Numerical simulation of stress transfer and triggered earthquake prediction along the Longmenshan-Foreland Basin driven by the Wenchuan Ms 8.0 earthquake

To investigate and analyze the impact of stress transfer and concentration driven by the 2008 Wenchuan M s 8.0 earthquake on the Longmenshan-foreland basin, this study aims to predict the regions where future triggered earthquakes may occur and assess their seismic hazard levels.This paper utilizes finite element numerical simulations to assess the changes in regional stress fields after the Wenchuan earthquake, analyzes the entire process of stress transfer and redistribution under strong earthquake conditions, and fits the results with subsequent seismic events. The results are further validated by the stress fields revealed through the extensive aftershock source mechanism solutions in the study area, exploring the trends for future earthquake triggering. Results indicate: (1) During the earthquake, the stress concentration characteristics of the Beichuan-Yingxiu Fault is prominent, with the maximum principal stress ranging from (1.05–1.75) MPa. The cumulative strain energy in the segment north of Yingxiu along the Longmen Shan Fault is approximately 4–5 times that of the segment south of Yingxiu, which is speculated to be one of the important reasons for the frequent aftershocks in the northern segment of the Longmen Shan Fault. (2) After the earthquake, significant strain enhancement is observed in the southern segment of the Longmen Shan Fault and the Longquanshan Fault, with strain values ranging from (2.00–2.50) × 10 −2 . This is inferred to be the cause of the triggering earthquakes that occurred sequentially in the southern segment of the Longmen Shan Fault and the Chengdu Basin after the Wenchuan earthquake. (3) Based on the simulation results and stress field data, we identify 4 seismic hazard zones in the study area. Notably, the fault segments in the Longmen Shan foothills, specifically the Dayi-Dujiangyan section and the southern segment of the Lushan-Yingxiu section (the Dayi seismic gap), exhibit high levels of seismic hazard. • Stress transfer and concentration induced by the Wenchuan M s 8.0 Earthquake. • Numerical simulation of the changes in the stress field in the study area. • Stress redistribution along the Longmenshan-foreland basin fault. • Predicting regions where future triggered earthquakes may occur.