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

更新提案：使用正向和逆向方法研究全球规模的地震地幔和核心结构

• 批准号: 0738284
• 负责人: Barbara Romanowicz
• 金额: $ 75.5万
• 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: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0738284&HistoricalAwards=false
• 关键词: Renewal; Proposal; Investigation; Global; Scale

The proposed program of investigation of deep earth structure aims at providing seismological constraints on global geodynamical models of the earth's mantle as well as the core, to help further our understanding of the mechanisms, deep inside the earth, that drive plate tectonics, causing earthquakes and volcanic eruptions. The resulting information on the location, shape and strength of major structures such as upwellings and downwellings will benefit a broader community of non seismologists in geosciences (geodynamicists, mineral physicists and geochemists. This program will directly contribute to the education of 6 graduate students and 2 post-docs. We estimate that it will result in at least 8 publications in refereed journals.This program is aimed at investigating the deep structure of the earth using seismic waveforms collected at global and regional arrays of digital broadband stations using forward and inverse methodology. A central goal is to implement a novel approach based on the combination of accurate seismic wavefield computations in complex three dimensional (3D) structures, as afforded by the efficient C-SEM ("Coupled spectral element method"), for the forward problem, and approximate estimation of Frechet derivatives for the inverse problem. This hybrid approach will allow us to keep the computational costs down while significantly improving resolution through the use of the complete wavefield. We plan, in particular, to:+ Develop models of 3D elastic, anelastic and anisotropic structure of the earth's upper mantle using C-SEM+ Address the issue of parametrization of large scale tomographic models of the mantle to better constrain the boundaries of major heterogeneous provinces both in the upper and in the lower mantle.+ Combine long period waveform and body wave data to map the anisotropic structure of the lithosphere/asthenosphere system at the global scale. + Continue our program of inner core sensitive data collection and interpretation + Investigate further the mechanisms of generation of the earth's low frequency "hum"

提议的地球深部结构研究计划旨在为地幔和地核的全球地球动力学模型提供地震学约束，以帮助我们进一步了解地球深处驱动板块构造、引起地震和火山爆发的机制。由此产生的关于主要构造（如隆起和隆起）的位置、形状和强度的信息将使地球科学中更广泛的非地震学家（地球动力学家、矿物物理学家和地球化学家）受益。该计划将直接促进6名研究生和2名博士后的教育。我们估计，这将导致至少8个出版物在referred journals.This计划的目的是调查地球深部结构使用地震波形收集在全球和区域阵列的数字宽带站使用正向和反向的方法。一个中心目标是实现一种新的方法，该方法基于复杂三维（3D）结构中的精确地震波场计算的组合，如由高效的C-SEM（“耦合谱元法”）提供的，用于正问题，以及用于逆问题的Frechet导数的近似估计。这种混合方法将使我们能够保持低的计算成本，同时通过使用完整的波场显着提高分辨率。我们计划，特别是：+开发使用C-SEM的地球上地幔的三维弹性，滞弹性和各向异性结构的模型+解决地幔的大规模层析成像模型的参数化问题，以更好地约束上地幔和下地幔中主要非均质区域的边界。结合联合收割机长周期波形和体波资料，绘制全球尺度岩石圈/软流圈系统各向异性结构图。+ 继续我们的内核敏感数据收集和解释计划+进一步调查地球低频“嗡嗡声”产生的机制