CSEDI Research - Fine Structure of the Lower Mantle

这是体波地震学、计算地球动力学和同位素地球化学学科之间对深部地幔的合作研究。该项目将系统地调查地震数据集，并将波形数据与一系列模型（包括层析、混合和对流模型）的合成数据进行比较。各种各样的建模技术已经组合起来，利用许多不同类型的地震相位来约束动态模型。随着两个大型数据集（南非阵列和沙特阿拉伯网络）的发布，以及不断扩大的IRIS和东非pascal实验，将有一个从下到上研究非洲大陆基础的绝佳机会。将共同努力制定、研究和应用最下部地幔的动力学模型，特别是上升流的非洲超级羽流。二维（包括圆柱几何）和三维笛卡尔有限元，地幔对流代码将用于理解下地幔和核心地幔边界动力学。具有板块运动历史作为边界条件的对流球形模型也将被使用。模型量（如温度、化学、相、熔体和各向异性）将被映射成二维和三维地震速度场。这些预测将直接用体波相位进行验证。先前地震学和地球动力学之间的跨学科研究支持了这样一种假设，即在地幔最下层有三种类型的结构，这些结构是羽流产生的地方：热化学超级羽流，底部有ULVZ的热上升流，以及通过古老的俯冲板块喷发的热羽流。这个正在进行的研究项目的一个新目标是利用地震学观测和动力学模型作为解释羽状相关玄武岩熔岩的地球化学的新组织原则。地震学和地球动力学将用于预测地图（预测羽流省），这些地图将通过morb和oib的地球化学进行测试。

This is a collaborative study of the deep mantle between the disciplines of body wave seismology, computational geodynamics, and isotope geochemistry. The project will systematically survey seismic data sets and compare waveform data with synthetics for a range of models (including tomographic, hybrid, and convection models). An assortment of modeling techniques have been assembled to take advantage of many different types of seismic phases to constrain dynamic models. With the release of two large datasets (South African array and Saudi Arabian network) along with the ever expanding IRIS and East African PASSCAL experiments, there will be an excellent opportunity to study the underpinning of the African continent from bottom-to-top. A concerted effort will be made to formulate, study, and apply dynamic models of the lower most mantle, especially the upwellings African superplume. Both 2-D (including a cylindrical geometry) and 3-D Cartesian finite element, mantle convection codes will be used to understand lower mantle and core mantle boundary dynamics. Spherical models of convection that have the history of plate motions imposed as boundary conditions will also be used. Model quantities (such as temperature, chemistry, phase, melt, and anisotropy) will be mapped into two and three dimensional seismic velocity fields. These predictions will be tested directly with body wave phases. Previous interdisciplinary work between seismology and geodynamics has allowed has supported the hypothesis that there are three types of structures within the lower most mantle where plumes arise: thermo-chemical super plumes, thermal upwellings which have ULVZ at their base, and thermal plumes which erupt through old subducted slabs. A new goal of this continuing research project is to use seismological observations and dynamical models as new organizing principles for interpreting the geochemistry of plume-related basaltic lavas. The seismology and geodynamics will be used to predict maps (predicted plume provinces) which will be tested with the geochemistry of MORBs and OIBs.