Collaborative Research: Geomagnetic Field for the Last 5 Ma

[8064553]本项目是一个多机构合作项目，旨在提高熔岩流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。具体来说：1)在历史和0-3 kyr（仅北半球叶）记录中看到的中高纬度通量叶和北极低通量叶是否在古地磁时间尺度上持续存在？ 2)时间平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计划在每个地点进行系统的古磁采样，采样范围尽可能广，然后进行详细的高质量实验室分析。在可能的情况下，将获得古强度和方向记录。已经选择了14个分布在全球的地点进行抽样：该计划旨在补充现有的高质量数据，并避免重复其他国际组织正在进行的已知重新抽样。选定的具体地点包括两个纬度非常高的地点，一个是贯穿美洲的南北样带，一个是澳大利亚东南部的地点。

9806453GansThis 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.