CGRG Bibliography of Canadian Geomorphology
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Author : Belliveau, K, ; Brown, T.; Forbes, D.; Catto, N.; Edinger, E.; and Hooper, R.
Date : 2004.
Title : Effects of climate change on coastal geomorphology and benthic biotic communities, south-western Banks Island, NWT.
Publication : Arctic Net. First Annual Scientific Meeting, Palace Royal, Quebec City. December 5-8, 2004. Program.
Issue :
Page(s) : 19-20.
Abstract
Theme 1.2 of ArcticNet examines high latitude coastalcoastal geomorphology along an E-W gradient across the Canadian Arctic, both above and below the waterline, in the context of climate change and variability. Anticipated (and emerging) changes in climate and coastal forcing in the western Arctic suggest the potential for accelerated coastal change in the future. Rapid changes in coastal morphology can also affect biotic communities, benthic habitats, and the living aquatic resources upon which people living in Arctic Canada depend. The first study site in our E-W survey is the southwest coast of Banks Island, NWT, in the vicinity of the community of Sachs Harbour. Residents of Sachs Harbour have compiled many observations of climate change, particularly reduced sea ice cover, thinner and less stable sea ice, earlier ice breakout, and greater wave exposure. Instrumental observations at other places on the Beaufort Sea coast have documented relative sea level rise, reduced sea ice, increased size and frequency of wave action, and temporal variance in storm frequency and intensity, including storm surges. In the vicinity of Sachs Harbour, these climate changes have induced extensive thermokarst erosion along the western shore of Banks Island, thermokarst lakes along the southwestern shore, and vigourous longshore sand transport in the immediate surroundings of Sachs Harbour.The geomorphological component of our project will document annual to decadal changes in shoreline morphology using airphoto and satellite image analysis, coupled to field observations and locally deployed 3D-GPS and tide gauge stations in and around Sachs Harbour. Field work in July 2005 will measure rates and patterns of thermal erosion, longshore sediment dynamics, tidal variation and wave action on the west and southwest coasts of Banks Island. The changes in coastal oceanography and geomorphology may induce changes in benthic marine habitats and biotic communities. Thermal erosion releases muds, which could smother epifaunal organisms normally adapted to exceptionally clear waters. Alternatively, increased wave exposure and the development of a swell regime in the Arctic Ocean could make bottom sediments more mobile, and limit epifaunal communities to those organisms that are most robust to physical disturbance. Effects on infauna are more likely to be indirect, through shifts in epifaunal predator composition. The biological component of our project will involve mapping of benthic substrates and communities using a combination of georeferenced side-scan sonar, underwater video, and benthic grab samples. Substrates and communities along the southwestern shore of Banks Island, subject to dramatic changes in sea ice cover, will be compared to analogous substrates and communites closer to Prince of Wales Strait, that have not experienced the same decrease in sea ice and concomitant increase in wave exposure.
Bibliography of Canadian Geomorphology