Seismogenic Structure and Stress State Associated with the 2023 Jishishan Earthquake, NE Tibetan Plateau

IF 1.9 4区地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS

pure and applied geophysics Pub Date : 2024-10-15 DOI:10.1007/s00024-024-03582-1

Yihai Yang, Qian Hua, Xuemei Zhang, Xiaofei Han, Chong Cao, Yurong Qiu

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引用次数: 0

Abstract

On December 18, 2023, an M6.2 earthquake shock the Jishishan County (JSSEQ) in the NE Tibetan plateau. In this study, we conducted a comprehensive analysis based on focal mechanism, seismic b-value and local S-wave splitting analysis to investigate the seismogenic structure and stress state associated with the JSSEQ. The focal mechanism solution shows that the JSSEQ occurs at a centroid depth of 13 km and is associated with a node plane dipping to NNE and the other node plane dipping to WSW. The JSSEQ and its aftershocks are dominated by thrust faulting under prominently sub-horizontal WSW-ENE compression, consistent with the regional stress field. We also observe the JSSEQ occurred in the periphery of a low b-value anomaly body and a ~ 2 year decrease of b-value surrounding the mainshock before the occurrence of JSSEQ. The fast directions are sub-parallel to the maximum horizontal compressive stress with an anticlockwise rotation to the north of the Daotanghe-Linxia fault. Combined with the InSAR observation and surface geology, we deduce that the JSSEQ occurred on a highly stressed asperity of a blind NNE-dipping seismogenic fault, under the control of northeastward expansion of the Tibetan plateau. Our results provide important information for understanding the seismogenic structure and dynamic background of this earthquake that occurred in a highly concerned region.

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来源期刊

pure and applied geophysics 地学-地球化学与地球物理

CiteScore

4.20

自引率

5.00%

发文量

240

审稿时长

9.8 months

期刊介绍： pure and applied geophysics (pageoph), a continuation of the journal "Geofisica pura e applicata", publishes original scientific contributions in the fields of solid Earth, atmospheric and oceanic sciences. Regular and special issues feature thought-provoking reports on active areas of current research and state-of-the-art surveys. Long running journal, founded in 1939 as Geofisica pura e applicata Publishes peer-reviewed original scientific contributions and state-of-the-art surveys in solid earth and atmospheric sciences Features thought-provoking reports on active areas of current research and is a major source for publications on tsunami research Coverage extends to research topics in oceanic sciences See Instructions for Authors on the right hand side.