East Antarctica - Nansen Ice Shelf Sheds Manhattan+ Sized Iceberg In Seven Days

Ever since 1999 a gigantic crack has been growing in the Nansen Ice Shelf in East Antarctica. By 2014, expansion of the crack accelerated. As of early 2016, the crevice had grown to 40 kilometers in length. Flooded by melt along the Ice Shelf’s warming surface and weakened by the heating of ocean waters from below, on April 7th, according to ESA reports, this East Antarctic Ice Shelf produced an immense 20 kilometer long iceberg. A towering block of ice covering an area larger than Manhattan floating on out toward the world’s shipping lanes.

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(Surface melt water flooding into a great crack along the Nansen Ice Shelf. Large volumes of melt water flooding into ice shelf cracks forces them to widen even as they dive toward union with the warming waters below. Image source. ESA.)

The Nansen Ice Shelf, before this most recent very large iceberg calving event, was a 10 mile wide and 30 mile long ice shelf that buttressed the Presley and Reeve Glaciers of East Antarctica. It abuts the north side of the Drygalski Ice Tongue, and runs out from Mount Nanson just inland of the coast of Victoria Land, Antarctica. And it’s yet another large shelf of ice that appears to be facing severe weakening as global average temperatures are driven above 1 C warmer than those experienced during the late 19th Century by an ongoing and reckless fossil fuel emission.

Nansen occupies a region of the world that has come under increasingly intense observation due to a number of scientific studies highlighting its accelerating rates of melt and a related risk of rapidly rising global sea levels. Human-forced heating of the world’s ocean has caused waters warm enough to accelerate glacial melt to encroach upon Antarctica from the Southern Ocean. These warmer waters are drawn along beneath the floating ice shelves as fresh melt water flooding out along the ocean surface generates a landward-moving bottom current. These warmer waters eventually push beneath the ice shelves — eating away at their undersides.

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(Massive ice berg breaks away from the Nansen Ice Shelf on April 7th in this ESA satellite shot.)

EDIT

https://robertscribbler.com/2016/04/25/melt-expanding-into-east-antarctica-as-nansen-ice-shelf-crack-produces-20-kilometer-long-iceberg/#comments