Active Volcano under ice Leigh Dayton, Science writer | January 22, 2008
AN active volcano has been found under Antarctica's rapidly melting western ice sheet. Although it has not erupted for more than 2000 years, heat from the geologically active Hudson Mountains Subglacial Volcano helps explain why nearby Pine Island Glacier shrinks by more than a kilometre every year, British scientists claim. The discovery follows reports last week that Antarctica's ice cap is melting faster than previously believed. According to those findings, the greatest loss was from the West Antarctic Ice Sheet and the Antarctic Peninsula. Together, they lost nearly 200billion tonnes of ice in 2006 alone. Glaciologists Hugh Corr and David Vaughan of the British Antarctic Survey in Cambridge claim the discovery of the first known subglacial volcanic eruption promises to improve predictions of future sea-level rise caused by the melting of the WAIS. "We believe this was the biggest eruption in Antarctica during the last 10,000 years," Dr Corr said. "It blew a substantial hole in the ice sheet and generated a plume of ash and gas that rose around 12km." The team identified a large layer of volcanic ash in the ice. Additional evidence for the eruption came from ice cores collected across the continent. Writing in Nature Geoscience, Dr Corr and Dr Vaughan suggested the increased heat from the eruption, which they dated to 325BC, led to melting of the surrounding and overlying ice which, in turn, increased the flow rate of nearby glaciers.
