Larsen C Ice Shelf Splits Off

When Ice Shelves Collapse, the Glaciers They Hold Back Flow Directly Into the Ocean, Rapidly Raising Sea Levels

[ UPDATE: One of the largest ice bergs (the size of Delaware) broke away on July 12, 2017. ]

The 1000 foot wide rift is cutting through the Larsen C Ice Shelf like a hot knife through butter. Once the rift traverses the remaining eight miles (which could happen within a matter of weeks), the last of the three massive ice shelves of the region will collapse and crash into the sea. The chunk of ice involved is the size of Delaware (about 2000 sq mi) and will reduce the Peninsula’s area by about 10%. Even beyond the fact that this calving event will create one of the largest ice bergs ever recorded, this is not business as usual.

When this massive berg breaks free, “It will fundamentally change the landscape of the Antarctic Peninsula,” said Adrian Luckman of the Midas Project, a UK Antarctic research institution. The West Antarctic Ice Shelves Larsen A and B have already collapsed (1999 and 2002 respectively).

Another significant uptick in sea level rise:

Ice shelves are different from both land based ice packs and floating sea ice. As a sort of hybrid, ice shelves are an extension of land based ice that are connected to land but form a floating barrier on coastal Antartica, Greenland and other polar regions. Ice shelves serve to hold back the massive glaciers that flow to the sea from the interior of the continent. When an ice shelf cracks away, the glaciers begin melt into the ocean.

Since the 1950s, accelerated warming trends in the region have driven temperatures up to 5°F higher in the region since the 1950s. They are expected to increase up to 7°F more by the end of the century.

If all the glaciers held back by Larsen C were to run into the ocean, global water level will increase by an additional four inches  (10 centimeters). Because the glaciers are comprised of fresh water, the also change the salinity of the ocean as they mix with the salt water.

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