Seismological Investigations of Earthquakes and Deep Earth Structure

地震和地球深层结构的地震学研究

• 批准号: 1111111
• 负责人: Peter Shearer
• 金额: $ 40.02万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1111111&HistoricalAwards=false
• 关键词: Seismological; Investigations; Earthquakes; Deep; Earth

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.

全球地震网络中大量高质量数字记录的可用性不断增加，使得研究地震和地球深层结构的各种新方法成为可能。 通过分析数百或数千个地震图，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。 该项目将继续分析加州大学伯克利分校的全球地震数据。圣地亚哥检查各种地球物理问题。 这些包括：(1) 使用接收函数和 SS 前兆检查岩石圈-软流圈边界，(2) 使用反投影方法对地震破裂进行成像，(3) 对主要体波地震阶段之间的散射能量进行观测和建模，以约束地幔非均质性的统计特性在比地震层析成像可以解析的尺度长度更短的情况下，（4）系统地搜索内核剪切相PKJKP（并测试先前的主张）。该项目支持加州大学伯克利分校的教育计划圣地亚哥为研究生和博士后学生提供资金。 这项研究可能会改进地球结构和地震破裂过程的模型，这将引起构造学、地球动力学和矿物物理学界的兴趣。 研究结果将通过出版物、会议演示以及向 SIO 的教育和推广计划提供的材料进行广泛传播。全球地震台网现在记录了大量数据，其中包含有关地震和地球深层结构的大量信息。 然而，对这些数据的分析已经滞后，因为传统方法非常耗时并且没有充分利用现代计算机的功能。 通过将自动化方法应用于数百或数千个地震图，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。 这个加州大学圣地亚哥项目开发并应用这些新方法来研究各种主题。 这些包括：（1）探测地球相对刚性的上层和下面更具塑性的层之间的边界，（2）使用高频地震波检查地震破裂，（3）研究散射地震波以了解小地震的频率和强度地球深处的尺度结构，以及（4）通过研究难以观测的称为 PKJKP 的地震波到达来测试地球内核的坚固性。 这项研究可能会改进地球结构和地震破裂过程的模型。