Heat source detected under Antarctic ice sheet

PASADENA, CALIFORNIA — A new NASA study bolsters the theory that a heat source exists under West Antarctica.

Researchers have found evidence that a geothermal heat source called a mantle plume lies deep below Antarctica's Marie Byrd Land, according to NASA.

Mantle plumes are narrow upwellings of hot rock that rise up from the Earth's mantle. They spread out like mushroom caps under the crust, causing it to bulge upward.

Using a numeric model, the flux of energy from the mantle plume was calculated to be 150 miliwatts, only 50 milliwatts less than the average heat flux under Yellowstone.

Researchers say the heat source could explain the melting that creates river and lakes under the West Antarctic ice sheet, but it is not a new or increasing threat.

However, global weather changes and rising sea levels can push warm water closer to the ice, causing it to become unstable and collapse — just as it did 11,000 years ago at the end of the last ice age.