Gopal Krishna
A vast river flowing from one Canada’s largest glaciers vanished in just four days last year, due to the glacier’s meltdown propelled by climate change.Canada’s Slims river which, according to a Guardian report, spanned up to 150 metres at its widest points had been flowing for hundreds of years, carrying water from the massive Kaskawulsh glacier.
Between 26 to 29 May 2016, spurred by a massive heat wave, the glacier began melting at a much faster pace. The severe meltdown ended up changing the flow of its water, which now started heading to the Gulf of Alaska — thousands of miles to the opposite of Slims river.
This dramatic effect of global warming was documented by team of experts who had been following the glacier and its steady retreat.
There observations were published in the journal Nature on Monday.
“We went to the area intending to continue our measurements in the Slims river, but found the riverbed more or less dry. The delta top that we’d been sailing over in a small boat was now a dust storm. In terms of landscape change it was incredibly dramatic,” James Best, a geologist at the University of Illinois, told Guardian.
These scientists are now calling this phenomenon a case of ‘river piracy’ — wherein the flow of one river is suddenly diverted into another.
According to the report, “river piracy can dramatically change the routing of water and sediment, with a profound effect on landscape evolution.” Experts also observed that though stream piracy has been investigated in glacial environments in the past, it has usually occurred over longer timescales.
In this case, however, Slims River was reduced to a thin stream in mere four day, while the south-flowing Alsek river (where water from Kaskawulsh glacier is now heading) became 60 to 70 times larger than the Slims. Both rivers had earlier been comparable in size.
The report also noted how the effect of river piracy is not limited to the immediately affected lake. In the case of Slims River, for example, two other rivers that Slims flowed into — the Kluane river and the Yukon river — have also been affected.
The biological effects of these rivers drying can be quite profound for neighbouring ecosystems. Scientists have already recorded massive sediment erosion in these areas, and are now worried about the long term implications on surrounding human and biological communities.
INDIATODAY.INTODAY.IN – Gopal Krishna Web: www.toxicswatch.org, www.asbestosfreeindia.org
Feedback: Dear Friends of the Western Ghats,
River vanishes ! not a new phenomena for me. It happened in the case of the KALI RIVER. The stretch of river vanishes due to the “river piracy” from the Bommanhalli Pick Up Dam onwards it is intentionally blocked to take it in a tunnel and it falls down at force to reach the Nagjari Power House. and reappears after Nagjari. From Bommanhalli Pick Up Dam downwards the river vanishes, I showed this phenomena to my many friends who visited this stretch of the Kali River. They all said – it is all for the POWER. natural course of water is diverted and only during rainy season one can find some water in the heart of the western ghats.
Impact on Biodiversity, local climate change there is no scientific study.
Regards, Hemanta R Naik 919844201252, Dandeli – 581325
Source: WaterWatch@yahoogroups.com
