NWT RESEARCH DATABASE

Tags: active layer, ground temperature, permafrost, climate change, land use planning, environmental baseline, surface disturbance

Objective(s): To provide baseline knowledge of permafrost and terrain conditions (specifically ground temperature and permafrost active layer thickness) and improve characterization of terrain sensitivity in the Mackenzie Valley. To provide information which contributes to environmental impact assessment and mitigation of northern development, land use planning and to climate change assessments.

Project Description: The objectives of this research are: • To provide baseline knowledge of permafrost and terrain conditions (specifically ground temperature and permafrost active layer thickness) and improve characterization of terrain sensitivity in the Mackenzie Valley. • Monitor ground temperature and active layer to detect changes in permafrost conditions resulting from surface disturbance or climate change and to improve prediction of future response. • Provide information which contributes to environmental impact assessment and mitigation of northern development, land use planning and to climate change assessments. The combined temperature and active layer monitoring network extends from Fort Simpson to the Arctic Coast. With monitoring instrumentation already in place through work under previous licences, the main work of this phase will be data collection. While different parts of the network are visited at different times by different researcher team members, all sites are expected to be visited briefly (less than an hour) once annually. Temperature data is also collected at many sites during this trip. The tubes consist of small diameter (2.5cm. or 1”) water filled pipes anchored at 4 meter (12') depth and protruding about 30cm (1') above the surface that record the maximum annual thaw depth at a site. Temperature loggers are installed in small screens above ground and buried just below the surface. The principal ground temperature monitoring trip will be in late September extending from south of Fort Simpson to Fort Good Hope. Instrumentation at these sites consists of ground temperature cables in cased boreholes 5 m to 20 m deep, attached to automatic data logging equipment recording temperatures at eight depths. At some sites, small temperature loggers are also installed in small screens above the ground and buried just below the surface. At each site, ground temperature monitoring visits of less than an hour will be used to retrieve data from on-site instrumentation, and service and re-program the instruments for continued data collection. Access will be mainly by helicopter and/or road (if near town, or in winter) and by foot. Visits will cause minimal disturbance. Accumulated over several years, the series of annual active layer thaw depth readings and the collection of long term ground temperature records in permafrost and unfrozen ground will show how changes in permafrost conditions are related to changing climatic and other environmental conditions. Information generated by the project will be made available through GSC publications (available for free download) and scientific publications. Permafrost temperature data will be disseminated through the Canadian Permafrost Monitoring Network website (www.canpfnetwork.com). Reports and publications from this study will be sent to the regional regulatory organizations. Dissemination to communities will occur through reports and/or presentations. The researchers will gladly provide any additional information required in any practical way. The fieldwork for this study will be conducted from July 15 to October 6, 2010, at 82 locations on a transect across the NWT, from near Trout Lake to the Arctic coast close to Tuktoyaktuk. A complete list of sites with coordinates can be found in the licence application, or also provided by the researcher or by the Aurora Research Institute.