Abundant Quasi-Repeating Earthquakes Occurring Within Repeater Sequences on the Erkenek‐Pütürge Fault (SE Turkey)
- Creators
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Zhou, Yijian1, 2
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Ghosh, Abhijit1
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1.
University of California, Riverside
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2.
California Institute of Technology
Abstract
Repeaters are known as earthquakes that rupture the same asperity in similar manners. However, the complexity of repeater asperities is poorly investigated. In this study, we developed a new strategy to systematically detect quasi-repeaters that rupture the same asperities in different ways. It begins by identifying repeaters using waveform cross-correlation (CC) ≥0.9 and CC-measured Δ(S-P) times ≤0.01 s. We then adopt a much lower CC threshold to detect quasi-repeaters, classifying repeater sequences as simple (lacking quasi-repeaters) or complex (including quasi-repeaters). Applying this workflow to the Erkenek-Pütürge fault in Turkey, we detected 43 repeater sequences during 2020–2023/04. Notably, 30 sequences (∼70%) are complex. The repeater magnitudes show weak correlation with their recurrence interval, with only complex sequences following the 2023 Mw 7.8 mainshock an exception. Moreover, ∼74% sequences have the first two events following the mainshocks exhibiting decreasing magnitude. These results suggest that slip rate and asperity complexity may be key factors in such modulation.
Copyright and License
© 2025. The Author(s).
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
Acknowledgement
We thank Prof. David Oglesby, Prof. Roby Douilly, Dr. Baoning Wu, and Binhao Wang for constructive discussions. This work is supported by the UC Riverside Senate CoR grant.
Contributions
Author Contributions: Conceptualization: Yijian Zhou. Data curation: Yijian Zhou. Formal analysis: Yijian Zhou. Investigation: Yijian Zhou. Methodology: Yijian Zhou. Resources: Yijian Zhou. Software: Yijian ZhouSupervision: Abhijit Ghosh. Validation: Yijian Zhou. Visualization: Yijian Zhou. Writing – original draft: Yijian Zhou. Writing – review & editing: Yijian Zhou.
Data Availability
The continuous data for the East Anatolian Fault Zone (2020–04/2023) is collected from the Disaster and Emergency Management Presidency https://tdvms.afad.gov.tr/continuous_data (AFAD, Last accessed 2024/11). The seismic catalog of EAFZ built with SAR-PAL and the repeater catalog of EPF built in this study are available via (Zhou, 2025). Active fault traces in Figure 2 come from Active Faults of Eurasia Database (AFEAD, Zelenin et al., 2022). Code for detecting repeaters and quasi-repeaters introduced in this study is available at Github https://github.com/YijianZhou/Quasi-repeater (Zhou, 2024).
Supplemental Material
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Additional details
- University of California, Riverside
- Accepted
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2025-02-10
- Available
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2025-03-26Version of Record online
- Caltech groups
- Division of Geological and Planetary Sciences (GPS)
- Publication Status
- Published