Researchers attempt to compact snow to preserve permafrost in the Northwest Territories

Snow is like a blanket that keeps the ground warm, and a researcher in Inuvik, Northwest Territories, is experimenting with crushing that blanket – in an attempt to halt permafrost thaw.

“The fluffiest and thickest [the snow] that is, the more heat it traps in the ground,” explained Alice Wilson, a permafrost scientist with the Geological Survey of the Northwest Territories. She’s leading an experiment that compacted snow at six sites along the Inuvik-Tuktoyakuk highway, to see if it releases heat and lowers ground temperatures.

If effective, Wilson said it could be used to slow permafrost thaw and lessen the damage it can cause to roads and infrastructure.

“It affects everything,” said Kurt Wainman, owner of Northwind Industries – an Inuvik-based construction and long-haul company that helped build the highway, which is now compacting snow as part of the experiment.

“We’re hoping to see there’s a real cure, maybe slowing it down and stabilizing it more. That would help a lot with our roads here,” he said, noting that thawing permafrost is creating “bumps and bumps” on the roads.

A Northwind Industries operator drives a snowcat at one of the experimental sites. Wilson said compaction typically decreases snow depth by 50%. (Aurora Research Institute)

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

Wilson said compaction is done by driving a snowcat, a large tracked machine, over a patch of land to make the snow thinner and denser. She said the ILA monitors provided advice for the project – including information on sites that would be interesting to study.

The compaction was done three times a winter and reduced snow depth by about 50%, Wilson said. Results so far show that compaction has made a difference.

Kurt Wainman is the owner of Northwind Industries, a company that helped build the Inuvik-Tuktoyaktuk highway and was hired to compact the snow as part of the experiment. (Joslyn Oosenbrug / Radio-Canada)

“We find that air temperatures are more closely related to ground temperatures,” said Wilson, of the experiment sites. But data collection is only winding down now, and she says more work needs to be done to understand the information and how variables — like wet soil in the summer — might have an effect.

Permafrost is defined as ground that is at or below zero degrees Celsius for more than two years, and it can consist of soil, rock, sand, and ice. It underpins most communities in the Northwest Territories, and thaws threaten highways, churches, schools and other infrastructure.

A report on climate change effect on NWT infrastructurereleased by the territory’s Department of Municipal and Community Affairs in December, says communities in the Mackenzie Delta — Inuvik, Tuktoyaktuk, Tsiigehtchic, Aklavik and Fort McPherson — are “most vulnerable” to permafrost thaw because the permafrost in the region is “hot” and contains a lot of ice.

A snowcat, a large tracked machine seen here on top of a flatbed truck, has been used to pack snow at six sites along the Inuvik-Tuktoyaktuk highway for the past three winters. (Karli Zschogner/CBC)

“The reason we want to keep the permafrost stable, at least in this region, is because the real concern is melting ice in the permafrost,” Wilson said. “When the ice melts, you’re going to have subsidence – that’s where the ground is sinking – which is a problem for infrastructure.”

Wilson said keeping permafrost cold in the winter can ensure it doesn’t thaw in the summer, making it more stable for the infrastructure that exists above it.

Wainman hopes the experiment will be a success and turn into a tool that can be used to halt permafrost thaw.

“For me, personally, it’s important. It’s my home. I was born and raised here. I would like to see my children and great-grandchildren also enjoy the delta, without it melting “, did he declare.

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

“It’s a pretty localized mitigation tool,” she said.