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.

Water usually flows downward, but something strange happened under Greenland’s ice sheet when a deluge punched through the surface to scour an area nearly twice the size of New York’s Central Park

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