Collaborative Research: Geomagnetic Field for the Last 5 Ma

9804737 Opdyke本提案是一个多机构合作项目，旨在改善熔岩流0-5~Ma古地磁记录的质量和时空分布。 该项目的最终目标是提高我们对地球发电机如何控制观测到的磁场的理解。 具体而言：1）在历史记录和0-3 kyr（仅分辨出北方半球波瓣）记录中所见的中高纬通量波瓣和北极低压在古地磁时间尺度上是否持续存在; 2）时均场和古长期变化是否存在半球差异？ 为了解决这些问题，P.I.s计划在每个地点对尽可能广泛的年龄范围内的流动进行系统的古地磁采样，然后进行详细的高质量实验室分析。 只要有可能，将获得古强度以及方向记录。 已选定分布在全球的14个地点进行抽样：该计划旨在补充现有的高质量数据，并避免重复其他国际团体正在进行的已知调查。 所选的具体地点包括两个高纬度地区，一个是南北横贯美洲的样带，另一个是澳大利亚东南部的样带。

9804737Opdyke This proposal is for a collaborative multi-institutional project to improve the quality and spatial and temporal distribution of the 0-5~Ma paleomagnetic record from lava flows. The ultimate goal of the project is to improve our understanding of how the geodynamo controls the observed magnetic field. Specifically: 1) Do the mid-high latitude flux lobes and north polar low seen in the historical and 0-3 kyr (only northern hemisphere lobes resolved) records persist over paleomagnetic time scales, and 2) Are there are hemispheric differences in the time-averaged field and paleosecular variation? In order to address these issues, the P.I.s have planned systematic paleomagnetic sampling of flows covering as wide an age range as possible at each location, followed by detailed high quality laboratory analyses. Wherever possible paleointensity as well as directional records will be acquired. Fourteen globally distributed sites have been selected for sampling: the plan is designed to complement existing data of high quality, and avoid duplication of known resampling being carried out by other international groups. The specific places chosen include two very high latitude locations, a north-south transect through the Americas, and a site from south-eastern Australia.