Permafrost slump near Alaska Highway in Yukon eats up 13 more metres of land

Not far from Whitehorse, and just a stone's throw from the Alaska Highway, a thawing permafrost slump eroded a further 13 metres this summer. 

Yukon University permafrost expert Fabrice Calmels said there is still potential for more erosion before the ground freezes for winter. 

"We will have to retrieve our instrumentation soon," said Calmels, noting the equipment used for measuring the growing slump is now at the edge of the head wall. 

Just below that equipment, the ancient ice continues to drip onto thick, oozing muck as the bank erodes down to the Takhini River. The North is warming faster than anywhere else in the world, and that means permafrost — made up of leftover ice from the last glaciation, frozen for thousands of years — is degrading.

The slump is about 30 kilometres from Whitehorse and so close to the Alaska Highway that the Yukon government is moving the road, creating a new section that will help protect the only year-round road linking parts of the Yukon, and the U.S. state of Alaska, to the rest of the continent. 

"Construction started in early August of this year and so far the contractor has cleared the trees, hauled gravel to construct the base of the road and install three new culverts," said Madison Guthrie, manager of communications for Yukon's department of Highways and Public Works.

That construction will wrap soon for the season and then start again next spring, according to Guthrie. 

Calmels is hopeful when the new section of road is ready, the old one will act as a barrier to prevent further erosion. 

"It should act, we hope, as a dam because the road in the past has made a lot of disturbance of permafrost … and we know that there is much less ice under the current road." Calmels told CBC news.  "So we hope that if the slump reaches the old road, it will stop there." 

The data collected onsite this summer will be analyzed at Yukon University over the next few months. This is part of Calmels' ongoing research into the impacts of a thawing permafrost on northern communities and how best to prepare for more.