利用地震层析成像方法处理唐山临时地震台网资料,得到该地震区中上地壳的速度图像。图像表明:上地壳速度在唐山断裂带两侧差异明显,速度结构特征是北西侧为高速区,东南侧为低速区,唐山断裂带为速度陡变带;中地壳速度表现为在研究区中部近东西向展布的低速带,其位置和方向与近东西向的丰台一野鸡坨断裂有对应关系;唐山震源区无论是在深度方向还是水平方向都存在地壳速度陡变。
Seismic tomography is used for processing the data of temporary seismostations networks in Tangshan region, and the velocity images of upper and mid crust in this earthquake region are obtained. The results show that, in the upper crust image, the velocity of two sides between the Tangshan fault zone are different,where the northwest side is high velocity zone while the southeast side is low and the Tangshan fault is belt with sharp velocity variety. Be- sides in the mid crust velocity image, it shows that there is low velocity belt near EW strike in the centre of the stud- ied area, and its location and strike are corresponding with the Fengtai-Yejituo fault which is near EW strike and in Tangshan epicenter region, along both of the depth and horizon, sharp velocity variety in crust exsits too.