During the 2012 Guerrero – Oaxaca earthquake , the SASMEX system ( at that time not fully unified ) provided 25 seconds of warning to Oaxaca City , 45 seconds to Chilpancingo and Acapulco , and 80 seconds to Mexico City . The system was also effective during the 2017 Chiapas earthquake SASMEX provided a few seconds ' advance warning to Mexico City of the 19 September 2017 earthquake , although some people may have taken the alert for a continuation of an earthquake drill held three hours before . Six stations reported , and alerts 12 to 48 seconds before the shock were also provided to Oaxaca , Acapulco , Chilpancingo , and Puebla
2017 Chiapas earthquake
2017 Chiapas earthquake
Mexican Seismic Alert System