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Documentation of Surface Fault Rupture and Ground-Deformation Features Produced by the 4 and 5 July 2019 Mw 6.4 and Mw 7.1 Ridgecrest Earthquake Sequence

Daniel J. Ponti, Alex E. Morelan, Salena E. Padilla, Michael E. Oskin, Brian Olson, Matt O'Neal, Johanna M. Nevitt, Stephanie Nale, Daniel D. Mongovin, Belle Philibosian, Chris Milliner, Devin McPhillips, James McDonald, Maxime Mareschal, Christopher M. Madugo, Robert J. Leeper, Tyler Ladinsky, jason R. patton, Ian Pierce, Rich D. Koehler, Jessica Thompson Jobe, Jade Zimmerman, Judith Zachariasen, Xiaohua Xu, Alana M. Williams, Joshua Vanderwal, Francesca N. Valencia, Jerry A. Treiman, Brian J. Swanson, Cynthia Pridmore, Eleanor Spangler, Bridget R. Smith-Konter, Drake M. Singleton, Gordon G. Seitz, Katherine M. Scharer, David T. Sandwell, Nathaniel Roth, Ozgur Kozaci, Katherine J. Kendrick, James Luke Blair, Nicolas C. Barth, Paul Burgess, Tom Bullard, Benjamin A. Brooks, Stephan Bork, Kelly Blake, Scott E. Bennett, Steven Bacon, Timothy Dawson, Jeffrey L. Bachhuber, Jean-Philippe Avouac, Stephen J. Angster, Sinan O. Akciz, Alexandra Pickering, Kate Thomas, Carla Rosa, Colin Chupik, Michael J. DeFrisco, Kenneth W. Hudnut, Nicholas A. Graehl, Peter Holland, Christopher Hitchcock, Janis L. Hernandez, John Helms, Alex Hatem, Elizabeth K. Haddon, Carlos Gutierrez, Ryan D. Gold, Jaime Delano, Gareth J. Funning, Erik Frost, Todd Ericksen, Christopher B. DuRoss, Andrea Donnellan, James F. Dolan, Stephen DeLong, & Robert Zinke

Published July 29, 2020, SCEC Contribution #10852

The M6.4 and M7.1 Ridgecrest earthquake sequence occurred on July 4 and 5, 2019 within the Eastern California Shear Zone of southern California. Both events produced extensive surface faulting and ground deformation within Indian Wells Valley and Searles Valley. In the weeks following the earthquakes, more than six dozen scientists from government, academia, and the private sector carefully documented the surface faulting and ground deformation features. As of December 2019, we have compiled a total of more than 6000 ground observations; approximately 1500 of these simply note the presence or absence of fault rupture or ground failure, but the remainder include detailed descriptions and other documentation, including tens of thousands of photographs. More than 1000 of these observations also include quantitative field measurements of displacement sense and magnitude. Site-specific field observations were supplemented by mapping of fault rupture and ground deformation features directly in the field as well as by interpreting the location and extent of surface faulting and ground deformation from optical imagery and geodetic image products. We identified greater than 68 km of fault rupture produced by both earthquakes as well as numerous sites of ground deformation resulting from liquefaction and slope failure. These observations comprise a dataset that is fundamental to understanding the processes that controlled this earthquake sequence and for improving earthquake hazard estimates in the region. This article documents the types of data collected during post-earthquake field investigations, the compilation effort, and the digital data products produced by these efforts.

Ponti, D. J., Morelan, A. E., Padilla, S. E., Oskin, M. E., Olson, B., O'Neal, M., Nevitt, J. M., Nale, S., Mongovin, D. D., Philibosian, B., Milliner, C., McPhillips, D., McDonald, J., Mareschal, M., Madugo, C. M., Leeper, R. J., Ladinsky, T., patton, j. R., Pierce, I., Koehler, R. D., Jobe, J., Zimmerman, J., Zachariasen, J., Xu, X., Williams, A. M., Vanderwal, J., Valencia, F. N., Treiman, J. A., Swanson, B. J., Pridmore, C., Spangler, E., Smith-Konter, B. R., Singleton, D. M., Seitz, G. G., Scharer, K. M., Sandwell, D. T., Roth, N., Kozaci, O., Kendrick, K. J., Blair, J., Barth, N. C., Burgess, P., Bullard, T., Brooks, B. A., Bork, S., Blake, K., Bennett, S. E., Bacon, S., Dawson, T., Bachhuber, J. L., Avouac, J., Angster, S. J., Akciz, S. O., Pickering, A., Thomas, K., Rosa, C., Chupik, C., DeFrisco, M. J., Hudnut, K. W., Graehl, N. A., Holland, P., Hitchcock, C., Hernandez, J. L., Helms, J., Hatem, A., Haddon, E. K., Gutierrez, C., Gold, R. D., Delano, J., Funning, G. J., Frost, E., Ericksen, T., DuRoss, C. B., Donnellan, A., Dolan, J. F., DeLong, S., & Zinke, R. (2020). Documentation of Surface Fault Rupture and Ground-Deformation Features Produced by the 4 and 5 July 2019 Mw 6.4 and Mw 7.1 Ridgecrest Earthquake Sequence. Seismological Research Letters, 91(5), 2942-2959. doi: 10.1785/0220190322.