RUI: Testing Models of Climate-Induced Geomagnetic Field Behavior with a Record of Pleistocene Paleomagnetic Directions

RUI：用更新世古地磁方向记录测试气候引起的地磁场行为模型

• 批准号: 8803406
• 负责人: Robert Negrini
• 金额: $ 7.66万
• 依托单位: California State University-Bakersfield
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-10-15 至 1991-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8803406&HistoricalAwards=false
• 关键词: RUI; Testing; Models; Climate; Induced

The main focus of this study is to test models of climate- induced geomagnetic field behavior which predict a correlation between time-dependent variations in the volume of global ice and time-dependent variations in the paleomagnetic vector. A previously-published record of Pleistocene variations in 18O from deep-sea sediment cores is used to represent changes in global ice volume for last 500,000 years. The variations in the magnetic field during this time interval are represented by a record of paleomagnetic directional data from a sedimentary sequence exposed in south-central Oregon. Prior to comparing the two records 1) a detailed sampling program was conducted to improve the accuracy of the existing paleomagnetic record and 2) a moving-window cross-spectral analysis was conducted to improve the age control. The latter method is one of three independent age control methods underway at three academic institutions to improve the age control. Angular dispersion analysis and band- pass filtering are among the methods used in the comparison between the improved paleomagnetic record and the 18O record. Whether or not the improvements in age control are sufficient to allow the testing of the above models, the paleomagnetic record will contribute significantly to research in geomagnetism, stratigraphy, and tectonics.

这项研究的主要重点是测试气候诱导的地磁场行为模型，这些模型预测全球冰量随时间变化和古地磁矢量随时间变化之间的相关性。先前发表的深海沉积岩芯18O年的更新世变化记录被用来代表过去50万年来全球冰量的变化。在此时间间隔内磁场的变化由俄勒冈州中南部暴露的沉积序列中的古地磁方向数据记录来表示。在对比两条记录之前，1)进行了详细的采样程序，以提高现有古地磁记录的精度；2)进行了移动窗口互谱分析，以改进年龄控制。后一种方法是三个学术机构正在实施的三种独立的年龄控制方法之一，以改善年龄控制。角散分析和带通滤波是改进的古地磁记录与18O记录进行对比的方法之一。无论年龄控制方面的改进是否足以测试上述模型，古地磁记录都将对地磁学、地层学和构造学的研究做出重大贡献。