Researchers have discovered the first evidence of a volcano under the ice in West Antarctica - a mountain that erupted about 2,300 years ago and still might be generating enough heat to speed up glacial melting.
The blast ripped through thousands of feet of ice and sent ash eight miles into the sky. The ash settled in a giant ellipse and, over the centuries, was buried in snowfall, undetected until scientists spotted it in radar images from a series of airplane flights.
The extent of the ash, its thickness and its depth beneath the ice's surface allowed the researchers to calculate the size and date of the eruption, according to the report being published tomorrow in the journal Nature Geoscience.
The volcano, part of the Hudson Mountain Range, is considered active.
"It may be producing a lot of heat underneath," said lead author Hugh Corr, a researcher at the British Antarctic Survey.
That heat could play a small role in the melting of Pine Island Glacier, a massive ice flow that sits near the volcano and has been accelerating its movement toward the ocean in recent decades.
The melting of Antarctica's glaciers is of interest to scientists because of fears that that it could raise sea levels.
But Corr and other researchers said that effect of the volcanic activity is too small to change the dominant theory that warming ocean water is melting sea ice, allowing glaciers to flow more quickly.
Alan Zarembo writes for the Los Angeles Times.