地质力学学报2025，Vol.31Issue(2)：223-234,12.DOI:10.12090/j.issn.1006-6616.2024039
2023年9月9日摩洛哥M 6.9地震静态应力触发研究
Static stress triggering of Morocco M 6.9 earthquake on 9 September 2023
摘要
Abstract
[Objective]Coulomb stress change is an important tool for studying earthquake triggering effects and assessing seismic hazard.In order to study the triggering of the static Coulomb Failure Stress(CFS)of the M 6.9 earthquake in Morocco on September 9,2023,the study determined the geometric configuration and slip properties of the seismogenic fault,analyzed the co-seismic displacement field and surface strain field generated by the earthquake,and evaluated the triggering effects of the mainshock on aftershocks and surrounding faults,revealing the impact of this earthquake on regional seismic activity.[Methods]Using the"central solution"algorithm,two possible nodal planes of the earthquake were determined,and the local stress field was projected onto these two planes.The nodal plane with higher Coulomb stress was selected as the seismogenic fault plane(strike 253.44°,dip 45.43°,rake 81.05°).Based on statistical formulas,the slip properties of the seismogenic fault plane were determined.Under the homogeneous elastic half-space theoretical model,the co-seismic displacement field and areal strain field of the region were constructed.Subsequently,assuming that the focal mechanisms of the aftershocks on the receiver faults were consistent with the mainshock,the triggering effect of the mainshock on the aftershocks was calculated.Finally,the Coulomb stress changes induced by the mainshock on the surrounding faults were computed to assess the seismic hazard.[Results]The results show that the material at the epicenter moved outward,while the material on the north and south sides moved inward,resulting in uplift at the epicenter and slight subsidence on the north and south sides.The static Coulomb stress generated by the mainshock promoted the occurrence of most shallow aftershocks,with a large number of aftershocks located in areas of high Coulomb stress change.Additionally,the western and southwestern segments of the South Atlas Fault,the southern segment of the North Atlas Fault,and the western segment of the South Sous Fault all exhibited Coulomb stress change values exceeding the 0.01 MPa threshold,indicating a very high seismic hazard that warrants attention.[Conclusion]The study demonstrates that the static CFS generated by the M 6.9 earthquake in Morocco significantly influenced the surrounding seismic activity.The mainshock not only promoted the occurrence of aftershocks but also increased the stress on surrounding faults,particularly in the western and southwestern segments of the South Atlas Fault,the southern segment of the North Atlas Fault,and the western segment of the South Sous Fault.[Significance]The study not only assessed the seismic hazard in the region but also provided a foundational dataset for geodynamic research in the area.It contributes to enhancing earthquake monitoring,prediction,and risk mitigation capabilities,promotes the formulation of relevant policies,and safeguards people's lives and property.Therefore,an in-depth exploration of earthquake triggering is of great significance for strengthening post-earthquake scientific research and improving society's ability to respond to earthquakes.关键词
摩洛哥M 6.9地震/应力触发/库仑应力/发震断层Key words
Morocco M 6.9 earthquake/stress triggering/Coulomb failure stress/seismogenic fault分类
天文与地球科学引用本文复制引用
王润妍,万永魁,关兆萱,黄少华,顾培苑,宋泽尧,周明月..2023年9月9日摩洛哥M 6.9地震静态应力触发研究[J].地质力学学报,2025,31(2):223-234,12.基金项目
国家自然科学基金项目(42174074,41674055,42364005)This research is financially supported by the National Natural Science Foundation of China(Grant Nos.42174074,41674055,and 42364005). （42174074,41674055,42364005）
