La estructura de velocidades y su relación con el peligro sísmico en Tuxtla Gutiérrez, Chiapas

Abstract

The soil structure of Tuxtla Gutiérrez valley has generated great interest because of observed structural damage caused by ground motion during different earthquakes. Previous studies identified high amplifications in a frequency band of 1 - 10 Hertz. At the moment there is not a reliable subsoil geologic-seismic model to depths that can define properly the site effect, despite the high seismic activity of the region and the relative proximity of the city to the coast and other seismogenic sources. This work uses the conventional Spatial Autocorrelation Method (SPAC), and another unpublished methods that we called Calicatas SPAC for assess the effect of the river vault on the seismic hazard in the city. The field work was carried out on June and July of 2011 using ten observation arrays. The obtained results provide a number of elements that allow us to interpret historical damage, to know with more precision the site effects in the city, to fortify the proposed seismic zones, as well as to evaluate the seismic hazard with more certainty.