Scientists have long studied the behavior of its massive ice sheets and the land underneath them in the hopes of understanding the unique geological quirks of the continent, but are frequently puzzled by new discoveries.
A recent NASA study has revealed evidence that a geothermal heat origin called a mantle plume lies embedded in Antarctica's Marie Byrd Land, elucidating some melted parts generate lakes and rivers under the sheet of ice.
"Although the heat source isn't a new or increasing threat to the West Antarctic ice sheet, it may help explain why the ice sheet collapsed rapidly in an earlier era of rapid climate change, and why it is so unstable today", the study says.
Mantle plumes are thought to be part of the plumbing systems that brings hot material up from Earth's interior. The buoyancy of the material in the streams causes the Earth's crust to bulge upward. However, the latest data could help researchers better estimate future ice loss in the area because "the stability of an ice sheet is closely related to how much water lubricates it from below, allowing glaciers to slide more easily", the NASA press release noted. Antarctica's bedrock is laced with rivers and lakes, the largest of which is the size of Lake Erie.
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". The concept was recently supported by seismic imaging.
The mantle plume theory has been the leading idea for at least 30 years now, but until now, the plume itself wasn't identified, only inferred from activity at the surface.
They scientists also used observations of changes in the altitude of the ice sheet surface, captured by NASA's IceSat satellite and airborne Operation IceBridge campaign. Evik Ivins said, "These place a powerful constraint on allowable melt rates- the very thing we wanted to predict".
Their findings showed that generally, the energy being generated by the mantle plume is no more than 150 milliwatts per square meter-any more would result in too much melting. Its presence would explain the regional volcanic activity seen in the area, as well as a dome feature that exists there. Under the suspiciously dome-shaped Marie Byrd Land in West Antarctica, it's 150-180 milliwatts per square meter.
It came into existence 50 to 110 million years ago, and has likely been fueling plenty of the ice realm's volcanoes throughout. Then about 11,000 years ago, at the end of the last ice age, the ice sheet went through a period of rapid ice loss. The global weather pattern and rising sea levels have been forcing the warm water to flow closer to the ice sheets.
The location of the mantle plume.