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等学科对地幔深部的合作研究。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被组合在一起，以利用许多不同类型的地震相来约束动态模型。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PASSCAL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、研究和应用最低地幔的动力学模式，特别是上升的非洲超强热柱。2-D(包括圆柱几何)和3-D笛卡尔有限元，地幔对流程序将被用来理解下地幔和核地幔边界动力学。还将使用具有板块运动历史作为边界条件的球状对流模型。模型参数(如温度、化学、相、熔体和各向异性)将被映射到二维和三维地震速度场中。这些预测将直接用体波相位进行检验。地震学和地球动力学之间以前的交叉学科工作已经支持了这样的假设，即在最下部地幔中有三种类型的结构，在那里产生热柱：热化学超级热柱，其底部为ULVZ的热上升流，以及通过旧的俯冲板块喷发的热柱。这一持续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新的组织原则来解释与羽流有关的玄武岩熔岩的地球化学。地震学和地球动力学将被用来预测MAP(预测的烟柱省)，这将用MORBs和OIBs的地球化学进行检验。

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.