20 October 2016, Climate Home, Antarctic ice shelf collapse pits fishing against science. The UK is calling for a ten-year fishing moratorium in seas vacated by Antarctica’s collapsing ice shelves. The proposal, which was shared with Climate Home, passed the scientific committee of the UN Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) on Thursday. Russia has the power to veto the move when it goes to a full commission debate in Tasmania next week, however, and has consistently opposed territorial limits to fishing vessels in the far south. The collapse of an ice shelf provides a one-of-a-kind scientific laboratory, said Phil Trathan, a scientist at the British Antarctic Survey and one of the authors of the proposal. The newly open waters provide a window into the hidden processes of ocean ecosystems. “All of these areas are covered by ice and when that goes then there’ll be a whole new community develop under there. And given that a lot of communities develop quite slowly in the Antarctic then we can look at how they develop through time,” said Trathan speaking from Hobart, where the CCAMLR meeting is taking place. “If fisheries are going to exploit those areas before we have a chance to look at them scientifically then it’s a lost opportunity.” Antartica’s great ice shelves project out over the ocean from the fringes of the land. They are in a state of rapid decline, losing a total of 310 cubic km of ice every year. Once a shelf becomes too thin to support its own weight, it collapses in dramatic style, as was witnessed by satellites when the 3,250 sq km Larsen B ice shelf disintegrated within a few months at the beginning of 2002. Read more here
Tag Archives: Antarctica
29 September 2016, The Conversation, Record high to record low: what on earth is happening to Antarctica’s sea ice? 2016 continues to be a momentous year for Australia’s climate, on track to be the new hottest year on record. To our south, Antarctica has also just broken a new climate record, with record low winter sea ice. After a peak of 18.5 million square kilometres in late August, sea ice began retreating about a month ahead of schedule and has been setting daily low records through most of September. It may not seem unusual in a warming world to hear that Antarctica’s sea ice – the ice that forms each winter as the surface layer of the ocean freezes – is reducing. But this year’s record low comes hot on the heels of record high sea ice just two years ago. Overall, Antarctica’s sea ice has been growing, not shrinking. So how should we interpret this apparent backflip? In our paper published today in Nature Climate Change we review the latest science on Antarctica’s climate, and why it seems so confusing. Antarctic surprises. First up, Antarctic climate records are seriously short. The International Geophysical Year in 1957/58 marked the start of many sustained scientific efforts in Antarctica, including regular weather readings at research bases. These bases are mostly found on the more accessible parts of Antarctica’s coast, and so the network – while incredibly valuable – leaves vast areas of the continent and surrounding oceans without any data. In the end, it took the arrival of satellite monitoring in the 1979 to deliver surface climate information covering all of Antarctica and the Southern Ocean. What scientists have observed since has been surprising. Read More here
19 September 2016, The Conversation, Disruption over Macquarie Island calls for some clever Antarctic thinking. The fate of the Australian Antarctic Division’s research base on Macquarie Island hangs in the balance, after last week’s surprise announcement that it would close in March 2017 was followed on Friday by a suggestion that the government could yet reprieve it. Why all the fuss over a scattering of buildings on a windswept island (admittedly a UNESCO World Heritage-listed one) perched on a tectonic ridge halfway between Australia and Antarctica? Macquarie Island is the perfect natural laboratory for scientific research. Unique climate, geological, biological and astronomical measurements are collected year-round. The data is fed into many large-scale, international science programs and reports, including those published by the Intergovernmental Panel on Climate Change. It is something of an anomaly in Australia’s national Antarctic program. Unlike Heard Island, Macquarie Island lies outside the areas covered by the Antarctic Treaty and the Convention on the Conservation of Antarctic Marine Living Resources. The Tasmanian government manages the island. The buildings at the island’s north end are home to research infrastructure and accommodation for various organisations. These include the Tasmanian Parks and Wildlife Service, the Bureau of Meteorology, and the Australian Radiation Protection and Nuclear Safety Agency, which monitors the Southern Ocean for evidence of nuclear events. These buildings are increasingly exposed to ocean inundation. Read More here
22 August 2016, Washington Post, A widening 80 mile crack is threatening one of Antarctica’s biggest ice shelves. For some time, scientists who focus on Antarctica have been watching the progression of a large crack in one of the world’s great ice shelves — Larsen C, the most northern major ice shelf of the Antarctic peninsula and the fourth largest Antarctic ice shelf overall. Larsen C, according to the British Antarctic Survey, is “slightly smaller than Scotland.” It’s called an ice “shelf” because the entirety of this country-sized area is covered by 350-meter-thick ice that is floating on top of deep ocean waters. The crack in Larsen C grew around 30 kilometers (18.6 miles) in length between 2011 and 2015. And as it grew, also became wider — by 2015, yawning some 200 meters in length. Since then, growth has only continued — and now, a team of researchers monitoring Larsen C say that with the intense winter polar night over Antarctica coming to an end, they’ve been able to catch of glimpse of what happened to the crack during the time when it could not be observed by satellite. The result was astonishing. The rift had grown another 22 kilometers (13.67 miles) since it was last observed in March 2016, and has widened to about 350 meters, report researchers from Project MIDAS, a British Antarctic Survey funded collaboration of researchers from Swansea and Aberystwyth Universities in Wales and other institutions. The full length of the rift is now 130 km, or over 80 miles. Read More here