drives rapid melting of parts of Antarctica's largest ice shelf</a>
</strong>
</em>
</p>
<hr>
<h2>What this means for the South Pole</h2>
<p>Our analysis reveals extreme variations in South Pole temperatures can be explained in part by natural tropical variability. </p>
<p>To estimate the influence of human-induced climate change, we analysed more than 200 climate model simulations with observed greenhouse gas concentrations over the period between 1989 and 2018. These climate models show recent increases in greenhouse gases have possibly contributed around 1°C of the total 1.8°C of warming at the South Pole. </p>
<p>We also used the models to compare the recent warming rate to all possible 30-year South Pole temperature trends that would occur naturally without human influence. The observed warming exceeds 99.9% of all possible trends without human influence - and this means the recent warming is extremely unlikely under natural conditions, albeit not impossible. It appears the effects from tropical variability have worked together with increasing greenhouse gases, and the end result is one of the strongest warming trends on the planet.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/344225/original/file-20200626-104543-nxqf2p.jpg?ixlib=rb-1.1.0&rect=5%2C77%2C1785%2C1111&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/344225/original/file-20200626-104543-nxqf2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/344225/original/file-20200626-104543-nxqf2p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/344225/original/file-20200626-104543-nxqf2p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/344225/original/file-20200626-104543-nxqf2p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/344225/original/file-20200626-104543-nxqf2p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/344225/original/file-20200626-104543-nxqf2p.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">The temperature variability at the South Pole is so extreme it masks anthropogenic effects.</span>
<span class="attribution"><span class="source">Keith Vanderlinde/NSF</span></span>
</figcaption>
</figure>
<p>These climate model simulations reveal the remarkable nature of South Pole temperature variations. The observed South Pole temperature, with measurements dating back to 1957, shows 30-year temperature swings ranging from more than 1°C of cooling during the 20th century to more than 1.8°C of warming in the past 30 years. </p>
<p>This means multi-decadal temperature swings are three times stronger than the estimated warming from human-caused climate change of around 1°C. </p>
<p>The temperature variability at the South Pole is so extreme it currently masks human-caused effects. The Antarctic interior is one of the few places left on Earth where human-caused warming cannot be precisely determined, which means it is a challenge to say whether, or for how long, the warming will continue. </p>
<p>But our study reveals extreme and abrupt climate shifts are part of the climate of Antarctica’s interior. These will likely continue into the future, working to either hide human-induced warming or intensify it when natural warming processes and the human greenhouse effect work in tandem.</p><img src="https://counter.theconversation.com/content/141536/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kyle Clem 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>Over the past 30 years, the South Pole has been one of the fastest changing places on Earth, warming more than three times quicker than the rest of the world.Kyle Clem, Research Fellow in Climate Science, Te Herenga Waka — Victoria University of WellingtonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/913602018-07-16T09:28:53Z2018-07-16T09:28:53ZPristine Antarctic fjords contain similar levels of microplastics to open oceans near big civilisations<figure><img src="https://images.theconversation.com/files/226612/original/file-20180708-122265-151f1tn.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption"></span> <span class="attribution"><span class="license">Author provided</span></span></figcaption></figure><p>In the middle of the last century, mass-produced, disposable plastic waste started washing up on shorelines, and to be found in the middle of the oceans. This has since become <a href="http://coastalcare.org/2009/11/plastic-pollution/">an increasingly serious problem</a>, spreading globally to even the <a href="https://www.weforum.org/agenda/2017/05/the-untouched-south-pacific-island-choking-on-38-million-bits-of-plastic">most remote places</a> on Earth. Just a few decades later, in the 1970s, scientists found the same problem was occurring at a much less visible, microscopic level, <a href="https://theconversation.com/in-the-ocean-the-most-harmful-plastic-is-too-small-to-see-35336">with microplastics</a>. </p>
<p>These particles of plastic are between 0.05mm and 5mm in size. Larger pieces of plastic can be broken down into microplastics but these tiny bits of plastic also come from deliberate additions to <a href="https://theconversation.com/ten-stealth-microplastics-to-avoid-if-you-want-to-save-the-oceans-90063">all sorts of products</a>, from toothpaste to washing power. </p>
<p>Now, with major global sampling efforts, it <a href="https://theconversation.com/plastics-in-oceans-are-mounting-but-evidence-on-harm-is-surprisingly-weak-93877">has become clear</a> that microplastics are dispersing all over the world – in the water column, sediments, and marine animal diets – even reaching as far south as the pristine environments of Antarctica.</p>
<h2>Glacial retreat</h2>
<p>While this plastic problem has become more prevalent, one of the most pristine ecosystems on Earth, the fjords of the Western Antarctic Peninsula, have been revealed by retreating glaciers.</p>
<p>Tucked between islands and the mainland, the coast along the Western Antarctic Peninsula has long, narrow inlets created by glaciers. During the last 50 years, these fjords have physically changed, due to reduced sea ice cover and because nearly 90% of glaciers have retreated in this region. These processes have exposed the ocean floor of many of the fjords for the first time. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/227576/original/file-20180713-27039-1h1jbso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/227576/original/file-20180713-27039-1h1jbso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/227576/original/file-20180713-27039-1h1jbso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=372&fit=crop&dpr=1 600w, https://images.theconversation.com/files/227576/original/file-20180713-27039-1h1jbso.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=372&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/227576/original/file-20180713-27039-1h1jbso.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=372&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/227576/original/file-20180713-27039-1h1jbso.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=468&fit=crop&dpr=1 754w, https://images.theconversation.com/files/227576/original/file-20180713-27039-1h1jbso.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=468&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/227576/original/file-20180713-27039-1h1jbso.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=468&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">The Antarctic fjords.</span>
<span class="attribution"><span class="source">Google Earth/US Geological Survey/DigitalGlobe/CNES/Airbus</span></span>
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<p>The potential for microplastics to impact this environment and its marine life is huge – and we’re now working to figure out the depth of the effect that microplastic pollution is having on the newly colonised habitats. Any microplastics recovered in the Southern Ocean, particularly in newly formed ecosystems, raise alarm. They not only indicate that the area has been affected, but that plastic pollution is increasingly ubiquitous too.</p>
<h2>New habitats</h2>
<p>In November 2017, our multidisciplinary UK-Chile-US-Canada research team – known as ICEBERGS – joined the <a href="https://www.bas.ac.uk/polar-operations/sites-and-facilities/facility/rrs-james-clark-ross/">RRS James Clark Ross</a> (an ice strengthened research ship) and headed to Antarctica’s northernmost fjords. Our goal was, and still is, to gain a better understanding of how the environment and organisms evolve in newly emerging and colonising habitats in Antarctica. We are particularly interested in the marine ecosystems on the ocean floor, so have been looking at areas such as Marian Cove and Börgen Bay on the Western Antarctic Peninsula, where communities have only developed in the last few decades – due to the retreating glaciers.</p>
<p>Thriving marine ecosystems can act as climate regulators. When ice retreats, new, pristine fjordic habitats are revealed and phytoplankton blooms occur. These help to counteract climate change because they take carbon dioxide gas out of the atmosphere. New productive seabed habitat also becomes available for the diverse shallow water fauna that eat this algae, and store the carbon long term. Not counteracting climate change, however, is the fact that new open water absorbs heat faster, in contrast to ice that would have reflected it. </p>
<p>The animals colonising the exposed fjords face challenging conditions. The sediment and fresh water flowing in the glacier melt runoff make it very difficult for many organisms to survive. And, if exposed to them, microplastics can be a serious concern for many marine animals, especially filter-feeding organisms (for example krill, and other zooplankton). As these creatures filter water to obtain food, <a href="https://www.sciencedirect.com/science/article/pii/S0169534718300090">they may ingest microplastics</a> which can clog and block their feeding appendages, limiting food intake. Ingested microplastics may be transferred to the circulatory system too, which can cause an increased immune response. </p>
<p>Microplastics may also bring in new bacteria and chemical pollutants attached to them too. So, because many filter-feeding organisms support the entire food web, any impact on them should be expected to have cascading effects on the ecosystem.</p>
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<a href="https://images.theconversation.com/files/226983/original/file-20180710-70051-9cxec8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/226983/original/file-20180710-70051-9cxec8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/226983/original/file-20180710-70051-9cxec8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/226983/original/file-20180710-70051-9cxec8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/226983/original/file-20180710-70051-9cxec8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/226983/original/file-20180710-70051-9cxec8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/226983/original/file-20180710-70051-9cxec8.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/226983/original/file-20180710-70051-9cxec8.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">On board the RRS James Clark Ross.</span>
<span class="attribution"><span class="license">Author provided</span></span>
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</figure>
<p>In newly revealed habitats, creatures are less likely to have been impacted by marine pollutants previously so they can help us learn about more recent changes in an environment. To our knowledge, microplastics have not been found in the Antarctic fjords before now, but our preliminary results have already found an alarmingly high presence – similar to those found in the open water of the Atlantic and Pacific Oceans, near big civilisations.</p>
<p>These results came from samples taken directly from the fjords, and we are now looking further at the evidence of how micro-organisms are being affected by microplastics. During the next two Antarctic summers, we will be collecting more geophysical, physical oceanographic, sedimentological and biological data from these pristine sites in the same locations, so we can compare the changes over time in the habitats that colonise new ocean floor in Antarctic fjords. </p>
<p>Only after such rigorous data collection and analysis will we be able to tell the true impact of microplastics on pristine environments. Until then, we can all do our bit to cut down on potential pollution and protect what may very well be the last pristine environments on Earth.</p><img src="https://counter.theconversation.com/content/91360/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David Barnes receives funding from Natural Environment Research Council grants. </span></em></p><p class="fine-print"><em><span>James Scourse received funding from the Natural Environmental Research Council and CONICYT for this research.</span></em></p><p class="fine-print"><em><span>Katrien Van Landeghem acknowledges the financial support provided by the Welsh Government and Higher Education Funding Council for Wales through the Sêr Cymru National Research Network for Low Carbon, Energy and Environment, and she receives funding from the Natural Environmental Research Council for this research. </span></em></p><p class="fine-print"><em><span>Alexis Janosik 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>Preliminary results of a study have shown microplastics have reached in a newly revealed Antarctic environment.Alexis Janosik, Assistant Professor of Biology, University of West FloridaDavid Barnes, Data Interpretation Ecologist, British Antarctic SurveyJames Scourse, Professor of Physical Geography, University of ExeterKatrien Van Landeghem, Senior Lecturer in Marine Geology, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/981772018-06-13T20:36:43Z2018-06-13T20:36:43ZOcean waves and lack of sea ice can trigger Antarctic ice shelves to disintegrate<p>Large waves after the loss of sea ice can trigger Antarctic ice shelf disintegration over a period of just days, according to our <a href="https://www.nature.com/articles/s41586-018-0212-1">new research</a>.</p>
<p>With other research <a href="https://www.nature.com/articles/s41586-018-0179-y">also published today in Nature</a> showing that the rate of annual ice loss from the vulnerable Antarctic Peninsula has quadrupled since 1992, our study of catastrophic ice shelf collapses during that time shows how the lack of a protective buffer of sea ice can leave ice shelves, already weakened by climate warming, wide open to attack by waves.</p>
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Read more:
<a href="https://theconversation.com/antarctica-has-lost-3-trillion-tonnes-of-ice-in-25-years-time-is-running-out-for-the-frozen-continent-98176">Antarctica has lost 3 trillion tonnes of ice in 25 years. Time is running out for the frozen continent</a>
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<p>Antarctica is covered by an ice sheet that is several kilometres thick in places. It covers an area of 14 million square kilometres – roughly twice the size of Australia. This ice sheet holds more than 90% of the world’s ice, which is enough to <a href="https://www.the-cryosphere.net/7/375/2013/tc-7-375-2013.pdf">raise global mean sea level by 57 metres</a>.</p>
<p>As snow falls and compacts on the ice sheet, the sheet thickens and flows out towards the coast, and then onto the ocean surface. The resulting “ice shelves” (and glacier tongues) buttress three-quarters of the Antarctic coastline. Ice shelves act as a crucial braking system for fast-flowing glaciers on the land, and thus moderate the ice sheet’s contribution to sea-level rise. </p>
<p>In the southern summer of 2002, scientists monitoring the Antarctic Peninsula (the northernmost part of mainland Antarctica) by satellite witnessed a dramatic ice shelf disintegration that was stunning in its abruptness and scale. In just 35 days, 3,250 square km of the Larsen B Ice Shelf (twice the size of Queensland’s Fraser Island) shattered, releasing an estimated <a href="https://visibleearth.nasa.gov/view.php?id=2288">720 billion tonnes of icebergs into the Weddell Sea</a>. </p>
<p>This wasn’t the first such recorded event. In January 1995, roughly 1,500 square km of the nearby Larsen A Ice Shelf <a href="https://www.tandfonline.com/doi/pdf/10.3402/polar.v18i2.6568">suddenly disintegrated</a> after several decades of warming and years of gradual retreat. To the southwest, the Wilkins Ice Shelf suffered a series of strikingly similar disintegration events in 1998, 2008 and 2009 — not only in summer but also in two of the Southern Hemisphere’s coldest months, May and July.</p>
<p>These sudden, large-scale fracturing events removed features that had been stable for centuries – up to <a href="https://www.nature.com/articles/nature03908">11,500 years in the case of Larsen B</a>. While ice shelf disintegrations don’t directly raise sea level (because the ice shelves are already floating), the removal of shelf ice allows the glaciers behind them to accelerate their discharge of land-based ice into the ocean – and this does raise sea levels. <a href="https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2004GL020697">Previous</a> <a href="https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2004GL020670">research</a> has shown that the removal of Larsen B caused its tributary glaciers to flow eight times faster in the year following its disintegration.</p>
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<strong>
Read more:
<a href="https://theconversation.com/cold-and-calculating-what-the-two-different-types-of-ice-do-to-sea-levels-59996">Cold and calculating: what the two different types of ice do to sea levels</a>
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<p>The ocean around ice shelves is typically covered by a very different (but equally important) type of ice, called sea ice. This is formed from frozen seawater and is generally no more than a few metres thick. But it stretches far out into the ocean, <a href="http://ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter04_FINAL.pdf">doubling the area of the Antarctic ice cap</a> when at its maximum extent in winter, and varying in extent throughout the year.</p>
<p>The response of Antarctic sea ice to climate change and variability is complex, and differs between regions. Around the Antarctic Peninsula, in the Bellingshausen and northwestern Weddell seas, it has clearly <a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2012GL050874">declined in extent and annual duration</a> since satellite monitoring began in 1979, at a similar rate to the Arctic’s rapidly receding sea ice.</p>
<p>The Southern Ocean is also host to the largest waves on the planet, and these waves are <a href="http://science.sciencemag.org/content/332/6028/451?sid=acdfca77-ed06-">becoming more extreme</a>. Our <a href="https://www.nature.com/articles/s41586-018-0212-1">new study</a> focuses on “long-period” swell waves (with swells that last up to about 20 seconds). These are generated by distant storms and carry huge amounts of energy across the oceans, and can potentially flex the vulnerable outer margins of ice shelves. </p>
<p>The earliest whalers and polar pioneers knew that sea ice can damp these waves — Sir Ernest Shackleton reported it in his iconic book <a href="https://books.google.com.au/books/about/South.html?id=xr4g1G4O-4IC&printsec=frontcover&source=kp_read_button&redir_esc=y#v=onepage&q&f=false">South!</a>. Sea ice thus acts as a “buffer” that protects the Antarctic coastline, and its ice shelves, from destructive ocean swells. </p>
<p>Strikingly, all five of the sudden major ice shelf disintegrations listed above happened during periods when sea ice was abnormally low or even absent in these regions. This means that intense swell waves crashed directly onto the vulnerable ice shelf fronts.</p>
<h2>The straw that broke the camel’s back</h2>
<p>The Antarctic Peninsula has experienced particularly strong climate warming (roughly <a href="http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.591.9578&rep=rep1&type=pdf">0.5°C per decade since the late 1940s</a>), which has caused intense surface melting on its ice shelves and exacerbated their structural weaknesses such as fractures. These destabilising processes are the underlying drivers of ice shelf collapse. But they do not explain why the observed disintegrations were so abrupt. </p>
<p>Our new study suggests that the trigger mechanism was swell waves flexing and working weaknesses at the shelf fronts in the absence of sea ice, to the point where they calved away the shelf fronts in the form of long, thin “sliver-bergs”. The removal of these “keystone blocks” in turn led to the catastrophic breakup of the ice shelf interior, which was weakened by years of melt. </p>
<p>Our research thus underlines the complex and interdependent nature of the various types of Antarctic ice – particularly the important role of sea ice in forming a protective “buffer” for shelf ice. While much of the focus so far has been on the possibility of ice shelves melting from below as the sea beneath them warms, our research suggests an important role for sea ice and ocean swells too.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/222936/original/file-20180613-153677-j5wbww.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/222936/original/file-20180613-153677-j5wbww.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/222936/original/file-20180613-153677-j5wbww.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/222936/original/file-20180613-153677-j5wbww.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/222936/original/file-20180613-153677-j5wbww.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/222936/original/file-20180613-153677-j5wbww.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/222936/original/file-20180613-153677-j5wbww.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/222936/original/file-20180613-153677-j5wbww.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">The edge of an ice shelf off the Antarctic Peninsula, with floating sea ice beyond (to the left in this image).</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Edge_of_Ice_Shelf_(8136346793).jpg">NASA/Maria Jose Vinas</a></span>
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<p>In July 2017 an <a href="https://theconversation.com/dont-worry-about-the-huge-antarctic-iceberg-worry-about-the-glaciers-behind-it-80314">immense iceberg broke away</a> from the Larsen C Ice Shelf, just south of Larsen B, prompting fears that it could disintegrate like its neighbours. </p>
<p>Our research suggests that four key factors will determine whether it does: extensive flooding and fracturing across the ice shelf; reduced sea ice coverage offshore; extensive fracturing of the ice shelf front; and calving of sliver-bergs.</p>
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Read more:
<a href="https://theconversation.com/dont-worry-about-the-huge-antarctic-iceberg-worry-about-the-glaciers-behind-it-80314">Don't worry about the huge Antarctic iceberg – worry about the glaciers behind it</a>
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<p>If temperatures continue to rise around the Antarctic, ice shelves will become weaker and sea ice less extensive, which would imply an increased likelihood of future disintegrations. </p>
<p>However, the picture is not that clear-cut, as not all remaining ice shelves are likely to respond in the same way to sea ice loss and swell wave impacts. Their response will also depend on their glaciological characteristics, physical setting, and the degree and nature of surface flooding. Some ice shelves may well be capable of surviving prolonged absences of sea ice.</p>
<p>Irrespective of these differences, we need to include sea ice and ocean waves in our models of ice sheet behaviour. This will be a key step towards better forecasting the fate of Antarctica’s remaining ice shelves, and how much our seas will rise in response to projected climate change over coming decades. In parallel, our new findings underline the need to better understand and model the mechanisms responsible for recent sea ice trends around Antarctica, to enable prediction of likely future change in the exposure of ice shelves to ocean swells.</p><img src="https://counter.theconversation.com/content/98177/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Luke Bennetts has previously funding from the Australian Research Council and the Australian Antarctic Science Program. </span></em></p><p class="fine-print"><em><span>Rob Massom receives funding from Australian Antarctic Division and the Australian Antarctic Science Program</span></em></p><p class="fine-print"><em><span>Vernon Squire currently receives funding from the US Office of Naval Research and the University of Otago. </span></em></p>Since 1995, several ice shelves off the Antarctic Peninsula have abruptly disintegrated. A new analysis suggests that these events are triggered when ice shelves lose their buffer of floating ice.Luke Bennetts, Lecturer in applied mathematics, University of AdelaideRob Massom, Leader, Sea Ice Group, Antarctica & the Global System program, Australian Antarctic Division and Antarctic Climate and Ecosystems CRC, Australian Antarctic DivisionVernon Squire, Deputy Vice-Chancellor Academic, Professor of Applied Mathematics, University of OtagoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/803142017-07-05T20:09:38Z2017-07-05T20:09:38ZDon’t worry about the huge Antarctic iceberg – worry about the glaciers behind it<p>Icebergs breaking off Antarctica, even massive ones, do not typically concern glaciologists. But the impending birth of a <a href="http://www.projectmidas.org/blog/another-step-closer/">new massive iceberg</a> could be more than business as usual for the frozen continent. </p>
<p>The Larsen C ice shelf, the fourth-largest in Antarctica, has attracted <a href="http://www.bbc.com/news/science-environment-40113393">worldwide attention</a> in the lead-up to calving an iceberg one-tenth of its area – or about half the area of greater Melbourne. It is still <a href="http://www.projectmidas.org/blog/berg-acceleration/">difficult to predict exactly when it will break free</a>.</p>
<p>But it’s not the size of the iceberg that should be getting attention. Icebergs calve all the time, including the occasional very large one, with nothing to worry about. Icebergs have only a <a href="https://theconversation.com/cold-and-calculating-what-the-two-different-types-of-ice-do-to-sea-levels-59996">tiny direct effect</a> on sea level. </p>
<p>The calving itself will simply be the birth of another big iceberg. But there is valid concern among scientists that the entire Larsen C ice shelf could become unstable, and eventually break up entirely, with knock-on effects that could take decades to play out.</p>
<p>Ice shelves essentially act as corks in a bottle. Glaciers flow from land towards the sea, and their ice is eventually absorbed into the ice shelf. Removal of the ice shelf causes glaciers to flow faster, increasing the rate at which ice moves from the land into the sea. This has a much larger effect on sea level than iceberg calving does.</p>
<p>While the prediction that Larsen C could become unstable is based partly on physics, it is also based on observations. Using aerial and satellite images, scientists have been able to track very similar ice shelves in the past, some of which have been seen to retreat and collapse. </p>
<h2>The death of an ice shelf</h2>
<p>The most dramatic ice shelf collapse observed so far is that of Larsen C’s neighbour to the north – the imaginatively named Larsen B. Over the course of just six weeks in 2002 the <a href="https://earthobservatory.nasa.gov/Features/WorldOfChange/larsenb.php">entire ice shelf splintered into dozens of icebergs</a>. Almost immediately afterwards, the glaciers feeding into it sped up by two to six times. Those glaciers <a href="https://www.nasa.gov/press-release/nasa-study-shows-antarctica-s-larsen-b-ice-shelf-nearing-its-final-act">continue to flow faster</a> to this day. </p>
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<a href="https://images.theconversation.com/files/176544/original/file-20170703-8225-1h27706.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/176544/original/file-20170703-8225-1h27706.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/176544/original/file-20170703-8225-1h27706.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/176544/original/file-20170703-8225-1h27706.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/176544/original/file-20170703-8225-1h27706.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/176544/original/file-20170703-8225-1h27706.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/176544/original/file-20170703-8225-1h27706.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/176544/original/file-20170703-8225-1h27706.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Satellite photo series of Larsen B Ice Shelf collapse from January 2002 to April 2002.</span>
<span class="attribution"><span class="source">NASA</span></span>
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<p>In our new study, <a href="https://authors.elsevier.com/a/1VKFJ,Ig49NjA">published in Earth and Planetary Science Letters</a>, we turn the clock back even further to look at the Wordie ice shelf, on the west coast of the southern Antarctic Peninsula, which began to retreat in the 1960s and eventually <a href="https://landsat.gsfc.nasa.gov/landsat-documents-rapid-disappearance-of-antarcticas-ice-shelves/">disappeared in January 2017</a>. </p>
<p>Over the past 20 years, observations have shown that the main glacier feeding into the Wordie ice shelf, the Fleming Glacier, has sped up and thinned. Compared with the glaciers feeding Larsen B and C, Fleming Glacier is massive: 80km long, 12km wide, and 600m thick at its front.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/176862/original/file-20170705-16510-iymhsl.gif?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/176862/original/file-20170705-16510-iymhsl.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/176862/original/file-20170705-16510-iymhsl.gif?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=380&fit=crop&dpr=1 600w, https://images.theconversation.com/files/176862/original/file-20170705-16510-iymhsl.gif?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=380&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/176862/original/file-20170705-16510-iymhsl.gif?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=380&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/176862/original/file-20170705-16510-iymhsl.gif?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=477&fit=crop&dpr=1 754w, https://images.theconversation.com/files/176862/original/file-20170705-16510-iymhsl.gif?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=477&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/176862/original/file-20170705-16510-iymhsl.gif?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=477&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Locations of the Larsen C Ice Shelf and the Wordie Ice Shelf-Fleming Glacier system with ice front positions from 1947 to 2016.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>We used historic aerial photographs from 1966 to create an elevation map of the Fleming Glacier, and compared it to elevation measurements from 2002 to 2015. Between 1966 and 2015 the Fleming Glacier thinned by at least 100m near the front. The thinning rate, which is the elevation change rate, rapidly increased: the thinning rate after 2008 is more than twice that during 2002 to 2008, and four times the average rates from 1966 to 2008.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/176322/original/file-20170629-5317-1j5zalo.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/176322/original/file-20170629-5317-1j5zalo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/176322/original/file-20170629-5317-1j5zalo.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=255&fit=crop&dpr=1 600w, https://images.theconversation.com/files/176322/original/file-20170629-5317-1j5zalo.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=255&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/176322/original/file-20170629-5317-1j5zalo.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=255&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/176322/original/file-20170629-5317-1j5zalo.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=320&fit=crop&dpr=1 754w, https://images.theconversation.com/files/176322/original/file-20170629-5317-1j5zalo.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=320&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/176322/original/file-20170629-5317-1j5zalo.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=320&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ice thinning rate of the Fleming Glacier region during (a) 2002-2008 and (b) 2008-2015.</span>
<span class="attribution"><span class="source">Author provided</span></span>
</figcaption>
</figure>
<p>Ice flow speeds have also increased by more than 400m per year at the front since 2008. This is <a href="http://www.the-cryosphere-discuss.net/tc-2017-75/">the largest speed change in recent years of any glacier in Antarctica</a>. These changes all point to ice shelf collapse as the cause.</p>
<p>We estimate the total glacier ice volume lost from all glaciers that feed the Wordie is 179 cubic kilometres since 1966, or 319 times the volume of Sydney Harbour. The weight of this ice moving off the land and into the ocean has caused the bedrock beneath the glaciers to lift by more than 50mm. </p>
<p>Other research has suggested this lift could have acted to slow the glacier’s retreat, but it’s clear that the bedrock deformation has not stopped the ice movement speeding up. It seems the Fleming Glacier has a long way to go before it will return to a new stable state (in which snowfall feeding the glacier equals the ice flowing into the oceans).</p>
<p>Fifty years after the Wordie Ice Shelf began to collapse, the major feeding glaciers continue to thin and flow faster than before. </p>
<p>We can’t yet predict the full consequences of the new iceberg calving from Larsen C. But if the ice shelf does begin to retreat or collapse, history tells us it is very possible that its glaciers will flow faster – making yet more sea level rise inevitable.</p><img src="https://counter.theconversation.com/content/80314/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Chen Zhao is a PhD student from the School of Land and Food, University of Tasmania. She receives funding from the Australian Government Research Training Program. </span></em></p><p class="fine-print"><em><span>Christopher Watson receives funding from the Australian Research Council and the Department of Environment.</span></em></p><p class="fine-print"><em><span>Matt King receives funding from the Australian Research Council and the Department of Environment.</span></em></p>A huge iceberg is set to break free from Antarctica. While the iceberg isn’t hugely concerning, it could herald the breakup of the entire Larsen C ice shelf, which could trigger more sea-level rise.Chen Zhao, PhD candidate of Antarctic Science, University of TasmaniaChristopher Watson, Senior Lecturer, Surveying and Spatial Sciences, School of Land and Food, University of TasmaniaMatt King, Professor, Surveying & Spatial Sciences, School of Land and Food, University of TasmaniaLicensed as Creative Commons – attribution, no derivatives.