Multifault Models of the 2019 Ridgecrest Sequence Highlight Complementary Slip and Fault Junction Instability
- Creators
- Jia, Zhe
- Wang, Xin
- Zhan, Zhongwen
Abstract
The 2019 Ridgecrest M_w 6.4 and M_w 7.1 earthquakes ruptured a complex fault system, posing challenges in understanding their physical processes. Modeling of the ruptures relies on fault geometries at depth, which are usually assumed based on surface traces and aftershocks. Here we use seismic and geodetic data to jointly constrain the fault geometries and slip distributions. We first represent the first‐order rupture processes with a series of subevents, then conduct slip inversions with subevent‐guided fault geometries. We find that the foreshock sequentially ruptured the NW and SW striking faults starting from their junction. The mainshock initiated at a complex three‐fault junction along the extension of the foreshock NW rupture, with major slip first occurring bilaterally near the hypocenter and then minor unilateral slip later to the southeast end. The slip distributions of the foreshock and mainshock are complementary to each other on the overlapping fault section.
Additional Information
© 2020. American Geophysical Union. Issue Online: 02 September 2020. Version of Record online: 02 September 2020. Accepted manuscript online: 30 August 2020. Manuscript accepted: 21 August 2020. Manuscript revised: 20 August 2020. Manuscript received: 14 July 2020. We thank Zachary Ross for the aftershock catalog (https://scedc.caltech.edu/research-tools/QTM-ridgecrest.html), Eric Fielding, Benjamin Idini, Ollie Stephenson for processing InSAR interferograms, and Kejie Chen for processing the HRGPS time series. We thank Kejie Chen, Jean‐Philippe Avouac, Joann Stock and Jennifer Jackson for helpful discussions. We thank two anonymous reviewers for suggestions. This work is supported by USGS grant G19AP00030. Data Availability Statement. We thank SCEDC for access to the strong‐motion data (https://scedc.caltech.edu), IRIS for the teleseismic waveforms (http://ds.iris.edu/wilber3/find_event), and UNAVCO for the HRGPS observations (https://www.unavco.org/projects/other-projects/high-rate-gps/high-rate-gps.html). We thank the JPL ARIA team for distributing the InSAR data (https://aria-share.jpl.nasa.gov/20190704-0705-Searles_Valley_CA_EQs/SRL-Data_Mine/) (Fielding et al., 2020). We thank SCEC for the Community Velocity Models (https://www.scec.org/research/ucvm).Attached Files
Published - 2020GL089802.pdf
Supplemental Material - downloadSupplement_doi=10.1029_2F2020GL089802_file=grl61148-sup-0001-2020GL089802-SI.pdf
Supplemental Material - downloadSupplement_doi=10.1029_2F2020GL089802_file=grl61148-sup-0002-2020GL089802-ds02.txt
Supplemental Material - downloadSupplement_doi=10.1029_2F2020GL089802_file=grl61148-sup-0003-2020GL089802-ds03.txt
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Additional details
- Alternative title
- Multi‐fault models of the 2019 Ridgecrest sequence highlight complementary slip and fault junction instability
- Eprint ID
- 105328
- Resolver ID
- CaltechAUTHORS:20200911-133129793
- G19AP00030
- USGS
- Created
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2020-09-15Created 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