HR: 0800h
AN: GP21A-0008    [Abstracts]
TI: The Role of Intensity Data in Global Millennial Scale Geomagnetic Field Models
AU: * Korte, M
EM: monika@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Constable, C G
EM: cconstable@ucsd.edu
AF: IGPP, Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0225 United States
AB: Global millennial scale geomagnetic field models currently suffer from a lack of intensity data compared to directional data, because only thermoremanently magnetized material can provide absolute information about the past field. Sediment cores provide time series of declination and inclination but also allow the determination of variations in magnetization, which can reflect the relative magnetic field variations if suitably normalised. We present an iterative robust approach to calibrating relative intensity data for inclusion in global models. Normalized sedimentary paleointensities from 22 broadly distributed locations reflect the field variations sufficiently well that we can expect improvements to global models from such data, including the possiblity of significantly extending the current 7 kyr time span. Using synthetic data we demonstrate that an increased number of intensity data with specific spatial distributions that include a broad range of latitudes would substantially improve existing models.
DE: 1503 Archeomagnetism
DE: 1521 Paleointensity
DE: 1522 Paleomagnetic secular variation
DE: 1532 Reference fields: regional, global
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005