2-D Elastic Wave Modeling By 25 Points Finite Difference Method

Because inersion needs to be improved,we need more and more accurate method to model the propagation of elastic wave.We always use finite difference method to model the propagation of elastic wave in semi-infinite space.However, when the model is complicated,we need use very detailed grid to split the inner domain. That will increase the requirement of memory and lower the computing time. Therefore,it is very important to find a kind of effective modeling method using finite difference.In addition,in the modeling of elastic wave,we used finite domains to substitute for infinite domains.There are great differences in physical quality between the inner and the outer of boundary,which make the artificial interface become a very strong reflecting boundary to incident wave.Because reflected wave from artificial boundary has strongly wreck to elastic wave field,the way of effectively absorbing reflected wave from artificial boundary is a very important research subject in elastic wave numerical simulation.In 2-D frequency domain,we model the propagation of elastic wave using 25-point weighted averaging scheme and attenuate the outgoing waves using perfectly matched layer(PML)as absorbing boundary condition.compared with other modeling methodS.we can see that the method described above is more efficiency and accurate to model real media,and the computational cost is smaller.In addition,the fi-equency method is more convenient to use parallel method.