Isotropic Source Components of Events in the 2019 Ridgecrest, California, Earthquake Sequence
Abstract
We investigate the non-double-couple components of 224 M ≥ 3.0 earthquakes in the 2019 M_w7.1 Ridgecrest sequence, which occurred on a complex fault system in the Eastern California Shear Zone. Full moment tensors are derived using waveform data from near-fault and regional stations with a generalized cut-and-paste inversion and 3-D velocity and attenuation models. The results show limited Compensated Linear Vector Dipole components, but considerable explosive isotropic components (5%–15% of the total moments) for approximately 50 earthquakes. Most of these events occur between the M_w6.4 foreshock and 1 day after the M_w7.1 mainshock and are mainly distributed around the rupture ends and fault intersections. The percentage of isotropic components is reduced considerably when data recorded by near-fault stations are not included in the inversions, highlighting the importance of near-fault data. The results suggest that high-frequency damage-related radiation and other local dilatational processes are responsible for the observed isotropic source terms.
Additional Information
© 2021. American Geophysical Union. Issue Online: 25 September 2021; Version of Record online: 25 September 2021; Accepted manuscript online: 13 September 2021; Manuscript accepted: 01 September 2021; Manuscript revised: 26 July 2021; Manuscript received: 25 May 2021. The manuscript benefitted from useful comments by two anonymous referees and editor German Prieto. The research was supported by the Southern California Earthquake Center (based on NSF Cooperative Agreement EAR-1600087 and USGS Cooperative Agreement G17AC00047). Xin Wang acknowledges support from the Young Elite Scientists Sponsorship Program by CAST (Grant 2020QNRC001). Data Availability Statement: The employed earthquake catalog of Ross et al. (2019) is available online (at https://scedc.caltech.edu/data/qtm-ridgecrest.html). The used earthquake waveform data is available from the Southern California Earthquake Data Center (http://scedc.caltech.edu). The used moment tensor solutions are available through the supporting information (Datasets S1 and S2) and the Mendeley Data (https://dx.doi.org/10.17632/w4t3k63779.1) (Cheng et al., 2021).Attached Files
Published - 2021GL094515.pdf
Accepted Version - 2021GL094515_acc.pdf
Supplemental Material - 2021gl094515-sup-0001-supporting_information_si-s01.pdf
Supplemental Material - 2021gl094515-sup-0002-data_set_si-s01.txt
Supplemental Material - 2021gl094515-sup-0003-data_set_si-s02.txt
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Additional details
- Eprint ID
- 111236
- Resolver ID
- CaltechAUTHORS:20211006-153617768
- Southern California Earthquake Center (SCEC)
- EAR-1600087
- NSF
- G17AC00047
- USGS
- 2020QNRC001
- China Association for Science and Technology
- Created
-
2021-10-06Created from EPrint's datestamp field
- Updated
-
2023-10-04Created from EPrint's last_modified field
- Caltech groups
- Seismological Laboratory, Division of Geological and Planetary Sciences