Discovered biggest under-ice eurption in Antarctica in 10,000 yrs

London, Jan 22 (UNI) It is believed to be the biggest eruption in Antarctica during the last 10,000 years and is the primary evidence in understanding the future sea-level rise.

Science journal Nature Geosciences this week reported the first evidence of a volcanic eruption from beneath Antarctica's most rapidly changing ice sheet.

The volcano on the West Antarctic Ice Sheet erupted 2000 years ago (325BC) and remains active.

Scientists from British Antarctic Survey (BAS) discovered a layer of ash produced by a 'subglacial' volcano extending across an area larger than Wales using ice-sounding radar.

Lead author, Hugh Corr of the BAS says, "The discovery of a 'subglacial' volcanic eruption from beneath the Antarctic ice sheet is unique in itself. We believe this was the biggest eruption in Antarctica during the last 10,000 years. It blew a substantial hole in the ice sheet, and generated a plume of ash and gas that rose around 12 km into air." "This eruption occurred close to Pine Island Glacier on the West Antarctic Ice Sheet. The flow of this glacier towards the coast has speeded up in recent decades and it may be possible that heat from the volcano has caused some of that acceleration. However, it cannot explain the more widespread thinning of West Antarctic glaciers that together are contributing nearly 0.2mm per year to sea-level rise. This wider change most probably has its origin in warming ocean waters." The volcano is located beneath the West Antarctic ice sheet in the Hudson Mountains at latitude 74.6South, longitude 97West.

Volcanoes are an important component of the Antarctic region. They formed in diverse tectonic settings, mainly as a result of mantle plumes acting on the stationary Antarctic plate.

Volcanic eruptions were common during the past 25 million years, and paralleled with the great period of climatic deterioration that effected the formation of the Antarctic ice sheet.

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