Permafrost is ground that remains frozen for at least two years [1]. Tuktoyaktuk sits in the continuous permafrost zone, meaning there is frozen ground under 90-100% of the ground surface. Within the community, the upper 1.8 to 3.1 meters of soil (the active layer) thaws in the summer and re-freezes in the winter [2].

There has been an overall increase in permafrost temperatures across the world; between 2007 and 2016, permafrost warmed by an average of 0.29°C [5]. Permafrost degradation can manifest in a number of ways. The decrease in near-surface moisture and increase in nutrient availability associated with permafrost thaw in upland or ice-poor areas can cause ground subsidence, modify ecosystem species composition [6]. In low-lying or ice-rich areas, thermokarst and wetland formation are observed [6]. Ground thaw can also increase soil erosion, in extreme cases initiating retrogressive thaw slumping. 

Tuktoyaktuk is built on ice-rich ground– in fact, the community sits on a massive ice lens that is up to 4 meters thick and lies approximately at mean sea level [7]. This massive ice and the frozen ground surrounding it thaws in contact with sea water and warm air temperatures, causing ground subsidence and coastal erosion [7]. Historical aerial imagery of the existing thermokarst lakes in the community suggest that there has been little inland permafrost degradation [8]. However, areas immediately on the coast have been identified as being at high risk for thaw settlement in the short term, and areas with massive ice identified as moderate hazard dependent on future climate conditions [9]. The total onshore thaw settlement within the community by the year 2100 is projected to be up to 2.6 meters (RCP8.5) [9].

Links

Digital borehole geotechnical database for the Mackenzie Valley/Delta region (2005)

Index models for predicting ground heat flux to permafrost during thawing conditions (1978)

Thermal conductivity of base-course materials (2005)

Modelling of deep seated hill slope creep in permafrost (1998)

Climate-driven thaw of permafrost preserved glacial landscapes, northwestern Canada (2017)

Extremes of summer climate trigger thousands of thermokarst landslides in a High Arctic environment (2019)

Pingo Growth and collapse, Tuktoyaktuk Peninsula Area, Western Arctic Coast, Canada: a long-term field study (2021)

Massive ice of the Tuktoyaktuk area, western Arctic coast, Canada (1992)

Acceleration of thaw slump activity in glaciated landscapes of the Western Canadian Arctic (2016)

Growth of Retrogressive Thaw Slumps in the Noatak Valley, Alaska, 2010–2016, Measured by Airborne Photogrammetry (2018)

The environment and permafrost of the Mackenzie Delta area (2009) (Paid)

Deep-seated creep of massive ground ice, Tuktoyaktuk, NWT, Canada (1996) (Paid)

Ground Temperatures and Permafrost Warming from Forest to Tundra, Tuktoyaktuk Coastlands and Anderson Plain, NWT, Canada (2017) (Paid)

Snow and Ice-Related Hazards, Risks and Disasters, Chapter 10: Permafrost Degradation (2015) (Paid)

References

[1] Washburn. 1973. Periglacial processes and environments. London: E. Arnold.

[2] Baird. 2021. Tuktoyaktuk Erosion Mitigation. Report for the Hamlet of Tuktoyaktuk and the Inuvialuit Regional Corporation.

[3] Brown et al. 2002. Circum-Arctic Map of Permafrost and Ground-Ice Conditions, Version 2. NSIDC: National Snow and Ice Data Center. doi:10.7265/skbg-kf16. [accessed Jan. 6 2021]

[4] Statistics Canada. 2016. 2016 Census - boundary files: provinces/territories [shapefile]. Statistics Canada Catalogue.

[5] Biskaborn et al. 2019. Permafrost is warming at a global scale. Nat. Commun., 10. doi: 10.1038/s41467-018-08240-4

[6] Xiao-Ling et al. 2021. Impacts of climate-induced permafrost degradation on vegetation: A review. Advances in Climate Change Research, 12(1). doi: 10.1016/j.accre.2020.07.002

[7] Kolberg & Shah. 1976. Shore erosion protection study – study 2, Tuktoyaktuk, N.W.T. Department of Public Works Canada, Marine Directorate, report No. 41.

[8] Baird. 2019. Tuktoyaktuk Coastal Erosion Study. Report for the Government of the Northwest Territories, Municipal and Community Affairs.

[9] BCG Engineering. 2019. Tuktoyaktuk Coastal Erosion Study – Geothermal Modelling Results. In : Baird, 2019. Tuktoyaktuk Coastal Erosion Study.