Antarctic volcanic eruption occurred under ice 2,000 years ago

Washington, Jan 21 : Scientists have for the first time found evidence of a 2,000 year old volcanic eruption from beneath Antarctica's most rapidly changing ice sheet.

According to a report in the journal Nature Geosciences, this eruption, caused by an under-ice volcano, was found on the West Antarctic Ice sheet by a team of scientists from the British Antarctic Survey (BAS).

For detecting the volcanic eruption, the team used airborne ice-sounding radar, which led them to discover a layer of ash produced by a 'subglacial' volcano, which extends across an area larger than Wales.

The techniques also allowed scientists to determine that the eruption had occurred 2000 years ago (325 BC), with the volcano still active.

According to lead author Hugh Corr of the BAS, "The discovery of a 'subglacial' volcanic eruption from beneath the Antarctic ice sheet is unique in itself. But our techniques also allow us to put a date on the eruption, determine how powerful it was and map out the area where ash fell."

"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," he added.

The discovery is another important piece of evidence that will help determine the future of the West Antarctic Ice Sheet and refine predictions of future sea-level rise.

"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," said Co-author Professor David Vaughan (BAS).

"However, it cannot explain the more widespread thinning of West Antarctic glaciers that together are contributing nearly 0.2 mm per year to sea-level rise. This wider change most probably has its origin in warming ocean waters," he added.

ANI