Crack in the Earth: Greenland glacier loses ice island twice the size of Manhattan

It’s business as usual at the Petermann glacier, doing what a glacier does, calving ice into the sea. We reported on another chunk in 2010, four Manhattans in size. Borrowing from an oft used media ploy, at this rate, it will be down to ice cube size in ten years. I wonder though, if we’d ever have noticed any of this without MODIS? Keep that in mind when reading the claims.

From the University of Delaware — An ice island twice the size of Manhattan has broken off from Greenland’s Petermann Glacier, according to researchers at the University of Delaware and the Canadian Ice Service. The Petermann Glacier is one of the two largest glaciers left in Greenland connecting the great Greenland ice sheet with the ocean via a floating ice shelf.

Andreas Muenchow, associate professor of physical ocean science and engineering in UD’s College of Earth, Ocean, and Environment, reports the calving on July 16, 2012, in his “Icy Seas” blog. Muenchow credits Trudy Wohleben of the Canadian Ice Service for first noticing the fracture.

The discovery was confirmed by reprocessing data taken by MODIS, the Moderate Resolution Imaging Spectroradiometer aboard NASA’s Terra and Aqua satellites.

At 46 square miles (120 square km), this latest ice island is about half the size of the mega-calving that occurred from the same glacier two years ago. The 2010 chunk, also reported by Muenchow, was four times the size of Manhattan.

“While the size is not as spectacular as it was in 2010, the fact that it follows so closely to the 2010 event brings the glacier’s terminus to a location where it has not been for at least 150 years,” Muenchow says.

“The Greenland ice sheet as a whole is shrinking, melting and reducing in size as the result of globally changing air and ocean temperatures and associated changes in circulation patterns in both the ocean and atmosphere,” he notes.

Muenchow points out that the air around northern Greenland and Ellesmere Island has warmed by about 0.11 +/- 0.025 degrees Celsius per year since 1987.

“Northwest Greenland and northeast Canada are warming more than five times faster than the rest of the world,” Muenchow says, “but the observed warming is not proof that the diminishing ice shelf is caused by this, because air temperatures have little effect on this glacier; ocean temperatures do, and our ocean temperature time series are only five to eight years long — too short to establish a robust warming signal.”

The ocean and sea ice observing array that Muenchow and his research team installed in 2003 with U.S. National Science Foundation support in Nares Strait, the deep channel between Greenland and Canada, has recorded data from 2003 to 2009.

The Canadian Coast Guard Ship Henry Larsen is scheduled to travel to Nares Strait and Petermann Fjord later this summer to recover moorings placed by UD in 2009. These mooring data, if recovered, will provide scientists with ocean current, temperature, salinity and ice thickness data at better than hourly intervals from 2009 through 2012. The period includes the passage of the 2010 ice island directly over the instruments.

According to Muenchow, this newest ice island will follow the path of the 2010 ice island, providing a slow-moving floating taxi for polar bears, seals and other marine life until it enters Nares Strait, the deep channel between northern Greenland and Canada, where it likely will get broken up.

“This is definitely déjà vu,” Muenchow says. “The first large pieces of the 2010 calving arrived last summer on the shores of Newfoundland, but there are still many large pieces scattered all along eastern Canada from Lancaster Sound in the high Arctic to Labrador to the south.”

Prior to 2010, the last time such a sizable ice island was born in the region was 50 years ago. In 1962, the Ward Hunt Ice Shelf, on the northern coast of Ellesmere Island in Nunavut, Canada, calved a 230-square-mile island.

From the comments:

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David Ross says:

July 17, 2012 at 7:52 pm

“An ice island twice the size of Manhattan has broken off from Greenland’s Petermann Glacier … At 46 square miles (120 square km), this latest ice island is about half the size of the mega-calving that occurred from the same glacier two years ago.”

For perspective, the, later mentioned, ice island that broke free from the Ward Hunt Ice Shelf, in (pre-CAGW) 1962, was 230-square-miles, so equivalent to 10 Manhattans, which is still 4 Manhattans more than the 2010 and 2012 ice islands combined.

But if we took that ice and put it in a Lake Michigan amount of whiskey and vermouth and had a maraschino cherry the size of a small moon we’d have a Manhattan to beat them all :)

Can you even imagine the amount of shaved ice for martinis one could obtain from that hunk of ice. Similar actions over the eons in that part of Greenland probably have repeated the particular activity hundreds of times over the past thousand cycles. What should be brought out is that this particular area contains the few ground stations left in all of Canada, and respective Greenland.
It always is a "hot spot" in that vast area. Go a few hundred miles westward or northward and the temp gradients are different. Colder through all seasons. I can remember this point being brought out in one of Rusbo's rants some six or more years ago, as he was examining the ground station weather activities in that region.
Same deal. One witnessed the breaking off of parts of the protruding glaciers on the Greenland coast.
Normal for that particular geology.

“Iceland got its modern name from another visitor, the Norwegian Viking Flóki Vilgerðarson. The Landnámabók makes it clear that Flóki chose the uninviting name ísland (”ice land”) for the view of a distant fjord full of sea-ice that he glimpsed from a tall mountain. No doubt his choice was influenced by the fact that he was not at first taken with the land, and he bad-mouthed the place after his return to Norway. But eventually he changed his mind about it and moved there himself. The Landnámabók account is at odds with the common notion that Iceland was named for its glaciers, some of which are bigger than any in Europe.

You sometimes hear the story that Iceland was so named to discourage excessive immigration, but there seems to be no basis for this claim. Even if it’s true, it didn’t work very well. Between about 870 and 930, a period called the landnám, productive land in Iceland was free for the taking to all comers, and thousands of people immigrated from Norway, which was in political upheaval at the time. Landnám is usually translated “settlement,” but “land grab” is a more literal translation and comes closer to the point. Incidentally, the Irish priests disappeared around the beginning of the landnám, probably muttering to themselves, “There goes the neighborhood.”

Greenland got its name because its inhabitants sported blue-green skin from living near the sea. At least that’s what Adam of Bremen wrote (in Latin) in the eleventh century. As the old proverb says, “A fool, unless he knows Latin, is never a great fool.” I think it’s safe to say that Adam of Bremen was a great fool, at least on this point.

The real story behind the name is given in Erik the Red’s Saga, based on oral tradition and written down in the early thirteenth century in Iceland. After the Icelandic landnám was over, Erik the Red and his father Thorvald were forced to leave Norway because one or both of them was involved in killings (details are not given). After Thorvald died, Erik was involved in yet more killings, for which his punishment was three years’ vacation—er, I mean banishment from Iceland. (And you thought O. J. got off easy.)

He used the time to explore the rumored lands to the west. When his term of banishment expired, he returned to Icleand to invite his neighbors and friends to settle the new country with him. He purposely chose the pleasant name Grænland (”green land”) to attract settlers, but the choice wasn’t exactly misleading. Some parts of Greenland, especially the parts the Norse settled, really are green, as these pictures from the tourist board attest (www.greenland-guide.dk/outdoor_life_photo.htm). He may have been a killer, but at least he wasn’t a real-estate scam-artist. He didn’t have that much to gain by lying anyway, since he didn’t charge anyone for the land. As in Iceland a century before, the land was free for the taking. Natives had lived in the area in the past, but at the time of Erik’s voyage, only the northern part of Greenland was occupied by the Inuit (Eskimos).”

Here’s the source link:

http://www.straightdope.com/columns/read/1965/shouldnt-greenland-be-known-as-iceland-and-vice-versa

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