At The Bottom of the World...

Antarctica's Twaites Glacier, one of the six glaciers of the Amundsen Sea Embayment of the West Antarctic Ice Sheet.
Credit: NASA

Sea level rise estimates are going to need to be revised upward: A portion of the West Antarctic Ice Sheet that is home to some of the fastest-flowing glaciers on the continent appears to have entered a state of retreat and melt that is “unstoppable,” two new studies have found.

“It has passed the point of no return,” said Eric Rignot, lead author on one of the studies and a glaciologist at the University of California, Irvine, and NASA’s Jet Propulsion Laboratory.

The West Antarctic Ice Sheet has been of concern to climate scientists because it contains enough ice to add 10 to 13 feet to global sea level rise were it all to melt. (Because the ice sheet’s ice is bound to land, it increases the volume of the ocean as it flows into it, like ice cubes added to a glass of water; sea ice, on the other hand, doesn’t change the ocean’s volume as it melts because it is already displacing that volume, just as a melting ice cube doesn’t add volume to the glass.)

Scientific American: Melt of Key Antarctica Glaciers "Unstoppable"

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