Modeling 3-D Seismic Wave Propagation with a Pseudospectral Method

9706169 Tromp这项研究涉及使用伪谱或谱搭配方法，将开发技术来模拟复杂的局部、区域和全球地球模型中弹性和非弹性地震波的传播。与空间有限差分技术相比，该方法需要更少的网格点来达到相当的精度，没有网格各向异性和有限的网格色散，并且由于使用有限傅里叶变换（FFT）而需要更少的CPU时间。在局部范围内，它将被用于基于详细的地质模型模拟波士顿、洛杉矶和东京盆地的地震波传播。球形版本将用于模拟澳大利亚的区域波传播，其中密集SKIPPY阵列的数据可用于比较和反演。在全球范围内，目标是用伪谱波形代替基于路径平均近似计算的波形。这些更精确的波形将用于哈佛质心矩张量项目和我们的全球层析反演。这项研究是国家减少地震危害计划的一个组成部分。＊＊＊

9706169 Tromp This research involves the use of a pseudospectral or spectral collocation method with which techniques will be developed to simulate the propagation of elastic and anelastic seismic waves in complex local, regional, and global Earth models. This method requires significantly fewer grid points than spatial finite- differencing techniques to achieve comparable accuracy, exhibits no grid anisotropy and limited grid dispersion, and requires less CPU time because of the use of Finite Fourier Transforms (FFT). On a local scale, it will be used to simulate seismic wave propagation in the Boston, Los Angeles and Tokyo basins based upon detailed geological models. A spherical version will be used to simulate regional wave propagation across Australia where data from the dense SKIPPY array are available for comparison and inversion. On a global scale, the goal is to replace waveforms calculated based upon the path-average approximation with pseudospectral waveforms. These much more accurate waveforms will be used in the Harvard centroid moment-tensor project and in our global tomographic inversions. This research is a component of the National Earthquake Hazard Reduction Program. ***