CRESCENT CFM: Constructing a 2-D and 3-D Community Fault Model for the Cascadia Region

Rebecca A. Fildes, Colin B. Amos, Emily Roland, Ashley R. Streig, Scott E. Bennett, Alex Hatem, Anna Ledeczi, Andrew J. Meigs, Richard H. Styron, & Harold Tobin

Submitted September 7, 2025, SCEC Contribution #14764, 2025 SCEC Annual Meeting Poster #TBD

The Cascadia convergent margin contains multiple sources of earthquake hazards including the plate boundary megathrust and faults within the upper (North America) and lower (Juan de Fuca) plates. Subduction-related active faults occur throughout southern British Columbia, Washington, Oregon, and northern California. Active faults associated with the complex plate motion near the Mendocino Triple Junction at the southern terminus of Cascadia in northern California are another piece of the earthquake hazard. Many faults across Cascadia are close to population centers and pose significant hazard. The Cascadia Region Earthquake Science Center (CRESCENT) Community Fault Model (CFM) includes 2D and 3D representations of Quaternary-active faults in both the onshore and offshore portions of the North America plate, models of the plate interface, and accompanying metadata for each fault. Models of fault geometries are constructed based on available data in published, peer-reviewed literature and undergo revision through community member evaluation. The initial framework for onshore faults is based on the USGS National Seismic Hazard Model 2023 fault sections database with the addition of documented active faults in the Canadian forearc. These faults are systematically evaluated and modified to reflect more complex fault structures where data is available. Recent high-resolution seismic data and fault analysis of offshore Cascadia help expand the location and geometry of faults located within the accretionary wedge. The CFM includes many newly mapped offshore splay faults across the margin that are important for understanding megathrust rupture propagation and tsunami hazard. Ongoing collaboration with the Statewide California Earthquake Center (SCEC) CFM, which geographically overlaps with the southern portion of the CRESCENT CFM, is important for the development of both CFMs. The CRESCENT CFM has several potential applications beyond seismic hazard analyses, including stress modeling, multi-cycle rupture modeling, providing constraints in the CRESCENT Community Velocity Model, and in probabilistic tsunami hazard analyses. We continue to grow and improve the CRESCENT CFM through ongoing community engagement and feedback.

Citation
Fildes, R. A., Amos, C. B., Roland, E., Streig, A. R., Bennett, S. E., Hatem, A., Ledeczi, A., Meigs, A. J., Styron, R. H., & Tobin, H. (2025, 09). CRESCENT CFM: Constructing a 2-D and 3-D Community Fault Model for the Cascadia Region. Poster Presentation at 2025 SCEC Annual Meeting.

Related Projects & Working Groups
Community Earth Models (CEM)