MEXICO CITY ACCELEROGRAPH NETWORK (RACM)
1.What is RACM?
Those are the abbreviations of Accelerographic Network of Mexico City. The RACM is conformed by 79 accelerographs distributed in the following way: 66 in surface, 5 in two buildings and 8 are underground integrating three stations. These accelerographs have as objective to record the effects of an earthquake in the ground of Mexico City.
2.Which is the function of the RACM?
This quick technological resource is only a service of seismic measurement and not of warning. The result of the study of these measurements helps to mitigate the vulnerability of the urban zone of the valley of Mexico before the occurrence of an earthquake, and promotes activities of research on design factors and seismic risk that are applied in the regulation of construction of civil works of the Federal District.
3.Where are the accelerographs that form the RACM?
The accelerographs are installed in the different characteristics zones of soil in the valley of Mexico that means, in zones of firm ground, intermediate ground and soft ground.
The sites of each one of the stations of the RACM were selected in agreement with the criteria of experts in mechanic of grounds and seismic engineering, during 1986.
4. When did the RACM start to function?
In January of 1986, after observing the devastation that occurred in Mexico City in September of 1985, the Centro de Instrumentación y Registro Sísmico (CIRES), with the support of the National Council of Sciences and Technology (CONACyT), initiated the design and the construction of the RACM and during 1987 the Foundation of Civil Engineers Associated (FICA) complemented this effort. Finally the RACM started to function in 1987.
5.Who has access to the information generated by the RACM?
Seismic Accelerograms recorded by the systems of registry in charge of the RACM has been put available to investigators and
specialists in seismic engineering of Mexico and abroad who ask for it, as well as to the public in general by the bulletin publication, presentations in congresses and seminaries, and with the participation in the group of institutions that contribute in the conservation and update of Mexican Data Base of Strong Earthquakes (BMDSF).
6. Who could I ask for seismic acelerograms generated by the RACM?
In order to ask for acelerograms of the RACM, go to the section of Registers in the main http://www.cires.org.mx
SEISMIC ALERT SYSTEM OF MEXICO CITY (SAS)
1.What is SAS?
Those are the abbreviations of the Seismic Alert System of Mexico City. SAS operates in a continuous way since August of 1991 and its objective is to emit early warnings of earthquakes seismicity to Mexico City, in case an earthquake occurs whose forecast prognosis of magnitude is bigger than 5, in the region covered by the sensorial stations in Guerrero.
2.Why the necessity of a seismic Alert?
Historical information of principles of XX century and studies of the seismic activity of the coast of Guerrero, prove that an absence of seismicity between the ports of Zihuatanejo and Acapulco exists, region where a seismic movement of similar proportions to which in 1985, it caused great damages in the city of Mexico, will have to happen. In 1986 to CONACyT, it was recommended to develop a study of a system of seismic alert, with sensors in the coast of Guerrero, useful to reduce the possibilities of a future seismic disaster that can undergo the valley of Mexico.
3.In which states of the Republic are the System of Seismic Alert installed at the moment?
At the moment SAS covers the coast of Guerrero and recently in 2003 it was implement the System of Seismic Alert for the state of Oaxaca (SASO) that covers the coast and part of the center of the same state.
4.Why does not always the Seismic Alert sound when an earthquake is felt in Mexico City?
The Seismic Alert System (SAS) only emits warning of seismic alert when the energy of the earthquake detected by the sensor stations of SAS in Guerrero exceeds a certain magnitude. There are earthquakes originated in other seismic regions of the country, not necessarily in the Coast of Guerrero, like the one of 1985, whose epicenter was located in the coast of Michoacán. That is why even though an earthquake is felt in Mexico City; the SAS may not emit an alert, if the epicenter is out of the coast of Guerrero.
5.How does the System of Seismic Alert work?
The seismic alert has 12 sensorial stations in the coast of Guerrero that consider the forecast of magnitude of the local seismic activity, and send it by radio to the central station in the D. F. With this information, the computers of the system control the automatic emission of the warnings of seismic alert, that they diffuse in the valley of Mexico and Toluca to anticipate the arrival of the effect of the earthquake.
The anticipation of the effects of an important earthquake that it begins in the coast of Guerrero is possible, because the radio waves are faster than the seismic waves and because its epicenter could be more than 300 km away from the city of Mexico.
6.When is a Warning of Seismic Alert emitted?
The System of Seismic Alert (SAS), emits automatic warnings to the users connected to the system, when more than a sensor station in Guerrero foretell that the developing earthquake is Moderate. On the other hand, when the developing earthquake is Strong, a Public warning is transmitted by radio and television to the population of the valley of Mexico and Toluca.
7.Where can the System of Seismic Alert are listened?
SAS uses equipment called SASPER, to diffuse the Signal of Seismic Alert, It is installed at the moment in institutions of government, state schools, universities, the Subway, radio stations and in channel 7, 11, 13, 22, 34 and 40. This way, when an earthquake is detected by the SAS; It sends a radio signal to SASPER equipment, signal that will be listened to in the sites mentioned before. It is important to indicate that when the earthquake is considered Strong it also it emits a signal of alert by radio and television.
8.Can SASPER be installed at home, school or office?
Civil Protection Unit is the institution in charge to determine if the place where the equipment, SASPER is propitious for its diffusion and later the CIRES, A.C., is in charge to install the equipment.
Civil Protection of the D.F and the Centro de Instrumentación y Registro Sísmico (Cires), are the institutions in charge to approve and to install respectively, the equipment that diffuse the seismic alert in the valley of Mexico and Toluca. For more information please communicate to telephones 5687-4542, 5687-4582 ext. 114.
9.How much time do we have to evacuate a building before the effect of an earthquake, originated in the coast of Guerrero, is felt in the valley of Mexico?
About 60 seconds to evacuate the site, before the earthquake makes its arrival to the city of Mexico, It is possible to mention that the time varies depending on the location of the epicenter of the earthquake.
10.Has the the cover of the System of Seismic Alert been extended to other states of the Mexican Republic?
In the 2003 the System of Seismic Alert of the State of Oaxaca (SASO) began to operate, but not as the System of Seismic Alert of Guerrero (SAS) that gives warning of earthquake to the Cd of Mexico, the SASO gives warning of earthquake only to the Oaxaca City.
11.Is there some type of information referring to the earthquakes recorded by the System available to the public?
The Centro de Instrumentación y Registro Sísmico (CIRES), institution that is in charge of the System of Seismic Alert (SAS), sends a bulletin of Recent Report when the SAS registers an earthquake in their zone of capture, by e-mail to the users of the System, this bulletin can be deliver to people who ask for it. Send a mail to the following electronic direction
email@example.com, if you want to receive the bulletin of Recent Report.
SYSTEM OF SEISMIC ALERT OF THE STATE OF OAXACA (SASO)
1.What is SASO?
This is the abbreviation of the System of Seismic Alert of the State of Oaxaca, SASO. The SASO operates in a continuous way since 2003 and its objective is to emit early warnings of seismicity to the population of Oaxaca, in case of an earthquakes whose forecast of magnitude is bigger than 5 occurs.
2.Why the necessity of a Seismic Alert in Oaxaca?
The city of Oaxaca can possibly suffer the effect of strong earthquakes that happen in the north and in the south of the Central valley, also by the movements that cause some deep earthquakes that the region of the isthmus generates. The distribution of the seismic danger and its proximity to the urban region of its capital city, has required that the System of Seismic Alert of the State of Oaxaca (SASO), uses efficient methods to recognize and to alert opportunely since the beginning of the earthquakes that might have a destructive effect for the population.
3.How does the Seismic Alert System of Oaxaca work?
Seismic Alert System of Oaxaca has 29 of 36 projected sensor stations, which are located in the coast of Oaxaca, the north and center of the state, that consider the forecast of magnitude of the local seismic activity and send it by radio, to the central station in the Capital of the State. With this information, the computers of the system control the automatic emission of the warnings of seismic alert that they give to the city of Oaxaca, to anticipate the arrival of the effect of the developing earthquake.
4.When is a Warning of Seismic Alert given?
The System of Seismic Alert of the State of Oaxaca (SASO), gives an automatic Preventive alerts to the users connected to the system, when more than one sensor station in Oaxaca foretell that the developing earthquake is Moderate. The commercial stations of radio of Oaxaca give Public Alert, when the developing earthquake is Strong.
5.Where can the System of Seismic Alert be listened?
The Seismic Alert System of Oaxaca (SASO), uses equipment named SASPER, in order to diffuse the signal of seismic alert, this is installed at schools and local radio stations, at the moment.
This way, when an earthquake is detected by the SASO, this one sends a radio sign to the equipment SASPER, signal that will be heard in the places mentioned before.
6.Can Seismic Alert be installed at home, school or office?
Civil Protection of the State of Oaxaca is the institution in charge to transact the installation of a SASPER that is the device that distributes the signal of Seismic Alert to the population of the Capital of the State. For more information please communicate to Civil Protection of the State.
Phone:01(951)33-440, 33-444, 85-136.