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中国地震局地球物理研究所在 1 989年 1 0月 5.8级和 1 991年 3月 5.5级大同地震之后使用由数字地震仪组成的小孔径流动台网对其余震进行了流动观测。通过利用多道地震数据分析软件正确地确定震相 ,修改地壳速度模型等方法 ,高精度地确定了部分余震的震源位置。两次大同地震部分余震的震中分布表明 ,大同地震的主干断裂是北北东走向的断裂 ,同时伴随北西走向的分支断裂的活动。盆地的速度结构可以以双层速度结构模拟 ,其上层为 P波速度为3.1 km/s的沉积层 ,符合大同盆地为火山喷发堆积物的实际情况。
The Institute of Geophysics, China Earthquake Administration, conducted a flow observation of the aftershocks using a small-aperture mobile network composed of digital seismometers after the 1998 Massacre 5.8 in January 1989 and Datong 5.5 in March 1991. By using multi-channel seismic data analysis software to correctly determine the seismic phases and modify the crustal velocity model and other methods, the focal position of some aftershocks can be determined with high accuracy. The epicentral distribution of some aftershocks during the Datong earthquake shows that the main fault of the Datong earthquake is a north-north-easterly fracture accompanied by a northwest-trending branched fault. The velocity structure of the basin can be simulated by a double-velocity structure. The upper layer is a sedimentary layer with a P-wave velocity of 3.1 km / s, which accords with the actual situation of the volcanic eruption in the Datong Basin.