Chilean Patagonia’s Vanishing Lake

Lake Cachet II, located in Chilean Patagonia,was reduced to a few puddles and large blocks of ice, after 200 million cubic liters of its water spilled out into the Baker River.

The Jorge Montt glacier, which has receded significantly in recent years. Photo: Centro de Estudios Científicos

The water in Cachet II is normally contained by the Colonia Glacier, which acts as a dam. However, rising temperatures have weakened the glacier wall. Since the walls are weaker, the water from the lake has twice this year made a tunnel between rocks and the glacier wall, thus managing to leak out.

This time it took less than 24 hours for the lake’s contents to drain out into the Baker River, dropping 31 meters in height and tripling the river’s contents.

It is the eleventh time since 2008 that the phenomenon, known as a Glacier Lake Outburst Flood (GLOF), has occured at Lake Cachet II. Indeed, experts believe that the rise of global temperatures will see its frequency increase further still. Of the 53 cases of GLOFs in Chile between 1896 and 2010, the majority have occurred in recent years.

The lake’s emptying has been used as an argument against the contentious HydroAysén project, since it aims to see dams built along the Baker River, into which Lake Cachet II empties.

GLOFs are not the only problem posed by rising global temperatures; a large number of Patagonian glaciers are receding, the most notable case in Chile being that of the Jorge Montt glacier. Although it is not certain that the shrinkage of these glaciers is due to global warming, it is thought to be a large contributing factor. This phenomenon is also a problem in Peru, whose glaciers have shrunk by over 22 percent in the last 38 years.

The disappearance of the lake has been observed for several years now, with experts warning about the negative environmental impacts.