13 Sep 2013:
Warmer Ocean Water Is Key
Factor in Melting Ice Shelves, Study Says
Recent research into one of West Antarctica's most rapidly melting glaciers and ice shelves has shown that rising ocean temperatures and a series of channels lacing the underside of the shelf are the key factors in the rapid thinning of the shelf
and the swift advance of the glacier behind it. Reporting in
Edge of Pine Island ice sheet
, U.S. scientists said that instruments deployed on and under the Pine Island Glacier and ice shelf over the past two years have shown that warmer ocean water has been flowing through a series of channels under the shelf, causing the 31-mile-long floating slab of ice to thin at the alarming rate of 2.4 inches per day and loosening the shelf's hold on the bedrock below. The melting ice shelf itself doesn't contribute to sea level rise, but as it thins it allows more of the land-based Pine Island Glacier to flow into the sea,
which is contributing to sea level rise. The researchers said that warmer ocean temperatures are playing a role in the thinning of ice shelves in both the Arctic and Antarctic. "The Antarctic has been relatively quiet as a contributor to sea level rise," said Sridhar Anandakrishnan, a Penn State researcher who contributed to the study. "What this work shows is that we have been blind to a huge phenomenon, something that will be as big a player in sea level rise in the next century as any other contributor."