Kinematics of the virtual geomagnetic poles during Brunhes–Matuyama times

Abstract

AbstractTwenty magnetostratigraphic profiles from IODP (International Oceanic Drilling Project) sediment cores distributed on the Earth's surface allowed the scatter of virtual geomagnetic poles (VGPs) during Brunhes–Matuyama times to be examined. We identified two groups of recording sites which give different paths for the VGPs during a time interval of about 1.1 myr. Calculations of the VGP velocities and accelerations, as well as the corresponding azimuths, resulted in mean/median values like those observed for recent times. No significant differences were observed during the ‘stable’ and transitional fields. The acceleration azimuths show variations from north–south to east–west depending on the field state: normal/reversed or transitional. Despite the uncertainties in the magnetization of the sediments (overprints and/or low-resolution records), we demonstrate that the use of this database is valid for obtaining kinematic parameters of the geomagnetic field when analysed on a statistical basis.