Heat Transport in the Hadean Mantle: From Heat Pipes to Plates

冥古宙地幔中的热传输：从热管到板块

• 批准号: 1246983
• 负责人: William Moore
• 金额: $ 20.55万
• 依托单位: National Institute of Aerospace Associates
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-15 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1246983&HistoricalAwards=false
• 关键词: Heat; Transport; Hadean; Mantle; Pipes

Earth is unique among the known planets in exhibiting plate tectonics as the primary means of transporting internally generated heat. Plate tectonics is responsible for Earth's unusual topography distribution, geochemical interaction between the surface and the deep interior, and the strength of the geodynamo, among other factors that make our home planet special. The timing of the origin of plate tectonics on Earth has been difficult to establish observationally, but there are hints of very early (Hadean) geochemical processes with modern plate tectonic analogues. The mechanism and timing of plate tectonic initiation have direct bearing on models of the geochemical and thermal evolution of our planet, the uniqueness of Earth as an abode for life, and our understanding terrestrial planets in general.This project will primarily support a graduate student to carry out, under the mentoring of the PI, numerical simulations of heat transport in the pre-plate tectonic Earth in order to understand the transition to plate tectonic behavior. This period of history is dominated by volcanic heat transport, called the heat-pipe mode of planetary cooling. Numerical simulation of the flow of Earth?s mantle materials including heat transport by melting and melt segregation (volcanism) will be accomplished using a specialized code. A systematic investigation of the parameters governing convection and melting will be undertaken, and bounds on the transition to plate tectonics will be established. The implications for early Earth will be compared with published petrological and geochemical data.

地球在已知的行星中是独一无二的，它展示了板块构造作为传输内部产生的热量的主要手段。 板块构造是地球不寻常的地形分布，地表和内部深处之间的地球化学相互作用，以及地球发电机的强度，以及其他使我们的家园变得特别的因素。地球上板块构造的起源时间很难通过观测确定，但有迹象表明，现代板块构造类似于极早期（冥古宙）的地球化学过程。板块构造形成的机制和时间与地球的地球化学和热演化模型、地球作为生命栖息地的独特性以及我们对类地行星的总体认识有直接关系。本项目将主要资助一名研究生在PI的指导下，板块构造前地球热传输的数值模拟，以了解板块构造行为的过渡。 这一历史时期主要是火山热传输，称为行星冷却的热管模式。 地球流动的数值模拟？的地幔物质，包括热传输熔融和熔融分离（火山作用）将完成使用一个专门的代码。 将对控制对流和熔化的参数进行系统的研究，并建立向板块构造过渡的界限。 对早期地球的影响将与已发表的岩石学和地球化学数据进行比较。