2014年8月3日云南鲁甸发生M_S6.5地震，造成重大人员伤亡和财产损失。此次地震发震构造复杂，引起了地震学界的广泛关注。本文基于三维建模方法，建立鲁甸地区三维层状非均匀速度模型，采用逐段迭代射线追踪方法对鲁甸M_S6.5地震进行三维射线追踪走时计算；利用震中距150km范围内的近震Pg波震相走时数据，通过射线追踪走时拟合获得鲁甸地震的震源深度约为12km，与前人研究成果基本一致，表明了本文采用的三维建模和射线追踪方法的有效性。

An M_S6.5 earthquake occurred in Ludian,Yunnan Province on August 3,2014,and caused heavy casualties and property losses. The seismogenic structure of Ludian M_S6.5 earthquake was quite complex,and had attracted wide attention of seismologists. In this paper,a 3D layered heterogeneous velocity model in Ludian area is established based on a 3D modeling method,and a segmentally iterative ray tracing method is used in the traveltime calculation of Ludian M_S6.5 earthquake. We utilize the first arrivals recorded by the regional stations within 150km of epicenter distance,and calculate the focal depth of Ludian M_S6.5 earthquake through the method of traveltime fitting. The focal depth of Ludian M_S6.5 earthquake obtained in this study is about 12km,which is close to the results of previous studies. Numerical tests indicate the effectiveness of our methods of blocked modeling and ray tracing.

P315

国家自然科学基金（41604054）资助