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Melting moments: under East Antarctica’s biggest glacier Tas van Ommen Senior Principal Research Scientist, Climate and Ice at Australian Antarctic Division
The Totten Glacier, the largest in East Antarctica, has deep channels running beneath it that may allow relatively warm water into its belly. Image credit: Tas van Ommen. It’s 11 o’clock on a January evening in 2011 as our venerable old DC-3 aircraft banks over Casey Station, in the last golden rays of an Antarctic sunset. Offshore, an armada of giant icebergs sits stalled in the relative shallows along Peterson Bank, a mix of dusky pink highlights and violet shadows. Inside the aircraft we shut down our instruments, and I strap myself back in my seat before the gentle bump and swoosh of the snowy landing – another mission under our belts. The ICECAP (International Collaboration for Exploration of the Cryosphere through Aerogeophysical Profiling) project—a collaboration between US, British and Australian Antarctic researchers—has been mapping the East Antarctic ice sheet to look for changes. On our many flights, we have used radar, laser, geomagnetic and gravity
Bulletin of the Australian Meteorological and Oceanographic Society Vol. 28 page 33
instruments to survey an area the size of New South Wales, inland from Casey Station. So far, the flights have covered a total of 150,000 km over the frozen continent’s vast eastern expanse. And it turns out that East Antarctica needs careful watching. The project is giving us a new look at the underside of the ice sheet in East Antarctica, and causing significant concerns for future increases in sea level. One of the project’s major recent discoveries is that the terrain under the region’s biggest and most important glacier may make it more vulnerable to melting than we thought. Before embarking on the ICECAP project, there were huge gaps in our maps of the bedrock under the ice. The region contains some of the thickest, deepest ice on the continent, more than 4 km thick, and it’s a place we need to map as we look for a good site to drill an elusive