CSEDI: Collaborative Research: Paleomagnetism, the Geodynamo and Core-Mantle Interactions

CSEDI：合作研究：古地磁、地球发电机和核幔相互作用

• 批准号: 0112469
• 负责人: Jeremy Bloxham
• 金额: $ 12.48万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-15 至 2004-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0112469&HistoricalAwards=false
• 关键词: CSEDI; Collaborative; Research; Paleomagnetism; Geodynamo

Bloxham Constable It is proposed to undertake a collaborative study of mantle influences on the geodynamo, combining geodynamics, geodynamo modeling and paleomagnetism, focusing on three timescales. First, by looking at the last 5 million years the long timescale behavior of the dynamo over a period for which both the time averaged field and the paleosecular variation can be determined paleomagnetically will be examined. Furthermore, on this timescale the lowermost mantle is essentially unchanged from that which is imaged using seismic tomography, so modern tomographic images of the mantle can be used. Second, changes in reversal frequency, concentrating on the period from the Cretaceous Normal Superchron to the present day will be examined, including the effect of plume formation at the base of the mantle on the occurrence of reverse flux patches in the magnetic field. Third, preliminary investigations will be conducted on the very long-term changes in the magnetic field occurring over timescales of several hundred million years. This work will involve a statistical re-analysis of the available paleomagnetic measurements to assess what kinds of geodynamo experiments will be relevant to understanding such long-term changes. The dynamo modeling and geodynamical modeling will be performed at Harvard; the paleomagnetic aspects of the proposal, involving data compilation, analysis, and field modeling will be performed at Scripps Institution of Oceanography. The work will be coordinated between the two institutions primarily by electronic means, supplemented by visits and short-term exchange of students between the institutions.

Bloxham Constable建议进行地幔对地球发电机影响的合作研究，结合地球动力学，地球发电机模拟和古地磁学，重点放在三个时间尺度上。首先，在过去的500万年的发电机在一段时间内的时间平均场和古地磁变化可以确定的长时间尺度的行为将被检查。此外，在这个时间尺度上，最低的地幔基本上是不变的，从使用地震层析成像，因此可以使用现代层析成像的地幔。第二，反转频率的变化，集中在从白垩纪正常超时到现在的一天将被检查，包括在地幔底部的羽流形成的影响发生在磁场中的反向通量补丁。第三，将对数亿年时间尺度上发生的磁场长期变化进行初步调查。这项工作将涉及对现有的古地磁测量结果进行统计重新分析，以评估哪些类型的地球发电机实验与理解这种长期变化有关。发电机建模和地球动力学建模将在哈佛进行;该提案的古地磁方面，包括数据汇编、分析和场建模将在斯克里普斯海洋研究所进行。这两个机构之间的工作将主要通过电子手段进行协调，并辅之以机构间的互访和短期交换学生。