Geomagnetic Field Variations in the Past: New Data, Applications and Recent Advances
In the last decades, palaeomagnetic research has provided important information about the past variation of the Earth's magnetic field (EMF) from its origin to the present day. However, questions regarding the origin and evolution of the EMF as well as the frequency and spatial distribution of its variations still remain open to debate. This Special Publication provides new insights into the study of the temporal and spatial evolution of the EMF presenting new data from palaeomagnetic and rock magnetic studies of archaeological materials, sediments and lavas. The papers presented cover a wide range of topics related to archaeology, stratigraphy and climate, including new data from several parts of the world, such as Europe, Africa, Australia, New Zealand, India and the Baltic Sea. This Special Publication aims to present an overview of the most recent secular variation studies and their use to disclose fundamental properties of the EMF evolution.
Kinematics of the virtual geomagnetic poles during Brunhes–Matuyama times
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Published:September 23, 2020
Abstract
Twenty 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.
- Arctic Ocean
- Atlantic Ocean
- Blake-Bahama Outer Ridge
- Brunhes Chron
- Cenozoic
- cores
- data bases
- data processing
- East Pacific
- global
- Great Australian Bight
- Indian Ocean
- Integrated Ocean Drilling Program
- Irminger Basin
- kinematics
- Leg 104
- Leg 152
- Leg 168
- Leg 172
- Leg 182
- Leg 184
- magnetic properties
- magnetostratigraphy
- marine sediments
- Matuyama Chron
- North Atlantic
- North Pacific
- Northeast Pacific
- Northwest Pacific
- Norwegian Sea
- Ocean Drilling Program
- ODP Site 644
- ODP Site 919
- ODP Site 1028
- ODP Site 1060
- ODP Site 1131
- ODP Site 1145
- Pacific Ocean
- paleomagnetism
- Pleistocene
- polar wandering
- pole positions
- Quaternary
- sediments
- South China Sea
- statistical analysis
- upper Quaternary
- Voring Plateau
- West Pacific
- world ocean
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