2013年辽宁灯塔M5.1地震震源机制中心解及震源区构造应力场特征分析  

Central Focal Mechanism of the Dengta,Liaoning M5.1 Earthquake in 2013 and the Analysis of Its Surrounding Tectonic Stress Field

作　　者：戴盈磊[1] 万永革[2,3] 孔祥雪 王承伟[1] 索锐[1] DAI Yinglei;WAN Yongge;KONG Xiangxue;WANG Chengwei;SUO Rui(Liaoning Earthquake Agency,Shenyang 110034,Liaoning,China;Institute of Disaster Prevention,Sanhe 065201,Hebei,China;Hebei Key Laboratory of Earthquake Dynamics,Sanhe 065201,Hebei,China)

机构地区：[1]辽宁省地震局,辽宁沈阳110034 [2]防灾科技学院,河北三河065201 [3]河北省地震动力学重点实验室,河北三河065201

出　　处：《地震研究》2022年第4期570-580,共11页Journal of Seismological Research

基　　金：沈抚新区浑河断裂带活断层探测与地震危险性评价项目(LNZC2018-0173)资助。

摘　　要：采用HASH方法计算得到辽宁灯塔M5.1地震震源机制解:节面Ⅰ走向为12.85°,倾角为89.42°,滑动角为175.83°。结合不同震源机制结果确定了本次地震震源机制中心解:节面Ⅰ走向为13.16°,倾角为88.64°,滑动角为171.01°;节面Ⅱ走向为103.38°,倾角为81.01°,滑动角为1.37°。为进一步研究本次地震的孕育背景和发生条件,收集2001—2013年辽宁地区128个M_(L)2.5~4.8地震的震源机制解资料,反演该地区构造应力场,模拟在其作用下产生的各种震源机制及相对剪应力和相对正应力的分布情况。结果表明:辽宁地区在主压应力轴为NEE向,主张应力轴为NNW向的走滑构造应力体系作用下,经过一段时间的应力积累,在剪应力最大区域、沿应力场最优节面发生破裂,从而发生灯塔M5.1地震。In this paper,the focal mechanism solution of the Dengta,Liaoning M5.1 earthquake is calculated by the HASH method.The strike of one nodal plane is 12.85°,the dip angle is 89.42°,and the slip angle is 175.83°.Its central focal mechanism solution is determined in combination with other results.The strike of nodal planeⅠ is 13.16°,the dip angle is 88.64°,and the slip angle is 171.01°;the strike of nodal planeⅡ is 103.38°,the dip angle is 81.01°,and the slip angle is 1.37°,which solve the problem of non-unique focal mechanism data selection for subsequent related studies.In order to further research the seismogenic background and occurrence conditions of this earthquake,128 focal mechanism solutions in Liaoning region over the past 10 years are collected.The tectonic stress field is inverted to simulate the various focal mechanisms and the distribution of relative shear stress,relative normal stress generated under its action.The results show that the Dengta M5.1 earthquake is a result from strike-slip tectonic stress system with NEE principal compressive stress axis and NNW stress axis in Liaoning.After a period of stress accumulation,the fracture occurs along the optimal nodal plane of the stress field in the area of maximum shear stress.

关 键 词：灯塔M5.1地震 震源机制中心解 构造应力场 剪应力 辽宁地区 

分 类 号：P315.7[天文地球—地震学]