Downstream from the crater left behind by the drainage, researchers identified an odd region of disrupted ice. Though the ice in that area had previously been pristine, giant cracks and uprooted ice chunks suddenly covered four million square feet, and the surrounding 2.3 square miles of ice showed clear traces of flowing water.

Scientists were caught by surprise after discovering a massive flood of subglacial lakewater had burst through Greenland's ice sheet.

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.

A violent subglacial flood in Greenland ruptured the ice from below—forcing scientists to rethink ice sheet behavior.