Ice Canyon
The ice canyons in Greenland were carved by meltwater and are as deep as 150 feet.
In late July 2006, a 2.2-square-mile lake atop the Greenland Ice Sheet sprung a leak. Like a draining bathtub, the entire lake emptied from the bottom, sending water through a crack that reached the base of the ice sheet 3,215 feet below. Most of the 11.6 billion gallons of water in the lake drained out in 90 minutes—at times flowing out faster than the water going over Niagara Falls.