(Lisa Tauxe, Cathy Constable, Catherine Johnson, and Hubert Staudigel )
Current models of the time averaged geomagnetic field have significant long term departures from a geocentric axial dipole. The models shown to the right (from Johnson and Constable, Phil. Trans. Roy. Soc, Ser. A, 354, 89-141, 1996) are based on records of the ancient geomagnetic field stored in lava flows from the last five million years.
The
SIO paleomagnetic/geomagnetic group has taken part in a multi-institutional
project to collect reliable data of the geomagnetic field over the last 5 million
years to build a new time averaged field model. The goal is to collect and analyze
samples from lava flows erupted over the
last 5 million years from a pole to pole transect. The locations that Scripps
was responsible are shown to the left.
Related Publications:
Johnson, C. L., J. R. Wijbrans, Tauxe, L., Gee, J., and others, 40Ar/39Ar ages and paleomagnetism of Sao Miguel lavas, Azores, Earth Planet. Sci. Lett. 160, 637-649, 1998.
Tauxe, L., Staudigel, H., Wijbrans, J.R., Paleomagnetism and 40Ar/39Ar ages from La Palma in the Canary Islands, Geochem. Geophys. Geosyst., 1, 2000GC000063 [6717 words, 8 figures, 3 tables, 1 appendix], 2000.
Tauxe, L., Constable, C., Johnson, C.L., Miller, W.R., Staudigel, H., Paleomagnetism of the southwestern U.S.A. recorded by 0-5 Ma igneous rocks, Geochem., Geophys., Geosyst., DOI 10.1029/2002GC000343, 2003.
Johnson, C.L., Constable, C.G., and Tauxe, L., Mapping long-term changes in the Earth's magnetic field, Science, 300, 2044-2045, 2003.
Tauxe, L., Gans, P., Mankinen, E.A., Paleomagnetic and 40Ar/39Ar ages from Matuyama/Brunhes aged volcanics near McMurdo Sound, Antarctica, Geochem., Geophys., Geosyst., in press, 2004.
Tauxe, L., Kent, D.V., A new statistical model for the geomagnetic field and the detection of shallow bias in paleomagnetic inclinations: Was the ancient magnetic field dipolar?, AGU Monograph, in press, 2004.