Refined Seismic Hazard Assessment of Fault Intersection Zones in Sichuan-Yunnan Region Based on OpenQuake
Zhang Yizhe
Mao Wuwei
Huang Yu
Zheng Hu
Abstract：This study aims to evaluate the applicability of existing seismic ground motion zoning maps in earthquake risk assessment for active fault zones under complex tectonic settings and improve the accuracy of seismic hazard analysis.Focusing on the affected area of the 2022 Ms 6.8 Luding earthquake in the Sichuan-Yunnan region,probabilistic seismic hazard analysis(PSHA)was conducted using the OpenQuake platform.Through seismic catalog processing,magnitude conversion,source parameter estimation,and fault modeling,a regional seismic model incorporating both background seismic sources and fault sources was established.Multiple ground motion prediction equations(GMPEs)suitable for active shallow crustal tectonics were selected to generate seismic motion parameter distribution maps and exceedance probability analysis results.The findings demonstrate that OpenQuake-simulated ground motion distributions align fundamentally with China's fifth-generation seismic ground motion zoning map,particularly showing enhanced accuracy in identifying high peak ground acceleration(PGA)zones.As PGA thresholds increase,high-exceedance probability areas gradually diminish and concentrate near major faults.By adopting 0.1 magnitude increments,this research avoids the underestimation of seismic moment release rates observed in the fifth-generation zoning map.Furthermore,results indicate concentrated strong earthquake risks in fault intersection zones,suggesting these areas should be prioritized for monitoring and protective measures.
Keywords：hazard analysisOpenQuakeSichuan-Yunnan areatruncated Gutenberg-Richter relationengineering geology
Publication Date：2025-10-30
Online Publishing Date：2025-11-11(First online date of this platform, not the publication date of the document)
Pages：12( 3997-4008 )