NASA: Evidence of geothermal heat source below Antarctica
A geothermal heat source called a mantle plume is likely contributing -- along with climate change -- to the instability of the West Antarctic ice sheet.

By Harry Marcolis | 17 hours ago

A geothermal heat source called a mantle plume likely lurks deep beneath the ice in Anatarctica's Marie Byrd Land, according to a new study by NASA.

While the heat source is not a new threat to the West Antarctic ice sheet, it explains at least some of the melting that creates lakes and rivers below the ice. It also may be a contributing factor -- in addition to climate change -- in the collapse of the ice sheet and explain why it is so unstable today.

When water lubricates the ice sheet from below, it allows glaciers to slide more easily and undermines its stability.

"Understanding the sources and future of the meltwater under West Antarctica is important for estimating the rate at which ice may be lost to the ocean in the future," explained NASA's Jet Propulsion Laboratory (JPL), in a statement.

When recent seismic imaging supported the idea of a mantle plume beneath the ice a concept that has been around for 30 years researchers from JPL used enhanced numerical modeling to measure natural sources of heating and heat transport.

They also relied on observations of changes in the ice sheet's surface made by NASA's IceSat satellite and airborne Operation IceBridge campaign.

At the end of the last ice age, about 11,000 years ago, the ice sheet underwent rapid losses because of warmer weather patterns and rising sea levels similar to what is occurring today. The researchers suggest the mantle plume could be contributing to the rapid undermining of the ice sheet.

JPL's Helene Seroussi and Erik Ivins detail their work in the Journal of Geophysical Research.

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