2017-04-17. Climate Change Reroutes a Yukon River in a Geological Instant.

posted Apr 21, 2017, 9:14 AM by Alan Gould

By John Schwartz, The New York Times. For GSS Climate Change chapter 8. Excerpt: In the blink of a geological eye, climate change has helped reverse the flow of water melting from a glacier in Canada’s Yukon, a hijacking that scientists call “river piracy.” This engaging term refers to one river capturing and diverting the flow of another. It occurred last spring at the Kaskawulsh Glacier, one of Canada’s largest, with a suddenness that startled scientists. A process that would ordinarily take thousands of years — or more — happened in just a few months in 2016. Much of the meltwater from the glacier normally flows to the north into the Bering Sea via the Slims and Yukon Rivers. A rapidly retreating and thinning glacier — accelerated by global warming — caused the water to redirect to the south, and into the Pacific Ocean. Last year’s unusually warm spring produced melting waters that cut a canyon through the ice, diverting more water into the Alsek River, which flows to the south and on into Pacific, robbing the headwaters to the north. The scientists concluded that the river theft “is likely to be permanent.” The impacts of climate change, like sea level rise or the shrinkage of a major glacier, are generally measured over decades, not months as in this case. “It’s not something you could see if you were just standing on the beach for a couple of months,” Professor Shugar said....  https://www.nytimes.com/2017/04/17/science/climate-change-glacier-yukon-river.html