NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: physical sciences, geology, active layer, ground temperature, permafrost degradation, ground ice, erosion, slope stability

Objective(s): Historical temperature trends show a warming of nearly 2C during the last century in the western Canadian Arctic. In addition, extreme conditions such as the El Nino year of 1998 resulted in mean annual temperatures as much as 5C warmer than average conditions for the last 30 years. This recent warming is expected to have a significant impact on the stability of permafrost in the Mackenzie Delta and Yukon North Slope regions. Primary impacts due to climate warming include warming of permafrost ground temperatures and increased thickening of the active layer which may induce an increase in melting of ground ice (eg. ice wedges), thawslide processes, active layer detachments and other forms of erosion and slope instabilities. Past research by the Geological Survey of Canada and others has documented ground temperatures, active layer thicknesses and slope stability in the region. The objective of the present study is to assess the impact of recent warming, including the warm summer of 1998, on active layer thicknesses and slope stability in the Mackenzie Delta, N.W.T. and Yukon North Slope. Field activities during the summer of 1999 will be tied to results from ongoing monitoring at specific sites, and into earlier observations made since the 1970's. Together, these studies will contribute to understanding the impacts of recent climate warming on the region.

Project Description: The objective of the present study is to assess the impact of recent warming, including the warm summer of 1998, on active layer thicknesses and slope stability in the Mackenzie Delta, N.W.T. and Yukon North Slope. The main mode of transportation will be by helicopter (206L) and by boat to transport people. The helicopter will be based out of Inuvik with a fuel cache at Tuktoyaktuk. The helicopter will be used to place two small camps at North Head on northern Richards Island and on Kendall Island. The field camps will be of short duration (maximum of seven days each) and consist of trained GSC scientists and personnel conducting field work primarily by boat. A third small field camp will be located near King Point along the Yukon Coast. This site will be accessed by boat from Inuvik and the intended field duration will be from 7-10 days. Coastal exposures as far west as Kay Point will be accessed from the King Point camp location. A final reconnaissance survey to the eastern Tuktoyaktuk Peninsula will be made via helicopter. No field camp will be set up for this survey. Data collection will include simple physical observations and, reading of existing data collection sites and collection of ice and soil samples from naturally exposed sites. Disturbance related to the field activities will be minor due to the short duration of investigation and few people involved in these activities.