Climate crisis causes “river piracy” in Canada
A Journal of People report
March and February 2017 were the second warmest March and February in 137 years of modern record-keeping, according to a monthly analysis of global temperatures by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York.
News reports from NASA’s Goddard Institute for Space Studies (NASA, Global Climate Change) in March and April said:
March 2017 was 1.12 degrees Celsius warmer than the mean March temperature from 1951-1980. The two top March temperature anomalies have occurred during the past two years.
March 2016 was the hottest on record, at 1.27 degrees Celsius warmer than the March mean temperature. March 2017’s temperature was 0.15 degrees Celsius cooler than March 2016, but 0.2 degrees Celsius warmer than any previous March.
The monthly analysis by the GISS team is assembled from publicly available data acquired by about 6,300 meteorological stations around the world, ship- and buoy-based instruments measuring sea surface temperature, and Antarctic research stations.
The modern global temperature record begins around 1880 because previous observations didn’t cover enough of the planet. Monthly analyses are sometimes updated when additional data becomes available, and the results are subject to change.
February 2017 was 1.1 degrees Celsius warmer than the mean February temperature from 1951-1980. The two top February temperature anomalies have occurred during the past two years.
February 2016 was the hottest on record, at 1.3 degrees Celsius warmer than the February mean temperature. February 2017’s temperature was 0.20 degrees Celsius cooler than February 2016.
A team of scientists say a melting glacier in Canada’s Yukon has caused a river to completely change course.
An April 18, 2017 datelined BBC report said:
“Their findings, published in Nature Geoscience, show how climate change can cause surprising geological events.
“The Slims River once flowed out to the Bering Sea, but now it flows into the Kaskawulsh River instead.
“This phenomenon, known as ‘river piracy’, typically takes centuries but the study documented it over the course of one spring.”
The “Slims River: Climate change causes ‘river piracy’ in Canada’s Yukon” headlined report said:
“‘Nobody’s ever seen a river piracy occur in modern times, at least to my knowledge,’ lead author Dan Shugar told the BBC.
“The geoscientist at the University of Washington Tacoma says he and six researchers from Canadian and American universities had planned to study the Slims River last summer.
“But when they arrived in the Yukon it was barely flowing. They discovered that a small channel had eroded in a large glacier that fed a number of small lakes.
“The glacial lakes used to feed two river systems – the Slims River and the Kaskawulsh River – but when water from one lake poured through the channel into another, it cut the Slims off from its water source.
“The event is known as river piracy or stream capture, and can take thousands of years. But the researchers documented the piracy of the Slims River in just one spring.”
The BBC report said:
“Prof Shugar said his colleague, John Clague, at Simon Fraser University in British Columbia, had predicted this event just a decade before because of the area’s unique geological formation. But no one knew when or how quickly the stream capture would occur.
“River gauges show an abrupt four-day drop in late May 2016, which then continued over the summer, the study found.
“By the time Prof Shugar and his associates got there, the Slims was basically ‘a long, skinny lake’.
“‘The Slims River was essentially cut off from how it was flowing before,’ he said.”
“The change in the river’s flow affected the whole landscape. Sheep are now grazing on the exposed river bank while other rivers in the area are running high. Fish population, wildlife and lake chemistry will continue to be affected, the study noted.
“In the big picture, Prof Shugar said, the piracy of the Slims is a reminder that climate change ‘may bring surprises that we are not appreciating fully and that we’re not necessarily prepared for’.”