The disappearance of the lake in Bernardo O’Higgins National Park was discovered in late May by park rangers, who were stunned to find a 130-foot-deep crater where a large lake had been just two months earlier, when they last visited the area.
Possible causes for the dam to be breached include a sudden input of water into the lake, an earthquake or avalanches of ice or rock. Casassa said the Chilean lake was fed by two glaciers, the Bernardo and the Tempano, "and both are receding."
The water level of the lake could have risen with the increasing flow from the melting glaciers. "At the same time, the increased amount of water opens a tunnel under the ice, emptying the lake," Casassa said.
Another glaciologist, Andres Rivera, said "most glaciers in the region are receding as a result of the global warming." This may both create new lakes or cause others to empty, he said. Casassa said glaciers can recede for other reasons than global warming. It can be the result of the natural dynamic of glaciers, which recede or grow.
"But I am convinced that in this case, it is the result of global warming," he said. The empty lake is about 4,921 feet above sea level. Romero, the head of the forest service, said another theory is that the water disappeared through huge cracks at the bottom of the crater. He said the cracks may have been caused by the strong quake that rocked the region on April 21.
The Australian, 23/6/2007, p. 14
Source: Erisk Net