Applying finite element analysis to the memory variable formulation of wave propagation in anelastic media

Finite-element methods are applied to solution of seismic wave motion in li near viscoelastic media using the memory variable formalism. The displaceme nts are represented as a superposition of a set of basis functions. It is s hown that if memory variables are represented using the spatial derivatives of those basis functions, rather than the basis functions themselves, the equations to be solved are simpler and require less computer memory. Using this formulation, results for SH waves in one and two dimensions are calcul ated using a simple explicit finite-element-in-space/finite -difference-in- time scheme. These results agree with those found with a "method of lines" solution. Results in a homogeneous medium also agree with the frequency dom ain solutions of Kjartansson's constant-e method.