HR: 0800h
AN: GP11C-0844    [Abstracts]
TI: Geomagnetic Dipole Moment of the Past 7000 Years - New Results From a Global Model
AU: * Korte, M
EM: monika@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Constable, C
EM: cconstable@ucsd.edu
AF: Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 United States
AB: Evolution of the geomagnetic field's dipole strength is studied by geomagnetists from global spherical harmonic models and by paleomagnetists using virtual (axial) dipole moments (VDM, VADM). Based on a recently published global model of the past 7000 years we study whether these three dipole moment descriptions can be considered equivalent, and compare the results to previous global VADM studies and recent global model dipole moments. We conclude that VADM and VDM results averaged over centennial and millennial time scales are systematically higher than the true dipole moment by about 20 percent. The current dipole decrease is part of a process that has been going on for about 1700 years. The average rate of decrease is lower than the current one, but has varied significantly so that the current rate cannot be regarded as exceptional.
DE: 1503 Archeomagnetism
DE: 1521 Paleointensity
DE: 1522 Paleomagnetic secular variation
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2004 AGU Fall Meeting