Antarctica

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GUEST OBSERVER
Domestic animals are rarely associated with Antarctica. However, before non-native species (bar humans) were excluded from the continent in the 1990s, many travelled to the far south.
These animals included not only the obvious sledge dogs, but also ponies, sheep, pigs, hamsters, hedgehogs and a goat. Perhaps the most curious case occurred in 1933, when US Admiral Richard E. Byrd’s second Antarctic expedition took with it three Guernsey cows. 
The cows, named Klondike Gay Nira, Deerfoot Guernsey Maid and Foremost Southern Girl, plus a bull calf born en route, spent over a year in a working dairy on the Ross Ice Shelf. They returned home to the US in 1935 to considerable celebrity. 
Keeping the animals healthy in Antarctica took a lot of doing – not least, hauling the materials for a barn, a huge amount of feed and a milking machine across the ocean and then the ice. What could have possessed Byrd to take cows to the icy south? 
The answer we suggest in our recently published paper is multi-layered and ultimately points to Antarctica’s complex geopolitical history.
Solving the “milk problem”
The cows’ ostensible purpose was to solve the expedition’s so-called “milk problem”. By the 1930s, fresh milk had become such an icon of health and vigour that it was easy to claim it was needed for the expeditioners’ well-being. Just as important, however, were the symbolic associations of fresh milk with purity, wholesomeness and US national identity. 
Powdered or malted milk could have achieved the same nutritional results. Previous expeditions, including those of Ernest Shackleton and Roald Amundsen, had survived just fine with such products. What’s more, William Horlick of Horlick’s Malted Milk sponsored Byrd’s second Antarctic expedition; the seaplane Byrd used was named for this benefactor. 
So if fresh milk was not actually a health requirement, and other forms were readily available, why go to the trouble of lugging three cows and their accoutrements across the ice?
Maximising publicity
The cows represented a first, and Byrd well knew that “firsts” in the polar regions translated into media coverage. The expedition was privately funded, and Byrd was adept at attracting media attention and hence sponsorship. His backers expected a return, whether in the form of photographs of their product on the ice or mentions in the regular radio updates by the expedition. 
The novelty value that the cows brought to the expedition was a valuable asset in its own right, but Byrd hedged his bets by including a pregnant cow – Klondike was due to give birth just as the expedition ship sailed across the Antarctic Circle. The calf, named “Iceberg”, was a media darling and became better known than the expeditioners themselves. 
The celebrity attached to the cows helped the expedition remain in the headlines throughout its time in Antarctica, and they received an enthusiastic welcome upon its return. Although the unfortunate Klondike, suffering from frostbite, had to be put down mid-expedition, her companions made it home in good condition. They were feted on their return, meeting politicians in Washington, enjoying “hay cocktails” at fancy hotels, and making the front page of The New York Times.
It would be easy, then, to conclude that the real reason Byrd took cows south was for the publicity he knew they would generate, but his interest in the animals may also have had a more politically motivated layer.
Eyeing a territorial claim
A third reason for taking cows to Antarctica relates to the geopolitics of the period and the resonances the cows had with colonial settlement. By the 1930s several nations had claimed sectors of Antarctica. Byrd wanted the US to make its own claim, but this was not as straightforward as just planting a flag on the ice. 
According to the Hughes Doctrine, a claim had to be based on settlement, not just discovery. But how do you show settlement of a continent covered in ice? In this context, symbolic gestures such as running a post office – or farming livestock – are useful. 
Domestic animals have long been used as colonial agents, and cattle in particular were a key component of settler colonialism in frontier America. The image of the explorer-hero Byrd, descended from one of the First Families of Virginia, bringing cows to a new land and successfully farming them evoked this history. 
The cows’ presence in Antarctica helped symbolically to turn the expedition base – not coincidentally named “Little America” – into a frontier town. While the US did not end up making a claim to any sector of Antarctica, the polar dairy represented a novel way of demonstrating national interest in the frozen continent.
The Antarctic cows are not just a quirky story from the depths of history. As well as producing milk, they had promotional and geopolitical functions. On an ice continent, settlement is performed rather than enacted, and even Guernsey cows can be more than they first seem.
<a href="https://theconversation.com/profiles/hanne-e-f-nielsen-139245" target="_blank">Hanne E.F. Nielsen</a> is PhD Candidate in Antarctic Representations, University of Tasmania.
<a href="https://theconversation.com/profiles/elizabeth-leane-267090" target="_blank">Elizabeth Leane</a> is Associate Professor of English and ARC Future Fellow, University of Tasmania.
Both are authors for <a href="https://theconversation.com/au" target="_blank">The Conversation</a>.
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Cows in Antarctica? How one expedition milked them for all their worth

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GUEST OBSERVER
Icebergs breaking off Antarctica, even massive ones, do not typically concern glaciologists. But the impending birth of a new massive icebergcould be more than business as usual for the frozen continent. 
The Larsen C ice shelf, the fourth-largest in Antarctica, has attracted worldwide attention in the lead-up to calving an iceberg one-tenth of its area – or about half the area of greater Melbourne. It is still difficult to predict exactly when it will break free.
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 tiny direct effect on sea level. 
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.
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.
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. 
<h2>The death of an ice shelf</h2>
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 entire ice shelf splintered into dozens of icebergs. Almost immediately afterwards, the glaciers feeding into it sped up by two to six times. Those glaciers continue to flow faster to this day. 
In our new study, published in Earth and Planetary Science Letters, 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 disappeared in January 2017. 
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.
<a href="https://www.propertyobserver.com.au/images/2017/07/28/file-20170705-16510-iymhsl.gif" target="_blank">Click to enlarge</a>
<img src="https://www.urban.com.au/images/2017/07/28/file-20170705-16510-iymhsl.gif" alt="">
<div class="enlarge_hint">
Locations of the Larsen C Ice Shelf and the Wordie Ice Shelf-Fleming Glacier system with ice front positions from 1947 to 2016. Author provided
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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.
<a href="https://www.propertyobserver.com.au/images/2017/07/28/file-20170629-5317-1j5zalo.png" target="_blank">Click to enlarge</a>
<img src="https://www.urban.com.au/images/2017/07/28/file-20170629-5317-1j5zalo.png" alt="">
Ice thinning rate of the Fleming Glacier region during (a) 2002-2008 and (b) 2008-2015. Author provided
Ice flow speeds have also increased by more than 400m per year at the front since 2008. This is <a href="https://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.
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. 
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).
Fifty years after the Wordie Ice Shelf began to collapse, the major feeding glaciers continue to thin and flow faster than before. 
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.
<a href="https://theconversation.com/profiles/chen-zhao-382317" target="_blank">Chen Zhao</a> is PhD candidate of Antarctic Science, University of Tasmania
<a href="https://theconversation.com/profiles/christopher-watson-159793" target="_blank">Christopher Watson</a> is Senior Lecturer, Surveying and Spatial Sciences, School of Land and Food, University of Tasmania.
<a href="https://theconversation.com/profiles/matt-king-15004" target="_blank">Matt King</a> is Professor, Surveying &amp; Spatial Sciences, School of Land and Food, University of Tasmania.
All are authors for <a href="https://theconversation.com/au" target="_blank">The Conversation</a>.
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Don’t worry about the huge Antarctic iceberg – worry about the glaciers behind it

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GUEST OBSERVER
When you think of Antarctica, you probably picture vast, continuous ice sheets and glaciers, with maybe a penguin or two thrown in.
Yet most Antarctic plants and animals live in the permanently ice-free areas that cover about 1 percent of the continent. Our new research predicts that these areas could grow by a quarter during this century, with mixed prospects for the species that currently live there. 
Besides everyone’s favourite Emperor and Adélie penguins, terrestrial Antarctic species also include beautiful mosses, lichens, two types of flowering plants, and a suite of hardy invertebrates such as nematodes, springtails, rotifers and tardigrades, many of which are found nowhere else on Earth. Tardigrades – tiny creatures sometimes nicknamed “waterbears” – are so tough they can survive in space.
Antarctica’s ice-free areas are currently limited to a scattering of rocky outcrops along the coastline, or cliff faces, or the tops of mountain ranges. They form small patches of suitable habitat in a huge sea of ice, much like islands. 
As a result, the plants and animals that live there are often isolated from each other. But as Antarctica’s climate warms, we expect ice-free areas to get bigger and eventually start joining up. This would create more habitat for native species, but also new opportunities for non-native species to spread. 
Our study, published today in Nature, forecasts that climate change will expand Antarctica’s ice-free areas over the course of this century. Under the most severe scenario that we modelled (which is also the one on which the globe is currently tracking), more than 17,000 square km of new ice-free area could emerge across the continent by 2100. 
This would increase the current total ice-free area by nearly a quarter. The majority of this new ice-free land will be on the Antarctic Peninsula, which could have three times as much ice-free area as it does today.  
Brave new world
As the ice-free areas expand, the distances between them will decrease, giving plants and animals more opportunity to spread through the landscape. On the Antarctic Peninsula, which has already warmed more than anywhere else in Antarctica, many of the ice-free patches will expand so much that they will start joining together.
Will this increase in habitat availability benefit the plants and animals that live there? It will definitely provide new opportunities for some native plants and animals to expand their range and colonise new areas. The warming climate may also give a boost to species that are currently hampered by the lack of warmth, nutrients and water. Some Antarctic mosses, for example, are expected to grow faster as temperatures rise, and Antarctica’s two flowering plant species are already expanding southward.
However, the potential benefits seem likely to be outweighed by the negatives. The joining-up of habitat patches could allow species that have been isolated for much of their evolutionary past to meet suddenly. If the newcomers to a particular area outcompete the native species, then it may lead to localised extinctions. Over the coming centuries this could lead to the loss of many plants and animals, and the homogenisation of Antarctica’s ecosystems.
Antarctic aliens
An even bigger concern is that Antarctica’s great thaw could provide new opportunities for species to invade. Antarctica’s best bulwark against non-native species is its harsh climate and extreme weather, to which native Antarctic species have spent many thousands of years adapting. 
We already know that many plants and invertebrates are reaching Antarctica, most often in food or cargo shipments. As the climate warms, some of these non-native species may be able to establish themselves on the Antarctic Peninsula, and the increasing connectivity will allow them to easily move through the landscape. Many of these animals and plants may become invasive, competing with the native species for space and resources. 
We don’t know how Antarctica’s species will cope with the increasing competition. But if the sub-Antarctic islands provide any indication, the outlook is depressing. Australia’s World Heritage-listed Macquarie Island, for example, was severely impacted by invasive cats, rats, rabbits and mice (although it has since been declared free of these pests after an intensive eradication effort).
Several non-native species have already come to Antarctica, including the invasive annual meadowgrass Poa annua (a common weed around the world), which has colonised newly ice-free areas left behind by retreating glaciers. It is thought to outcompete Antarctica’s native plants, although we don’t yet know what the impact will be on animals. 
Humans – both scientists and tourists – are key transporters of non-native species to the continent, and tourist numbers continue to grow (almost 37,000 visited in the 2016-17 summer). 
Biosecurity is paramount for the ongoing protection of Antarctica. If bags, shoes, clothes and field equipment are not properly cleaned and inspected before arriving on the continent, then non-native seeds, microbes and insects could be transported to Antarctica and begin to spread. 
We call for protection of ice-free areas that will remain intact in a changing climate, and for the Antarctic scientific and tourism communities to pinpoint key areas where greater biosecurity and monitoring for invasive species may be needed.
<a href="https://theconversation.com/profiles/jasmine-lee-171931" target="_blank">Jasmine Lee</a> is PhD candidate, biodiversity conservation and climate change, The University of Queensland.
<a href="https://theconversation.com/profiles/justine-shaw-299755" target="_blank">Justine Shaw</a> is Conservation Biologist, The University of Queensland.
<a href="https://theconversation.com/profiles/richard-fuller-169469" target="_blank">Richard Fuller</a> is Associate Professor in Biodiversity and Conservation, The University of Queensland.
All are authors for <a href="https://theconversation.com/au" target="_blank">The Conversation</a>.
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Antarctica

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