The Slims River in northern Canada has dried up in just four days, according to a scientific study published Monday.
The Alsek River has flown water from its neighboring Slims River. Finally, climate change has pushed it a bit.
The phenomenon is known as “ river piracy “, explained by scientists by the melting of the source glacier responsible for distributing water to different paths. It is the first “river piracy” known in the modern period, and the first to be directly attributable to global warming , researchers said in a study published Monday (April 17th) by the British scientific journal Nature Geoscience.
A new consequence of unprecedented climate change. “So far, a lot of scientific work has looked at the surrounding glaciers and climate change as a source of rising sea levels,” said Dan Shugar of the University of Washington, one of the authors of the study , In a press release . “Our study shows that there may be other underestimated and unanticipated consequences of melting ice.”
“Day after day we could see the level of the river drop”
The piracy of the Slims River began last year on the edge of the gigantic Kaskawulsh glacier that stretches over 25,000 square kilometers across the Yukon Territories in northern Canada. For hundreds of years the glacier had supplied water to the basins of the Slims River, which flows into the Bering Sea, and the Kaskawulsh River, which empties into the Gulf of Alaska.
The researchers found that a new 30-meter canyon had formed in the glacier and diverted its water currents from the adjacent lake that usually feeds the Slims River. A diversion to the Kaskawulsh River, which supplies the Alsek River with water.
As a result, the Alsek River – a popular destination for rafting enthusiasts – boosted by “stolen” water became much higher than last summer at the same time.
Meanwhile, the Slims River has turned into a common creek. Kluane Lake, fueled by its waters, was so low that the residents had difficulty putting their boats into the water. Dust fled from the dried-up valley, making air traffic difficult on some days, local media Yukon News said last June.
Dan Shugar and the rest of the team, including Jim Best of the University of Illinois and John Clague of Simon Fraser University in Canada, were expected to observe the Slims River in August 2016. Except that The Slims River suddenly turned into a “long, thin lake,” said Dan Shugar. The river, normally three meters deep, had suddenly dried up from 26 to 29 May, shortly after a canyon had formed in the source glacier.
“Day after day, we could see the level of the river down,” recalls the researcher.
Whose fault is it ?
Scientists have identified two main reasons why the glacier has retreated several kilometers from where it was in the last century. After having spread out during a cold period several centuries ago – the small ice age – the glacier naturally readjusted its size in the warmer times that followed. Then, the greenhouse gas emissions hit it hard.
The team goes even further by explaining that the probability of the glacier melting because of “constant climate warming” would be 0.5%, which leaves 99.5% “chance” that the real culprit is the Climate change.
Canadian scientists who observed the phenomenon last year are still divided on the role of climate change caused by men in the melting of the glacier.
“Would this event have occurred without anthropogenic climate change? Probably,” said Kristen Kennedy, a geologist at the Yukon Geological Survey Center last summer.
“It’s incredible to see. It’s a natural phenomenon that happens right in front of you, few people have the opportunity to see that kind of thing in their lives,” she explained.
Richard Alley, a glacier expert at the University of Pennsylvania, who was not part of the study, told The Associated Press that the findings reconfirmed “that climate change has wide, widespread and surprising changes.”