Seismic Activity
In 1985, Mexico City suffered a disastrous earthquake that measured 8.1 on the Richter scale—the worst in its history—leaving an estimated 10,000 dead and 30,000 injured. Shortly thereafter, the National Disaster Prevention Center (CENAPRED) was established to study, detect, and monitor earthquakes, developing a means of minimizing the effects of a quake, educating people, and advising governments on technical matters.
The National Disaster Prevention Center(CENAPRED) has pinpointed the areas of the city at greater risk, enabling the government to design superior construction laws. The area most sensitive to seismic activity is the Zona Antigua (historical zone), where the city was built on the Texcoco lake bed. This area is principally found on the inside of the Periférico freeway, with the exceptions of Ciudad Universitaria, Pedregal, Lomas, and Cerro de la Estrella, which were built upon more solid foundations.
Colonia Roma, one of Mexico City’s oldest neighborhoods, is one of the more vulnerable to tremors, and to a lesser degree the neighboring, trendy Condesa neighborhood. For more information and to view a map illustrating the zones sensitive to seismic activity, visit www.cires.org.mx.
In the last decade there has been one earthquake, in Puebla and Oaxaca, large and specific enough to damage some national monuments and to alarm people who found them-selves near the epicenter. Thanks to a lack of seismic activity along the coast of Guerrero (where most quakes have their epicenter, including the tragic quake of 1985), Mexico City has had no major recurrence.
In 1991 Mexico City developed a seismic alert system (SAS) to reduce the possibilities of a future disaster in the Valley of Mexico. This has 12 sensor stations built between the Pacific coast cities of Acapulco and Zihuatanejo that can anticipate and track a major event. When seismic readings report activity greater than 6 on the Richter scale, every broadcasting system in Mexico City immediately alerts the population.
Similarly, due to seismic danger in the north and south of the Central Valley, Oaxaca State developed the Seismic Alert System of Oaxaca (SASO) in 2003. SASO currently has 29 of 36 projected sensor stations located on the coast of Oaxaca and to the north and center of the state. SASO warns the public through every broadcasting system in Oaxaca when the magnitude of seismic activity is greater than 5.5 on the Richter scale.
Though these new measures will help, 60 seconds is not enough to guarantee your safety. With a little knowledge, however, you can increase your chances of survival. The National Seismological Service (SSN) recommends you keep a first-aid kit, fire extinguisher, and flashlight with batteries on hand and check to see that furniture, wall hangings, and light fixtures are secure and non-threatening. If you are on ground level during a quake, keep calm, leave the building if indoors, and keep a safe distance from furniture, windows or wall hangings.
Be sure to turn off the gas or electrical switches. If you are unable to reach an exit, get under a strong, non-glass table, cover your head with your hands and place your head between your knees. If you find yourself in a tall building, protect yourself under a strong table, under the door frame, or near a column or corner. Do not flee to an exit or use the elevators.
If you are in an automobile during a quake, park your car in an open area and remain inside. Do not stop on bridges or elevated roadways. If you are a pedestrian, keep clear of buildings, posts, walls, or cables. Do not stand on potholes in the street and, if possible, go to an open area and remain there until the quake is over.
