利用密集台阵研究滇西北地区地震活动性

Seismicity in Northwest Yunnan Studied Using Dense Station Array

采用双差定位方法对2018-04~2020-09滇西北密集台阵记录到的15816个地震进行重定位,得到14110个重定位事件,获得滇西北地区精确的地震空间分布。结果表明:1)研究区地震活动分布不均匀,多数地震沿着深大断裂呈条带状分布,充分展示了断裂在地表的展布形态;2)研究区内地震的震源优势深度范围为7~11 km,说明本区地震多发生在中上地壳内;3)地震在各个剖面深度的分布特征显示出断裂在深部的构造特征。

We use the double difference location method to relocate the 15816 earthquakes recorded by dense station array in northwest Yunnan from April 2018 to September 2020.14110 relocation events are obtained.We obtain the accurate spatial distribution of earthquakes in northwest Yunnan.The results show that:1)The distribution of earthquakes in the study area is not uniform.Most of the earthquakes are distributed along the boundary of the deep and large faults,which fully shows the pattern of faults;2)The predominant focal depth of the earthquakes is 7-11 km,indicating that the earthquakes mostly occur in the middle and upper crust;3)The depth distribution characteristics of the earthquakes in each profile show the structural characteristics of the fault in the deep.