台湾集集地震对福州小震群的动态库仑破裂应力分析

1.江西省地震局,南昌 330096;2.福建省地震局,福州 350003

台湾集集7.6级地震;福州ML3.8级地震;东南沿海东部地区;动态库仑破裂应力

Dynamic Coulomb Failure Stress Analysis of Fuzhou Small Earthquake Swarm Caused by Chi-Chi Earthquake in Taiwan Province
DONG Feifei1,YUAN Liwen2,DENG Hui1

1.Jiangxi Earthquake Agency , Nanchang 330096, China;2.Fujian Earthquake Agency , Fuzhou 350003, China

Chi-Chi MS7.6 earthquake in Taiwan Province;Fuzhou ML3.8 earthquake;East of the southeast coast;Dynamic Coulomb fracture stress

DOI: 10.13512/j.hndz.2022.04.08

备注

根据库仑破裂准则,采用离散波数法计算了1999年台湾集集7.6级地震对福州ML3.8级地震的动态库仑应力变化影响,结果显示:震后105.1s、114.51s、116.08s以及127.84s时应力变化值超过了触发阈值,116.08s时达到最大值约为0.74MPa,说明台湾集集7.6级地震能够动态应力触发福州ML3.8地震。此外根据台湾集集7.6级地震发生后不同时刻的动态库仑破裂应力场传播图可看出,其最大余震的发生可能受到了台湾集集7.6级地震的动态和静态触发共同作用。
In this paper, according to Coulomb fracture criterion, the discrete wave number method is used to calculate the dynamic Coulomb stress variation of the 1999 Chi-Chi MS7.6 earthquake in Taiwan on Fuzhou ML3.8 earthquake. The results show that the stress change value exceeds the trigger threshold at 105.1,114.51,116.08 and 127.84 seconds after the earthquake, and the maximum value is about 0.74 MPa at 116.08 seconds, which shows that the Chi-Chi MS7.6 earthquake in Taiwan can trigger the Fuzhou ML 3.8 earthquake by dynamic stress. In addition, according to the dynamic Coulomb fracture stress field propagation diagram at different times after the 7.6 earthquake,it can be seen that the occurrence of the largest aftershock may be jointly triggered by the dynamic and static triggering of the Chi-Chi earthquake.
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