Properties of Magnetic Viscosity

粘性剩磁（VRM）是在暴露于环境磁场期间不可阻挡地获得的剩磁。在自然界中，VRM是由地磁场引起的二次叠加。 该VRM通常构成古地磁学中不期望的噪声。 尽管VRM在古地磁解释中普遍存在，但它仍然给古地磁解释带来很大困难。 特别是，VRM的性能随着实验条件的变化而变化。 因此，将实验室中个别研究的结果推广到古地磁标本的自然参考模型是危险的。 因此，研究人员提出了一个系统的实验和理论方法，旨在探索VRM的基本行为，使用定义明确的天然和合成样品。 VRM的预历史，温度和时间依赖性的属性将被检查。 他们将监测剩磁矢量的变化以及VRM的退磁特性。 此外，将在高达300 ℃的高温下进行实验，以表征热粘滞回复磁化（TVRM）的特性。 鉴于TVRM/VRM在自然界中的普遍存在，这些调查将为更完整地表征VRM及其对过去地磁场矢量确定的影响铺平道路。

Viscous remanent magnetization (VRM) is a remanent magnetization that is inexorably acquired during exposure to ambient magnetic fields. In nature, VRM is a secondary overprint resulting from the geomagnetic field. This VRM generally constitutes undesirable noise in paleomagnetism. Despite its ubiquity, VRM still presents great difficulty in paleomagnetic interpretation. In particular, properties of VRM vary substantially as experimental conditions change. As a result, it is dangerous to generalize the outcome of individual investigations in the laboratory to the NRM of paleomagnetic specimens. The investigators therefore propose a systematic experimental and theoretical approach that intends to explore fundamental behavior of VRM using well-defined natural and synthetic samples. Properties of pre-history, temperature, and time-dependence of VRM will be examined. They will monitor changes in the magnetic remanence vector as well as the demagnetization characteristics of VRM. In addition, experiments will be performed at elevated temperatures up to 300C to characterize properties of thermoviscous remanent magnetization (TVRM). Given the prevalence of TVRM/VRM in nature, these investigations will pave the way for a much more complete characterization of VRM and its affects on the determination of past geomagnetic field vectors.