Investigations of the Variations of the Cenozoic Magnetic Field in the Pacific

太平洋新生代磁场变化的研究

• 批准号: 8619982
• 负责人: Charles Helsley
• 金额: $ 8.5万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-04-15 至 1989-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8619982&HistoricalAwards=false
• 关键词: Investigations; Variations; Cenozoic; Magnetic; Field

Analyses of paleomagnetic data generally assume that the earth's magnetic field, when averaged over several thousand years, conforms to that of a geocentric axial dipole. Nevertheless, long-term non-dipolar components have been found to be important. In fact, recent analyses suggest that during the Cenozoic, multipolar field components have varied so as to produce alternating "far-sided" and "near-sided" effects of significant magnitude. Understanding the nature and magnitude of these deviations from an axial dipole are important in plate tectonic reconstructions using paleomagnetic data, since such reconstructions generally assume that the deviations are small when compared to other uncertainties in the paleomagnetic data. The objective of the present recommended award is to assemble and compile the paleomagnetic data from a large number of piston core sites from the Pacific Ocean. These data were generated during a number of separate projects during the last fifteen years and form an ideal data set for examining both spatial and temporal aspects of the non-dipole field. Initial activity on this project will be to determine sediment ages using a consistent stratigraphy for the cores. Additionally, individual data points will be examined for both their consistency and potential source of error. Once this task is completed, the nondipole field will be examined in several areas of the Pacific Ocean basin. The principal investigator on this project is highly qualified to undertake the proposed study. Funding is highly recommended at $85,000 in FY87 for 18 months.

对古地磁数据的分析通常假设地球磁场在数千年的平均时间内符合地心轴偶极子的磁场。 然而，人们发现长期非偶极成分很重要。事实上，最近的分析表明，在新生代期间，多极场分量发生了变化，从而产生了显着强度的交替“远端”和“近端”效应。了解这些与轴向偶极子的偏差的性质和大小对于使用古地磁数据进行板块构造重建非常重要，因为这种重建通常假设与古地磁数据中的其他不确定性相比，偏差很小。 本推荐奖项的目的是收集和汇编来自太平洋的大量活塞核心地点的古地磁数据。这些数据是在过去十五年中的许多单独项目中生成的，形成了用于检查非偶极子场的空间和时间方面的理想数据集。该项目的初步活动将是使用一致的岩心地层学来确定沉积物年龄。 此外，还将检查各个数据点的一致性和潜在的错误来源。 一旦这项任务完成，将在太平洋盆地的几个区域检查非偶极场。 该项目的主要研究者非常有资格开展拟议的研究。强烈建议 2087 财年提供 85,000 美元的资金，为期 18 个月。