Big chunk of Greenland glacier breaks off

Seven-square miles of a Greenland glacier broke up on July 6 and 7, moving the edge of the glacier a mile inland in one day, the furthest inland it has ever been observed. While such calving of glaciers isn't rare, seeing it happen at high resolution by satellite in almost real time is.

NASA-funded researchers have been monitoring Greenland's Jakobshavn Isbrae using satellite images from the Landsat, Terra, Aqua and DigitalGlobe's WorldView 2 satellites. The breakup was detected hours after it happened by Ian Howat of the Byrd Polar Research Center at Ohio State University and Paul Morin, director of the Antarctic Geospatial Information Center at the University of Minnesota.

"This event is unusual because it occurs on the heels of a warm winter that saw no sea ice form in the surrounding bay," Thomas Wagner, cryospheric program scientist at NASA Headquarters, said in a release. "While the exact relationship between these events is being determined, it lends credence to the theory that warming of the oceans is responsible for the ice loss observed throughout Greenland and Antarctica."

Jakobshavn Isbrae is located on the west coast of Greenland. It has retreated more than 27 miles since 1850, six of them in the last decade. Jakobshavn is also believed to be the single largest contributor to sea level rise in the northern hemisphere.