High-Resolution Shear-Wave Velocity Structure of the 2019 Ms 6.0 Changning Earthquake Region and Its Implication for Induced Seismicity
| Autor: | Qiaoxia Liu, Ming Zhou, Xiaofeng Tian, Yong Qiu, Zhichao Shen, Qingdong Wang, Chongpeng Wang |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Seismological Research Letters. |
| ISSN: | 1938-2057 0895-0695 |
| Popis: | Fluid injection activities related to hydraulic fracturing (HF) and salt mining may induce moderate earthquakes. In the Changning area in southwest China, the Ms 6.0 earthquake on 17 June 2019 is the largest and the most damaging event ever recorded in this region. This earthquake occurred in the Changning anticline, which hosts multiple active faults and industrial production activities, raising an extensive controversy on the cause of the earthquake. Beyond seismogenic faults, a detailed 3D velocity structure of the source region is missing. Here, we applied an improved ambient noise tomography method to seismic data recorded by a portable dense seismic array to reveal the characteristic of 3D shear-wave velocity (VS) structure with high resolution in the Changning region. Our VS structure model provides some new observational evidence favoring that the Ms 6.0 Changning earthquake and the related seismicity in Shangluo shale gas field were, respectively, induced by fluid injection for salt mining and hydraulic fracturing. Moreover, it is suggested that the shallow segment of the pre-existing thrust faults were reactivated by fluid injection. This result provides some implications of VS structure of the induced-seismicity source region and warn us to pay more attention to the seismic risk assessment for such areas that have both similar industrial operation intensity and tectonic settings. |
| Databáze: | OpenAIRE |
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