The 2021 Mw 7.4 Madoi Earthquake: An Archetype Bilateral Slip-Pulse Rupture Arrested at a Splay Fault
Abstract
We combine measurements of ground deformation from Synthetic Aperture Radar images, high-rate Global Navigation Satellite System and tele-seismic waveforms to study the rupture kinematics of the Madoi Earthquake, which occurred in eastern Tibet on 21 May 2021 and reached a moment magnitude M_w 7.4. The data show nearly pure left-lateral motion along a 170 km long rupture and a total duration of 36 s. The earthquake initiated near the middle of the main segment and evolved in a bilateral slip pulse rupture which propagated at a sub-Rayleigh speed of 2.6–2.8 km/s. In our model, slip is concentrated at depth of less than ∼15 km and reaches a maximum of 4.2 m. The rupture arrested ∼10 s after branching on the extensional splay faults at both extremities. The branching onto the splay faults and the eventual arrest of the rupture is used to provide constraints on the fault frictional properties.
Additional Information
© 2022. American Geophysical Union. Issue Online: 19 January 2022. Version of Record online: 19 January 2022. Accepted manuscript online: 10 January 2022. Manuscript accepted: 28 December 2021. Manuscript revised: 17 December 2021. Manuscript received: 22 July 2021. This research was funded by the National Natural Science Foundation of China (Grant No. 42074024), the Young Talent Promotion Project of China Association for Science and Technology, and National Key Research and Development Program of China (2018YFC1503601). We have further benefited from fruitful discussions with Shiqing Xu, Lingling Ye, and Jing Liu. We also thank three anonymous reviewers and the Editor Germán Prieto for helpful reviews. Data Availability Statement: Original Copernicus Sentinel-1 data were acquired by the European Space Agency (https://scihub.copernicus.eu/) and downloaded from the Alaska Satellite Facility (https://search.asf.alaska.edu/#/). GNSS stations QHMD and QHMQ were operated by the Crustal Movement Observation Network of China, and other GNSS data were from the continuously operating reference stations network operated by the local government (Li et al., 2021). Teleseismic waveforms were obtained through the Data Management Center of the Incorporated Research Institutions for Seismology (https://ds.iris.edu/wilber3/find_stations/11417068). All of the links are last accessed 2021 June and the SAR data are stored at https://doi.org/10.5281/zenodo.5090461, and high-rate GNSS in Seismic Analysis Code (SAC) format is provided in the supplementary data set. The preferred slip model parameters are listed in Table S4 in Supporting Information S1. Most of the figures in this paper were prepared using Generic Mapping Tools (Wessel et al., 2013).Attached Files
Published - 2021GL095243.pdf
Accepted Version - 2021GL095243-acc.pdf
Supplemental Material - 2021gl095243-sup-0001-supporting_information_si-s01.docx
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Additional details
- Eprint ID
- 113025
- Resolver ID
- CaltechAUTHORS:20220120-890583000
- 42074024
- National Natural Science Foundation of China
- Young Talent Promotion Project of China Association for Science and Technology
- 2018YFC1503601
- National Key Research and Development Program of China
- Created
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2022-01-21Created from EPrint's datestamp field
- Updated
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2023-10-06Created from EPrint's last_modified field
- Caltech groups
- Seismological Laboratory, Division of Geological and Planetary Sciences