HR: 09:30h
AN: S41C-07    [Abstracts]
TI: Shear-wave splitting and mantle dynamics beneath the Rivera and Cocos subduction zone
AU: * Leon Soto, G
EM: gleon@nmsu.edu
AF: Department of Physics, MSC 3D, New Mexico State University, Las Cruces, NM 88003,
AU: Ni, J
EM: jni@nmsu.edu
AF: Department of Physics, MSC 3D, New Mexico State University, Las Cruces, NM 88003,
AU: Grand, S
EM: steveg@maestro.geo.utexas.edu
AF: Department of Geological Sciences, University of Texas at Austin, Austin, TX 78712,
AU: Wilson, D
EM: dwilson@usgs.gov
AF: USGS Hawaiian Volcano Observatory, 1 Crater Rim Drive, Hawaii National Park, HI 96718,
AU: Guzman Speziale, M
EM: marco@geociencias.unam.mx
AF: UNAM, Centro de Geociencias Campus Juriquilla, Queretaro, QRO 76001, Mexico
AU: Gomez Gonzalez, J
EM: gomez@geociencias.unam.mx
AF: UNAM, Centro de Geociencias Campus Juriquilla, Queretaro, QRO 76001, Mexico
AU: Dominguez Reyes, T
EM: tonatiuhdr@hotmail.com
AF: University de Colima, Observatorio Vulcanologico Universidad de Colima, Av Gonzalo de Sandoval 444, Colima, 28040, Mexico
AB: Shear-wave splitting measurements are determined using data collected from MARS (Mapping the Rivera subduction zone) project to study the origin of seismic anisotropy in the mantle beneath the wedge of the subduction zone. The MARS project consists of the deployment of 50 broadband temporary stations in Mexico covering the Jalisco block from the coast to the Tepic-Chapala rift in the north and about 150 km to the west of the Colima rift. Results show that the fast directions are oriented in a SSW-NNE direction beneath the western Jalisco block, while the fast directions beneath the eastern Jalisco block show a predominantly N-S oriented fast direction. If the divergence of the fast direction is a measure of the mantle flow within the wedge of the subduction zone, then the overriding continental margin is being pulled apart. The Colima rift and active volcano are situated above the tear. Fast splitting directions in the vicinity of the volcano are generally trending N-S with a small delay time between the fast and slow split SKS waves.
DE: 7203 Body waves
DE: 7208 Mantle (1212, 1213, 8124)
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Seismology [S]
MN: 2007 Fall Meeting