An immense river that flowed from one of Canada’s largest glaciers vanished over the course of four days last year, scientists have reported, in an unsettling illustration of how global warming dramatically changes the world’s geography.

    The abrupt and unexpected disappearance of the Slims river, which spanned up to 150 metres at its widest points, is the first observed case of “river piracy”, in which the flow of one river is suddenly diverted into another.

    Between 1956 and 2007, the Kaskawulsh glacier retreated by 600-700m. In 2016, there was a sudden acceleration of the retreat, and the pulse of meltwater led to a new channel being carved through a large ice field. The new channel was able to deliver water to the Alsek’s tributary whose steeper gradient resulted in the Slims headwater being suddenly rerouted along a new southwards trajectory.

CBC story is here.

The Guardian story is here



posted by lil: 571 days ago