Identifying potentially active faults in mainland British Columbia using available datasets

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Many developed countries consider shallow, crustal faults in their hazard assessments, where there is evidence that faults are either active or capable. In British Columbia (BC), however, only one such crustal fault has been included in our national seismic hazard model to date. Treating the southwest BC mainland as if devoid of shallow, crustal faults is at odds with both our tectonic understanding of how subduction zone stresses are imparted to the upper crust, and the neighbouring United States (US) Geological Survey assessment which includes numerous faults extending at least to the border and presumably further north. Thus, the threat of active faults, and their secondary hazards, in the densely populated Lower Mainland region remains largely unknown. Currently, I lead the development of the National Seismic Risk Model Scenario Earthquake Catalogue (release in November 2020). This work requires knowledge of faults across Canada as well as an understanding of how those faults impact the built environment and communities. Now, we hope to extend this work to as-yet unmapped faults. We propose to use existing data to hunt for possibly active faults in the southern Coast Mountain region extending from the Strait of Georgia East to Manning Park, and from the Canada/US border North to the Pemberton Icefields - a region home to approximately 2.8 million people and assets valuing roughly 41% of Canada's gross domestic product. This research program will improve our understanding of crustal faults on the mainland by: [1] using recently collected digital elevation data to visually identify potentially active faults based on their geomorphic expression, [2] modelling their potential stress accumulation using a newly developed tectonic block model, [3] quantitatively assessing the potential physical impacts and socioeconomic consequences of ruptures using seismic risk assessment, [4] going into the field to document geologic evidence of recent displacement along prospective faults, such as volcanic dike offsets, and [5] using geodetic and other geophysical data to characterize the current deformation and activity rate of faults. Through the Earthquake Scenario Catalogue, a Fault Database we will create, and RiskProfiler.ca - a user-friendly web platform - citizens, scientists, city planners, and policy makers will be able to freely access the evidence they need to enact risk reduction strategies. We hope to `finish drawing' faults which currently only exist on the US side of the border, and identify faults which are well-suited to more detailed and expensive studies through paleoseismic trenching, campaign Global Navigation Satellite System (GNSS) with helicopter access, or high resolution Light Detection and Ranging (LiDAR). This program will contribute to the scientific community by allowing a young, female PI to train 2 new scientists, to be selected from groups currently under-represented in geosciences.