Seismological Investigations of Deep Earth Structure

来自全球地震台网的大量高质量数字记录的日益增多使研究地球深部结构的各种新方法成为可能。通过分析成百上千的地震记录，通常有可能解决数据中的新特征，或者对以前在较小规模上解决的问题进行更全面的分析。该项目将继续并扩大加州大学圣地亚哥分校的全球地震数据分析，以解决各种地球物理问题。这些措施包括：(1)利用反射和转换地震相解决上地幔中的地震不连续性，(2)不连续地形和地幔三维地震速度变化的综合反演，(3)分析纵波和横波以解决地幔衰减结构的细节，(4)寻找可能将地幔分成不同对流单元的假想的中地幔不连续，(5)研究和模拟从小尺度地幔结构散射的高频波，以及(6)波形互相关和聚类分析技术的发展和应用于长周期波形。这项研究可能会改进地震数据分析的方法，并对地球深部的结构、组成和演化产生新的限制。大部分资金将提供研究生和博士后支持，这将进一步促进地球科学的教育。

EAR-0229323Peter M. ShearerThe increasing availability of large numbers of high-quality digital records from the global seismic networks has made possible a variety of new ways to study deep Earth structure. By analyzing hundreds or thousands of seismograms, it is often possible to resolve new features in the data, or to perform more comprehensive analyses of problems that were previously addressed on smaller scales. This project will continue and extend analyses of global seismic data at U.C. San Diego to address a variety of geophysical issues. These include: (1) Resolution of seismic discontinuities in the upper mantle using reflected and converted seismic phases, (2) Integrated inversions for discontinuity topography and three-dimensional seismic velocity variations in the mantle, (3) Analyses of both compressional and shear waves to resolve details of mantle attenuation structure, (4) A search for hypothesized mid-mantle discontinuities that may separate the mantle into different convecting cells, (5) Study and modeling of high-frequency waves scattered from small-scale mantle structure, and (6) Development and application of waveform cross-correlation and cluster analysis techniques to long-period waveforms. This research is likely to lead to improved methods for seismic data analysis and new constraints on deep Earth structure, composition and evolution. The bulk of the funding will provide graduate student and postdoc support that will further education in the Earth Sciences.