Underground volcanoes accelerate glacier melting in Antarctic

AUSTIN, Texas, June 9 (UPI) -- The list of things that don't contribute to glacier melting keeps getting shorter. Now, the list-keeper can cross off "underground volcanoes."

According to a new study by researchers at the University of Texas at Austin (UT), the Thwaites Glacier of Western Antarctica -- which recently made the news headlines for its accelerated melting and structural vulnerabilities -- is also being eroded from beneath by geothermal heat released by underground volcanoes.

Ice-penetrating airborne radar clued the researchers from UT's Institute for Geophysics into the fact that geothermal heat sources are more extensively distributed beneath Antarctica than previously thought. They also learned that Antarctica's hotspots put out a much larger amount of heat than expected.

Beneath the Thwaites Glacier, geothermal sources give off an average of 114 milliwatts per square meter, with 200 milliwatts per square meter emanating for the most concentrated hotspots. (A square meter is roughly the equivalent of ten square feet.) Similar underground volcanoes in North America give off only around 65 milliwatts per square meter.

"It's pretty hot by continental standards," said researcher Don Schroeder, speaking of Antarctica. Schroeder helped author the new study, published this week in the Proceedings of the National Academy of Sciences.

But Schroeder and co-author Don Blankenship say more research is needed to accurately predict how and at what rate geothermal warming will contribute to the predicted collapse of the Thawites Glacier -- as well as the rest of the West Antarctic ice sheet.

"It's the most complex thermal environment you might imagine," said Blankenship. "And then you plop the most critical dynamically unstable ice sheet on planet Earth in the middle of this thing, and then you try to model it. It's virtually impossible."