Seismological Investigations of Earthquakes and 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震和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。该项目将继续在加州大学圣地亚哥分校对全球地震数据进行分析，以检查各种地球物理问题。这些措施包括：(1)使用接收函数和SS前兆检查岩石圈-软流圈边界，(2)使用反投影方法成像地震破裂，(3)观测和模拟主要体波地震相之间的散射能量，以约束尺度长度短于地震层析成像的地幔不均匀的统计特性，(4)系统地搜索(和检验)核内剪切相PKJKP的先前主张。该项目通过为研究生和博士后提供资金来支持加州大学圣地亚哥分校的教育项目。这项研究可能会改进地球结构和地震破裂过程的模型，这将对构造学、地球动力学和矿物物理学产生兴趣。结果将通过出版物、会议报告和提供给S教育和外展项目的材料广泛传播。全球地震台站网络现在记录了大量数据，其中包含关于地震和地球深部结构的丰富信息。然而，这些数据的分析一直滞后，因为传统的方法是时间密集型的，没有充分利用现代计算机的能力。通过将自动化方法应用于数百或数千个地震记录，通常可以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。加州大学圣地亚哥分校的这个项目开发并应用了这些新方法来研究各种主题。这些措施包括：(1)探测地球相对坚硬的上层和下面更具塑性的层之间的边界；(2)利用高频地震波检查地震破裂；(3)研究散射地震波以了解地球深处小规模结构的频率和强度；以及(4)通过研究一种难以观测的地震波到达(称为PKJKP)来测试地球核心的坚固性。这项研究可能会改进地球结构和地震破裂过程的模型。

The 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 earthquakes and 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 analyses of global seismic data at U.C. San Diego to examine a variety of geophysical issues. These include: (1) Examining the lithosphere-asthenosphere boundary using receiver functions and SS precursors, (2) Imaging earthquake rupture using back-projection methods, (3) Observation and modeling of scattered energy between major body-wave seismic phases to constrain the statistical properties of mantle heterogeneity at scale lengths shorter than can be resolved using seismic tomography, (4) Systematic searches for (and tests of prior claims of) the inner-core shear phase PKJKP. This project supports the educational program at U.C. San Diego by providing funds for graduate and postdoctoral students. This research is likely to lead to improved models of Earth structure and earthquake rupture processes, which will be of interest to the tectonics, geodynamics and mineral physics communities. Results will be widely disseminated through publications, conference presentations, and material provided to SIO?s education and outreach programs. Networks of global seismic stations now record vast amounts of data, which have a wealth of information about both earthquakes and deep Earth structure. However, analysis of these data has lagged because traditional methods are time-intensive and do not fully exploit the capabilities of modern computers. By applying automated methods to 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 U.C. San Diego project develops and applies these new methods to examine a variety of topics. These include: (1) Probing the boundary between Earth's relatively rigid upper layer and the more plastic layer below, (2) Examining earthquake rupture using high-frequency seismic waves, (3) Studying scattered seismic waves to understand the frequency and strength of small-scale structures in the deep Earth, and (4) Testing the solidity of Earth's inner core through study of a hard-to-observe seismic wave arrival called PKJKP. This research is likely to lead to improved models of Earth structure and earthquake rupture processes.