Abstract Earthquakes not only release the long-term accumulated stress on the seismogenic fault but may also increase the stress on some surrounding faults or other segments of the seismogenic fault, thereby raising the seismic risk on these faults. This study investigates the impact of the April 2, 2024, Mw 7.4 earthquake in Hualien, Taiwan, on the surrounding faults and aftershocks. We analyze stress-triggering effects by calculating Coulomb stress changes (ΔCFS) using rupture models and focal mechanism data. Historical focal mechanism nodal planes serve as receiver fault parameters for ΔCFS calculations. Our findings indicate significant Coulomb stress loading on the Longitudinal Valley fault and Central Range structure due to the mainshock, promoting their seismic activity. Loading effects vary by fault type, with thrust and strike-slip faults experiencing more stress loading than normal and odd faults. Conversely, the rupture’s coseismic slip concentration area shows predominant stress unloading, inhibiting seismic activity in the region. Aftershocks mainly experience increased ΔCFS, suggesting that the stress-triggering induced by the mainshock considerably influences the earthquake sequence evolution. These insights are crucial for understanding aftershock patterns and enhancing seismic hazard assessments.
Fund: This study was supported by the National Natural Science Foundation of China (42364005, 42174074, 42064008 and 41704053),Science & Technology Fundamental Resources Investigation Program (Grant No. 2023FY201500), Science and Technology Plan Project of Jiangxi Province (20212BCJ23002, 20232ACB213013) and the East China University of Technology Research Foundation for Advanced Talents (ECUT) (DHBK2019084).
Corresponding Authors: S. Z. Sheng (ssz@cea-igp.ac.cn).
E-mail: ssz@cea-igp.ac.cn
About author: Sheng Shu-Zhong, Professor, graduated from Anhui University in 2005 with a Bachelor of Science degree in physics. In 2008 and 2016, he obtained Master of Engineering and Doctor of Science degrees from the Institute of Geophysics, China Earthquake Administration, respectively. From 2008 to 2018, he worked as an associate professor in the Institute of Disaster Prevention, and currently works in East China University of Technology. He is mainly engaged in the research of tectonic stress fi eld and stress-triggering.
Cite this article:
. Static Stress Triggering Effect on the Surrounding Major Faults and Aftershocks of the 2024 M 7.4 Earthquake in Hualien, Taiwan[J]. APPLIED GEOPHYSICS, 2025, 22(2): 511-522.
2025, Vol. 22 
