HR: 1400h
AN: S43B-02 [Abstracts]
TI: Geometry of Cocos Plate Beneath Guerero Using Receiver Functions
AU: * Greene-Gondi, F
EM: fgondi@gmail.com
AF: Programa de Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de
México, Circcuito de la Investigación, Ciudad Universitaria, Mexico, DF 04510, Mexico
AU: Espejo-Arellano, L
EM: espejito@gmail.com
AF: Programa de Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de
México, Circcuito de la Investigación, Ciudad Universitaria, Mexico, DF 04510, Mexico
AU: Pérez-Campos, X
EM: xyolipc@gmail.com
AF: Departamento de Sismología, Instituto de Geofísica; Universidad Nacional Autónoma de
México, Circcuito de la Investigación, Ciudad Universitaria, Mexico, DF 04510, Mexico
AU: Kim, Y
EM: ykim@gps.caltech.edu
AF: Seismological Laboratory, California Institute of Technology, 1200 E. California Blvd.,
Pasadena, CA 91115, United States
AU: Clayton, R W
EM: clay@gps.caltech.edu
AF: Seismological Laboratory, California Institute of Technology, 1200 E. California Blvd.,
Pasadena, CA 91115, United States
AB:
The MesoAmerican Subduction Experiment (MASE) began on December 2004, and its goal is to model the
dynamic behavior of the subducting Cocos Plate beneath the North American Plate. One hundred broadband
seismic stations were installed along a line that starts in Acapulco and ends close to the Gulf of Mexico. Our
particular objective is to find the geometry along its southern segment (38 stations) by means of a receiver
function analysis. Receiver functions for each station were ordered by back azimuth, distance, and ray parameter.
Stacked profiles in the back azimuth ranges (90°-180°, 180°-270°, 270°-360°) were obtained
to get arrival times of the converted Ps corresponding to the oceanic crust boundaries (top and bottom) and the
continental Moho. Results show that the slab has three dip variations: from coast to ~70 km inland, the slab
dips at ~16°, then up to ~130 km, it dips at ~3°; after that point, the downgoing slab
becomes almost horizontal until ~210 km from the coast; finally, it shows an increases to ~30°,
sinking into the mantle. In addition, with the slab geometry we observe, receiver functions pulses from
earthquakes coming from a back azimuth between 270° to 360° show arrival time delays. Among
other possibilities, this suggests a possible lateral dip component to the slab.
DE: 7200 SEISMOLOGY
DE: 7230 Seismicity and tectonics (1207, 1217, 1240, 1242)
DE: 7240 Subduction zones (1207, 1219, 1240)
SC: Seismology [S]
MN: 2007 Joint Assembly