Researchers try packing down snow to preserve permafrost in N.W.T.

Snow is like a blanket that keeps the ground warm, and a researcher in Inuvik, N.W.T. isexperimenting with squishing that blanket to try and curb permafrost thaw.

"The fluffier and thicker [the snow] is, the more it traps heat into the ground" explained Alice Wilson, a permafrost scientist with the N.W.T. Geological Survey. She's leading an experiment that has been compacting snow at six sites along the Inuvik-Tuktoyakuk Highway, to see if it releasesheat and lowers the temperature of the ground.

Ifeffective, Wilson saidit could be used to slow permafrost thawand mitigate the damage it can do to roads and pieces of infrastructure.

"It affects everything," said Kurt Wainman, the owner of Northwind Industries an Inuvik-based construction and long-distance hauling business that helped build the highway, that is now compacting snow as part of the experiment.

"We're hoping to see there's an actual cure for it, maybe slow it down and stabilize it more. That would help out a lot with our roads around here," he said, noting that thawing permafrost creates "bumps and lumps" on roads.

The project, which is being done in partnership with the Aurora Research Institute and the Inuvialuit Land Adminstration(ILA),is in its third and final year. Northwind went out to compact snow for the last time this week.

Wilson said compaction is done by driving a snowcat, a large machine on tracks, over a plot of land to make the snow less deep and more dense. She said monitors with the ILA provided guidance for the project including information about what sites would be worthwhile to study.

The compaction has been carried out three times per winter and decreases thesnow depth by about 50 per cent, said Wilson.So far, the results show compaction has made a difference.

"We are seeing that the air temperatures are more closely linked with the ground temperatures," said Wilson, of the experiment sites. But data collection is only just ending now, and she says more work needs to be done to understand the information and how variables like a wet ground in the summer might have an effect.

Permafrostis defined as groundthat is at or below zero degrees Celsius for more than two years, and it can consist of soil, rock, sand and ice. It underliesthe majority of communities in the N.W.T., and the fact that it's thawing threatens highways, churches, schools and other pieces of infrastructure.

A report about climate change's effect on N.W.T. infrastructure, released by the territory's Department of Municipal and Community Affairs in December, says that communities in the Mackenzie Delta Inuvik, Tuktoyaktuk, Tsiigehtchic, Aklavik and Fort McPherson are "most vulnerable" to thawing permafrost becausepermafrost in the region is "warm" and contains a lot of ice.

"The reason we want to keep permafrost stable, at least in this region, is because the real concern comes from the melting of ice within the permafrost," said Wilson. "When the ice melts, you're going to have subsidence which is where the ground sinks down which is an issue for infrastructure."

Wilson said keeping permafrost cold in the winter can make sure it doesn't thaw in the summer, making it more stable for the infrastructure that exists on top of it.

Wainman hopes the experiment is a success, and that it turns into a tool that can be used to curb permafrost thaw.

"To me, personally, it's important. This is home. I was born and raised here. I'd like to see my children and great grandchildren enjoy the Delta as well, without it melting away," he said.

Wilson said next steps for the project could be to extend it, to continue monitoring plots without compacting them, or to compact snow in areas where permafrost thaw is causing damage.

"It is quite a localized, mitigative tool," she said.