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Title:: Study on Stress Triggering of 2014 Kangding M_S6.3 and M_S5.8 Earthquakes

作者:: 解朝娣¹; 2; 王英楠¹; 闫如玉¹; 杨颖¹; 李孟洋¹; 于海英³; 刘本玉¹; (1.云南大学地球科学学院,云南昆明 650091; 2.中国地震局地质研究所地震动力学国家重点实验室,北京 100029; 3.上海市地震局,上海 200062)

Author(s):: XIE Chaodi¹; 2; WANG Yingnan¹; YAN Ruyu¹; YANG Ying¹; LI Mengyang¹; YU Haiying³; LIU Benyu¹; (1.School of Earth Sciences,Yunnan University,Kunming 650091,Yunnan,China)(2.State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China)(3.Shanghai Earthquake Agency,Shanghai 200062,China)

Keywords:: Kangding earthquake; Coulomb failure stress change; earthquake triggering; fault interaction effect

摘要:: 以2014年四川康定M_S6.3和M_S5.8地震为研究对象,计算了2次主震在近场和周围断层造成的库仑破裂应力变化,研究主震与余震的触发关系,以及2次主震对周围断层施加的应力负荷作用。结果表明:2次主震的共同作用控制了后续地震活动的演化趋势,其中康定M_S6.3地震产生的库仑破裂应力变化对后续余震事件的触发占主导作用。鲜水河断裂带南段和安宁河断裂带受到了一定的应力加载作用,未来地震活动的趋势可能会加强。

Abstract:: In this study,the problem of earthquake triggering is discussed by using the M_S6.3 earthquake on Nov.22,2014 and the M_S5.8 earthquake on Nov.25,2014 in Kangding,Sichuan Province.Firstly,based on the regional tectonic stress field in this area,we calculated the spatial distributions of static stress changes caused by the Kangding M_S6.3 and M_S5.8 earthquakes on the optimal fault planes,and studied the stress triggering effect of the main shock to the aftershocks.Furthermore,we analyzed the stress loading and unloading effects of the two main-shocks on the surrounding faults by calculating the Coulomb rupture stress changes on the surrounding faults.The results show that the joint action of the two main earthquakes controls the evolution trend of the subsequent seismicity.Moreover,the Coulomb failure stress change produced by the Kangding M_S6.3 earthquake has a good correlation with the aftershocks,and the triggering effect on the subsequent events is dominant.In addition,the southern segment of the Xianshuihe fault and the Anninghe fault are subjected to certain stress loading by two earthquakes,and the seismic activity may be strengthened in the future.