The Seismic Alert System of Mexico and their automatic Alert Signals broadcast improvements
Abstract
The Mexican Seismic Alert System (SASMEX), is integrated by the Seismic Alert System of Mexico City (SAS), in continuous operation since 1991, and the Seismic Alert System of Oaxaca City (SASO) that started its service in 2003. The SAS generates automatic broadcast of Public and Preventive Alert Signals to the cities of Mexico, Toluca, Acapulco and Chilpancingo, and SASO by now only to Oaxaca City. Two types of SASMEX Seismic Alert Signal ranges were determinated in accordance with each local Civil Protection Authorities: Public Alert if they expect strong earthquake effects and Preventive Alert Signal, for moderated once. SAS has 12 field sensor stations covering partial segment of the Guerrero coast, and the SASO has 35 field sensor stations operating in the coast, central and north of the Oaxaca, covering the seismic danger territory. Since 1993, the SAS is pioneer in the automatic public alert broadcast services, thanks to the support of the Asociación de Radiodifusores del Valle de México, A.C. (ARVM). Historically in Mexico City, due to their great distance to the coast of Guerrero, the SAS has been issued its Alert Signals with an opportunity average of 60 seconds. In Oaxaca City the SASO gives 30 seconds time opportunity, if the earthquake detected is occurring in the Oaxaca coast region, or less time, if the seismic event hits near of this town. Also the SASO has been supported since its implementation for local commercial radio stations. Today the SAS and SASO have been generated respectively 13 and 3 Public Alert signals, also 63 and 5 Preventive Alerts ones. Nevertheless, the final effectiveness of the SASMEX Alert Signal services is sensible to the particular conditions of the user in risk, they must have their radio receiver or TV set turned on, also they must know what to do if the seismic warning is issued, other way they do not have opportunity to react reducing their vulnerability, mainly at night. These reason justify the support of the Government of the Federal District through the Authority of the Historical Center, in 2008 to innovate the SAS installing VHF transmitters, similar to the communication technology like the National Weather Radio (NWR) and Specific Area Message Encoding (SAME) called NWR-SAME, following the code standards of the National Oceanographic and Atmospheric Administration (NOAA) and the Emergency Alert Systems (EAS) of United States to enhance the effectiveness in the Alert Signals required in real time communication . This technology also will be implemented in the SASO. The SASMEX seismic data base includes accelerations gathered during more than 2200 earthquakes detected since 1993.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.S21C..08E
- Keywords:
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- 7200 SEISMOLOGY;
- 7212 SEISMOLOGY / Earthquake ground motions and engineering seismology;
- 7223 SEISMOLOGY / Earthquake interaction;
- forecasting;
- and prediction;
- 7294 SEISMOLOGY / Seismic instruments and networks