ABR: Experimental Studies of Thermo-Chemical Convection in the Mantles of Terrestrial Planets

在类地行星的演化过程中，地幔内部的热边界层和化学边界层之间的热质传递起着主导作用。虽然行星的内部无法直接观测，但地震、矿物物理、大地测量和地球化学数据仍然为地幔动力学提供了约束。将这些观测结果与地球动力学过程联系起来，对于提高我们对地球演化的理解至关重要。本项目将利用实验室实验来表征地幔成分非均质性的时空演化。重点将是由夹带和搅拌产生的精细结构。将采用实验方法，因为它非常适合热化学对流。实验的总体目标是：1)阐明成分不均匀地幔中传热和流动的耦合；2)表征夹带过程并量化夹带速率；3)表征成分不均匀的时空演化；4)了解热化学羽流的起源和消失。第二个项目将关注热化学对流和与板块运动相关的流动之间的相互作用。这些研究的结果将为解释和从间接观测，特别是地震学和地球化学中得出结论提供基础。该项目将为研究生提供培训机会，并为本科生提供研究入门。除了直接参与研究的小组外，还将通过加州大学伯克利分校的课程、科学会议和评审出版物进行推广。这个项目应该导致工程和地球动力学社区之间新的跨学科合作。

Heat and mass transfer across thermal and chemical boundary layers within the mantle play a dominant role in the evolution of the terrestrial planets. Although the interior of planets is not accessible for direct observation, there are still seismological, mineral physics, geodetic, and geochemical data that provide constraints on mantle dynamics. Relating these observations to geodynamic processes is critical for advancing our understanding of the Earth's evolution.This project will use laboratory experiments to characterize the spatial and temporal evolution of compositional heterogeneity in the mantle. The focus will be on fine-scale structures produced by entrainment and stirring. An experimental approach will be used because it is well suited for thermo-chemical convection. The overall goals of the experiments are to 1) elucidate the coupling of heat transfer and flow in a compositionally heterogeneous mantle, 2) characterize entrainment processes and quantify entrainment rates, 3) characterize the spatial and temporal evolution of compositional heterogeneity, 4) understand the initiation and extinction of thermo-chemical plumes. A second project will focus the interaction between thermo-chemical convection and flow associated with plate motions.The results of these studies will provide a basis for interpreting and drawing conclusions from indirect observations, in particular seismology and geochemistry.This project will provide a training opportunity for a graduate student, and an introduction to research for undergraduates. Outreach beyond the group involved directly in the research will be through classes at UC Berkeley, scientific conferences and refereed publications. This project should lead to new interdisciplinary collaborations between the engineering and geodynamics communities.