Atmosphere Journal Entry

Antarctic Ice Bridge Collapses (April 20, 2009)

Recent satellite pictures reveal that the thin ice bridge connecting Antarctica's Wilkins Ice Shelf to the rest of the Antarctic Peninsula has collapsed. As a result, huge chunks of broken ice and icebergs will be set adrift into the Southern Ocean. The collapse will likely speed the break up of the rest of the ice shelf.

The collapse highlights the alarming changes taking place in Antarctica due to rapidly changing climate. The Antarctic Peninsula, where huge ice shelves have existed for thousands of years, has been hit especially hard.

Scientists are keeping an eye on the Wilkins Ice Shelf as it disintegrates with rising temperatures. The ice shelf was stable for most of the 20th century, covering an area of roughly 6,000 square miles (16,000 square km). It started breaking apart in the 1990s. The shelf lost more than 700 sq. miles (1,800 sq. km) of ice in the past year alone.

An ice shelf is a ledge of ice floating on the ocean but attached to the land. Antarctica has lost several of them over the past two decades. Because ice shelves already float on the sea, they don't add to global sea level when they melt. It's a different story when land ice melts. If all of West Antarctica were to melt away, sea level could rise as much as 20 feet (6 meters), swamping coastal cities worldwide. If all of Antarctica melted away, sea level could climb a catastrophic 190 feet (57 m).