C21B-0320:
16 Year Ice Velocity Record of the Larsen-B and –C Ice Shelves Based on Spaceborne Synthetic Aperture Radar Data.
Tuesday, 16 December 2014
Bernd Scheuchl1, Jeremie Mouginot1, Eric J Rignot1, Ala Khazendar2 and Christopher P Borstad3, (1)University of California Irvine, Irvine, CA, United States, (2)NASA Jet Propulsion Laboratory, Pasadena, CA, United States, (3)University Centre in Svalbard, Longyearbyen, Norway
Abstract:
The Antarctic Peninsula is a significant contributor for sea level rise from Antarctica and has undergone significant changes over the last two decades. This includes the 1995 collapse of the Larsen-A ice shelf, the 2002 collapse of the Larsen-B ice shelf, a large iceberg breaking off of Larsen-B remnant ice shelf in 2006, and the 2008-2009 collapse of the Wilkins ice shelf. We present a series of ice velocity maps of the Larsen-B (remnant) and -C ice shelves and their tributaries spanning from 1997 to 2013. Velocity Measurements are based on spaceborne SAR data from RADARSAT-1 and -2, ALOS PALSAR, ENVISAT ASAR, TerraSAR-X and TanDEM-X. These Earth Science Data Records (ESDR) will be made available to the science community as part of a NASA funded MEaSUREs project. Our results show that the adjustment period following the Larsen-B collapse is not yet over. The surface velocity of the Larsen B remnant ice shelf continues to increase following the Larsen-B collapse. The speed at the ice front has more than doubled compared to 2000. Its major tributaries, Flask and Leppard Glacier, show an increase velocity increase in velocity on the trunk over that period. For Crane glacier, which lost ice shelf buttressing entirely following the 2002 collapse, the speed near the 2013 ice front almost tripled between 2000 and 2006. After that the speed started to recede, however, it is still about twice of what it was before the collapse of the shelf. In contrast, the Larsen-C ice shelf appears mostly stable in terms of surface velocity with a small increase over the last 13 years. The ice shelf is well bounded by a number of ice rises and islands. The southern tip of the ice shelf between Hearst Island and Dolleman Island, where ice flow is more or less insulated from the rest of Larsen-C, shows a slowdown for the observable period. Spaceborne SAR data were made available for this project courtesy of the Polar Space Task Group.
