模拟地震波场的伪谱和高阶有限差分混合方法  

Hybrid PSM/FDM method for seismic wavefield simulation

作　　者：魏星[1] 王彦宾[2] 陈晓非[3] 

机构地区：[1]中国地震台网中心,中国北京100045 [2]北京大学地球与空间科学学院地球物理学系,中国北京100871 [3]中国科学技术大学地球和空间科学学院,中国合肥230026

出　　处：《地震学报》2010年第4期392-400,共9页Acta Seismologica Sinica

基　　金：国家自然科学基金项目(40474012,40821062);国家公益性行业科研专项(20070804)联合资助

摘　　要：伪谱法是一种高效、高精度计算非均匀介质地震波传播的数值方法,但是由于它的微分算子的全局性,使得该方法不适用于分散内存的并行计算.本文将有限差分算子的局部性和伪谱法算子的高效、高精度相结合,发展基于两种方法的伪谱/有限差分混合方法.该方法在一个空间坐标方向上利用交错网格高阶有限差分算子,在另外的空间坐标方向上利用交错网格伪谱法算子,既保留了后者的高效、高精度优势,又便于在PC集群上实现并行计算.对二维模型的计算显示,混合方法能有效处理介质不连续面,在保证伪谱法计算精度的情况下,提供了一种并行计算的可能途径.The pseudospectral approach is an efficient and accurate numerical method for seismic wave modeling in heterogeneous medium.However,due to the global nature of its spatial derivative operator,it is difficult to implement this method in parallel computation on distributed memory cluster system.In this paper,we propose a hybrid scheme based on the pseudospectral method （PSM） and finite difference method （FDM）,which combines the local nature of the FDM operator and the high accuracy and efficiency of PSM.In the hybrid method,the spatial derivative in one of the space coordinates is approximated using the high-order staggered grid FDM,while in other coordinates are approximated by staggered PSM.This method retains the advantages of the PSM and can be easily implemented on a parallel PC cluster for large scale parallel computation.Numerical tests for 2D models showed that the hybrid method can be used to effectively calculate seismic wavefield in heterogeneous medium,and it provides a possible parallel scheme without loosing accuracy of the results.

关 键 词：交错网格 伪谱法 高阶有限差分法 混合方法 地震波场模拟 

分 类 号：P315.31[天文地球—地震学]