In Chilean Patagonia resides Bernardo O'Higgins National Park, the largest of Chile's protected areas.
The park includes a great part of the Southern Patagonian Ice Field. One of its main attractions is the glacier Pío XI, from which enormous ice blocks periodically spall. The Pío XI glacier is the largest glacier of the South hemisphere outside of Antarctica, covering an area of 1,265 km², advancing over the past 50 years by more than 10 kilometers; one of its tongues measures approximately 6 kilometers. The ice face of the glacier is approximately 75 meters in height (about 30 floors of a conventional building) and the falling ice generates waves exceeding 10 meters in height; significant enough to rock larger vessels. Other outlet glaciers are Chico, O'Higgins, Jorge Montt, Bernardo, Témpano, Occidental, Greve, Penguin and Amalia.
In May, it was discovered that a lake which had been 10-12 acres in size was no longer there, leaving a 130 foot deep crater. Two months prior, all had appeared to be normal.
On Monday, scientists were able to draw preliminary conclusions that the lake's disappearance was a caused by global warming.
Chile's Center of Scientific Studies glaciologist Andres Rivera believes that melting glaciers in the area raised the water level in the lake to an extreme level, resulting in water pressure sufficient to overwhelm a glacier that had been acting as a dam. Water was then able to flow into a nearby fiord and ultimately to the sea.
"On one side of the Bernardo glacier one can see a large hole or gap, and we believe that's where the water flowed through," Rivera said in a navy communique. "This confirms that glaciers in the region are retreating and getting thinner."...
As glaciers retreat lakes form behind natural dams of ice or moraine, earth and stones pushed up by a glacier. Those relatively weak dams can be breached suddenly, causing the lake to drain.
The advance and retreat of glaciers is part of the normal dynamics of the Patagonia but climate change was distorting the process, Rivera said.
"This would not be happening if the temperature had not increased," Rivera said.
Cross-posted at Ecotality Blog
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