地壳垂直形变散度场特征及其物理意义探讨

推导了用富里叶级数表示的地壳垂直形变场所产生的散度场公式。对华北地区３０多年的资料及河西地区近期资料进行了计算，绘制出各时间段的散度等值线图，并对该区地震活动的散度场背景进行了分析研究，得到如下认识：①在散度图象中正源区和负源区之间通常有散度密集带，零散度线恰好位于散度密集带；②散度密集带和地壳厚度变异带在分布上呈现一致性，且在多数情况下二者方向一致；③中强地震通常发生在地壳垂直形变散度场的零散度区，这里是地壳隆起和沉降的交汇部位；④地壳垂直形变散度场图象和地壳深部构造图象有一定的相似性

CHARACTERISTICS OF THE DIVERGENCY FIELD OF VERTICAL CRUST DEFORMATION AND ITS PHYSICAL MEANING

The formula of the divergency field of vertical crust deformation is deduced from Fourier series, and the data of the precise levelling in northern China for more than 30 years are calculated. The isograms of divergency for each period are drawn, and the relations between earthquake activity and divergency field in the area are analysed. The conclusions are as follows:(1)the dense divergency field distributes between the positive and negative source region, and the naught divergency line just locates the dense divergency belt. (2)The distribution of dense divergency belt and crustal variation belt is unanimous, and so are many directions of which. (3) The stronger earthquake always occures in the naught region.(4)There is a certain similarity between the vertical crust deformation divergency image and the deep crust structural image.