HR: 0800h
AN: S31B-0447    [Abstracts]
TI: Earthquake Ground Motion in the Valley of Mexico: Basin Effects
AU: * Ramirez, L
EM: lramirez@andrew.cmu.edu
AF: Civil & Environmental Engineering; Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, United States
AU: Contreras, M
EM: moy@servidor.unam.mx
AF: Instituto de Ingeniería, UNAM., Torre de Ingenieria, Piso 2, Ala Sur, DF 04510, Mexico
AU: Bielak, J
EM: jbielak@andrew.cmu.edu
AF: Civil & Environmental Engineering; Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, United States
AU: Aguirre, J
EM: joagg@pumas.iingen.unam.mx
AF: Instituto de Ingeniería, UNAM., Torre de Ingenieria, Piso 2, Ala Sur, DF 04510, Mexico
AB: We present a study of the ground motion and resulting amplification in the Mexico City Basin due to strong earthquakes in the Mexican Pacific Coast. We propose an approximation of the regional structure and Mexico City's basin and analyze their response to two shallow earthquakes generated near the coast. We compare two sets of three dimensional simulations: the first includes a soft structure similar in shape and properties to the Valley of Mexico, while the second excludes the soft soil deposits. Our 3D computations, with a maximum resolution of 0.75 Hz, reproduce the amplitude and long durations characteristics usually observed in the basin. We confirm that stations inside the Mexican Volcanic Belt experience amplification. In the frequency band 0.2-0.4 Hz additional amplification occurs inside the valley due to the shallow soil deposits in the lake bed region. We compare the normalized durations of the ground motion at several stations against observed data, and speculate on the durations of the soil motion as being a local effect due to the basin's shape and low velocities.
DE: 0545 Modeling (4255)
DE: 0550 Model verification and validation
DE: 0560 Numerical solutions (4255)
SC: Seismology [S]
MN: 2007 Fall Meeting