Digital Journal -- The volcano in the West Antarctic Ice Sheet erupted about 2,325 years ago and is still active, according to the British Antarctic Survey (BAS).

In this week's journal, Nature Geosciences, scientists from BAS present the first evidence of a volcanic eruption below ice in Antarctica. The hidden volcano erupted through several hundreds metres of ice above it, and researchers say it's the first time they have seen a volcano beneath the ice actually blow a hole through the ice sheet.

Scientists fly above Antarctica to perform an aerial survey. - Photo by Carl Robinson, British Antarctic

The volcano, covering a distance larger than Wales (20,000 square kilometres/12,427 square miles), was found when scientists used airborne ice-sounding radar to find a layer of ash produced by a "subglacial volcano." Scientists say heat from the volcano could still be melting the ice.

The explosion that happened more than 2,000 years ago under an ice sheet in West Antarctica has been rated as "cataclysmic" or "severe" using an international scale of volcanic force. Scientists say it would have created a huge hole in the ice sheet when it exploded, and likely spat out a plume of ash and gas about 12 km (8 miles) into the sky.

“The discovery of a ‘subglacial’ volcanic eruption from beneath the Antarctic ice sheet is unique in itself," says lead author, Hugh Corr, in a statement. "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."

Team photo from the Hudson Mountain survey flight season in Antarctica. - Photo by Carl Robinson, British Antarctic Survey

Scientists believe the volcano is still active and the finding has led the international community to start asking questions about ice loss. As climate change researchers debate the finer points on humankind's impact on changing global temperatures, scientists say this volcano could also be a factor contributing to melting ice in the region.

Co-author, professor David Vaughan, says this finding is a vital piece of the puzzle needed to predict how high sea levels will rise.

“This eruption occurred close to Pine Island Glacier on the West Antarctic Ice Sheet," Vaughan said in a statement. "The flow of this glacier towards the coast has [sped] 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.”

British Antarctic Survey Twin Otter taking off with full survey fit. The plane is fitted with 8 radar antennas and magnetometer pods for this research. - Photo by Carl Robinson, British Antarctic Survey