Coupled Core-Mantle Thermal Evolution and the History of the Geodynamo

地核的演化是地球物理学中最基本的课题之一，因为它与行星的吸积和分化过程有关。地幔和地核温度的历史；以及地球磁场的产生。本研究计划将地球动力学理论、矿物物理数据和地幔对流计算（参数化和数值化）结合成一个综合模型。模型结果将与观测结果和对地核和地幔随时间变化行为的推断进行比较，以研究以下问题。(1)岩心钾是否需要符合观测值？(2)地核和地球发电机的年龄有多大？(3)地幔成分分层和板块构造在确定地球动力活动中的作用是什么？对于每一个问题，考虑到不确定因素，将注意评估结果的稳健性。该提案试图将地球动力学研究和地幔对流这两个经常分离的领域联系起来。此外，由于地球发电机的作用之一是使太阳风偏转，因此提出的研究将对陆地大气物种的早期植入和损失产生影响。带电粒子突变或杀死原始生物，因此地球发电机的早期历史也与生命的起源有关。地球发电机演化的改进模型同样适用于其他硅酸盐体，其中许多具有或曾经具有类似的发电机。因此，这项研究应该对整个地质和行星科学界产生广泛的影响。它还促进了国际合作，并将促进一个或几个本科生的教育发展。

EAR-0309218NimmoThe evolution of the Earth's core is one of the most fundamental topics in geophysics, relating as it does to the processes of planetary accretion and differentiation; the history of mantle and core temperatures; and the generation of the Earth's magnetic field. This proposal plans to combine geodynamo theory, mineral physics data and mantle convection calculations (both parameterized and numerical) into an integrated model. Model results will be compared with observations and inferences of core and mantle behaviour over time to to investigate the following questions. (1) Is core potassium required to fit the observations? (2) How old are the inner core and the geodynamo? (3) What is the role of mantle compositional layering and plate tectonics in determining geodynamo activity?For each question care will be taken to assess the robustness of the results in view of the uncertainties.The proposal seeks to link the often separate fields of geodynamo studies and mantle convection. Furthermore, because one effect of the geodynamo is to deflect the solar wind, the proposed investigation will have implications for the early implantation and loss of terrestrial atmospheric species. Charged particles mutate or kill primitive organisms, so the early history of the geodynamo is also relevant to the origin of life. Improved models of geodynamo evolution are equally applicable to other silicate bodies, many of which possess or once possessed comparable dynamos. The study should thus have a broad impact across the geological and planetary science community. It also promotes international collaboration and will foster the educational development of one or several undergraduates.