NASA's Terra Earth-observing satellite captured this image of Pine Island Glacier in West Antarctica on Nov. 13, 2011, after a research team discovered a huge 19-mile (30-km) -long crack running across it.

Members of the Operation IceBridge mission spotted the crack during a DC-8 flight over Pine Island Glacier (PIG) on Oct. 14, 2011. It's estimated to be up to 260 feet (80 meters) wide and 195 feet (60 meters) deep.
Eventually the crack will shear the glacier off completely, creating an ice island spanning 350 square miles (900 sq. km).
The Pine Island Glacier is a major ice stream that drains 10 percent of the entire West Antarctic Ice Sheet. Although a warming climate and warmer seas have affected glaciers elsewhere in Antarctica, calving events like this have been happening steadily on PIG over the past few decades, at least. 
"It's part of a natural cycle, but it's still very interesting and impressive to see up close," said IceBridge project scientist Michael Studinger in Oct. 2011. "It looks like a significant part of the ice shelf is ready to break off."
Due to fuel supply issues Operation IceBridge was forced to cancel their last flight, departing Antarctica on Nov. 22. Nevertheless the mission was a success, providing scientists with valuable data on ice thickness and trends affecting global sea-level rise... even if a few cracks were discovered along the way

Source：http://news.discovery.com/earth/antarctic-crack-nasa-big-pic-120201.html

Provided by:

Center for Earth Observation and Digital Earth,CAS;The Lanzhou Branch of the National Science Library/The Scientific Information Center for Resources and Environment,CAS