Investigation of Global Scale Seismic Mantle and Core Structure Using Forward and Inverse Approaches

使用正向和逆向方法研究全球尺度地震地幔和核心结构

• 批准号: 0308750
• 负责人: Barbara Romanowicz
• 金额: $ 66.46万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0308750&HistoricalAwards=false
• 关键词: Investigation; Global; Scale; Seismic; Mantle

RomanowiczThis grant will support a program of investigation of lateral heterogeneity in the earth's mantle and core at the global scale, using seismological methods. There are two main components in this research program. The first is global seismic waveform tomography and related forward modeling. Global seismic tomography can provide constraints on key mantle dynamics questions such as: the fate of subducted slabs, the role of D" as a thermo-mechanical boundary layer, the depth of origin and role of mantle plumes in the global circulation, or the nature of coupling between upper and lower mantle and the distribution of geochemical reservoirs. The second component is the investigation of core-sensitive phases and their interpretation in terms of structure/anisotropy of the core and of the deep mantle. While a very small part of the earth, the inner core is thought to play an important role in the dynamics of the outer core and the magnetic field generation. Evidence for complexity in its anisotropic structure has been accumulating, and trade-offs between core and mantle structure need to be further explored.Under component (1), the investigators will extend their waveform tomography approach to include a combination of approximate analytical and exact numerical methods in the computation of synthetic waveforms and partial derivatives. Under component (2), they will continue to collect and analyze core sensitive travel time data to test recently proposed complex models of the inner core and further evaluate trade-offs between inner core, outer core and mantle structure.Broader Impacts: The proposed program of investigation of deep earth structure will benefit a broader community of non-seismologists in geophysics (geodynamicists, mineral physicists) and geochemists, in that it aims at providing seismological constraints on global geodynamical models of the earth's mantle (part 1 of this proposal) as well as the core (part 2 of this proposal).

罗曼诺维茨这笔赠款将支持一项利用地震学方法在全球范围内调查地幔和地核横向不均匀性的计划。这个研究项目有两个主要组成部分。第一个是全球地震波形层析成像和相关的正演模拟。全球地震层析成像可以提供关键地幔动力学问题的约束条件，如：俯冲板片的命运，D”作为热-机械边界层的作用，地幔柱在全球环流中的起源深度和作用，或上下地幔耦合的性质和地球化学储层的分布。第二个组成部分是调查的核心敏感阶段和他们的解释方面的结构/各向异性的核心和深地幔。虽然内核是地球的一个很小的部分，但它被认为在外核的动力学和磁场的产生中起着重要的作用。关于其各向异性结构的复杂性的证据正在积累，核幔结构之间的权衡需要进一步探索。在第（1）部分中，研究人员将扩展他们的波形层析成像方法，在合成波形和偏导数的计算中包括近似分析和精确数值方法的组合。在组成部分（2）下，他们将继续收集和分析核心敏感的旅行时间数据，以测试最近提出的复杂的内核模型，并进一步评估内核、外核和地幔结构之间的权衡。提议的地球深部结构调查计划将使地球物理学中更广泛的非地震学家群体受益它是地球动力学家（地球动力学家、矿物物理学家）和地球化学家的一项重要工作，因为它的目的是为地幔（本提案第一部分）和地核（本提案第二部分）的全球地球动力学模型提供地震学约束。