HR: 08:40h
AN: C11A-03 INVITED     [Abstracts]
TI: Modeling Block Failure in Vertical Cliffs of Arctic Coasts Underlain by Permafrost
AU: * Pollard, W H
EM: pollard@geog.mcgill.ca
AF: McGill University, Department of Geography 805 Sherbrooke St. W., Montreal, QC H3A 2K6 Canada
AB: Arctic coasts lie at the interface between terrestrial systems dominated by permafrost, and marine systems that are characterized by long periods of ice cover and short periods of open water when wave action and storm activity are important. Permafrost, sea ice and wind-wave conditions are driven by regional and local climate forcing and interact in such a way that a change in one produces feedbacks affecting the other two. However, under predicted climate change scenarios of warming, increased storm activity and sea level rise will profoundly affect all three leading to potentially devastating rates of coastal erosion and permafrost degradation. Permafrost coasts are subject to complex erosional processes, however one of the most poorly understood but probably most important is block failure. Thermo-abrasional falls or block collapses provide the most spectacular form of coastal recession in permafrost areas. This study provides computational models for block failure mechanisms and investigates the relative contribution of horizontal thermo-erosional niches and ice wedges to block failure of permafrost cliffs fronted by a beach.
DE: 1823 Frozen ground
DE: 1625 Geomorphology and weathering (1824, 1886)
DE: 1635 Oceans (4203)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting