分层重力图像方法及其应用

STRATIFIED GRAVITY IMAGE AND ITS APPLICATION

分层重力图像方法是依据三维地震波速的层析成像结果，通过速度与密度相关关系，转换得到分层的密度结构模型，计算并给出各分层在地表的重力异常分布图像．以中国大陆为例，给出其不同深度的7个分层的重力异常图像和不同分层叠加的综合（或总合）重力异常分布图像．经过与实测的中国布格重力异常资料对比分析，结果表明两者的重力场特征相当一致；分层重力图像的结果能较好地反映地下不同深度的物质分布．

The Stratified Gravity Image (SGI) is based on the theory of gravity and data of seismology. The density structure of each layer in the internal media of the earth can be obtained by means of the transformation relation of velocity-density correlation using the velocity structure of the seismic tomography results. The images of gravity anomaly of each layer of various depths and the superposition of different layers can be obtained by calculating the gravity effect of the density model. In this paper, the Chinese continent is chosen as an example of application of SGI. The images of gravity anomaly of each layer and total gravity anomaly of seven layers in China and adjacent areas are obtained. By comparing the total gravity anomaly with the Bouguer gravity anomaly, the result shows that the features of both gravity fields are quite conform, i.e., the result of SGI reflects fairly the distribution of the internal media of the earth. This method provides a new idea and possible way to solve the difficulty problem in stratified analysis of interior structure of the earth by gravity method and data.