Thursday, January 14, 2010

Now that's an Iceberg!

Within the past couple days a massive piece of ice broke off of Antarctica's Filchner Ice Shelf. The images above taken on January 12 and January 13 by NASA’s Terra and Aqua satellites captured the huge piece of ice as it was breaking away. At about 150 kilometers long by 25 kilometers wide, the piece of the ice shelf that broke away was larger than the state of Rhode Island.

The ice shelf is a portion of Antarctica’s expansive ice sheets that extend over the ocean. As fresh snow falls on the ice sheet, the weight compresses it out like pancake batter spreading on a pan. The ice shelf grows out until waves and ocean currents break off the edge, forming a new iceberg.

This process is known as "ice calving" --
a sudden release and breaking away of a mass of ice from an iceberg, ice shelf or glacier. Although calving can be caused by tidal and seismic events, periodic calving and disintegration of ice masses are considered normal geological processes.