HR: 11:20h
AN: V31F-04    [PDF]
TI: Motion of Hotspots Relative to the Paleomagnetic Axis
AU: * Harada, Y
EM: harada@scc.u-tokai.ac.jp
AF: Tokai University, 3-20-1 Orido Shimizu, Shizuoka, 424-8610 Japan
AU: Wessel, P
EM: pwessel@hawaii.edu
AF: University of Hawaii at Manoa, 1680 East-West Road, Honolulu, HI 96822 United States
AB: Southward motion of the Hawaiian hotspot plume relative to the paleomagnetic axis has been observed (Tarduno et al.,2003), and this can be explained by either motion of the Hawaiian hotspot relative to other Pacific hotspots, or motion of the group of hotspots relative to the paleomagnetic axis. First, we examined whether inter-hotspot motion is essential or not for the explanation of observed data of seamounts in the Pacific basin. We found that both the Polygonal Finite Rotation Method (Harada and Hamano, 2000) and the Hotspotting Method (Wessel and Kroenke, 1997) can successfully be used to develop models of the Pacific and the Nazca plate motion relative to hotspots. This indicates that no inter-hotspot motion is needed to explain ages and positions of hotspot tracks in the Pacific basin. Second, combining the Pacific plate motion relative to hotspots and Pacific paleomagnetic poles (Acton and Gordon, 1994, Johnson, 2000), we calculated the motion of Pacific hotspots relative to the paleomagnetic axis (Pac-PWP). Based on this analysis, southward drift of the Hawaiian hotspot is predicted and it is quite in harmony with the newly observed southward motion of paleolatitude for the Emperor seamount chain. Similarly, we constructed a model of the African plate motion relative to African hotspots, and calculated the motion of African hotspots relative to the paleomagnetic axis (Af-PWP). Pac-PWP and Af-PWP are quite similar and we conclude that there is no significant relative motion between Pacific hotspots and African hotspots since 70 Ma.
DE: 1525 Paleomagnetism applied to tectonics (regional, global)
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
DE: 8120 Dynamics of lithosphere and mantle--general
DE: 8157 Plate motions--past (3040)
DE: 9604 Cenozoic
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting