Researchers witness overnight breakup, retreat of Greenland glacier

Jul 12, 2010 by Mike Carlowicz
Images courtesy of DigitalGlobe

NASA-funded researchers monitoring Greenland's Jakobshavn Isbrae glacier report that a 7 square kilometer (2.7 square mile) section of the glacier broke up on July 6 and 7, as shown in the image above. The calving front - where the ice sheet meets the ocean - retreated nearly 1.5 kilometers (a mile) in one day and is now further inland than at any time previously observed. The chunk of lost ice is roughly one-eighth the size of Manhattan Island, New York.

Research teams led by Ian Howat of the Byrd Polar Research Center at Ohio State University and Paul Morin, director of the Antarctic Geospatial Information Center at the University of Minnesota have been monitoring satellite images for changes in the and its outlet glaciers. While this week's breakup itself is not unusual, Howat noted, detecting it within hours and at such fine detail is a new phenomenon for scientists.

"While there have been ice breakouts of this magnitude from Jakonbshavn and other glaciers in the past, this event is unusual because it occurs on the heels of a warm winter that saw no sea ice form in the surrounding bay," said Thomas Wagner, cryospheric program scientist at NASA Headquarters. "While the exact relationship between these events is being determined, it lends credence to the theory that warming of the oceans is responsible for the ice loss observed throughout Greenland and Antarctica."

The researchers relied on imagery from several satellites, including Landsat, Terra, and Aqua, to get a broad view of ice changes at both poles. Then, in the days leading up to the breakup, the team received images from DigitalGlobe's WorldView 2 satellite showing large cracks and crevasses forming.

DigitalGlobe Inc. provides the images as part of a public-private partnership with U.S. scientists. Howat and Morin are receiving near-daily satellite updates from the Jakobshavn, Kangerlugssuaq, and Helheim glaciers (among the islands largest) and weekly updates on smaller outlet .

Jakobshavn Isbrae is located on the west coast of Greenland at latitude 69°N and has been retreated more than 45 kilometers (27 miles) over the past 160 years, 10 kilometers (6 miles) in just the past decade. As the glacier has retreated, it has broken into a northern and southern branch. The breakup this week occurred in the north branch.

Scientists estimate that as much as 10 percent of all ice lost from Greenland is coming through Jakobshavn, which is also believed to be the single largest contributor to sea level rise in the northern hemisphere. Scientists are more concerned about losses from the south branch of the Jakobshavn, as the topography is flatter and lower than in the northern branch.

In addition to the remote sensing work, Howat, Morin, and other researchers have been funded by NASA and the National Science Foundation to plant GPS sensors, cameras, and other scientific equipment on top of the to monitor changes and understand the fundamental workings of the ice. NASA also has been conducting twice-yearly airborne campaigns to the Arctic and Antarctic through the IceBridge program and measuring ice loss with the ICESat and GRACE satellites.

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User comments : 7

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TegiriNenashi
1 / 5 (9) Jul 12, 2010
For a balanced, but not Politically Correct view see
http://www.iceage...iers.htm
Parsec
4.6 / 5 (11) Jul 12, 2010
No one who knows anything about climate change has ever suggested that ALL of the glaciers in the world are retreating. Climate change theories predict changes in global circulation ( lowering the temperature, perhaps drastically, in Europe) and lots of changes in rainfall patterns, with an overall global increase.

Basically, glaciers that are in areas that still experience very cold temps will grow because of the increased rainfall.

70-80% of the glaciers and ice packs in the world are not in this category and will continue their documented shrinking. Most if not all of Tegir's so called balanced view is in fact predicted by current climate change models. Its important to know the facts of what your criticizing before doing so, because you might end up supporting it, as is the case here.
TegiriNenashi
1 / 5 (10) Jul 12, 2010
I see: those glaciers that are shrinking are due to warming, and those that are growing are due to increased precipitation, how convenient!

There is no temperature increase, to begin with. The dog ate those guys homework (CRU records), didn't it? Sure we have relatively short track of satellite records and those show no temperature increase either. In the absence of temperature increase evidence any claim that "most of glaciers are shrinking" is dubious.
omatumr
1.8 / 5 (10) Jul 13, 2010
I see: those glaciers that are shrinking are due to warming, and those that are growing are due to increased precipitation, how convenient!


Right! "Newscience", purchased with public tax funds, is like "Newspeak" in George Orwell's novel "1984".

In reviewing the budgets of federal research agencies like EPA, NASA, DOE, etc, the National Academy of Sciences seems to have responsibilities like those handled by the Ministry of Truth in George Orwell's book.

With kind regards,
Oliver K. Manuel
antialias_physorg
3.9 / 5 (7) Jul 13, 2010
I see: those glaciers that are shrinking are due to warming, and those that are growing are due to increased precipitation, how convenient!

When you understand the difference between weather and climate then you will understand why this is so.
fixer
4.7 / 5 (6) Jul 13, 2010
Climate is what you expect,weather is what you get!
ppnlppnl
3 / 5 (2) Jul 13, 2010


Again we see the idiotic meme that it is the scientist and science journals that are somehow selling out. Keeriiist people. Exxon earned like 40 billion on on 400 billion of revenue a year or so ago. Thats just one oil company among many. And thats only one industry among many. Compare this to NOAA's budget of less than six billion.

I mean you have one thing correct. Government always has and always will sell out to the highest bidder. But that high bidder isn't scientist and it isn't environmentalists.

The irony is that the very people most concerned by intrusive unaccountable government are the very people most responsible for selling it to the highest bidder. As a result if global warming is addressed at all it will probably be by a liberal trying to run our economy on flower nectar and hugs.

Wait, my check just got here. I apologize to BP for my thoughtless rant and promise to move to Texas so I can vote for Joe Barton. I for one welcome our corporate overlords.

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