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

点击翻译按钮获取中文摘要

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.