Part of the Pacific Ring of Fire, México is one of the most seismically active places on earth. The Pacific Ring of Fire accounts for 75% of the earth's active and dormant volcanoes, along with about 90% of the earthquakes, including 80% of the worst earthquakes ever recorded.
Geologically, México sits atop the North American tectonic plate, near its points of collision with the Cocos and Pacific tectonic plates. The movement and stress from the interaction between these three tectonic plates makes México prone to major earthquakes and volcanic activity.
Although the entire country is at risk of seismic activity, the most active and likely region to be struck with a major earthquake is the southern half of the country, especially the Pacific coast from the state of Nayarit all the way to the border with Guatemala.
México's last major earthquake was on September 19, 1985. The epicenter was located just off the Pacific coast about 215 miles (350 km) from México City. Measuring 8.1 on the Rickter scale, it killed nearly 10,000 people and caused between 3-4 billion USD in damages in México City.
Don't let the fear of earthquakes stop you from visiting México. You should, however, know how to respond in the event of one.
First, remain calm and immediately take steps to protect yourself.
Outside near a building in the drop zone of debris is the most dangerous place to be while an earthquake is in progress. Poorly secured facades crumbling and glass shattering from windows is often the first debris to fall. Consider this area a danger zone and steer clear of it. If already outdoors, move away from buildings. If indoors, stay there until the shaking stops.
If you are...
- Indoors: Do not try to go outside. Move as few steps as possible to take cover under a sturdy table or desk and hold on to it. The table or desk may move with the shaking, move with it. If nothing sturdy is nearby or available drop to the floor against the wall and cover your head and neck with your arms or go to a doorway. Try to steer clear of walls with heavy objects hanging on them, windows, tall furniture, or anything that looks like it may fall on you while the shaking is going on. If in a modern building constructed to withstand a major earthquake moving to a doorway is not any safer. In older buildings the doorway is safer because the walls are more likely to crumble.
- In a high-rise: Follow the same procedures as Indoors. To evacuate the building once the shaking is over use the stairs not the elevators. The sprinkler system or fire alarm may be activated by the shaking.
- In bed: It is best to stay in bed. Place a pillow over your head for protection.
- Outdoors: Move to an area clear of buildings, power lines, large signs, trees, and other potential hazards if it is safe to do so.
- Driving: Drive away from bridges, overpasses, power line, signs and other potential hazards. Pull over to the side of the road, stop, set the parking brake, turn off the engine, and stay in the vehicle until the shaking stops. If a power line falls on the vehicle, stay inside until a trained person removes the wire. When driving is resumed, watch for breaks in the pavement, fallen rocks, and uneven and damaged traffic structures, such as bridges and underpasses.
- In a stadium or theater: Stay in your seat and protect your head and neck with your arms. Do not try to leave until the shaking is over. Then walk out slowly watching for anything that could fall in the aftershocks.
- Near an ocean shore: Try and estimate how long the shaking lasts. If the shaking is severe and lasts 20 seconds or longer a tsunami may have been generated by the earthquake. Evacuate away from the the coast or to higher ground immediately, do not wait for an official warning. Move 2 miles (3 km) inland or to higher ground (not a structure) that is at least 100 feet (30 m) above sea level. Walk quickly, rather than driving, to avoid traffic, debris and other hazards.
- Below a dam: Dams, in particular earthen, can fail during a major earthquake. Catastrophic failure is unlikely, but if downstream from a dam inquire immediately about official evacuations that may have been ordered.