A University of Delaware researcher captured headlines around the world when he reported that an “ice island” four times the size of Manhattan had calved from Greenland’s Petermann Glacier. The last time the Arctic lost such a large chunk of ice was in 1962.
“In the early morning hours of August 5, 2010, an ice island four times the size of Manhattan was born in northern Greenland,” said Andreas Muenchow, associate professor of physical ocean science and engineering in UD’s College of Earth, Ocean, and Environment. Muenchow’s research in Nares Strait, between Greenland and Canada, is supported by the National Science Foundation.
Satellite imagery of this remote area at 81° N latitude and 61° W longitude, about 620 miles south of the North Pole, revealed that Petermann Glacier lost about one-quarter of its 43-mile-long floating ice-shelf.
Trudy Wohlleben of the Canadian Ice Service discovered the ice island within hours after NASA’s MODIS-Aqua satellite took the data on Aug. 5, at 4:20 EDT, Muenchow said. These raw data were downloaded, processed and analyzed at UD in near real-time as part of Muenchow’s NSF research.
Petermann Glacier, the parent of the new ice island, is one of the two largest remaining glaciers in Greenland that terminate in floating shelves. The glacier connects the great Greenland ice sheet directly with the ocean.
The new ice island had an area of at least 100 square miles and a thickness up to half the height of the Empire State Building.
“The fresh water stored in this ice island could keep the Delaware or Hudson rivers flowing for more than two years. It could also keep all U.S. public tap water flowing for 120 days,” Muenchow said.
The island has since broken into two large pieces, which entered Nares Strait, a deep waterway between northern Greenland and Canada where, since 2003, a UD ocean and ice observing array has been maintained by Muenchow with collaborators in Oregon, British Columbia and England.
“In Nares Strait, the ice island encountered real islands much smaller in size and broke into smaller pieces as it was propelled south by the prevailing ocean currents. These pieces will likely follow along the coasts of Baffin Island and Labrador, to reach the Atlantic within the next two years,” Muenchow said.
The last time such a massive ice island formed was in 1962 when Canada’s Ward Hunt Ice Shelf calved a 230-square-mile island, smaller pieces of which became lodged between real islands in Nares Strait. The ice island was the largest piece of ice to break off Petermann Glacier since the Polaris Expedition of 1871.