Modeling Rough and Anisotropic Upper Mantle Structure Using Long-Period Seismograms

本研究旨在进行一系列的正演模拟实验，以研究粗糙和各向异性的上地幔结构对长周期地震波形的影响，并进行数据实验，以推断这种结构的大小和程度。这包括利用晶格择优取向理论合成从简单对流导出的地震各向异性模型。这将与有限振幅热对流模型和自由振荡计算相结合，为从物理第一原理导出的各向异性非球面模型生成合成地震图。这项研究的目的包括了解长周期面波数据中粗糙的横向结构和滞弹性之间的权衡，各向同性和各向异性的地幔结构之间的权衡，以及粗糙和/或各向异性速度结构在平滑层析反演中引入的偏差。

This research is to perform a series of forward modelling experiments to study the effect of rough and anisotropic upper mantle structure on long-period seismic waveforms, and data experiments to infer the size and extent of such structure. This includes the synthesis of seismic anisotropy models derived from simple convective flows using the theory for lattice-preferred orientation. This will be combined with finite amplitude thermal convection models and free oscillation calculations to generate synthetic seismograms for anisotropic aspherical models derived from physical first principles. Objectives of the study include an understanding of the tradeoff between rough lateral structure and anelasticity in long-period surface-wave data, the tradeoff between isotropic and anisotropic mantle structure, and the bias introduced into smooth tomographic inversions by rough and/or anisotropic velocity structure.