Geothermal Heat Accelerates Glacier Melting in Antarctic

Geothermal heat is accelerating the melting of the glacier in the Antarctic, a new study reveals.

Researchers at the Institute for Geophysics from the University of Texas, Austin, say the Thwaites Glacier, of the West Antarctic Ice Sheet is melting not only due to the ocean but also because of geothermal heat. This new finding alters our understanding of the conditions existing beneath the Ice Sheet.

The Thwaites Glacier has been the focus of attention because researchers say that the future of the glacier is bleak as it may collapse soon.  But in order to determine when the collapse will begin, the researchers need more valid data to build a computer model to study the collpase.

In this study the researchers estimated the rate at which the ice is melting using radar techniques. They identified the geothermal heat under the glacier and found that the source is widely spread and much hotter than previously thought.

"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 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," researchers explain.

This finding helps ice sheet modelers to accurately estimate the response of the glacier to the warming of ocean. Till date scientists couldn't measure the strength and location of the heat flow under the glacier. If the Thwaites Glacier collapses, it would eventually raise the global sea level by  1- 2 meters. 

Prior to this, the researchers used ice-penetrating airborne radar sounding data to duplicate vast interacting subglacial water systems under the Thwaites Glacier. Based on this finding, the new research used the distribution of water under the glacier to estimate the location and levels of heat flow.

According to this finding, "The minimum average geothermal heat flow beneath Thwaites Glacier is about 100 milliwatts per square meter, with hotspots over 200 milliwatts per square meter. For comparison, the average heat flow of the Earth's continents is less than 65 milliwatts per square meter."

The finding was documented in National Academy of Sciences.