Global Analyses of Body Wave Travel Times and Amplitudes: Whole-Mantle Tomography and Simulations of 3-D Wave Propagation

体波传播时间和振幅的全局分析：全地幔层析成像和 3D 波传播模拟

基本信息

批准号：
0106666
负责人：
Jeroen Tromp
金额：
$ 15.6万
依托单位：
California Institute of Technology
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2001
资助国家：
美国
起止时间：
2001-07-15 至 2003-06-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=0106666&HistoricalAwards=false
关键词：
Global Analyses Body Wave Travel

项目摘要

Abstract for proposal EAR0106666 (PH # 53x)Title: Global Analyses of Body Wave Travel Times and Amplitudes: Whole-mantle Tomography and Simulations of 3-D Wave PropagationPI's: Jeroen Tromp and Jeroen E. Ritsema, Cal TechSeismic tomographic models are beneficial to researchers from a wide variety of disciplines in the Earth Sciences. They provide images of the structure of oceanic and continental lithosphere, and play a central role in constraining the planform of convection in the mantle.To improve these models, we will construct new tomographic models in which we will take advantage of the extensive seismic data set that we have compiled in the past several years. It includes unique data types, such as higher-mode Rayleigh wave phase-velocity measurements and travel times of converted body-wave phases (e.g., SP, SKP), which have not been fully exploited in tomography.In a parallel research effort, we apply the new Spectral Element Method of Komatitsch and Tromp [1999] to study the effects of 3-D mantle structure on long-period body-wave propagation. Specifically, we will test the applicability of ray theory to wave propagation in `low-degree' seismic models, whether small-scale structure in the deep mantle, such as plumes, produce characteristic, observable travel-time or waveform variations, and whether the large-scale pattern of long-period body-wave amplitude anomalies can be explained by large-scale variation of seismic velocity in the mantle. These analyses provide insight into the quality of present-day tomographic models and help us design the next generation of tomographic inversions when fully 3-D forward theories can be incorporated.

提案摘要 EAR0106666 (PH # 53x) 标题：体波传播时间和振幅的全局分析：全地幔层析成像和 3-D 波传播模拟 PI：Jeroen Tromp 和 Jeroen E. Ritsema，加州理工学院地震层析成像模型对研究人员有益来自地球科学的各个学科。它们提供了海洋和大陆岩石圈结构的图像，并在限制地幔对流平面形态方面发挥着核心作用。为了改进这些模型，我们将构建新的层析成像模型，在该模型中我们将利用广泛的地震数据集我们在过去几年中编制的。它包括独特的数据类型，例如高模瑞利波相速度测量和转换体波相位的传播时间（例如 SP、SKP），这些数据类型尚未在断层扫描中得到充分利用。在一项并行研究工作中，我们应用Komatitsch和Tromp [1999]的新谱元方法来研究3-D地幔结构对长周期体波传播的影响。具体来说，我们将测试射线理论在“低度”地震模型中波传播的适用性，深部地幔中的小尺度结构（例如地幔柱）是否产生特征、可观测的走时或波形变化，以及是否长周期体波振幅异常的大尺度模式可以通过地幔中地震速度的大尺度变化来解释。这些分析提供了对当今层析成像模型质量的深入了解，并帮助我们在完全结合 3-D 正演理论时设计下一代层析成像反演。