Images capture rapid retreat of glacier in Patagonia

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Images capture rapid retreat of glacier in Patagonia

Updated: December 10, 2011 - 5:01 PM

Researchers released a series of time-lapse photos showing the dramatic retreat of a glacier in Patagonia.

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This combo of four photo grabs taken form a video released by the private organization 'Centro de Estudios Cientificos', CECs, shows the retreat of the Jorge Montt glacier in Chile's Patagonia in a year time period, from Feb. 2010 until Jan. 2011. According to Chilean scientist Andres Rivera, Chief of the Glaciology Lab at CECs, the images show that the snout of Jorge Montt Glacier retreated 1 kilometer (more than half a mile) between Feb. 2010 and Jan. 2011.

Photo: Ho, Associated Press - Ap

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SANTIAGO, CHILE

Researchers released a series of time-lapse photos showing the dramatic retreat of a glacier in Patagonia. ¶ The Jorge Montt Glacier is shrinking faster than any other in Chile, with its snout retreating 1 kilometer (more than a half mile) between February 2010 and January 2011, glaciologist Andres Rivera said. ¶ Rivera said that global warming is a factor and that the glacier also is melting especially quickly because it partly rests in the waters of a deep fjord.

Rivera has studied dozens of glaciers as a researcher at the Center of Scientific Studies in Valdivia, Chile. He said he and his colleagues didn't know how rapidly the glacier was shrinking until they put up two cameras with solar panels to charge the batteries and programmed them to shoot four frames a day.

"It was more or less clear that this was one of those retreating most quickly. But we didn't expect in the year of working with these cameras that it would retreat a kilometer more. That was a surprise," he said.

The glacier is about 1,100 miles south of Santiago in the Southern Patagonian Ice Field, which blankets a wide swath of the Andes between Chile and Argentina. "Patagonia has experienced climate changes at levels much more moderate than those observed in the rest of the world," Rivera said. "However, almost all the glaciers of the region have lost area, and Jorge Montt is the one that has the record retreat."

The researchers believe that based on a map from 1898, this glacier has retreated about 12 miles since then, Rivera said. It is a tidewater glacier that calves and releases icebergs as it advances into the fjord. "Such glaciers typically do retreat in response to warming. But the speed of the retreat is controlled by the ability of icebergs to break off in the fjord, not by the rate of warming," said Richard Alley, a glaciologist at Penn State University.

Rivera agreed, saying that he thinks climate change is the key trigger and that local conditions are also having a big influence. The retreat rate "is quite exceptional," said Michel Barer, a researcher at McGill University in Montreal.

Neil Glasser, a British glaciologist, said: "We know that many glaciers in South America are retreating, but this one is retreating ten times faster than the land-based glaciers. It shows how sensitive calving glaciers are to warming atmospheric [conditions] and ocean waters."

Patagonia's mountain glaciers are so colossal that scientists believe they aren't in danger of vanishing in the coming centuries. But elsewhere, scientists expect glaciers to dwindle. Western Canada is losing its mountain glaciers and many of them are likely to disappear in the next century, said Garry Clarke of University of British Columbia.

ASSOCIATED PRESS