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

提案EAR0106666（PH # 53x）摘要标题：体波传播时间和振幅的全球分析：全地幔断层扫描和三维波传播模拟PI：Jeroen Tromp和Jeroen E. Ritsema，Cal TechSeismic层析成像模型对地球科学中各种学科的研究人员都有好处。它们提供了海洋和大陆岩石圈结构的图像，并在限制地幔对流的平面形状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，其中我们将利用我们在过去几年中收集的大量地震数据集。它包括独特的数据类型，例如高模式瑞利波相速度测量和转换体波相位的传播时间（例如，SP，SKP），在一个平行的研究工作中，我们应用Komatitsch和Tromp [1999]的新谱元方法来研究三维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的适用性波传播的“低度”地震模型，无论是小规模的结构，在深地幔，如羽流，产生特征，可观察到的旅行时间或波形变化，以及是否可以解释的大规模模式的长期体波振幅异常的地震速度在地幔中的大规模变化。这些分析提供了深入了解当今的层析模型的质量，并帮助我们设计下一代的层析反演时，完全三维正演理论可以纳入。

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.