A mantle plume producing almost as much heat as Yellowstone supervolcano appears to be melting part of West Antarctica from beneath.
Researchers at NASA have discovered a huge upwelling of hot rock under Marie Byrd Land, which lies between the Ross Ice Shelf and the Ross Sea, is creating vast lakes and rivers under the ice sheet. The presence of a huge mantle plume could explain why the region is so unstable today, and why it collapsed so quickly at the end of the last Ice Age, 11,000 years ago.
Mantle plumes are thought to be part of the plumbing systems that brings hot material up from Earth’s interior. Once it gets through the mantle, it spreads out under the crust, providing magma for volcanic eruptions. The area above a plume is known as a hotspot.
For 30 years, scientists have suggested that a mantle plume may exist under Marie Byrd Land. Its presence would explain the regional volcanic activity seen in the area, as well as a dome feature that exists there. However, there was no evidence to support this idea.
Now, scientists from NASA’s Jet Propulsion Laboratory have created advanced numerical models to show how much heat would need to exist beneath the ice to account for their observations—including the dome and the giant subsurface rivers and lakes we know are present on Antarctica’s bedrock. As lakes fill and drain, the ice thousands of feet above rises and falls, sometimes by as much as 20 feet.
Study author Hélène Seroussi, from JPL, said when she first heard that a mantle plume might be heating Marie Byrd Land she thought the idea was “crazy.”
"I didn't see how we could have that amount of heat and still have ice on top of it,” she said in a statement.