2023年8月6日山东德州平原M 5.5地震同震变形及地震活动性变化数值模拟  

Numerical simulation of co-seismic deformation and seismicity following the Pingyuan M5.5 earthquake in Shandong Province on August 6,2023

作　　者：孟秋 王子韬 张怀 MENG Qiu;WANG Zitao;ZHANG Huai(Key Laboratory of Computational Geodynamics of Chinese Academy of Sciences,College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Earthquake Forecasting,China Earthquake Administration,Beijing 100036,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai,Guangdong 519080,China;Beijing Yanshan Earth Critical Zone National Research Station,University of Chinese Academy of Sciences,Beijing 101408,China)

机构地区：[1]中国科学院大学地球与行星科学学院,中国科学院计算地球动力学重点实验室,北京100049 [2]中国地震局地震预测研究所,北京100036 [3]南方海洋科学与工程广东省实验室(珠海),广东珠海519080 [4]北京燕山地球关键带国家野外科学观测研究站,中国科学院大学,北京101408

出　　处：《地质学报》2024年第7期2101-2109,共9页Acta Geologica Sinica

基　　金：国家自然科学基金联合基金项目(编号U2239205,U2039207);国家重点研发计划项目(编号2020YFA0713400,2020YFA0713401);中央级公益性科研院所基本科研业务费专项(编号CEAIEF20230209);中央高校基础研究经费联合资助的成果。

摘　　要：2023年8月6日,山东省德州市平原县发生M 5.5地震,造成了严重的经济损失,打破了山东省近40年未发生M≥5.0地震的平静期。平原地震震中区域人口稠密,经济发展迅速,其引起的区域地震活动性变化与未来强震发生的可能性是社会关注的热点。本文通过有限元数值模拟方法,建立三维模型研究震中孕震环境及其邻区同震形变应力场,利用假定破裂模型模拟地震同震位错,根据库仑应力变化理论探究周围区域地震活动性变化。结果表明,本次地震主要形变集中于发震断层10 km范围内,震中位置库仑应力下降超过500 kPa,未来短期内强震发生概率不大。平原地震对附近地震活动性造成了一定影响,可能促进了北部走滑型中小震活动,抑制了西侧正断型地震的发生。对于华北平原及邻近断层地震活动性变化仍需要更长时间地震数据和更深入的研究工作。On August 6,2023,M5.5 earthquake occurred in Pingyuan County,Dezhou City,Shandong Province,causing significant economic losses and ending the nearly 40-year period of M≥5.0 seismic quiet in Shandong Province.The epicenter of the Pingyuan earthquake is located in a densely populated area,with rapid economic development.The changes in regional seismicity resulting from this earthquake and the potential for future strong earthquakes are significant social concerns.We use the finite element numerical simulation with a three-dimensional model to study the co-seismic deformation and stress changes in the seismogenic environment at the epicenter and its surroundings.Additionally,we utilize the assumed rupture model to simulate the co-seismic dislocation.Based on the Coulomb stress change theory,we investigate the seismicity changes in the surroundings.The results indicate that the primary deformation caused by the earthquake is concentrated within 10 km of the seismogenic fault,and the Coulomb failure stress at the epicenter decreases by more than 500 kPa.The probability of a strong earthquake occurring is low in the near future.The Pingyuan earthquake has a significant impact on the seismicity in the surroundings.It may increase the occurrence of slip-type small and medium earthquakes in the north,while reducing the occurrence of normal fault-type earthquakes in the west.Longer seismic data and more comprehensive research are still needed to understand the seismicity changes in the North China Plain and its adjacent faults.

关 键 词：平原地震 地震活动性 库仑应力变化 有限元数值模拟 

分 类 号：P315[天文地球—地震学]