The Yellowknife-Grays Bay transportation corridor may become a key component for resource and economic development in both the Northwest Territories and Nunavut. Our research goals are to identify permafrost-related geohazards to mineral exploration and development and to anticipate future landscape evolution with permafrost thaw. Knowledge of surficial geology and permafrost is well-synthesized in the south of this corridor within discontinuous permafrost terrain, but remains sparse for the central and northern regions, where till, glaciofluvial sediments, and marine deposits play a key role in terrain stability. Within GEM-GeoNorth, we are collaboratively assessing current and projected permafrost conditions within the corridor region in relation to surficial sediments, geomorphic processes, and a warming climate via three foundational activities: i) remote permafrost terrain mapping and synthesis; ii) data-mining to synthesize permafrost knowledge and support mapping and modelling; and iii) regional ground ice modelling.
In summer 2021, we acquired new high-resolution satellite imagery for a 10-km swath of the corridor and adjoining areas with high development potential, and are mapping permafrost-related landforms to determine their associations with surficial geological conditions. These data will support our ground ice modelling, the selection of field sites for future investigation, and validation of ongoing, collaborative, broad-scale thermokarst mapping with our collaborators. We also conducted helicopter-based aerial photo surveys in the corridor in September 2021, which will contribute to synthesis activities.
Borehole data on permafrost conditions are not readily available or compiled for this region. With co-developers at CNGO and NTGS we are compiling geotechnical reports, extracting permafrost data, and making these data accessible through Open Files and databases. This will support our permafrost-landform interpretation and ground ice modelling.
Using a similar methodology to recent national-scale mapping, we are modelling the abundance of segregated, wedge, and buried glacier ice in the region using more detailed surficial geology information from recent Canadian Geoscience Maps. The mapping and data synthesis activities serve to enhance validation of these ground ice model outputs. The modelled regions represent developed and undeveloped terrains, and we are compiling the relevant modelling and validation datasets and developing model refinements for downscaling.
Our results have implications for planning, management, and mitigation strategies on the impacts of permafrost thaw to the development of sustainable transportation and mining infrastructure, and our findings may inform environmental assessments of proposed infrastructure.
This presentation provides an update on our activities and preliminary results.