'River Piracy' In Focus: How Climate Change Made Canadian Glacier River Disappear Within Days
In yet another manifestation of the warming induced by climate change, the overnight disappearance of a river in North Canada has been reported in a study.
The phenomenon, known as river piracy, has been attributed to global warming caused by the rapid rise of greenhouse gasses in the atmosphere and the consequent heating up caused by the trapped gasses such as carbon dioxide and methane.
The Slim River's piracy was the first ever case in modern times.
Millennium Long Activity In A Few Days
The study highlights the rapid retreat of the flow of water from the Kaskawulsh Glacier in Canada's Yukon territory.
River Piracy, one river capturing the flow of another river, normally takes thousands of years to establish. In northern Canada, however, river piracy has happened in a short span of a few days in 2016.
"Nobody to our knowledge has documented it happening in our lifetimes," commented Daniel Shugar, co-author and an academic with the University of Washington.
The meltwater emanating from the Kaskawulsh Glacier normally flows to the Bering Sea to the north through the Slims and Yukon Rivers, according to the study.
However, a rapidly thinning glacier abetted by global warming pushed the water to the south and to the Pacific Ocean.
The trigger was the unusually warm spring in 2016 that caused the melting of waters cutting a canyon through the ice and diverting the water into the Alsek River flowing to the south and to Pacific. That made the headwaters bound for the north going to the south.
"For the last 300 years, Slims River flowed out to the Bering Sea, and the smaller Kaskawulsh River flowed to the Gulf of Alaska. What we found was the glacial lake that fed Slims River had actually changed its outlet," noted Shugar.
Warming Effect From Climate Change
In the Slims River piracy case, the drainage shifted overnight and showed how the heating of the atmosphere by fossil-fuel emissions has driven up the river's dramatic disappearance.
"To me, it is kind of a metaphor for what can happen with sudden change induced by climate," said John Clague, a chair in natural hazard research at Simon Fraser University and a co-author of the report.
Climate Change Rapid And Unexpected
The incident is also a wake-up call to all and a caution to the thinking that climate change is a slow and gradual process. The vanishing act of the river showed that the effects of climate change can be rapid and there will be drastic implications for the society.
According to experts, river piracy or stream capture mainly happens from the tectonic motion of the Earth's crust. In the case of Slims River, the change came as a glacial dam and was a least anticipated shift.
In a Nature Geoscience paper, Rachel M. Headley, the glacier expert at the University of Wisconsin-Parkside, said this "unique impact of climate change" will be strewn with broad consequences. She said as the world warms, there will be more melting of glaciers. Populations relying on glacial meltwater will have to pay special attention to the emerging processes and consequences.