HR: 1340h
AN: S53B-0226    [Abstracts]
TI: Evaluation of Philippine Sea Plate Reconstructions Based on Seismic Tomography of Subducted Slabs in the Western Pacific.
AU: * Handayani, L
EM: handayani@neo.tamu.edu
AF: Texas A&M University, Department Geology & Geophysics, College Station, TX 77843 United States
AU: Hilde, T W
EM: geodynamics@tamu.edu
AF: Texas A&M University, Department Geology & Geophysics, College Station, TX 77843 United States
AB: Mantle seismic tomography of the Western Pacific region (Yoshio Fukao and Sri Widiyantoro, personal communication) shows the distribution of subducted oceanic slabs. Plate reconstruction models for the Philippine Sea Plate are evaluated based on the correlation between past locations of subduction zones in the reconstructions and the distribution of subducted slabs in the mantle. Massive high velocity anomalies at transition zone depths and deeper beneath the Japan Sea, adjacent areas and the northern Philippine Sea are best explained by past northward subduction of the Philippine Sea Plate and westward subduction of the Pacific Plate. Greater than 700 km deep high velocity anomalies beneath the Philippine arc/Eastern Indonesia region are best associated with northward Indian Ocean Plate subduction. Other high velocity anomalies correlate well with present day Philippine Sea Plate boundaries. Deep high velocity anomalies are lacking beneath the central and southern Philippine Sea Plate. Mantle tomography supports neither southward subduction along a past northern boundary or large clockwise rotation of the Philippine Sea Plate.
DE: 8180 Tomography
DE: 8150 Plate boundary--general (3040)
DE: 8157 Plate motions--past (3040)
DE: 3040 Plate tectonics (8150, 8155, 8157, 8158)
SC: Seismology [S]
MN: 2004 AGU Fall Meeting