Modelado de la respuesta sísmica en el subsuelo de la ciudad de México, con registros a profundidad

Abstract

We compare seismic responses at three depth levels at the PCC site (Puesto Central de Control) in Mexico City, using downhole three-component accelerometers installed by Fundaci6n ICA. Comparison is made of the spectral contents and peak amplitudes of acceleration. Transfer functions were computed from the observations, and compared with one-dimensional models. For the horizontal peak acceleration, there was no difference between the observed values at 40 and zero meters depth, whereas at the 20 m level there was a large amplification. A pair of well differentiated spectral bands of information was observed, for periods lower than 1.0 s, and for periods greater than 1.8 s. The dominant period (-2.1 s for this zone) is not present or dominant at the 40 m level, but is clearly observed at the 20 m level and at the surface.