An iceberg has been born — and it’s big
An iceberg twice the size of Manhattan tore off one of Greenland’s largest glaciers, illustrating another dramatic change to the warming island in the North Atlantic.
For several years, scientists had been watching a long crack grow near the tip of the Petermann Glacier. On Monday, NASA satellites showed it had broken completely, freeing an iceberg measuring 46 square miles.
A massive ice sheet covers about four-fifths of Greenland. Petermann Glacier is mostly on land, but a segment sticks out over water like a frozen tongue, and that’s where the break occurred.
The same glacier spawned an iceberg twice that size two years ago. Together, the breaks made a large change that’s got the attention of researchers.
Global warming: “It’s dramatic. It’s disturbing,” said University of Delaware professor Andreas Muenchow, who was one of the first researchers to notice the break. “We have data for 150 years and we see changes that we have not seen before.”
Researchers suspect global warming is to blame, but can’t prove it conclusively yet. Glaciers do calve icebergs naturally, but what’s happened in the last three years to Petermann is unprecedented, Muenchow and other scientists say.
If the break-off cycle continues, and more of the Petermann is lost, the melting would push up sea levels, one scientist said. The ice lost so far was already floating, so the breaks don’t add to global sea levels.
Northern Greenland and Canada have been warming five times faster than the average global temperature, Muenchow said. Temperatures have increased there by about 4 degrees Fahrenheit in the last 30 years, Scambos said.
Where do they go? The new iceberg is likely to follow the path of the one in 2010, Muenchow said. That broke apart into smaller icebergs headed north, then west and last year started landing in Newfoundland, he said.
It’s more than glaciers in Greenland that are melting. Scientists also reported this week that the Arctic had the largest sea ice loss on record for June.
University of Delaware on the iceberg: http://www.udel.edu/udaily/2013/jul/glacier-071612.html
National Snow and Ice Data Center: http://nsidc.org/
Reported by SETH BORENSTEIN of the Associated Press. He can be followed at http://twitter.com/borenbears