HR: 0800h
AN: GP21A-0003    [Abstracts]
TI: Tracking Geomagnetic Impulses at the Core--Mantle Boundary
AU: * DORMY, E
EM: dormy@phys.ens.fr
AF: Institut de Physique du Globe de Paris, 4 place Jussieu, Paris, 75252 France
AU: MANDEA, M
EM: mioara@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 France
AB: The main magnetic field of the Earth is generated and maintained by convective motions in the fluid outer core. Temporal field variations occur on an impressive variety of scales, ranging from months to millions of years. Among these, the most intriguing features are geomagnetic ``impulse'' or ``jerks''. Here, we investigate these very rapid events at the surface of the Earth's core using a global model, designed for use at this depth. We identify two regions of very active variations, where wave-like structures propagate. The geometrical characteristics of these wave-like motions provide new constraints on the intricate dynamics of the core.
UR: http://authors.elsevier.com/sd/article/S0012821X05003602
DE: 1507 Core processes (1213, 8115)
DE: 1530 Rapid time variations
DE: 1555 Time variations: diurnal to decadal
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005