This image provided by the Byrd Polar Research Center, Columbus, Ohio, taken July 25, 2008, shows a growing giant crack

August 22, 2008—Greenland's glaciers are breaking up at a worrisome pace, new satellite images show.

A gigantic, 11-square-mile (29-square-kilometer) chunk of the Petermann Glacier in northern Greenland broke off between July 10 and July 24.

The collapsed section is comparable in size to half of Manhattan Island (see the breakup in three images above).

Petermann covers 500 square miles (1,295 square kilometers). (See a Greenland map.)

The broken chunk has led scientists to predict a section of Petermann, the Northern Hemisphere's longest-floating glacier, will disappear by 2009.