Greenland glacier slide speeds 220 percent in summer

Reuters: A glacier in Greenland slides up to 220 percent faster toward the sea in summer than in winter and global warming could mean a wider acceleration that would raise sea levels, according to a study published Sunday. A group of experts led by Ian Bartholomew at Edinburgh University in Scotland said the variability was much stronger than earlier observations of glacier movement in Greenland.

The study, published in the journal Nature Geoscience, is a new piece of a puzzle to understand the world's second biggest ice sheet behind Antarctica. Greenland has enough ice to raise world sea levels by about 7 meters (23 ft) if it all melted.

…The scientists said that the summer slide might be linked to melt water seeping under the ice. It did not speculate if the change in speed between summer and winter was part of natural shifts or was influenced by a changing climate.

But they wrote: "In a warming climate, with longer and more intense summer melt seasons, we would expect that water will reach the bed farther inland and a larger portion of the ice sheet will experience summer velocity changes."…

Grooves in a Greenland glacier, shot by Steve Jurvetson, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license