Free Oscillations and Large-Scale Lateral Heterogeneity of the Earth

本研究旨在进一步发展利用长周期地震资料确定三维大地结构的理论基础。下一个主要的进展将是反演一个更大的数量级的数据集，即50000个源-接收对的数量级，这将在其他地方开发。这里的注意力将集中在精确度和可能的偏差的各种近似和技术，将不得不在这样一个大规模的研究中使用。具体主题是合成长周期地震图的精确计算，近似方法和反演技术的评估，几何光学，各向异性和玻恩近似的理论研究。

This research is to develop further the theoretical basis for determining 3-D earth structure from long-period seismic data. The next major advance will be to invert a dataset that is an order of magnitude larger, of the order of 50,000 source-receiver pairs which will be developed elsewhere. Attention here will be focused on the accuracy and possible biases of the various approximations and techniques that will have to be employed in such a large-scale study. Specific topics to be addressed are the accurate computation of synthetic long-period seismograms, evaluation of approximate methods and inversion techniques, and theoretical studies of geometrical optics, anisotropy, and the Born approximation.