Channelized bottom melting and stability of floating ice shelves

• Published in: Geophysical Research Letters
• Main Authors: Rignot, E, Steffen, K
• Format: Article in Journal/Newspaper
• Language: English
• Published: eScholarship, University of California 2008
• Subjects: Arctic; Arctic Ocean; Greenland; glacier; Ice Shelf; Ice Shelves; Petermann glacier
• Online Access: http://www.escholarship.org/uc/item/0b88p676

The floating ice shelf in front of Petermann Glacier, in northwest Greenland, experiences massive bottom melting that removes 80% of its ice before calving into the Arctic Ocean. Detailed surveys of the ice shelf reveal the presence of 1-2 km wide, 200-400 in deep, sub-ice shelf channels, aligned with the flow direction and spaced by 5 km. We attribute their formation to the bottom melting of ice from warm ocean waters underneath. Drilling at the center of one of channel, only 8 m above sea level, confirms the presence of ice-shelf melt water in the channel. These deep incisions in ice-shelf thickness imply a vulnerability to mechanical break up and climate warming of ice shelves that has not been considered previously. Copyright 2008 by the American Geophysical Union.