Microtremor studies using the SPAC method: Experiences and applications to four sites in Mexico

recording and analysis of microtremors is used in seismic risk evaluation. we discuss the applicability and results for the spatial autocorrelation method (spac), which estimates a site velocity model for id propagation wave modeling and more complete site response estimation. we present results for four mexican cities with different spatial, urban and geological conditions. the purpose and requirements are different for each particular study. this affects the spatial array settings and the depth resolution for the spac method. we discuss these studies and their corresponding results. we conclude that it is possible to characterize site effects and site response using small linear arrays. depending on the geological conditions, it is possible to reach deep layers.