Reconstruction of geomagnetic paleointensity over the past 350,000 years based on Beryllium-10 records from two high accumulation sites in the Atlantic Ocean

根据大西洋两个高堆积点的 Beryllium-10 记录重建过去 35 万年的地磁古强度

• 批准号: 5434873
• 负责人: Professor Dr. Augusto Mangini
• 金额: --
• 依托单位: Institut für Umweltphysik
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5434873?language=en
• 关键词: Reconstruction; geomagnetic; paleointensity; over; past

A record of geomagnetic paleointensity over the past 350,000 years will be generated based on high resolution 10Be-Records from two highly accumulating marine sediment cores: ODP Leg 172, Site 1063 and ODP Leg 177, Site 1089. To extract the global 10Be-production rate from the sedimentary records, a special transport-correction procedure is applied. This procedure comprises the Thorium-normalization method to correct for sediment redistribution and ocean model calculations to quantify the lateral transport of Th and 10Be in the ocean. The well known relation between relative geomagnetic dipole field strength and 10Be production rate is used to reconstruct geomagnetic paleointensity over the past 350,000 years. This provides a totally independent tool for the reconstruction of the Earth`s magnetic field strength that can be used complementary to conventional paleomagnetic methods. By using an inverse approach, variability of North Atlantic deep water formation on glacial/interglacial timescales and/or a possible solar long term magnetic variability can be assessed by analyzing the deviations between the 10Be-based and magnetization-based reconstructions of geomagnetic paleointensity. Furthermore, the variability of the "lock in depth" of the magnetization signal may be examined by analyzing the offset in time between the 10Be signal and the magnetization signal.

将根据来自两个高度积累的海洋沉积物岩心的高分辨率10 Be记录生成过去35万年的地磁古强度记录：ODP 172航段，1063号站点和ODP 177航段，1089号站点。为了从沉积记录中提取全球10 Be生产率，应用了特殊的运输校正程序。该程序包括钍标准化方法，以纠正沉积物再分布和海洋模型计算，以量化Th和10 Be在海洋中的横向运输。利用相对地磁偶极场强度与10 Be产生率之间的关系，重建了35万年来的古地磁强度。这为重建地球磁场强度提供了一个完全独立的工具，可用于补充传统的古地磁方法。通过使用一个逆的方法，变化的北大西洋深水形成冰川/间冰期的时间尺度和/或可能的太阳长期磁变率可以评估通过分析之间的偏差10 Be为基础的和磁化为基础的重建地磁古强度。此外，可以通过分析10 Be信号和磁化信号之间的时间偏移来检查磁化信号的“锁定深度”的可变性。