68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

CHARACTERIZATION OF PERMAFROST THERMAL STATE IN THE SOUTHERN YUKON

Session: Permafrost Degradation I / Dégradation du pergélisol I

Sharon Smith, Geological Survey of Canada, Natural Resources Canadad (Canada)
A Lewkowicz, University of Ottawa (Canada)
Mark Ednie, Geological Survey of Canada, Natural Resources Canada (Canada)
Maxime Duguay, BGC Engineering Inc. (Canada)
Alexandre Bevington, Ministry of Forests, Lands and Natural Resources Operations (Canada)

Boreholes in the northwestern portion of the Alaska Highway Corridor, Yukon were instrumented for temperature measurement between 2011 and 2013. The data acquired has enabled characterization of the ground thermal regime in this section of the corridor. Permafrost is generally warm with temperatures above -1.5°C. However, colder permafrost at temperatures as low as -3°C was found in the immediate vicinity of the Alaska border. Comparison of recent ground temperatures with those measured in boreholes by the Geological Survey of Canada in the late 1970s indicates that warming of permafrost has occurred. These instrumented boreholes complement those established previously in the southern and central Yukon and facilitate an improved understanding of the regional thermal state of permafrost.