SCEC Award Number 16065 View PDF
Proposal Category Individual Proposal (Data Gathering and Products)
Proposal Title Continuing to Evaluate 3D Fault Geometry in Special Fault Study Areas and to Update & Improve the SCEC Community Fault Model
Name Organization
Craig Nicholson University of California, Santa Barbara
Other Participants Chris Sorlien, Andreas Plesch, John Shaw and Egill Hauksson through related SCEC or USGS-funded projects
SCEC Priorities 4c, 4a, 4b SCEC Groups USR, Seismology, SDOT
Report Due Date 03/15/2017 Date Report Submitted 03/15/2017
Project Abstract
During SCEC4 (2012-2016), I and my colleagues Andreas Plesch, Chris Sorlien, John Shaw and Egill Hauksson continued to make steady and significant improvements to the SCEC Community Fault Model (CFM), culminating in the release of CFM-v5.1 [Plesch et al., 2016]. This systematic update to CFM represents a substantial improvement of 3D fault models for southern California. The CFM-v3 fault set was expanded from 170 faults to over 820 3D fault objects and alternative representations that define over 380 faults organized into 105 complex fault systems. Of the ~650 new fault objects added to CFM, most of these updated 3D fault models (~525) were developed by UCSB or to which UCSB made significant contributions. This includes all the major faults of major fault systems (e.g., San Andreas, San Jacinto, Elsinore-Laguna Salada, Newport-Inglewood, Imperial, Garlock, etc.), and most major faults in the Mojave, Eastern & Western Transverse Ranges, offshore Borderland, and updated faults within the Ventura & San Gorgonio Pass Special Fault Study Areas [e.g., Nicholson et al., 2012, 2013, 2014, 2015, 2016; Sorlien et al, 2012, 2014, 2015, 2016; Sorlien and Nicholson, 2015]. These new models allow for more realistic, curviplanar, complex 3D fault geometry, including changes in dip and dip direction along strike and down dip, based on the changing patterns of earthquake hypocenter and nodal plane alignments and, where possible, subsurface imaging of fault geometry with industry seismic reflection data. In 2015-2016 alone, 120 new or updated fault objects were added to CFM-v5.1 since the initial release of v5.0.