A squad of scientists Monday chronicle what they're describing as the first case of large-scale river restructing as a result of human-caused climate change.
They found that in mid-2016, the withdrawl of a very large glacier in Canada's Yukon territory led to the rerouting of its broad 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, a bit than to the Bering Sea.
The Scientists 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," said lead study author Daniel Shugar of the University of Washington, Tacoma of the Slims River, which lost much of its flow due to 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."
The study was advertised in Nature Geoscience. Shugar attented the study with researchers from six different Canadian and U.S. universities.
The study found that the filling of the Slims River in turn deprived Kluane Lake, the largest body of water in the Yukon area. The lake level was at a record low last August, and two small association that live on the lake may now have to adjust to the lower water levels.
"The Kluane lake level dropped last year and is likely to continue dropping," Shugar said. "If it drops enough that the lake level is below its other outlet, at the north end, it becomes what is called a closed basin. That will have changes to the chemistry, the structure of the lake, the biology.”