Cascading and pulse-like ruptures during the 2019 Ridgecrest earthquakes in the Eastern California Shear Zone
Abstract
On July 4 2019, a M_w 6.5 earthquake, followed 34 h later by a M_w 7.1 event, struck Searles Valley, California. These events are part of a long-lived cluster of historical earthquakes along the Eastern California Shear Zone (ECSZ) which started in 1872 and are associated with temporarily elevated strain rates. We find that the M_w 6.5 event initiated on a right-lateral NW striking fault and then ruptured a left-lateral fault to the surface. This event triggered right-lateral slip during the M_w 7.1 earthquake. It started as a bilateral, crack-like rupture on a segment brought closer to failure by the M_w 6.5 event. The rupture evolved to pulse-like as it propagated at a relatively slow velocity (2 km/s) along a segment that was unloaded by the M_w 6.5 event. It stopped abruptly at the Coso volcanic area and at the Garlock Fault and brought some neighbouring faults closer to failure.
Additional Information
© 2020 The Author(s). This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. Received 20 August 2019; Accepted 19 November 2019; Published 07 January 2020. This work was partially supported by the National Science Foundation through grant EAR-182185. Part of this research was also supported by the National Aeronautics and Space Administration, and performed at the Jet Propulsion Laboratory, California Institute of Technology. We are grateful to ARIA project of the Jet Propulsion Laboratory for making their ALOS-2 and Sentinel-1 displacements publicly available and Cunren Liang for discussions of the InSAR data processing. Data availability: The Sentinel-2 and Planet Labs images are stored at https://doi.org/10.5281/zenodo.3542274 and https://doi.org/10.5281/zenodo.3542132, respectively. 1-Hz raw GPS observations are achieved by UNAVCO and publicly available at ftp://data-out.unavco.org/pub/highrate/1-Hz/rinex/2019/185 and ftp://data-out.unavco.org/pub/highrate/1-Hz/rinex/2019/187. Static co-seismic GPS offsets are provided by the Nevada Geodetic Laboratory (http://geodesy.unr.edu/). The interferograms were generated from Sentinel SAR images from ESA and Japanese Aerospace Agency Advanced Land Observing Satellite 2, which were distributed by the ARIA team at the Jet propulsion Laboratory (https://aria-share.jpl.nasa.gov/20190704–0705-Searles_Valley_CA_EQs/Interferograms/). The broadband teleseismic seismograms are publicly available from Incorporated Research Institutions for Seismology (http://ds.iris.edu/wilber3/find_stations/11058875). The earthquake catalogues are obtained from the Southern California Earthquake Center at Caltech (http://service.scedc.caltech.edu/eq-catalogs/date_mag_loc.php). The focal mechanisms plotted in Fig. 2b can be accessed at Global Centroid Moment Tensor catalogue (https://www.globalcmt.org/CMTsearch.html). All other data can be obtained from the lead author upon reasonable request (kjchen@caltech.edu). Code availability: The Mudpy software package to invert the co-seismic slip distribution is available at https://github.com/dmelgarm/MudPy, the COSI-Corr software package is for free download from http://www.tectonics.caltech.edu/slip_history/spot_coseis/. The various scripts for Coulomb stress change calculation, data analysis and plotting are available from the authors upon request. Author Contributions: K.C. carried out finite source modelling and edited the paper; S.A. and C.M. processed optical offset data and edited the paper; J.P.A. conceived, supervised this study and edited the paper; F.Z. and C.S. processed the GPS data. All authors discussed the results and took part in finalizing this manuscript. The authors declare no competing interests.Attached Files
Published - s41467-019-13750-w.pdf
Supplemental Material - 41467_2019_13750_MOESM1_ESM.pdf
Supplemental Material - 41467_2019_13750_MOESM2_ESM.pdf
Supplemental Material - 41467_2019_13750_MOESM3_ESM.pdf
Supplemental Material - 41467_2019_13750_MOESM4_ESM.mp4
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Additional details
- PMCID
- PMC6946662
- Eprint ID
- 100557
- Resolver ID
- CaltechAUTHORS:20200108-110234385
- EAR-182185
- NSF
- NASA/JPL/Caltech
- Created
-
2020-01-08Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Seismological Laboratory, Division of Geological and Planetary Sciences