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 M_w = 7.3 Landers and 1999 M_w = 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.
Additional Information
© 2016 Macmillan Publishers Limited. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ Received: 03 November 2015; Accepted: 09 May 2016; Published online: 03 June 2016. This research was funded by the US National Science Foundation (NSF EAR-1147436 grant to Dolan). We thank Dimitri Zigone for helpful discussions in earlier versions of the manuscript and the USGS for the EarthExplorer website (http://earthexplorer.usgs.gov/), which greatly simplified access to the aerial photographs. Author Contributions: C.W.D.M. performed the image processing, subpixel image correlation, spectral analyses, synthetic tests and preparation of manuscript. C.S. and A.A.A. contributed to data interpretation, spectral analysis and preparation of manuscript. J.F.D. and J.H. contributed to data interpretation and preparation of manuscript. S.L. and F.A. contributed to image processing, supplying of data and synthetic tests. The authors declare no competing financial interests.Attached Files
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Additional details
- PMCID
- PMC4891690
- Eprint ID
- 68661
- Resolver ID
- CaltechAUTHORS:20160624-125541986
- EAR-1147436
- NSF
- Created
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2016-06-24Created from EPrint's datestamp field
- Updated
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2022-04-26Created from EPrint's last_modified field