3D forward modeling by four way domain decomposition and four way I/O concurrent management with absorbing boundaries implemented on the Cray X-MP/48

A 3D acoustic wave equation modeling program was designed and implemented on the CRAY X-MP vector processor. Domain decomposition is used to split the problem into two or more concurrent sub-tasks. The program is designed to handle problems of the order 256x256x128 spatial gird points and approximately 3000 time steps. The Fast Fourier Transformation method is used as the computional basis of the 3D modeling program, A brief overview of the CRAY X-MP system is given and the algorithm used in solving the wave eqution is also discussed. The design of the 3D forward modeling program has the following properties : (1) Four way concurrent I/O management (SLICE4); (2) Physical model input facility; (3) Domain decomposition and (4) Absorbing boundaries. The measured times, snapshots and time section graphs of the test models are presented. Factors affecting the computing time and improvements of the 3D forward modeling program will also be discussed. Finally the physical model results (tank data) is compared with the numerical results of the forward modeling to obtain comparisons of seismic events.