They found that in mid-2016, the retreat of a very large glacier in Canada’s Yukon territory led to the rerouting of its vast stream of meltwater from one river system to another — cutting down flow to the Yukon’s largest lake, and channeling freshwater to the Pacific Ocean south of Alaska, rather than to the Bering Sea.
The researchers dubbed the reorganization an act of “rapid river piracy,” saying that such events had often occurred in the Earth’s geologic past, but never before, to their knowledge, as a sudden present-day event. They also called it “geologically instantaneous.”
“The river wasn’t what we had seen a few years ago. It was a faded version of its former self,” lead study author Daniel Shugar of the University of Washington at Tacoma said of the Slims River, which lost much of its flow because of the glacial change. “It was barely flowing at all. Literally, every day, we could see the water level dropping, we could see sandbars popping out in the river.” [Continue reading…]