--> --> The SCEC Community Fault Model Version 5.0: An Updated And Expanded 3D Fault Set For Southern California
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Pacific Section AAPG Convention

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The SCEC Community Previous HitFaultNext Hit Model Version 5.0: An Updated And Expanded 3D Previous HitFaultNext Hit Set For Southern California

Abstract

A major goal of the Southern California Earthquake Center is to improve estimates of earthquake hazard and predictions of strong ground motion by using more realistic models of 3D Previous HitfaultNext Hit geometry in its earthquake rupture forecasts. To this end, SCEC has developed and continually updates its Community Previous HitFaultNext Hit Model (CFM), a digital 3D representation of major active Previous HitfaultNext Hit surfaces for the region. Here we present a new release of CFM (Version 5.0) that includes a number of major improvements, including refinement and additions of new 3D Previous HitfaultNext Hit surfaces using primarily detailed Previous HitfaultNext Hit surface trace, industry well, seismic reflection, relocated hypocenter and focal mechanism nodal plane data. CFM 5.0 now contains 90 distinct Previous HitfaultNext Hit zones or separate Previous HitfaultNext Hit systems defined by over 300 individually named faults with 625 primary and alternative 3D Previous HitfaultNext Hit representations, and includes an updated Previous HitfaultNext Hit database with an improved hierarchical Previous HitfaultNext Hit naming and numbering system. The results document a wide variety of complex Previous HitfaultNext Hit deformation styles, including: various aspects of strain partitioning and Previous HitfaultNext Hit-related folding; sets of both high-angle and low-angle faults that mutually interact; blind and emergent structures; significant non-planar, multi-stranded faults with variable dip along strike and with depth; and active mid-crustal detachments at different structural levels. In places, closely-spaced Previous HitfaultNext Hit strands or Previous HitfaultNext Hit systems can remain surprisingly subparallel to seismogenic depths, while in other areas, major strike-slip to oblique-slip faults can merge or diverge with depth. An good example is in the Ventura-Santa Barbara area, where new Previous HitfaultNext Hit models – that include a substantially revised set of alternative representations for the Ventura, Pitas Point, North Channel, Red Mountain, Mission Ridge, Santa Ynez, San Cayetano, Oak Ridge and Simi-Santa Rosa faults – were developed that indicate many of these Previous HitfaultNext Hit systems tend to merge at depth. The updated CFM 3D Previous HitfaultNext Hit surfaces thus help characterize a more complex pattern of Previous HitfaultNext Hit interactions at depth between various Previous HitfaultNext Hit sets and linked Previous HitfaultNext Hit systems, and a more complex Previous HitfaultNext Hit geometry than typically inferred or expected from projecting near-surface data down-dip, or modeled from surface strain and potential field data alone. CFM 5.0 is provided as a series of digital, triangulated Previous HitfaultTop surfaces, and is available by browsing to the SCEC-CFM webpage accessible from the structure.harvard.edu website.