Warming-stoked tides eating huge holes in Greenland glacier

This 2010 image shows a piece of the Petermann Glacier that cracked in Greenland. (Jesse Allen and Robert Simmon/NASA Earth Observatory via AP)

Daily tides stoked with increasingly warmer water ate a hole taller than the Washington Monument at the bottom of one of Greenland’s major glaciers in the last couple years, accelerating the retreat of a crucial part of the glacier, a new study found.