2022年四川泸定M_(s)6.8地震前后库仑应力变化分析

Analysis on Coulomb Stress Changes Pre-and After the 2022 Luding M_(s)6.8 Earthquake

计算和研究了巴颜喀拉块体南、东边界地区发生的10次M_(s)≥6.5地震引起的静态库仑应力变化图像,认为先发生的9次地震对2022年9月5日泸定M_(s)6.8地震具有触发作用。泸定M_(s)6.8地震发生后,对震中附近主要断裂应力转移的计算结果显示:在巴颜喀拉块体东、南边界地区10次M_(s)≥6.5地震的共同作用下,鲜水河断裂带道孚—康定段、龙门山断裂带南段及安宁河断裂带北段库仑应力水平升高,具有触发作用,应该关注其未来短期内发生强震的可能性。

In this paper,patterns of static Coulomb stress changes induced by a sequence of 10 M_(s)≥6.5 earthquakes occurred along the southern and eastern boundary of the Bayan Hara block from 1973 to 2022 are calculated and studied.The results show that pre-occurred earthquakes played a triggering role on the M_(s)6.8 Luding earthquake of September 5,2022.After the Luding M_(s)6.8 earthquake,the calculation results of stress transfer of main faults near the epicenter show that under the combined influence of 10 earthquakes with M_(s)≥6.5 in the eastern and southern border area of the Bayan Hara block,the Coulomb stress level on the Kangding-Daofu section of the Xianshuihe fault zone,southern section of the Longmenshan fault zone,and the northern section of the Anninghe fault zone has increased,which has triggering effect for future strong earthquakes.