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Proactive disclosure Print version   | |  Permafrost Regional Studies
Major TSD permafrost research programs include studies in the Mackenzie Valley, the Mackenzie Delta, the Slave Geological Province, and more recently the Rankin Inlet area. The work is undertaken in collaboration with other government agencies, industrial partners, and universities, and has been strongly supported by funding from the Federal Panel for Energy Research and Development (PERD).
Over the last 25 years a large research effort has focused on the Mackenzie Valley and Delta, in response to knowledge needs required for hydrocarbon exploration, development and transportation. Research continues today with a renewed level of activity in order to assess and address the impact of climate change on permafrost. The Mackenzie District has experienced the greatest rise in mean annual air temperature in Canada in the last century. Air temperature increases in the Mackenzie region, in response to modelled climate warming from increased greenhouse gas emissions, are predicted to be amongst the highest in Canada. In the 1990s, regional studies in the Slave Geological Province began in response to the increased level of mineral exploration and development in the region, in particular for diamonds. Preliminary field work in the Rankin Inlet area has recently been undertaken in collaboration with the western Churchill NATMAP project (also see Hydrogeology / Contaminants for a discussion of work at Rankin related to investigations of reclaimed mine tailings).
Permafrost research in the Mackenzie Delta area has included onshore, coastal and offshore investigations. Large bodies of ground ice are common in the Mackenzie Delta and Tuktoyaktuk Coastlands, including massive beds, ice wedges and pingos. GSC has conducted field studies on the origin and distribution of massive ground ice, and long-term studies on the stability (creep) of ice-cored slopes. The migrating channels of the Mackenzie River and Delta, and the coastal retreat through thermal erosion and slumping of ice-rich soils result in a dynamic permafrost environment. GSC has examined the effects of shoreline movement on permafrost distribution and thermal regime at several sites along the Lower Mackenzie River and Beaufort Coast. Numerous lakes in the area also contribute to a complex permafrost distribution, where thawed zones may extend partially or completely beneath lake bottoms (or river channels). The existence of thick permafrost, transitions from frozen to unfrozen conditions associated with lakes and rivers, and warm (and often unbonded and saline) offshore permafrost present many challenges to the exploration, drilling and development of the hydrocarbon resources in the Mackenzie/Beaufort region. Two major transects in the early 1990s, one onshore-offshore and the other across the Delta, were established by the GSC, with industry partnership, to examine the geothermal, geotechnical and geological conditions of permafrost. Each transect involved several deep geotechnical coreholes as well as surface geophysical soundings. Results of the cross-delta transect were published as a comprehensive multimedia CD - "The Mackenzie Delta Borehole Project", and included new information on the occurrence of natural gas hydrates. In 1998, GSC lead a multidisciplinary and multinational science program for the drilling in the Mackenzie Delta of the first exploration well to study intra and sub-permafrost gas hydrates. Studies of drilling sumps from 1970s hydrocarbon exploration wells in the Mackenzie Delta were recently initiated. This work investigates the thermal regime and the long-term behaviour and movement of drilling mud contaminants in a permafrost environment.
The Mackenzie Valley provides a north-south section through the continuous and discontinuous permafrost zones, from thick and cold permafrost in the north to warm thin permafrost in the south. The Valley contains widespread ice-rich and thaw sensitive sediments, and the impact of climate change on the stability of these materials is one component of GSC's climate change research. Several GSC permafrost studies involve transects through the Valley, including collaborative research on permafrost-pipeline interactions along the Norman Wells Pipeline, the first completely buried pipeline in permafrost in Canada. The pipeline research, undertaken through a network of over 20 instrumented study sites along the pipeline right-of-way, is designed to document permafrost response to construction and operation, assess the performance and environmental impacts of mitigative measures, and ensure that knowledge and lessons learned are available and contribute to the design and regulation of future northern pipelines. Studies of permafrost-climate interactions are underway at a network of sites in the Valley established for monitoring active layers, air and ground temperatures. These sites also provide critical data for the development and validation of GIS based models for mapping permafrost distribution (see Mapping, Monitoring and Modelling) and predicting its response to climate warming. GSC's research includes a focus on landslides and slope stability. Slope failures due to thawing of ice-rich unconsolidated sediments, thermal and mechanical erosion along shorelines, or pressure exerted by groundwater confined by permafrost, are abundant in the Valley, with over 3000 mapped landslides. A regional synthesis of the physical environment and geologic processes in the Valley has recently been completed. The 20 chapter Mackenzie document entitled "The physical environment of the Mackenzie Valley, Northwest Territories: a baseline for the assessment of environmental change" was released as GSC Bulletin 547.
Permafrost research in the Slave Geological Province is being conducted in conjunction with the Slave NATMAP, and with industry and government partners including the Department of Indian and Northern Affairs (INAC). Permafrost is a critical element of the tailings design and management plan of the recently opened Ekati Diamond Mine, some 250 km northeast of Yellowknife. Frozen core dams have been used at the mine both for drainage diversion and tailings containment. Such dams are also planned for the proposed nearby Diavik Diamond Project, which is currently undergoing federal environmental assessment review. In the last three years, GSC expertise has been sought to assist federal and territorial governments in the review of permafrost aspects related to the assessment and mitigation of environmental impacts for both of these projects. Technical advice was also provided to INAC concerning the Environmental Agreement established for the Ekati Mine.
A significant public outreach effort has been underway in the Yellowknife area in the last few years, culminating in the production of a guidebook, "Living with Frozen Ground", in 1998. The guidebook on local permafrost conditions and its challenges to development was prepared for the 7th International Conference on Permafrost, held in Yellowknife, June 23-27, 1998. The guidebook was produced in collaboration with the municipal government and the local geotechnical consulting industry. In addition, local field trips and a public lecture were offered during the conference.
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