HR: 1340h
AN: S33A-1052    [Abstracts]
TI: Crustal structure beneath Southwestern Mexico
AU: * Suhardja, S
EM: s4ndy104@mail.utexas.edu
AF: University of Texas at Austin, Dept of Geological Sciences, University of Texas at Austin, Austin, TX 78712, United States
AU: Grand, S
EM: steveg@geo.utexas.edu
AF: University of Texas at Austin, Dept of Geological Sciences, University of Texas at Austin, Austin, TX 78712, United States
AU: Wilson, D
EM: davew@speer.geo.utexas.edu
AF: University of Texas at Austin, Dept of Geological Sciences, University of Texas at Austin, Austin, TX 78712, United States
AU: Guzman Speziale, M
EM: marco@geociencias.unam.mx
AF: UNAM, Centro de Geociencias Campus Juriquilla, UNAM, Queretaro, QRO, Mexico, 76001, Mexico
AU: Gomez Gonzalez, J
EM: gomez@geociencias.unam.mx
AF: UNAM, Centro de Geociencias Campus Juriquilla, UNAM, Queretaro, QRO, Mexico, 76001, Mexico
AU: Ni, J
EM: jni@nmsu.edu
AF: New Mexico State University, Department of Physics New Mexico State University, Las Cruces, NM 88003, United States
AU: Dominguez Reyes, T
EM: tonatiuhdr@hotmail.com
AF: Universidad de Colima, Observatorio Vulcanologico Universidad de Colima Av Gonzalo de Sandoval 444, Colima, 28040, Mexico
AB: The MARS ( Mapping the Rivera Subduction zone ) project started in January 2006 deploying 50 broadband seismometers across southwestern Mexico for one and a half year duration. The stations were deployed in Jalisco, Michoacan and Colima states. The goal of the project is to understand the geometry of the Rivera and Cocos subducting plates and the effect of the subduction on the overriding plate. In this study, we employ the teleseismic receiver function technique to map out the lateral variation in Moho depth as well as the Vp/Vs ratio of the crust in this tectonically and magmatically active area. The ambiguity between the delay time of Ps and crustal Vp/Vs ratio is reduced by stacking later phases, the PpPs and PpSs + PsPs, for different values of Moho depth and Vp/Vs ratio (Zhu et al. ). An average crustal depth and crustal Vp/Vs ratio is obtained by finding the highest combination of parameters that give the largest amplitude stack. We find that the average Moho depth is 39 km but varies significantly from 25 to 45 km thick. The average crustal Vp/Vs ratio is 1.82 but is also variable ranging from 1.7 to 1.9. We will discuss correlations of crustal thickness and Vp/Vs ratio with crustal composition and magmatic activity.
DE: 7200 SEISMOLOGY
DE: 7205 Continental crust (1219)
SC: Seismology [S]
MN: 2007 Fall Meeting