Discovery of high geothermal heat at South Pole
The team believes the heat source is a combination of unusually radioactive rocks, and hot water coming from deep under the ground. This heat melts the base of the ice sheet, producing melt-water which drains away beneath the ice sheet filling subglacial lakes downstream. The presence of this extra water may help lubricate the fast flowing ice in this area.
https://phys.org/news/2018-11-discovery-high-geothermal-south-pole.html