Collaborative Research: The Dynamics of Plume-Ridge Interaction

理查兹行星9707192 大量的地球物理和地球化学证据表明，地幔柱与附近的洋脊强烈相互作用。 PI提出了一项由四部分组成的研究，以调查这一动态 过程及其地球物理意义。 第一个涉及数值模拟羽脊相互作用润滑理论，3-D对流模型与可变粘度，边界积分方法。主要目的是确定受羽流影响的脊长度、到达脊的羽流通量的比例以及羽流-脊相互作用的最大距离的比例律。 第二项任务是进行实验室实验，研究羽流与静止和移动洋脊之间的化学和热力相互作用。这项工作将提供第1部分中确定的标度律的实验测试。 第三项任务是将三维对流模型应用于加拉帕戈斯热点，目的是约束热点下方地幔动力学和结构的关键方面，例如 超温和浮力物质的分布以及地球化学不均匀性。第四个项目任务是对冰岛热点附近的地震各向异性和剪切波分裂观测进行三维动态模拟。其目的是解决有争议的问题，即产生冰岛的羽流的宽度和过高的温度。 ***

9707192 Richards Extensive geophysical and geochemical evidence indicates that mantle plumes interact strongly with nearby ocean ridges. The PIs propose a four-part study to investigate the dynamics of this process and its geophysical implications. The first involves numerical modeling of plume-ridge interaction using lubrication theory, a 3-D convection model with variable viscosity, and boundary integral methods. The principal aim will be to determine scaling laws for the length of ridge affected by the plume, the fraction of the plume flux reaching the ridge, and the maximum plume-ridge interaction distance. The second task is laboratory experiments on the chemical and thermal the interaction of plumes with stationary and migrating ridges. This work will provide an experimental test of the scaling laws determined in part 1. The third task is the application of the 3-D convection model to the Galapagos hotspot with the goal of constraining critical aspects of the dynamics and structure of the mantle beneath the hotspot, such as the excess temperature and the distribution of buoyant material and geochemical heterogeneities. 3-D dynamical modelling of seismic anisotropy and shear-wave splitting observations near the Iceland hotspot are the fourth project task. The aim is to resolve the controversial question of the width and excess temperature of the plume that generates Iceland. ***