Advancing correlation-based Bayesian modeling of the geomagnetic field to include paleomagnetic sediment records

推进基于相关性的地磁场贝叶斯建模，以纳入古地磁沉积物记录

• 批准号: 388291411
• 负责人: Professor Dr. Matthias Holschneider
• 金额: --
• 依托单位: Sektion 2.3: Geomagnetismus
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/388291411?language=en
• 关键词: Advancing; correlation; based; Bayesian; modeling

Global reconstructions of the geomagnetic core-field on millennial timescales have broad applications e.g. for studying characteristics of the geodynamo process and Earth's core dynamics; for comparison to numerical dynamo simulations; as a dating tool for sediment cores, volcanic material and archaeological artifacts; or to study cosmogenic isotope production rates. These models are inferred from two classes of data: Data from materials with thermoremanent magnetization, such as volcanic rocks, bricks or burnt clay fragments from archaeological sites, and data from marine or lacustrine sediments with embedded magnetic particles. In an ongoing project, a novel Bayesian and correlation-based modeling method for the archeomagnetic core-field was developed. This method provides robust and realistic uncertainty estimates, together with an improved field model. However, the method is based only on the former class of data so far. This is due to challenges associated with modeling sediment records:1. In sediment records of the magnetic field, intensity and declination are only known relative to the rest of the core. A calibration is necessary.2. Data along a single core cannot be considered independent and their temporal errors are correlated.3. Sediment records inevitably present smoothed versions of magnetic field variations.The aim of the proposed project is to overcome these challenges and to extend the developed correlation-based modeling method to be applicable to sediment records as well. This includes the Bayesian modeling of dating uncertainties and sedimentation related processes, such as smoothing. The extended framework will not only allow the exploitation of all available data for the Holocene in a consistent manner, but also to apply the method further back in time, when fewer thermoremanent records are available and the database is dominated by sediments.

在千年时间尺度上全球重建地磁核心场具有广泛的应用，例如，用于研究地球发电机过程和地球核心动力学的特征;与数字发电机模拟进行比较;作为沉积物核心、火山物质和考古文物的定年工具;或研究宇宙成因同位素生产率。这些模型是从两类数据中推断出来的：来自具有热释电磁化的材料的数据，例如来自考古遗址的火山岩、砖块或烧过的粘土碎片，以及来自具有嵌入的磁性颗粒的海洋或湖泊沉积物的数据。在一个正在进行的项目中，开发了一种新的贝叶斯和相关的建模方法的古地磁场。这种方法提供了强大的和现实的不确定性估计，以及改进的现场模型。然而，到目前为止，该方法仅基于前一类数据。这是由于与模拟沉积物记录相关的挑战：1。在磁场的沉积物记录中，强度和衰减仅相对于地核的其余部分而已知。校准是必要的。2.沿着单个核沿着的数据不能被认为是独立的，它们的时间误差是相关的。沉积物记录不可避免地呈现出磁场变化的平滑版本，该项目的目的是克服这些挑战，并将已开发的基于相关性的建模方法扩展到也适用于沉积物记录。这包括对测年不确定性和沉积相关过程（如平滑）的贝叶斯建模。扩展后的框架将不仅允许以一致的方式利用全新世的所有现有数据，而且还可以在时间更早的时候应用该方法，那时可获得的热释光记录较少，数据库主要是沉积物。