Earthquakes can strike at any time, almost anywhere in the world. They are probably one of the most feared natural disasters, and their unpredictable nature makes them one of the hardest to prepare for.
The extent of the threat depends on a number of factors, but the two key factors that usually determine how big the quake can be are your geographical location and the geographical makeup of the ground in your area.
If you live in a known earthquake zone, or in an area where the ground increases the destructive power of an earthquake, you need to take the threat seriously. Exactly when the Big One will hit can’t be predicted, but you can be sure that at some point it will happen, so you need to take precautions.
While there are a number of different methods for calculating the size of an earthquake, one of the most common methods cited is usually the Richter magnitude scale. Developed in 1935 by Charles Richter, the Richter scale is used to measure the magnitude of most earthquakes, and gives scientists the ability to track and compare the strength of earthquakes at different times and locations.
The Richter scale is based on a base-10 logarithmic scale, meaning for every whole number jump in magnitude the amplitude of the ground motion goes up ten times. So a magnitude 5 quake on the Richter scale would result in ten times the level of ground shaking as a magnitude 4 earthquake (and 31.7 times as much energy would be released). Quakes below 4.9 are considered fairly minor and cause a minimum amount of damage. Quakes that are 5.0 to 5.9 are considered moderate and can cause damage, particularly to poorly constructed structures, but few deaths. Quakes over 6.0 will cause significant damage to even well-constructed buildings, which greatly increases the risk of death and injury.
The dangers associated with an earthquake really depend on the size, location, and how long the quake lasts. While earthquakes pose little direct danger to a person, the resulting damage to buildings, vital infrastructure, and roads can make them extremely dangerous. Some earthquake side effects that can be dangerous to people include:
One of the most immediate dangers from an earthquake comes from falling debris. The shaking from a quake can cause almost anything in your home to fall over, and can even cause glass windows to shatter and ceilings to crumble. Heavy items like large appliances and bookshelves or hutches also present a significant risk to anyone who’s near them during the quake.
Falling electrical lines, ruptured gas and water lines, and badly damaged roadways are all common occurrences after a large quake. After an earthquake, stay alert to these hazards, be on the lookout for aftershocks, and stay away from damaged areas.
Buildings can be damaged by the shaking itself or by ground displacement that can literally rip a building right in half. Aftershocks can continue to cause structural damage for days, weeks, and even months after the initial quake, adding to a building’s instability.
Those who live in low-lying coastal areas need to be aware of tsunamis, which can be triggered by the seismic energy of an earthquake. This was the case after the 2011 Tōhoku Japan earthquake, which generated waves over 100 feet (30 m) high, killing thousands and destryoying entire coastal communities.
Not all earthquakes cause tsunamis, but it is a possibility if the quake strikes anywhere near an ocean. If you live in a known tsunami zone, the best thing you can do is evacuate following any sizable earthquake.
While it’s impossible to predict an earthquake, there are some things that you can be pretty sure will happen following a large quake:
Because of their unpredictable nature, earthquakes are probably one of the most difficult natural disasters to prepare for. Because there are no effective early warning systems for earthquakes, you need to take the time to understand the dangers and take the proper precautions before a quake hits.
However, there are a number of safety precautions you can take before an earthquake to protect yourself and minimize damages:
Knowing what to do and then acting quickly during an earthquake can help prevent injuries and save lives.
After the shaking stops, the threat is far from over; in fact, the potential dangers might be even higher during the immediate aftermath of the quake.