HR: 12:05h
AN: V21F-07    [PDF]
TI: Revised Indo-Atlantic absolute plate rotations and their uncertainties based on moving hotspots
AU: * O'Neill, C J
EM: craig@geosci.usyd.edu.au
AF: The University of Sydney, School of Geosciences, Edgeworth David Building F05, Sydney, NSW 2006 Australia
AU: Muller, R D
EM: dietmar@geosci.usyd.edu.au
AF: The University of Sydney, School of Geosciences, Edgeworth David Building F05, Sydney, NSW 2006 Australia
AU: Steinberger, B
EM: bernhard@jamstec.go.jp
AF: IFREE, JAMSTEC, 2-25 Natsushima-cho, Yokosuka, 237-0061 Japan
AB: Inconsistencies between the paleomagnetic and hotspot reference frames have been ascribed to the effects of hotspot motion and true polar wander (TPW). While revised models based on moving hotspots have been shown to improve a measure of fit; namely the difference between the predicted and observed hotspot tracks, the real uncertainties in such models can be quite large. We present a method for constraining the uncertainties in absolute plate motion models using a modified version of the Hellinger criterion. We use the dated tracks of four of the best studied hotspots in the Indo-Atlantic hemisphere; namely, Kerguelen, Reunion, Tristan de Cunha and the New England hotspots, together with their present positions to obtain finite rotations for the African plate. We also use models of hotspot motion to obtain analogous rotations for a `moving hotspot' reference frame. The motion is consistent with available paleomagnetic constraints, and results in a significantly improved fit to the hotspot tracks. The uncertainty regions are less for the moving hotspot model due to the improved fit, and the covariance matrices obtained are equivalent to published relative plate rotation covariance matrices, and allow a combination of these uncertainties.
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 8155 Plate motions--general
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting