Modeling 3-D Seismic Wave Propagation with a Pseudospectral Method

9706169 TROMP这项研究涉及使用伪谱或谱配置方法，利用该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的弹性和滞弹性地震波的传播。与空间有限差分方法相比，这种方法需要更少的网格点才能达到相当的精度，没有网格各向异性和有限的网格色散，并且由于使用了有限傅立叶变换(FFT)，所需的CPU时间更少。在地方尺度上，它将被用来根据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。一个球形版本将被用来模拟穿过澳大利亚的区域波传播，在那里可以获得来自密集的Skippy阵列的数据以供比较和反演。在全球范围内，目标是用伪谱波形取代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大学的质心矩-张量项目和我们的全球层析反演法。这项研究是国家减少地震灾害计划的一部分。***

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. ***