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.
"The Greenland ice sheet is being reduced not just in size, but in volume," he said. "The big and broader climate change story is what's happening all around Greenland."
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."
"It's going to take awhile to understand how significant a loss this is," Scambos said.
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.
Air temperatures in the region have warmed more than 4.5 degrees Fahrenheit, or 2.5 degrees Celsius since 1987, a rate five times that of the rest of the world. But Muenchow cautioned against directly linking air temperatures to the glacier's behavior, noting it has a floating ice shelf.
"Air temperatures are not very important, because 80 percent of the melting of this glacier takes place from below, in the ocean," he said.
Top Picks
Ice split from Greenland glacier is twice the size of Manhattan
- Top Picks
-
-
Are the world's great cities ready for rising waters and freak storms?
The list of metropoles threatened by rising seas and freak storms is alarmingly long, if (from a U.S. viewpoint) reassuringly international.
-
How the world would vote in the U.S. election
Sure, polling may suggest that the world isn't following the 2012 U.S. election as closely as it did the 2008 presidential race, but that doesn't mean people overseas don't care about the campaign's outcome.
-
Talking to kids about elections - without bias
As much as we might want the election to be over, in these last few days of the campaign, there's a real opportunity for parents to help educate the next generation of voters.
-
Viral video: 4-year-old moved to tears over too much election talk
A 4-year-old girl from Colorado tells her mother she's tired of hearing about "Bronco Bamma and Mitt Romney." Elizabeth Evans told ABC News that her daughter, Abigael, had been listening to election coverage on NPR in the car after daycare when she got upset.
-
Sandy leaves devastation behind in N.Y., N.J.
Sandy, the hybrid hurricane/nor'easter, began to lose steam Tuesday as it drifted across Pennsylvania and veered toward Canada. But the damage was done, and it will go down as a historic storm.
-
Survivor cat reunites with family 17 months after tornado
The Kent family resigned themselves to life without their beloved cat, Simba, when a powerful tornado destroyed their home on May 22, 2011.
-
What growing tablet market means for gadget-lovers
This holiday season is turning into a battle among tech giants for the hand-held computer that every tech geek, executive, student and child will be carrying around next year.
-
Regulators, accreditors go after online colleges
The rising cost of college may change with the innovative use of new technologies, which show promise in offering high-quality instruction at a low cost. Unfortunately, government regulation and accrediting organizations may slow that progress.
-
Sandy moves west, leaving devastation, deaths in its wake
The Atlantic superstorm Sandy churned across Pennsylvania Tuesday after blacking out much of southern Manhattan and leaving a trail of flooding, death and destruction along the East Coast.
-
VIDEO: Sandy brings more snow to Appalachian Mountains
Snow continues to fall in the Appalachian Mountains thanks to superstorm Sandy, leaving an estimated 150,000 people without power.
- More Top Picks Headlines
-
Tim Cook Defends Apple's Tax Accounting
AP Photograher: 'It Was a Miracle' They Got Out
Raw: Crews Search for Survivors of Okla. Tornado
Raw: Tearful Reunion After Okla. Tornado
OKC Hospital Describes Treating Tornado Wounded
Obama Pledges Urgent Aid for Tornado Victims
Raw: Massive Funnel Clouds in Oklahoma
