ENVIRONMENTAL CONTROLS ON THE GENERATION OF SUBMARINE LANDSLIDES IN ARCTIC FIORDS: AN EXAMPLE FROM PANGNIRTUNG FIORD, EASTERN BAFFIN ISLAND, NUNAVUT

Abstract

High-latitude fiords are susceptible to hazardous submarine and subaerial mass movements. Landslide ages calculated from radiocarbon dating and 210Pb/137Cs activities indicate that 8 of the 11 dated landslides are younger than 500 years. Landslide-surface roughness was tested as a proxy for age, but the relationship was found to be weak, thus limiting the ability to accurately date all identified landslides. Four broad categories of submarine landslide environments were identified, and it was shown that at least 53% (96 of 180) of landslides are associated with subaerial sources and, at most, 31% (56 of 180) are shallow-water, non-subaerially influenced. These categories suggests that triggers of most submarine landslides within Pangnirtung Fiord include rapid flood-water input, subaerial debris flows and sea-ice loading during low tide.