Permafrost degradation affects Arctic communities

(Inuvik) On the side of the road, not far from the airport in Inuvik, Northwest Territories, among shrubs and spruce trees, a series of rusty metal bars are buried deep in the ground.


Installed in 2004, they help researchers measure the evolution of the ground over time.

Jennifer Humphries, a permafrost scientist at the Aurora Research Institute, says it’s the only place in the world south of the treeline that studies the ground’s long-term thermal expansion and contraction related to annual changes in the air temperature. She says the soil is gaining two centimeters every year.

Behind swarms of buzzing insects, several nearby trees sport metal platforms attached to their slender trunks, measuring their changes in inclination. As the permafrost degrades unevenly below, Mme Humphries explains that it can cause what are called “drunken forests,” where staggered trees lean in different directions.

It’s one of many places in the ice-rich Beaufort Delta where scientists are monitoring permafrost and other environmental changes. As the Arctic warms faster than anywhere else in the world, researchers find that permafrost degradation is having far-reaching effects.

“Here, permafrost is the foundation on which everything is built,” says Ms.me Humphries. “It affects the transport of people, animals, water and the environment, the development of vegetation. It affects and controls everything. »

The Western Arctic Research Center in Inuvik houses the headquarters of the Aurora Research Institute and the Permafrost Information Center. It supports several research projects, including permafrost monitoring along the Dempster and Inuvik-Tuktoyaktuk highways.

Erica Hille, the center’s acting director, says her work is collaborative and community-driven, and her team strives to make all of their data accessible. For example, the Inuvik Community Corporation asked them to monitor ground temperature and develop hazard maps at Caribou Hills, near Reindeer Station, where the Northwest Territories Geological Survey recorded 25 landslides in October. 2009 and 80 in September 2017.

“Community members know what is going on. I see us converging to understand why this is happening and what it could mean in the future,” she says.

Build with knowledge

Studying permafrost can be complex and challenging, says Ms.me Humphries. Although researchers can make generalizations about a region’s baseline conditions, each permafrost landscape is unique, she adds.

On the site near the airport, there is a transition zone between tundra and forest with a decent snowpack. Mme Humphries says temperatures at depth there are -0.9°C, likely warmer than people would expect.

“This tells us that permafrost conditions in the Inuvik region are actually more sensitive to climate change than people probably thought 20 years ago,” she notes.

Driving through the city, Mme Humphries points out that many houses are built on stilts rather than directly on the ground. Indeed, when the permafrost thaws and settles, it causes the displacement of the foundation, which may require regular leveling.

Inuvik’s iconic Our Lady of Victory Church, also known as the Igloo Church for its iconic shape, was also impacted by thawing permafrost.

Opened in 1960, the well-designed building has vents that keep the basement and foundations cool. During renovations several years ago, however, these vents were accidentally covered and the top insulated, causing permafrost degradation and settlement issues, Ms.me Humphries.

These vents have since been reopened and sensors installed in 2020 indicate that the structure has stabilized.

Solutions

There are a variety of solutions to deal with the effects of climate change on permafrost, including thermosyphons, tubes filled with carbon dioxide that can extract heat from the ground. Researchers from the Geological Survey of the Northwest Territories are also investigating whether snow compaction could help reduce temperatures and slow the thawing of permafrost.

Mme Hille adds that a Beaufort Sea coastal restoration project, focusing on retrogressive thaw collapses along the Kugmallit Bay coast, was completed last year. The researchers looked at the potential of using native plant species to revegetate the shoreline and reduce ground temperatures, which she says has yielded positive results.

“The limitation of many engineering solutions is that they’re only really good for distinct, smaller areas,” says M.me Humphries, noting that they can be expensive and labor intensive. “They’re not as good for generalized application. »

This dispatch was produced with financial assistance from the Meta Exchange and The Canadian Press for News.


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