Improved Holocene global geomagnetic field reconstructions based on sediment data

我们建议通过研究全新世古地磁沉积物记录的质量来改进过去千年的全球地磁场重建。全球磁场模型既用于研究地核的地球动力学过程，又用于考虑银河系宇宙射线与地球环境相互作用时地磁场的屏蔽作用。目前全新世磁场模型的分辨率和可靠性受到两个方面的限制：一是南半球古磁数据覆盖范围的稀疏，二是沉积物数据的大数据和年代的不确定性。基于岩性和与全球模式的比较，对所有已汇编的沉积物记录进行重新评价，将提高对沉积物数据质量的日益加深的理解，可能导致校正方法和改进的年龄模型。我们计划建立一个包含所有可用沉积物记录（如岩性、测年方法）相关元数据的数据库，然后利用这些信息研究单个记录的磁信号质量和年龄控制。目的是改进全新世磁场重建，作为研究地球磁屏蔽演变及其与行星环境相互作用的先决条件。

We propose to improve global geomagnetic field reconstructions spanning the past millennia by investigating the quality of Holocene paleomagnetic sediment records. Global field models are used both to study geodynamo processes in the Earth’s core and to take into account the shielding effect of the geomagnetic field in the interaction of galactic cosmic rays with our planet’s environment. The resolution and reliability of Holocene field models at present are limited for two reasons: firstly, the sparse southern hemisphere archeomagnetic data coverage, and secondly, large data and dating uncertainties particularly in sediment data. A re-evaluation of all compiled sediment records based on lithology and comparison to global models will improve the growing understanding of sediment data quality, possibly leading to correction methods and improved age models. We plan to compile a database containing relevant meta-data for all available sediment records (e.g. lithology, dating method) and then use this information to investigate the quality of the magnetic signal and age control in individual records. The objective is an improvement of Holocene field reconstructions as a prerequisite to investigate the evolution of our planet’s magnetic shield and its interaction with the planetary environment.