用地震层析成像方法研究北京西北地区的活动断裂

SEISMIC ACTIVE FAULTS IN THE NORTHWESTERN BEIJING BY SEISMIC TOMOGRAPHY

利用首都圈地震台网和中-德合作延庆数字地震台阵2001年10月—2005年12月获得良好记录的197次地震到时,运用地震震源位置和三维地壳速度结构联合反演程序对这些地震实行精确定位.震源位置分布表明,北京西北地区存在两条主要的地震活动断裂带.一条从清河、温泉一带向北西方向伸展,到怀来县以北的黄土窑一带;另一条是自南口、昌平一带向北东东向伸展的活动断裂带.

Using the arrival times of 197 earthquakes well recorded by the Beijing Seismic Network and the China-Germany cooperative Yanqing Digital Seismic Array in the period from October of 2001 to December of 2005, we accurately relocate these earthquakes by the joint-inversion program for hypocentralr position and 3-D velocity structure. The distribution of hypocenters shows that there are two major seismic active belts in the northwestern Beijing. The first belt stretches from Qinghe, Wenquan to the NW direction and the second extends from Nankou, Changping to the ENE direction.