New photos of disappearing glacier
Researchers in Chile have 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 more than a half a mile between February 2010 and January 2011, glaciologist Andres Rivera said.
Mr Rivera said global warming was a factor and that the glacier was also melting especially quickly because it partly rests in the waters of a deep fjord.
Researchers presented a video showing the glacier's year-long retreat through a total of 1,445 time-lapse photos. It is one of various similar projects by researchers around the world documenting the loss of glaciers.
Mr Rivera, who has studied dozens of glaciers as a researcher at the Centre of Scientific Studies in Valdivia, said he and his colleagues did not 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.
The glacier is about 1,100 miles south of Santiago in the Southern Patagonian Ice Field, which blankets a wide swathe 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," Mr 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 roughly 12 miles since then, Mr 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 prominent glaciologist at Penn State University.
Mr Rivera agreed, saying that he thinks climate change is the key trigger and that local conditions at the glacier are also having a big impact. He said his team measured the fjord's depth at about 1,300 feet in places, which was considerably deeper than they had thought.