|
|
Satellite imagery shows fragile Wilkins Ice Shelf destabilised   The figure displays the Envisat Advanced Synthetic Aperture Radar (ASAR) image from 27 April 2009 superimposed on an image from 24 April 2009. The margins of the collapsed ice bridge that formerly connected Charcot and Latady Islands are outlined in white. The demise of the ice bridge led to a destabilisation of the northern ice front of the Wilkins Ice Shelf, where the first icebergs calved off on 20 April 2009 (area denoted in red).  Animation of Envisat ASAR images over the Wilkins Ice Shelf from January 2008 - April 2009.
The animation includes the three successive break-up events in 2008: February, May, and July as well as the latest break-up event in April 2009 that triggered the recent iceberg calving from the northern front of the Wilkins Ice Shelf. This event follows the collapse of the ice bridge that had previously linked the Antarctic mainland to Charcot Island. The ice bridge, which effectively formed a barrier pinning back the northern ice front of the central Wilkins Ice Shelf, collapsed on 5 April removing about 330 sq km of ice. As a consequence of the collapse, the rifts, which had already featured along the northern ice front, widened and new cracks formed as the ice adjusted in the days that followed.  A TerraSAR-X stripmap image from 23 April 2009. The larger icebergs are bright, while smaller icebergs are capsized and appear as dark blocks. The inset shows two superimposed Envisat ASAR images from 24 and 27 April. The region outlined in red indicates the area of the TerraSAR-X image.  Map showing the Wilkins Ice Shelf in Antarctica. Release date: 28 February 2012 |