KAUST DepartmentEarth Science and Engineering Program
Permanent link to this recordhttp://hdl.handle.net/10754/622067
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AbstractThe 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from approximate to 1.0 to 6.0 m and average 3.31.1 m (2 sigma). Vertical offsets are predominantly east-down between approximate to 0.1 and 2.4 m, with a mean of 0.80.5 m. The average lateral-to-vertical ratio compiled at specific sites is approximate to 6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.41.5 m, corresponding to a geologic M-w approximate to 7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.12.0 m, 12.8 +/- 1.5 m, and 16.6 +/- 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between approximate to 0.6 and 1.6 mm/yr (1 sigma) over the late Quaternary.
CitationHaddon EK, Amos CB, Zielke O, Jayko AS, Bürgmann R (2016) Surface slip during large Owens Valley earthquakes. Geochemistry, Geophysics, Geosystems 17: 2239–2269. Available: http://dx.doi.org/10.1002/2015GC006033.
SponsorsData sets and expanded results contributing to this study are available in the supporting information. The EarthScope Southern and Eastern California Lidar Project (available online at http://opentopo.sdsc.edu) involved data acquisition and processing for the Plate Boundary Observatory (PBO) by NCALM (http://www.ncalm.org). UNAVCO operates the PBO for EarthScope (http://www.earthscope.org), supported by the National Science Foundation (EAR-0350028 and EAR-0732947). Funding for this study was provided by the Southern California Earthquake Center (SCEC) (Project 12140), the Geological Society of America Graduate Student Research fund, the Community Foundation of San Bernardino county, and the Western Washington University Geology Department. We thank G. Seitz, M. Price, and K. Morgan for assistance in the field, and S. Bacon, J. Arrowsmith, R. Weldon, K. Scharer, J. Unruh, C. Madden-Madugo, and D. Haddad for helpful discussions. Constructive reviews by D. Schwartz, R. Briggs, E. Schermer, D. Clark, and one anonymous reviewer substantially improved the paper. We also thank the staff at the UC White Mountain Research Center for facilitating this work. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.