The Study On The Elastic Parameter Inversion In Anisotropic Media With Finite Element Method And The Parallel Algorithm

The inversion of seismic wavefield based on elastic wave equations is an interesting issue for seismology. It is important to study the physical property of anisotropic media using the information of seismic wave aimed at probing into the earth.The thesis puts emphases on the research of elastic parameter inversion of anisotropic media with full wavefield. According to the second-order partial differential equations describing the propagation of elastic wave and Hamilton variational principle, the finite element equations for forward problem are obtained. In the time domain the equations are discretized for calculating the time sequence of wavefield displacement. In the phase space of the elastic parameter, the generalized linear inversion equations are presented. An expression is derived for directly calculating the Jacobi matrix. It has the same form as the finite element forward modeling equations. The results of the numerical experiments under the condition of homogenous and heterogeneous initial models prove that the method is feasible.It is necessary to parallelize the algorithm of the finite element inversion system in order to improve computation efficiency and to study more complex models. According to the character of the finite element method and the inversion equations, the feasibility of the parallel implementation is discussed.