A white continent extends below you, and it's smothered in enough frozen water to drown every coastline in the world in a 216-foot (66 meters) wave if it were to melt. Now, one of the biggest head-scratchers of all might finally have an answer and it all starts deep under the surface.
Usually, magma nears the surface only at the edges of tectonic plates. Marie Byrd Land is part of the bulging "elbow" leading to the Antarctic Peninsula, left center. They spread out like mushroom caps under the crust, causing it to bulge upward. John Tuzo Wilson was the first scientist to propose the theory of a mantle plume back in 1960's.
Despite its apparent icy stillness, Antarctica is alive with motion. This is because this water acts as a lubrication agent and causes the glaciers to slide.
A new NASA study suggests that a "mantle plume", almost as hot as the Yellowstone supervolcano, is causing ice to melt from underneath Antarctica's Marie Byrd Land. Something else was cooking the ice shelf.
About three decades ago, a scientist argued that the presence of a heat source underneath the Marie Byrd Land in Antarctica could explain the regional volcanic activity that takes place in the area.
Now, scientists know for sure.
Hélène Seroussi of NASA's Jet Propulsion Laboratory in Pasadena, California, said when she first heard the idea, she "thought it was insane". Researchers don't have probes under the ice, but they can detect the activity thanks to careful measurements of the rise and fall of the surface from NASA's ICESat satellite and IceBridge flyover missions. For comparison, in USA regions with no volcanic activity, the heat flux from Earth's mantle is 40 to 60 milliwatts. The heat underneath Yellowstone National Park generates about 200 milliwatts per square meter on average. By using the Ice Sheet System Model (ISSM) (a numerical depiction of the physics of ice sheets developed by scientists at JPL and the University of California, Irvine), researchers attempted to identify the natural sources of heating and heat transport from freezing, melting and liquid water in Antarctica. 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.
Researchers estimated that the mantle plume under Marie Byrd Land formed 50 to 110 million years ago, way before the time when the ice sheet came into being.