Huge iceberg breaks free from Greenland's Petermann Glacier

A chunk of ice twice the size of Manhattan has parted from Greenland's Petermann Glacier, a break researchers at the University of Delaware and Canadian Ice Service attributed to warmer ocean temperatures.

The separation along Greenland's northwest coast, which took place Monday, represents the second major calving event for the glacier in the past three years.

In August 2010, the Petermann Glacier lost an area of roughly 97 square miles, compared with the 46 square miles that just split off this week.

Andreas Muenchow, an associate professor of physical ocean science and engineering at the University of Delaware, said the glacier's end point is now at "a location where it has not been for at least 150 years."

"The Greenland ice sheet is changing rapidly before our eyes," Muenchow said in an interview, adding that while "no individual glacier will be the canary in the coal mine" recent warming has transformed the overall ice sheet.

Ted Scambos, the lead scientist for the National Snow and Ice Data Center at the University of Colorado, said scientists will now be monitoring whether the glacier's flow rate will accelerate "because of its loss of this chunk of ice at the front of it."

The Petermann Glacier's flow accelerated between 10 and 20 percent after the 2010 calving event, Muenchow said, adding researchers were still waiting to see if that was a short-term increase or would persist over time.

Polar researcher Jason Box of Ohio State University noted that the 2010 calving was "the largest in the observational record for Greenland."

He correctly predicted last summer that the piece that just broke off, about half the size, was on the brink.

Box could not be reached for comment Tuesday.

By Juliet Eilperin The Washington Post

By Juliet Eilperin
The Washington Post