HR: 0800h
AN: GP21A-0013    [Abstracts]
TI: The Time-Averaged Field Investigations Project: A Synthesis
AU: * Johnson, C L
EM: cljohnson@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093 United States
AU: * Johnson, C L
EM: cljohnson@ucsd.edu
AF: Department of Earth and Ocean Sciences, University of British Columbia, Vancouver, BC V6T 1Z4 Canada
AU: Constable, C
EM: cconstable@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093 United States
AU: Tauxe, L
EM: ltauxe@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093 United States
AU: Lawrence, K
EM: klawrence@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093 United States
AU: Staudigel, H
EM: hstaudigel@ucsd.edu
AF: Scripps Institution of Oceanography, 9500 Gilman Drive, La Jolla, CA 92093 United States
AU: Brown, L
EM: lbrown@geo.umass.edu
AF: Department of Geosciences, University of Massachussetts, Amherst, MA 01003 United States
AU: Mejia, V
EM: vmejia@ufl.edu
AF: Department of Geological Sciences, University of Florida, Gainesville, FL 32611 United States
AU: Opdyke, N
EM: drno@nersp.nerdc.ufl.edu
AF: Department of Geological Sciences, University of Florida, Gainesville, FL 32611 United States
AU: Coe, R
EM: rcoe@pmc.ucsc.edu
AF: Earth Sciences Department, University of California Santa Cruz, Santa Cruz, CA 95064 United States
AU: Stone, D
EM: dstone@gi.alaska.edu
AF: Geophysical Institute, University of Alaska, Fairbanks, AK 99775 United States
AB: The Time-Averaged Field Investigations (TAFI) project is a multi-institutional effort to study the behavior of Earth's magnetic field over the past 5 Ma. Paleomagnetic directions from over 800 lava flows and dikes at 15 globally distributed locations have been obtained. Radiometric and paleointensity measurements have been performed on suitable specimens from individual flows. The new data significantly improve geographical coverage of the paleofield, particularly in the southern hemisphere and at high latitudes. We have integrated data collected under the TAFI project with the highest quality paleosecular variation (PSV) data available from the IAGA PSVRL, Global Paleomagnetic Database, and with regional compilations of published PSV data for Hawaii, Mexico, the South Pacific, Reunion, and the western United States. The data are compatible with a geocentric axial dipole average field, but also permit small but persistent axial quadrupole (g_2^O) and axial octupole (g_3^O) terms. We report on latitudinal variations in PSV diagnostics from the TAFI data. Where sufficient data are available regionally we compare statistical distributions of paleodirections with those predicted by PSV models.
DE: 1522 Paleomagnetic secular variation
DE: 1545 Spatial variations: all harmonics and anomalies
DE: 1560 Time variations: secular and longer
DE: 1599 General or miscellaneous
SC: Geomagnetism and Paleomagnetism [GP]
MN: Fall Meeting 2005