Glacier retreated so much that its meltwater switched course, in an event not documented in modern times
Geoscientist Dan Shugar gazes out over exposed sediments and dust storms at Kluane Lake in the Yukon in the summer of 2016. Covered in water just months before, the delta top was left exposed and prone to wind erosion after meltwater from the Kaskawulsh Glacier changed direction due to climate change. (Jim Best/University of Illinois)
Instead of flowing into the Slims River and then north to the Bering Sea, the water has changed course and now flows south toward the Kaskawulsh River, the Gulf of Alaska and the Pacific Ocean, scientists have found.
Also known as stream capture, river piracy is a term used to describe a geologic phenomenon where a stream or river is diverted toward another body of water. It’s usually caused by a dramatic tectonic event, such as a landslide or glacial dam collapse.
“This was the first event we could find where river piracy occurred right under our noses and due to contemporary climate change,” said Dan Shugar, a geoscientist at the University of Washington Tacoma and lead author of a study published Monday in the journal Nature Geoscience.
Yukon’s Kaskawulsh glacier in Kluane National Park. (CBC)
Previous cases of river piracy may have taken place thousands of years ago or more, said Shugar in an interview with CBC News.
A river gone missing
The discovery of the change happened last summer, quite by accident for this team of scientists.
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