Group A, Poster #221, Community Earth Models (CEM)

CFM 7.0: Integration of southern, central, and northern California 3d fault representations into a uniform, statewide Community Fault Model

Andreas Plesch, Scott T. Marshall, John H. Shaw, Mei-Hui Su, Philip J. Maechling, Tran T. Huynh, & Edric Pauk
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Poster Presentation

2024 SCEC Annual Meeting, Poster #221, SCEC Contribution #13870 VIEW PDF
We present a new version of the SCEC Community Fault Model (CFM 7.0). The new model focuses on covering California with a statewide scope using uniform guidelines on inventory, fault hierarchy, documentation and model access. This first statewide CFM describes 556 fault objects, in the preferred model, that accommodate relative motions across the Pacific, Gorda, and North American plate boundaries and are deemed to be able to generate destructive earthquakes. The model builds on and fully incorporates CFM 6.1. CFM 6.1 is the model’s representation of the southern California fault system, with systematically updated and improved fault surfaces using detailed fault traces from the USGS Quatern...ary Fault & Fold database, precisely relocated earthquake and machine-learning enabled hypocenter catalogs, and new focal mechanism solutions (Lin et al., 2007; Yang et al., 2012; Hauksson et al., 2012 + updates), among other datasets. These updates resulted in fault representations that are more precise, and often more segmented and interconnected, than in previous model versions. CFM 6.1 was peer reviewed and includes preferred representations for each fault system along with alternative fault representations where appropriate. For CFM 7.0, we included 113 new 3d fault representations for the central and northern part of the state which had been constructed using the same type of underlying datasets and methods, and had been iterated through past workshops. Importantly, we then included all of these fault representations in the hierarchical naming system established for CFM 6.1, and to a unified database of metadata which supports the model by providing auxiliary information such as source data, slip sense. This allows us to represent the complete inventory of faults as triangulated surface meshes of varying resolutions and provision CFM 7.0 through a new website with map and 3-D viewer interfaces. The model is intended to support a wide range of applications in seismology, tectonic geodesy, and probabilistic and deterministic seismic hazard assessment.
Further, we quantitatively compared CFM 6.1 with CFM 5.0 based on the fault-to-earthquake association method of Evans et al. (2020). The fault representations in CFM 6.1 show an increased correlation with regional seismicity. The faults also show a much higher degree of inter-connectivity, which will have implications for the assessment of potential earthquake ruptures involving multiple, distinct faults.
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Citation: Plesch, A., Marshall, S. T., Shaw, J. H., Su, M., Maechling, P. J., Huynh, T. T., & Pauk, E. (2024, 09). CFM 7.0: Integration of southern, central, and northern California 3d fault representations into a uniform, statewide Community Fault Model. Poster Presentation at 2024 SCEC Annual Meeting.
Keywords: Faulting, CFM, damage zones
SCEC Award: 24027, 23120
Relevant SCEC Themes:
Advanced Modeling Frameworks