A hidden lake beneath the Greenland Ice Sheet unexpectedly drained more than a decade ago, fracturing the ice surface and forming a large crater — an event only recently uncovered by Earth-observing satellites.
The massive ice sheet, located in a remote region of northern Greenland, harbors a subglacial lake that appears to have flooded in 2014, releasing 23.8 billion gallons (90 million cubic meters) of meltwater over the course of 10 days — roughly equivalent to nine hours of peak flow over Niagara Falls.
