Rock slope behaviour and rock avalanches in glacial environments of NW North America

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The study will investigate the occurrence, behaviour and geomorphic impacts of rock avalanches originating in rock slopes adjacent to glaciers (periglacial rock slopes) and which run for all or part of their travel on the glacier surface itself. The investigation focuses on rock slopes and rock avalanches in the glacial environment of the western part of the Cordillera of NW North America (including western Washington, western British Columbia (BC), southwestern Yukon, and southern Alaska). Our data indicates that at least 55 rock avalanches of 1M m3 or greater in volume have occurred in the region since 1945 in three glacierised topographic/geologic settings, viz. Quaternary Volcanic Centres (e.g., the Cascade Volcanic Belt (BC and Washington)), the Coast Mountains of British Columbia and the mountains of southern Alaska, southwest Yukon, and NW BC (e.g., St Elias Mountains). We will establish a complete inventory of rock avalanches in the three glacier environments of the region from 1945 to 2012, determine its spatio-temporal signature, analyse the geomechanics and geomorphometrics of initial failure (including topographic controls and the role of glacier surface lowering), detect and measure periglacial rock slope movements by SAR interferometry, characterise the geometry and behaviour of rock avalanches and their deposits, evaluate the contribution of rock avalanches to periglacial rock slope denudation and to measure the relative contribution of seismic and climate forcing to volumetric rock loss from periglacial rock slopes. Three questions are of particular interest i) does a climate change signal exist in rock avalanche spatio-temporal occurrence as suggested by much recent literature? ii) to what extent is this amplified or offset by seismic forcing? iii) what is the precise contribution of rock avalanche-related rock slope denudation to high rates of glacial erosion in the region and to the so-called "glacial buzzsaw" effect (i.e., relief destruction above the perennial snowline or equilibrium line altitude (ELA). The 5-year research programme addresses Canada's critical shortage of highly-qualified personnel in the field of landslide research through the multi-skill training of 4 PhD and 2 MSc students.