摘要
本文探讨了利用地震面波和重力资料联合反演地壳—上地幔三维密度结构的反演问题。首先建立了地震面波和重力资料的观测方程，然后应用广义线性反演理论给出了反演问题的解。模型试验结果表明，与单纯面波反演的结果相比，联合反演的解在分辨率和方差两个方面都有改善，当加入扰动重力数据时。
Seismic surface waves have been a very useful tool to study the Earth's upper mantle. But as a geophysical inverse problem, inversion of seismic surface waves can only reach a non unique solution. In order to reduce the non uniqueness, one important approach is to increase the data set, namely, include data of other disciplines into the inversion. In this paper, a method for joint inversion of seismic surface waves and gravity data , is proposed and formulated to investigate three dimensional density structure of the crust upper mantle. The solution of this joint inverse problem is given using theory of linear generalized inverse based on Singular Value Decomposition(SVD) technique. In order to obtain an estimation of the solution with both stability and resolution, we cut off some relatively small singular values and make trade off between the variance and resolution of the solution. The results of simulation experiment indicate that: (1) The inclusion of gravity data can reduce the number of relatively small singular values of the kernel coefficient matrix,(2) The trade off curve of joint inversion is located left down to that of inversion using seismic data only, and both the variance and resolution of the solution estimation of joint inversion are improved, and(3) the resulting three dimensional density structure of joint inversion approach to the theory density model closer than do that of inversion using seismic data only, especially within the depth range of 0￣300km. This method is prospective in obtaining more reliable three dimensional density structures if more complicated situations are considered in practical use.
出处
《测绘学报》
EI
CSCD
北大核心
1999年第2期103-109,共7页
Acta Geodaetica et Cartographica Sinica
基金
国家杰出青年科学基金
关键词
地震面波
重力资料
反演
地壳
地幔
密度结构
Joint inversion, Inversion of seismic surface waves , Gravity, Three dimensional density structure, Crust Upper mantle
