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In January 1995, about 1,500 square kilometers of Larsen A broke apart. In January 2002, about 3,250 square kilometers of Larsen B—an area greater than that of Luxembourg—collapsed within a month. A portion of the Larsen B, known now as the Scar Inlet Ice Shelf, remained after the 2002 collapse.

The thickness of the remaining ice shelves has also changed. In September 2016, Shuman published a study showing that the Seal Nunataks Ice Shelf thinned at a rate of 2 to 3 meters (6 to 9 feet) per year between 2003 and 2009.

“The thinning is partly due to warm air melting the ice shelf from above and partly from warm ocean water melting it from below,” said Shuman. Most scientists think the combination of warming air and water were responsible for the 1995 and 2002 collapses. Shuman noted that the shelf remnants are still losing ice as icebergs break off into the sea in glacial calving events.

Since Larsen A and B floated on the water to start with, sea level did not increase when these parts of the ice shelf broke apart. But Shuman and colleagues have found that after Larsen A and B collapsed, feeder glaciers on landthinned and began to lose ice at a faster rate, a process that continues today.

“You can think of the Larsen or really any ice shelf like it is a cork in the neck of a champagne bottle lying on its side,” Shuman said. “Once you pop that cork, the wine inside—all that glacial ice sitting on land—will start flowing out. And that’s worrisome because such thinning land ice is directly increasing global sea levels. With other floating ice thinning and retreating elsewhere in Antarctica, it sure looks like many corks are ready to pop.”

Source More on : Antarctica’s Changing Larsen Ice Shelf

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