NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area, Sahtu Settlement Area, Dehcho Region

Tags: active layer, permafrost, climate change, monitoring, Mackenzie Valley

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

Project Description: This licence has been issued for the scientific research application No. 5776. This project continues the on-going monitoring program of the same title (Licence # 17182) Permafrost monitoring and collection of baseline terrain information in the Mackenzie Valley Corridor, NWT). This phase of the project is largely data collection. Objectives are: • To provide baseline knowledge of permafrost and terrain conditions (specifically ground temperature and active layer thickness) and improve characterization of terrain sensitivity in the Mackenzie Valley. • To 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. This includes investigations of any change resulting from wildfire, such as those that occurred recently or in the past few decades. • To 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 licenses, the main work of this phase will be data collection. While different parts of the network can be visited at different times by different researcher team members, most sites are expected to be visited briefly (less than an hour) annually, and all sites will be visited at least once every two years. Site visits are planned for July to September. Travel will be by road, small boat on the river and helicopter from Inuvik, Norman Wells or Fort Simpson. Access to the sites is always on foot from road or river. This year will be the 28th annual survey of a network of thaw depth measuring devices (thaw tubes) and temperature data loggers along a transect extending from Fort Simpson to Tuktoyaktuk. The thaw tubes consist of small diameter (2.5 cm or 1”) water filled pipes anchored at 4 meter (12') depth and protruding about 30 cm (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 to measure air and ground surface temperature. The ground thermal monitoring sites consist of multi-sensor temperature cables installed to depths of up to 20 m and connected to data loggers. Site visits are generally 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. 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. The research team communicates with NWT communities through the scientific license application process. Information generated by the project will be made available through GSC publications (available for free download at: https://geoscan.nrcan.gc.ca/geoscan-index.html) and scientific publications. 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 research will gladly provide any additional information required in any practical way. The fieldwork for this study will be conducted from: June 01 - October 31, 2024