Rock slopes and rock avalanches in glacial environments of NW North America

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As events in the mountains of British Columbia (BC) in 2010 and Alaska in 2012 have indicated, rock slopes in glacial environments are particularly prone to catastrophic failure. The research proposed here 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 (western Washington, western 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 (Quaternary Volcanic Centres, the BC Coast Mountains and the mountains of southern Alaska, SW Yukon, and NW BC). We note that the study area has an extensive glacier cover that has undergone dramatic climate-change-related ice loss since ca. 1900; our analysis will assume that the regionally-coherent glacier ice loss is an appropriate proxy for climate change. The research will utilise a novel integration of GPS-assisted field investigation, cutting-edge remote sensing and satellite technology, and advanced analytical software to establish a complete inventory of rock avalanches in the three glacier environments of the region from 1945 to 2013, determine its spatio-temporal signature, analyse the geomechanics of initial failure (including topographic controls and the role of glacier surface lowering), detect and measure periglacial rock slope deformation by satellite Synthetic Aperture Radar interferometry (InSAR), 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. Five questions are of particular current 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" denudation mechanism (i.e., relief destruction above the perennial snowline), iv) what is the spatial and hypsometric distribution of non-catastrophic periglacial rock slope movements and, v) what proportion (and under what conditions) of these deforming periglacial slopes experience catastrophic failure? Building on the successes of landslide and remote sensing research at Waterloo, the 5-year research programme addresses Canada’s critical shortage of highly-qualified people in the fields of landslide research, engineering geomorphology, quantitative earth observation, and analytical remote sensing through the multi-skill training of 4 PhD and 2 MSc students by March 31, 2019. In this training, each student will address a working objective (or group of objectives) identified in the research proposal, participate in at least one major geoscience conference during their research, and make key co-author contributions to scientific papers submitted to peer-reviewed journals. The resultant infusion of expertise will help position Canada to utilise the flood of earth observation data on its mountain environments generated by increased accessibility to existing satellite products and the data stream from near-future satellite launches (ESA's Sentinel 1 (2014) and Canada's RADARSAT Constellation Mission (RCM) (2018)).