2017年米林6.9级地震序列双差定位分析

Study on double difference positioning of Milin M6.9 earthquake sequence in 2017

使用双差定位法对2017年11月18日米林6.9级地震和余震进行重新定位,得到691个地震定位结果,发现:(1)余震序列分布更加集中,地震序列震中呈NW—SE向分布,与雅鲁藏布江断裂在NE向构造转弯处的走向基本一致;(2)地震序列的震源深度主要分布在5—15 km,东南侧地震数量较少,震源深度相对较深,西北侧地震数量较多,震源深度较浅。

The double difference location method was used to relocate the Milin earthquake with magnitude 6.9 on November 18,2017 and aftershocks.The location results of 691 earthquakes were obtained.After repositioning,the distribution of the aftershock sequence is more concentrated,the epicenter of the earthquake sequence is distributed along a northwestern-southeast direction,which is basically the same as the turning direction of the northeast direction Yarlung Zangbo River Fault.The focal depth of the earthquake sequence is mainly distributed in 5-15 km,the earthquakes in the southeast side are small,the depth of the earthquake source is relatively deep,the number of earthquakes in the northwest side is large,and the depth of the earthquake source is shallow.