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A 2D pseudodynamic rupture model generator for earthquakes on geometrically complex faults

Daniel T. Trugman and Eric M. Dunham
A 2D pseudodynamic rupture model generator for earthquakes on geometrically complex faults
Bulletin of the Seismological Society of America (February 2014) 104 (1): 95-112


Geologic observations indicate that faults are fractally rough surfaces, with deviations from planarity at all length scales. Fault roughness introduces complexity in the rupture process and resulting ground motion. We present a 2D kinematic rupture generator that emulates the strong dependence of earthquake source parameters on local fault geometry observed in dynamic models of ruptures on nonplanar faults. This pseudodynamic model is based on a statistical analysis of ensembles of 2D plane strain rupture simulations on fractally rough faults with rate-weakening friction and off-fault viscoplasticity. We observe strong anticorrelation of roughness-induced fluctuations in final slip, rupture velocity, and peak slip velocity with the local fault slope for right-lateral strike-slip ruptures. Spatial variability in these source parameters excites high-frequency seismic waves that are consistent with observed strong-motion records. Although accurate modeling of this high-frequency motion is critical to seismic-hazard analysis, dynamic rupture simulations are currently too computationally inefficient to be of practical use in such applications. We find that the seismic waves excited by the pseudodynamic model have similar intensity and spectral content to the corresponding dynamic model. Although the method has been developed in 2D, we envision that a similar approach could be taken for the 3D problem, provided that computational resources are available to generate an ensemble set of 3D dynamic rupture simulations. The resulting methodology is expected to find future application in efficient earthquake simulations that accurately quantify high-frequency ground motion.

ISSN: 0037-1106
EISSN: 1943-3573
Serial Title: Bulletin of the Seismological Society of America
Serial Volume: 104
Serial Issue: 1
Title: A 2D pseudodynamic rupture model generator for earthquakes on geometrically complex faults
Affiliation: Stanford University, Department of Geophysics, Stanford, CA, United States
Pages: 95-112
Published: 201402
Text Language: English
Publisher: Seismological Society of America, Berkeley, CA, United States
References: 82
Accession Number: 2014-018562
Categories: Seismology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 4 tables
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Abstract, Copyright, Seismological Society of America. Reference includes data from GeoScienceWorld, Alexandria, VA, United States
Update Code: 201412
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