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N.W.T. scientists predict 'catastrophic lake drainage' due to thawing permafrost

Scientists in the Northwest Territories have issued a warning of a 'catastrophic lake drainage' due to thawing permafrost at a remote lake just south of the treeline.

Flash flood could happen at any time during the summer or fall of 2015, scientists say

This lake, near Fort McPherson, N.W.T., is poised to disappear when a permafrost slump encroaches on its edges. A flash flood could happen at any moment, according to the N.W.T. Geological Survey. (Scott Zolkos, University of Alberta/NTGS)

Scientists in the Northwest Territories are warning of a "catastrophic lake drainage" due to thawing permafrost at a remote lake just south of the treeline. 

The Northwest Territories Geological Survey warns that a flash flood could happen any time without warning this summer or fall. But scientists expect it to happen sometime during the next couple of weeks. 

The lake lies about 20 km west of Fort McPherson, N.W.T., west of Husky Lake. (Google Maps)

No homes or people are threatened. However, the government is warning people to avoid travelling or camping in the area. 

Steve Kokelj, a permafrost scientist with the territorial government, said there is a traveller's cabin in the area, but it's rarely used in the summer.

"The risk to people is relatively low, but nonetheless it's something people in the area should be aware of," Kokelj said.

"Once the water starts to erode the permafrost in the head of this slump, [the water] will go very very quickly."

The small lake lies about 20 kilometres west of Fort McPherson, N.W.T., home to about 800 people. It's to the west of Husky Lake. 

It's right next to a growing permafrost slump, which is caused when permafrost in the ground begins to melt, causing the ground to sink.

"In this case we have a slump that's growing up a slope and there happens to be a lake at the top of that slope," Kokejl said. "Fortunately it's a relatively small lake, but as that slump grows and the ice thaws, it sort of chews its way up the slope."

The lake will be monitored as part of a government-led permafrost research project.

Looking northeast at the lake and the permafrost slump. (Scott Zolkos, University of Alberta/NTGS)
Looking south at the lake. (Scott Zolkos, University of Alberta/NTGS)
Point three on this map shows the small lake lies. It's west of Husky Lake, west of Fort McPherson, N.W.T. (NTGS)