HR: 1330h
AN: S32A-0839    [PDF]
TI: Imaging the Structure of the Subduction Zone Between Acapulco and Mexico City, Mexico
AU: * P\'{e}rez-Campos, X
EM: xyoli@gps.caltech.edu
AF: California Institute of Tehcnology, Seismology Laboratory MS 252-21 California Institute of Technology 1200 E. California Blvd., Pasadena, CA 91106 United States
AU: Clayton, R W
EM: clay@gps.caltech.edu
AF: California Institute of Tehcnology, Seismology Laboratory MS 252-21 California Institute of Technology 1200 E. California Blvd., Pasadena, CA 91106 United States
AB: The Mexican Subduction Zone exhibits a complex behavior with its dip angle varying from a steep angle at its northern end, to almost horizontal in Central Mexico, and then again to a steep angle at the southern end. A key factor in the variation is thought to be the shape and viscosity of the mantle wedge. Various earthquake location and refraction studies have mapped the slab interface and obtained velocity models along the Pacific Coast and the transect between this coast and Mexico City. In this study, we image the shape of the wedge and trace the slab using receiver functions. We analyze receiver functions from teleseismic earthquakes recorded only at six stations located between Acapulco and Mexico City. We are able to identify the converted P-to-S phase from the Moho as well as other converted phases that could be attributed to the slab. Along this profile the Moho depth varies; it is shallow closer to the coast and deeper below Mexico City. Also the slab has an initial dip angle that later becomes almost horizontal, as observed in previous work. Furthermore, the geometry of the mantle wedge is illuminated below three of the stations located in Central Mexico.
DE: 7205 Continental crust (1242)
DE: 7218 Lithosphere and upper mantle
SC: Seismology [S]
MN: 2003 Fall Meeting