Saturday 7 April 2012

Antarctic's Disappearing Ice Shelf

-- If you are watching, it is breathtaking how fast the ice is melting around the world.

As climate scientist Guy McPherson notes, mankind cannot survive on a planet without ice to participate in the creation and moderation of weather. And, as he points out, if our species is to avoid extinction, we have no choice but to stop all economic activity as we have known it, because there is a .96 correlation between economic acitivity and greenhouse gas emission. -- MCR

One Satellite Image Proves Antarctic Ice Shelves Are Totally Screwed
Recent images taken by the European Space Agency's (ESA) Envisat satellite show that an Antarctic ice shelf is less than 15 percent of its size 17 years ago

6 April, 2012

According to the ESA, In January 1995, Larsen B ice shelf was 4,373 square miles (11,521 square kilometers). Today, the large floating sheet of ice is just a fraction of that size at 634 miles (1,670 square kilometers). In the last decade alone, Larsen B lost 691 square miles (1,790 square kilometers).

Larsen B is one in a series of three ice shelves that extend along the eastern side of the Antarctic Peninsula. The smallest ice shelf, Larsen A, broke up in January 1995 while the largest ice shelf, Larsen C, has been stable with signs of thinning and longer summer melts, the ESA says.

The northern Antarctic Peninsula has been subject to atmospheric warming of about 2.5°C over the last 50 years – a much stronger warming trend than on global average, causing retreat and disintegration of ice shelves,” Prof. Helmut Rott from the University of Innsbruck said in a press release.

Ice shelves are large floating platforms of ice that are attached to land. Because floating ice displaces a volume of water about equal to the volume of water it would contribute as it melts, it does not have much effect on sea level (though there are many other consequences of melting ice shelves, including change in salinity and temperature of ocean waters).

This is different than ice sheets, or continental glaciers, which are thick layers of ice that cover Greenland and Antarctica and would have a significant impact on sea level if they melt.

The break-up of ice shelves in Antarctica, however, is a warning sign of future changes in the Antarctic Ice Sheet.

This animation below shows radar images from the Envisat satellite from 2002 to 2012 of the Larsen B ice shelf in Antarctica:

Here is a Wikipedia article about the Larsen B ice shelf

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