Geoscientist have recently brought an end to a once mind boggling mystery of how large lakes that sit above the Greenland ice sheet drain billions of gallons of water in hours! The Greenland ice sheet extends about 656,000 miles covering most of the island. As ice melts it creates huge lake but these massive lakes are soon empty of water; where does it go? “In 2006, Greenland's North Lake, a 2.2 square-mile (5.6 square kilometers) supraglacial meltwater lake, drained almost 12 billion gallons of water in less than two hours” reports Livescience. Where does all this water go? One theory thought was “giant hydro-fractures (water-driven cracks) can form directly beneath the lake basin and stretch down to the bed of the ice sheet, emptying the
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The ice sheets movement is contributed to by trickling water from melting. A phenomenon outlined by Livescience is “Most of Greenland's supraglacial lakes drain slowly when superficial streams route water into nearby, permanent crevasses or moulins (vertical conduits or shafts in a glacier). Fairly recently, however, satellite images showed that about 13 percent of the lakes drain quickly, emptying completely within 24 hours.” In 2008 there was research led by Sarah Das showing that temporary hydro-fracture could cause rapid lake drainage on a enormous scale. But once again the research failed in solving how the fractures came about. "The coverage of GPS stations was not dense enough," Stevens told Live Science. "This study goes beyond previous studies on the lakes, because we have 16 GPS stations, as opposed to one or four” said by head scientist Stevens. “When meltwater in the summer drains to the bed from the ice surface through crevasses or moulins, it can cause the area within and around the lake basin to be "jacked up," Stevens said. “Additionally, it can decrease the surface area of the ice-sheet bed that's in contact with the underlying bedrock, lubricating the bed and making it easier for the bed to move
The ice sheets movement is contributed to by trickling water from melting. A phenomenon outlined by Livescience is “Most of Greenland's supraglacial lakes drain slowly when superficial streams route water into nearby, permanent crevasses or moulins (vertical conduits or shafts in a glacier). Fairly recently, however, satellite images showed that about 13 percent of the lakes drain quickly, emptying completely within 24 hours.” In 2008 there was research led by Sarah Das showing that temporary hydro-fracture could cause rapid lake drainage on a enormous scale. But once again the research failed in solving how the fractures came about. "The coverage of GPS stations was not dense enough," Stevens told Live Science. "This study goes beyond previous studies on the lakes, because we have 16 GPS stations, as opposed to one or four” said by head scientist Stevens. “When meltwater in the summer drains to the bed from the ice surface through crevasses or moulins, it can cause the area within and around the lake basin to be "jacked up," Stevens said. “Additionally, it can decrease the surface area of the ice-sheet bed that's in contact with the underlying bedrock, lubricating the bed and making it easier for the bed to move