title: Resolving Fine-Scale Heterogeneity of Co-seismic Slip and the Relation to Fault Structure.
abstract: Fault slip distributions provide important insight into the earthquake process. We analyze high-resolution along-strike co-seismic slip profiles of the 1992 Mw = 7.3 Landers and 1999 Mw = 7.1 Hector Mine earthquakes, finding a spatial correlation between fluctuations of the slip distribution and geometrical fault structure. Using a spectral analysis, we demonstrate that the observed variation of co-seismic slip is neither random nor artificial, but self-affine fractal and rougher for Landers. We show that the wavelength and amplitude of slip variability correlates to the spatial distribution of fault geometrical complexity, explaining why Hector Mine has a smoother slip distribution as it occurred on a geometrically simpler fault system. We propose as a physical explanation that fault complexity induces a heterogeneous stress state that in turn controls co-seismic slip. Our observations detail the fundamental relationship between fault structure and earthquake rupture behavior, allowing for modeling of realistic slip profiles for use in seismic hazard assessment and paleoseismology studies.
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: C W D
authors.initials: CW
authors.lastname: Milliner
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: C
authors.initials: C
authors.lastname: Sammis
authors.affiliation: Geology and Geophysics, The University of Utah, Salt Lake City, Utah 84112, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Allam
authors.affiliation: Department of Earth Sciences, University of Southern California, Los Angeles, California 90089, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Dolan
authors.affiliation: Université Grenoble Alpes, ISTerre, Grenoble 38058, France.
authors.forename: J
authors.initials: J
authors.lastname: Hollingsworth
authors.affiliation: Navdy, 575 7th Street San Francisco, CA 94103, USA.
authors.forename: S
authors.initials: S
authors.lastname: Leprince
authors.affiliation: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: F
authors.initials: F
authors.lastname: Ayoub