Mapping seismic site classes in Oaxaca metropolitan Area, Mexico, based on microtremor records

Abstract

According to the Mexican National Seismological Service (SSN), about 25 % of Mexico’s seismic activity is concentrated in the state of Oaxaca. Over time, its population has suffered serious material damage and human losses. In the event of an earthquake, the rigidity of the subsoil beneath urban centers directly impacts the amount of damage to buildings and infrastructure. However, because damage is influenced by the soil seismic response and because there are as yet no updated site response studies that allow us to propose a seismic microzonation of the metropolitan area of Oaxaca, research of this type is very useful for educational and governmental institutions. In this study, seismic noise recording was carried out with broadband sensors to characterize the Horizontal to Vertical Spectral Ratio (HVSR). The main outcome of the study is a map representing the distribution of the seismic site response in the metropolitan area of the City of Oaxaca (ZMO). Furthermore, these results were correlated with the study area’s soil type records.