Hidden Volcanoes Melt West Antarctic Ice Sheet

Though Antarctic is a land of ice, it has fire inside it in the form of sub-glacial volcanoes. According to a new study, subglacial volcanoes and other geothermal areas hidden under the ice sheet are contributing to the glacial melt.

A team of researchers from Institute for Geophysics at University of Texas at Austin examined the Thwaites Glacier, which is melting at a rapid speed and is at high risk of collapsing. Some areas of the glacier above the geological features that are assumed to be volcanic, are melting much faster than the areas farther away from the volcanic sites, according to Dustin Schroeder, the study's lead author and a geophysicist at the University of Texas at Austin.

"The geothermal heat contributed significantly to melting of the underside of the glacier, and it might be a key factor in allowing the ice sheet to slide, affecting the ice sheet's stability and its contribution to future sea level rise," the researchers said in a press release.

"The cause of the variable distribution of heat beneath the glacier is thought to be the movement of magma and associated volcanic activity arising from the rifting of the Earth's crust beneath the West Antarctic Ice Sheet."

The melting could greatly affect West Antarctic– the area that is rapidly losing ice. 

"It's not just the fact that there is melting water, and that water is coming out. It's how that affects the flow and stability of the ice." Schroeder told Live Science.

In the past, it was not possible to obtain information regarding the areas underneath the glacier. Computer models were used to predict the future of ice mass but the major drawback with the models was that it couldnot provide information to the subglacial geothermal energy. But with the use of radar, researchers could study the subglacial streams.

"It's the most complex thermal environment you might imagine. 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," said study co-author Don Blankenship, a geophysicist at UT Austin, explained 

The streams revealed some unusually high melting spots close to the West Antarctic volcanoes, suspected volcanoes or other such hotspots.

"There's a pattern of hotspots. One of them is next to Mount Takahe, which is a volcano that actually sticks out of the ice sheet. Anywhere in the West Antarctic Ice Sheet is going to be a candidate for high melt areas. And we have radar data covering much of it," said Schroeder.

Thwaites Glacier, experiences minimum average heat flow of 114 milliwatts per square meter (or per about 10 square feet) underneath, while some areas experience even 200 milliwatts per square meter.  Whereas, the average heat flow of the rest of the continents is 65 milliwatts per square meter.

The melt caused by subglacial volcanoes could eventually make the ice sheet reduce its thickness from beneath and increase its flow toward the sea. Schroeder and his colleagues also plan to broaden their study to other glaciers in the region.

The details of the report was published in the journal Proceedings of the National Academy of Sciences.