Antarctica Just Got Smaller

Scientists at the University of Wisconsin-Madison have been keeping their eyes on a 4,200-square-mile iceberg that peeled off Antarctica's Ross Ice Shelf Thursday.

Researchers at the UW Antarctic Meteorological Research Center noticed the gigantic iceberg was about to separate after seeing it late last week on satellite images photographed from 435 miles in the atmosphere.

The iceberg is about 183 miles long and 23 miles wide - twice the size of Delaware.

"It's one of the biggies. We haven't seen one this large on this side of the continent in quite some time," said Matthew Lazzara, a senior research specialist at the UW center.

Lazzara, who has visited Antarctica several times, said the iceberg does not pose a threat to the South Pole's research stations, but could eventually barrel its way into the shipping lanes.

"I guess a berg of this magnitude breaks off every 50 to 100 years, and it's been that long for one to break off this size on this end of the continent," he said.

Lazzara said that it is soon to be certain if global warming is having any effect on Antarctica's icebergs.

"The ice shelves, this is their job. They calve off icebergs all the time, but they're usually much smaller," he said. "What we're hoping to learn is whether it will continue to do this and if that's the case, then we can say something about the atmosphere."