Slope stability in the Beaufort Sea, Canadian Arctic - Geohazard analysis focused on gas hydrate dissociation and permafrost thawing

• Main Author: Biller, Tiago
• Other Authors: Kopf, Achim
• Format: Master Thesis
• Language: English
• Published: Universität Bremen 2016
• Subjects: Gas hydrates; Slope stability assessment; Geohazard; Beaufort Sea; Arctic Ocean; Canadian Arctic; geophysics; Geotechnics; Permafrost; melting; dissociation; multibeam echosounder; Bathymetry; Sub-bottom profile; Sedimentology-marine cores; cone penetration testing (CPT); water temperature; Geochemistry; Mechanical properties; physical properties; modelling; prognosis; 550; 550 Earth sciences and geology; ddc:550; Arctic; Beaufort Shelf; Canada; permafrost
• Online Access: https://media.suub.uni-bremen.de/handle/elib/6352; https://doi.org/10.26092/elib/1914; https://nbn-resolving.org/urn:nbn:de:gbv:46-elib63525

The Beaufort Sea offshore Northern Canada is an Arctic region that has continuously gained the attention of private and governmental organizations due to its potential for future developments in mineral resource extraction, climatic modification forecasts, opening of navigation routes and several other matters of geopolitical, economic and scientific importance. Currently experiencing notable changes resulting from the warming associated with Holocene sea level rise, the Beaufort Shelf is still accommodating a thermal pulse of about 10°C that has been propagating since the last marine transgression, in which relatively warm waters flooded areas of permafrost occurrence. The harmonization of this thermal contrast creates circumstances where gas hydrates and permafrost can become destabilized, which in turn potentially undermines slope stability. Additionally to the warming rooted on the glacial-interglacial cycle, the broadly accredited present tendencies of anthropogenic climatic change are deemed of sufficient magnitude to be relevant in the problematic here examined. Though many sources of geohazards are at play in this region, this study focuses on the effects of temperature-induced gas hydrate dissociation and permafrost thawing in prompting mass wasting events. Through a number of computational steps based on empirical data and experiments on samples acquired during scientific research expeditions, it is reckoned that rather modest sediment temperature variations are sufficient to cause slope failure at the Beaufort Shelf and Slope.