Satellite spots giant crater in Antarctic ice cover above buried lake

A European satellite has spotted a vast crater in Antarctica's icy surface scientists say they think was formed when a lake under miles of ice suddenly drained. Combining new measurements from the European Space Agency's CryoSat spacecraft with older data from NASA's ICESat satellite, researchers have mapped the large crater left behind by the lake, and even determined the scale of the flood that formed it, an ESA release reported Tuesday. Scientists attempting to understand water transport and ice dynamics beneath the frozen Antarctic surface are studying freshwater lakes with no direct connection to the ocean that lie deep beneath the thick ice sheet covering Antarctica. Researchers said almost 1-1/2 cubic miles of water -- about the same amount in Scotland's Loch Ness -- drained from the lake from 2007 to 2008, making it the largest event of its kind ever recorded. The amount was equal to about 10 percent of the melting that occurs beneath Antarctica each year. The lake appears to have been refilling since the end of 2008, researchers said, but it could take decades to reform because it is filling much more slowly than it drained. About 400 lakes have been discovered beneath the Antarctic ice sheet that can disrupt subglacial habitats when they drain and cause the ice above to slide more quickly into the sea, they said.