Paleoseismic study of the XEOLXELEK–Elk Lake fault: A newly identified Holocene fault in thenorthern Cascadia forearc near Victoria, British Columbia, Canada
January 1, 2022
High-resolution topographic data show a tectonic scarp formed in Quaternary sediments near the city of Victoria in the northern Cascadia forearc on Vancouver Island, British Columbia, Canada. A paleoseismic trench excavation across the structure, the XEOLXELEK–Elk Lake fault, shows evidence for a Holocene (after 12.2 cal ka BP) surface-rupturing reverse-slip
earthquake that produced a fault-propagation fold and resulted in the formation of a ∼1.4 to 3.5 m-high scarp. Fault-propagation fold modelling indicates ∼3.2 m of reverse slip on a 50°-dipping fault plane reproduces the observed deformation, and fault-scaling relations suggest a single earthquake rupture with this surface displacement could occur during a ∼Mw 6.1–
7.6 earthquake. Given the fault’s location within the metropolitan area of Victoria, an earthquake near this magnitude would result in significant damage to local infrastructure and this fault is worth considering in future seismic hazard assessments.
Citation Information
| Publication Year | 2022 |
|---|---|
| Title | Paleoseismic study of the XEOLXELEK–Elk Lake fault: A newly identified Holocene fault in thenorthern Cascadia forearc near Victoria, British Columbia, Canada |
| Authors | Nicolas Harrichhausen, Theron Finley, Kristin D. Morell, Christine Regalla, Scott E.K. Bennett, Lucinda J. Leonard, Edwin Nissen, Eleanor McLeod, Emerson M. Lynch, Guy Salomon, Israporn Sethanant |
| Publication Type | Conference Paper |
| Publication Subtype | Conference Paper |
| Index ID | 70259664 |
| Record Source | USGS Publications Warehouse |
| USGS Organization | Geology, Minerals, Energy, and Geophysics Science Center |
Related
Pacific Northwest Geologic Mapping: Northern Pacific Border, Cascades and Columbia
The Pacific Northwest is an area created by active and complex geological processes. On its path to the Pacific Ocean, the Columbia River slices through a chain of active volcanoes located along the western margin of the U.S. in Washington, Oregon, and northern California. These volcanoes rest above the active Cascadia subduction zone, which is the boundary where the oceanic tectonic plate dives...
Related
Pacific Northwest Geologic Mapping: Northern Pacific Border, Cascades and Columbia
The Pacific Northwest is an area created by active and complex geological processes. On its path to the Pacific Ocean, the Columbia River slices through a chain of active volcanoes located along the western margin of the U.S. in Washington, Oregon, and northern California. These volcanoes rest above the active Cascadia subduction zone, which is the boundary where the oceanic tectonic plate dives...