Greenland glacier calves huge ice island
August 9th, 2010A number of stories appeared in the media last week about one of Greenland’s largest of “outlet” glaciers (glaciers ending in the sea) calving an enormous ”ice island” of more than 100 square miles in size.
None of the stories had a good graphic showing what happened. Fortunately, WWF Climate Blog has posted this one:
The glacier has lost about a quarter of its floating ice shelf.
A 2009 survey of 34 of the widest Greenland marine-terminating glacier outlets from the inland ice sheet found the loss rate has been nearly constant since 2000.
Above: cumulative annual area changes for 34 of the widest Greenland ice sheet marine-terminating outlets. Source: Byrd Polar Research Center.
To put the Petermann Glacier’s latest ice island in perspective, the island’s area of at least 260 km² is well over twice what all 34 glaciers surveyed by the Byrd Polar Research Center have been losing annually (-106 km² per year).
Scientists recently documented the breakup up of a 7 km² (2.7 square mile) section of another glacier in the region, the Jakobshavn Isbrae glacier. The calving front – where the ice sheet meets the ocean is now further inland than at any time previously observed.
Location of the successive calving fronts of the Jakobshavn Isbrae glacier between 1851 and 2009, overlain on a Landsat image from 7/29/2009. Source: NASA/Goddard Space Flight Center Scientific Visualization Studio. Historic calving front locations courtesy of Anker Weidick and Ole Bennike, Geological Survey of Denmark and Greenland.