Supervised by:

David Didier (Regular member)

Research project description

Mapping of coastal and underwater geohazards in Grise Fiord, Nunavut, Canada

IntroductionIn recent years, a rapid expansion of bathymetric mapping of Canadian Arctic fjords has led to the discovery of numerous coastal and submarine slope failures. Coastal and submarine slope failures in the nearshore waters of southern Baffin Island in the eastern Canadian Arctic present a challenge for coastal and seabed development. Fjords, narrow submerged valleys carved by glaciers and bordered by high landforms and steep sidewalls, are the most sensitive to these hazards. They represent major geologic hazards, particularly because they can trigger tsunamis with devastating consequences for coastal populations and their infrastructure. The low-lying community of Grise Fiord, located at the mouth of a fjord on southern Ellesmere Island, is particularly vulnerable to coastal and submarine landslides. ObjectivesThe primary focus of this project will be to generate a study of coastal and underwater natural hazards in Grise Fiord: To produce an initial mapping of the distribution and causality of coastal and underwater natural hazards of the entire fjord and its peripheries. To relate the sedimentary dynamics of the fjord to climate change-modelled coastal dynamics data. Study sitesThe fjord studied is located in the Qikiqtaaluk region on southern Ellesmere Island. It is nearly 44 km long and opens into Jones Sound. Located at the entrance, the low-lying community of Grise Fiord is particularly vulnerable to coastal and submarine landslides Material and methodsThe mapping of the fjord will be done by using a multibeam echosounder embarked on the RV Nuliajuk, which will make it possible to obtain topographic surveys of the underwater relief as well as sonar images presenting the local reflectivity of the bottom, and thus its nature. From the first sonar surveys, we will target sites potentially exposing remains associated with the geohazards that affected the fjord walls. Sediment coring at these sites will allow for geochronological analysis in the Geological Survey of Canada laboratories in Halifax. Expected resultsIn order to evaluate the potential triggering mechanisms, several maps, presenting the bathymetry of the fjord, the type of deposits and the spatial distribution of the slides and their morphological signatures, can be produced. These will allow us to establish the conditions that are conducive to submarine landslides, and thus determine the environments at risk in the fjord. Also, we will attempt to correlate sedimentary processes in the fjord with coastal dynamics by considering additional factors such as proximity to river sources, slope, tidal range, subaerial processes and the effect of storms.

Research Site Coordinates