68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

PERMAFROST OCCURRENCE IN SUBARCTIC FORESTS OF THE GREAT SLAVE REGION, NORTHWEST TERRITORIES, CANADA

Session: Geocryology II / Géocryologie II

Peter Morse, Geological Survey of Canada, Natural Resources Canada (Canada)
Stephen Wolfe, Geological Survey of Canada, Natural Resources Canada (Canada)
Steve Kokelj, Northwest Territories Geological Survey, Government of the Northwest Territories (Canada)
Adrian Gaanderse, Department of Geography and Environmental Studies, Carleton University (Canada)

Permafrost in the Great Slave region, Northwest Territories is absent beneath bedrock outcrops, but occurs beneath peatlands. A three-year (2010 to 2013) investigation determined that permafrost also occurs in unconsolidated fine-grained sediments beneath forested sites. Annual mean shallow permafrost temperatures range from -1.4 to 0°C, with spatial variation primarily reflecting organic-layer and soil moisture conditions. Discontinuous permafrost is extensive within Great Slave Lowland, in direct relation to the distribution of forested areas in unconsolidated fine-grained sediments, but is sporadic northward within Great Slave Upland where bedrock outcrops are more extensive.