| Autor: |
BaoFeng Tian, Huajian Yao, Lihua Fang, Xihui Shao, Hongfeng Yang, Ying Liu |
| Rok vydání: |
2022 |
| Předmět: |
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| Zdroj: |
Earth and Planetary Physics. 6 |
| ISSN: |
2096-3955 |
| DOI: |
10.26464/epp2022010 |
| Popis: |
The Anninghe fault is a large left-lateral strike-slip fault in southwestern China. It has controlled the deposition and magmatic activities since the Proterozoic, and has frequent seismic activities. The Mianning-Xichang segment of the Anninghe fault is a seismic gap and has been locked with high stress. Many studies suggest that this segment has a great potential for large earthquakes (magnitude>7). We obtained three vertical profiles of the Anninghe fault (between Mianning and Xichang) based on inversion of P-wave first arrival times. The travel time data were picked from seismograms generated by Methane Gaseous Source and recorded by three linearly distributed across-fault dense arrays. The inversion results show that the P-wave velocity structures at depths of 0-2 km corresponds well with the local lithology. The Quaternary sediments have low seismic velocities, while the igneous rocks, metamorphic rocks and bedrocks have high seismic velocities. Then we further discuss the fault activities of the two fault branches of Anninghe fault in the study region based on the small earthquakes (magnitude between M_L 0.5 and M_L 2.5) detected by the Xichang array. The eastern fault branch is more active than the western branch, and the fault activities in the eastern branch are different on the northern and southern segments at the border of 〖28〗^° 〖21〗^' N. The obtained high-resolution models are essential for future earthquake rupture simulation and hazard assessment of the Anninghe fault zone. Future studies of velocity models at deeper depths may further explain the complex fault activities in the study region. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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