NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: physical sciences, ground temperature, forestry, snow accumulation, biophysics

Objective(s): Permafrost in the Mackenzie Delta is sensitive to both climate warming and human development. The objective of the research is to better understand permafrost conditions in the delta by studying how near-surface ground temperatures vary within the region.

Project Description: An understanding of near-surface ground temperatures will provide a baseline to assess change and identify sensitive areas. The objective of this project is to determine the variation of near-surface ground temperatures within the Mackenzie Delta. Investigations have identified four spruce forest communities in the delta based on composition: spruce-alder-bearberry, spruce-feathermoss, spruce-crowberry-lichen and spruce-tamarack-sphagnum forests. Surface conditions vary between these communities. It is hypothesized that ground temperatures vary between forest communities due to differences in surface conditions, including elevation, canopy cover, organic layer thickness, and snow cover. Ground temperatures are being measured by thermistors placed in 24 boreholes drilled to approximately 20 m by water-jet in summer 2006 at locations away from lakes and channels to avoid thermal disturbance. Clusters of six thermistor cables distributed among the spruce forest types were established in four regions of the delta. Vegetation structure and soil physical characteristics were determined to establish boundary conditions. Ground temperatures were recorded at all sites after thermistor installation; however, these measurements may be elevated due to the introduction of water during drilling. To confirm ground temperatures, additional readings must be taken in January and April 2007. Snow depth, snow density and temperature at the base of the snow pack will be measured using a standard snow sampler. Field crews will be based in Inuvik or Aklavik for about two weeks in April 2007. Fieldwork will be conducted on daytrips using vehicles and snowmobiles. More remote sites will be accessed by helicopter. Reports and publications stemming from this study will be deposited at the Aurora Research Institute library. Fieldwork will be conducted from April 1-15, 2007 at locations near Reindeer Station (68 41' 31.7" N 134 08' 11.7" W); Taylor Channel (68 17' 49.1" N 134 49' 20.4" W); Peel Channel (67 51' 24.2" N 134 47' 02.0" W); and at locations near Kalinek Channel (67 59' 34.9" N 134 17'34.7" W).