THE COMPUTATION OF THEORETICAL SEISMOGRAMS AND SPECTRA OF SEISMIC WAVES RECORDED ON THE SURFACE AND UNDERGROUND OF STRATIFIED EARTH CRUST
Feng Deyi Wu Guoyou Nie Yongan Guo Ruizhi (Seismologies! Bureau of Tianjin City, Tianjin 300201)He Borong(Nankai University, Tianjin 300000)
The combinational method of partial separation of variables and finite differences has been applied to computing the theoretical seismograms of body waves recorded on the surface and underground of stratified media. For the simplification of numerical computation, the absorption boundary condition at an artificial boundary Z = L under the Moho discontinuity has been introduced. Second, the method of matrix has been applied to computing the theoretical spectra of seismic waves in stratified media.For the illustration of the methods, the theoretical seismograms and spectra for the two models of the stratified earth crust of North China have been obtained and analyzed. Among them the model A corresponds to the crust upper mantle structure of the Tangshan region and the model B is a simplified one of the crust. By using the theoretical results obtained, the models of the crust medium can be analyzed and assessed. And the optimum one may be chosen on the basis of the practical records of seismic waves observed on the surface and underground.