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Investigating Holocene-Active Faulting in the Strait of Georgia, British Columbia Through Archived Seismic Reflection Data

Description: 

Previous evidence of Holocene-active faulting in the central Strait of Georgia has been observed through limited interpretations of seismic reflection, bathymetric relief, and seismicity datasets. However, in part due to a dearth of attention and historic unavailability of subsurface data, our understanding of such active faulting in the region is incomplete. This has resulted in piecemeal knowledge of the presence, spatial extent, and seismogenic capacity of faults in the region, despite their potential hazard to critical infrastructure near the city of Vancouver, British Columbia. Thick deposits of Holocene muds, a result of rapid sedimentation in the Fraser River Delta, limit the usefulness of 3.5 kHz sub-bottom profiling techniques and may rapidly infill surface fault expressions, complicating interpretation. Furthermore, modern permitting requirements associated with minimizing submarine noise make obtaining the necessary deeper seismic reflection data challenging.

The Geological Survey of Canada (GSC) has a vast archive of paper seismic reflection records in the Strait of Georgia, collected in the 1980s-2000s, which have been recently scanned and digitized. This presents a new opportunity to examine the subsurface in an area with high potential seismic risk and partially identified evidence of active faulting. This study utilizes the GSC’s archived data to look for evidence of Holocene faulting in the central Strait of Georgia. We aim to present preliminary structures identified through this investigation and tie these findings with other recent work to characterize potentially active faults in the region surrounding Vancouver. Our work highlights the importance of leveraging existing subsurface datasets to fill knowledge gaps and inform hazard assessments.

Session: Cryptic Faults: Advances in Characterizing Low Strain Rate and Environmentally Obscured Faults [Poster Session]

Type: Poster

Date: 5/1/2024

Presentation Time: 08:00 AM (local time)

Presenting Author: Anna

Student Presenter: Yes

Invited Presentation: 

Authors