2014年云南鲁甸6.5级地震震源位置及震源区速度结构联合反演

Simultaneous Inversion for Focal Location of Yunnan Ludian M_S6. 5 Earthquake Sequence in 2014 and Velocity Structure in the Source Region

利用震源位置和速度结构的联合反演,得到了2014年云南鲁甸6.5级地震序列的震源位置及震源区速度结构。结果表明,鲁甸地震序列呈共轭分布,余震主要分布在NNE向包谷垴—小河断裂上,另一小部分分布在近EW向的共轭未知断裂上。震源深度剖面结果显示包谷垴—小河断裂是一个走向NNW、高倾角、且倾向为SWW的断裂。震源区地壳结构复杂,存在大面积高速区,地震主要分布在P波速度较高的地区。

The focal location of Ludian Ms6. 5 earthquake on Aug. 3, 2014 and the velocity structure model in the source region were obtained by using a simultaneous inversion method for focal location of and velocity structure. The results show that the characteristic of Ludian earthquake sequence is a conjugate rupture, the aftershocks dominantly occurred along the Baogunao-Xiaohe Fault in NNW-trending and a small part of earthquakes extended toward a blind fault in EW-trending. The section along different focal depth revealed that the Baogunao-Xiaohe Fault is a NNW strike, high dip angle and SWW rake fault. The crustal velocity structure was very complicated in the source region, and there was a large area of high velocity. The aftershocks were mainly happened in the high velocity regions of P wave.