NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: physical sciences, geology, climate change, prediction models, geomorphology, coastline, erosion, coastal stability, sea level change

Objective(s): One of the most confidently predicted impacts of climate warming is a rise in sea level. Rates of sea-level rise vary geographically, and will also be affected by vertical motion of the earth's crust. The implications of these changes for the western Arctic coastal zone may be significant, particularly when combined with other climate change factors such as reduced sea ice and a resulting increase in wave energy. Northern coasts may be particularly affected by these issues, as climate warming is projected to be more severe in the north and may lead to unexpected rapid coastal change by waves and ice. As the zone of submergence in the western Arctic can be expected to expand eastward to affect communities and coasts beyond those already subject to rising sea level, stakeholders require improved knowledge and understanding of coastal hazards and other issues related to climate change and sea-level rise. Therefore, the proposed research project will involve the following: (1) mapping the western Canadian Arctic coastline in terms of its sensitivity to coastal erosion under climate change and sea-level rise; (2) monitoring coastline changes and the processes responsible; (3) defining rates of relative sea-level change and contributions from vertical motion of the crust; (4) determining coastal sensitivity to other climate changes (increased air, ground, and water temperatures, diminished sea ice and higher wave energy); and (5) collecting information on coastal geology and geomorphology for ground-truthing of remote sensing data (to calibrate predictive models of coastal change).

Project Description: This project involves monitoring changes in the coast and refining estimates of land uplift or subsidence using passive geodetic and survey measurements at sites throughout the western Arctic, supported by existing data on coastal submergence and emergence from geological observations. Long-term coastal change under existing climate and sea-level trends will be determined at reference sites of the Geological Survey's coastal monitoring network, which will be expanded to provide useful information near communities. This data will be used to forecast future impacts of climate change on northern coasts, infrastructure, natural habitats, cultural resources and communities. The project will use previously proven and permitted methods: (1) passive geodetic GPS, gravity, and water-level measurements; (2) coastal surveying with global positioning and conventional optical survey equipment; (3) airborne photography, video and satellite remote sensing; (4) echosounding surveys and seabed sampling; (5) probing of the seabed and beaches to depths of 3-4 m using small-diameter water jet drills; (6) conventional installation of in-ground survey benchmarks; (7) seabed coring to depths of 3-4 m using small push corers and augers; and (8) airphoto analysis of past changes and developing predictive models of future change. All activities proposed for this project have been observed to have a minimal impact on the local environment over the past several years. Ground surveys involve walking or riding four-wheel ATV's. Small fly camps of 2-3 people will be set up for periods of 1-2 weeks. Interaction with local fauna is minimal and care is taken to make camps unattractive to bears and scavengers. Boat travel will be restricted to within 1 km from the shoreline. Airphoto surveys will take place at height in excess of 1000 m.