What Causes an Earthquake?
Contrary to the legend, earthquakes are actually caused by the movement of the earth’s tectonic plates. These plates move or rub against each other, releasing massive amounts of energy or seismic waves that cause the ground to shake. The line where these tectonic plates meet is called a fault or fault line.
The US has its fair share of fault lines. One of them is the San Andreas fault system, which stretches for 1,200 kilometers through the state of California. Movement along San Andreas caused the devastating Loma Prieta earthquake of 1989. At magnitude 6.9, it resulted in 63 deaths and more than 3,000 injuries. Many other fault systems are located all over the country, including the massive New Madrid fault system which runs along the states of Missouri, Tennessee, Arkansas, and Kentucky.
What Makes an Earthquake Dangerous?
Unlike the weather or any other natural phenomenon, earthquakes are impossible to predict. There’s no tell-tale sign that a big one is about to happen. While scientists can study fault activities and quake probabilities, they have been unable to forecast a major tremor so far.
We can’t predict the exact time, place, and magnitude of earthquakes, making them very dangerous and life-threatening indeed.
Before an Earthquake
Since we can’t predict earthquakes, it’s important to be ready at all times. Here are a few ways to prepare for earthquakes:
- Practice “drop, cover, and hold” earthquake drills with your family.
- Prepare a communication system so you know how to reach your family members after the quake.
- Secure large appliances and furniture to walls.
- As much as possible, don’t store heavy items on high shelves.
- Know how to turn the gas and electricity off.
- Store chemicals and flammable items properly to avoid spillage. Store them away from heat as well.
- Secure paintings, plants, and other hanging objects so they don’t fall off, especially if they are near the bed or couch.
- Have a professional evaluate the structural integrity of your house and do necessary repairs and improvements.
- Carry a whistle or flashlight with you at all times, so you can signal for help in case you get trapped.
- Be familiar with your area’s earthquake and tsunami warnings, especially if you live near the coast.
During an Earthquake
An earthquake can last for several seconds up to a few minutes. A lot of damage can happen in this short window, so make sure to act fast. Here’s what to do during a quake:
When you are indoors
- The standard safety practice advocated by the American Red Cross is to drop, cover, and hold.
- Drop to the ground on your hands and knees. Bend forward and protect your head and neck with your arms.
- Take cover under a sturdy piece of furniture like a table or desk. This protects you from any falling debris. Standing in a doorframe is not a good practice because it doesn’t protect you from debris or projectile objects. In case of a violent earthquake, the door might even cause you harm.
- Stay away from windows and external walls as they can shatter or break apart. Also, stay away from tall furniture like cabinets and bookshelves as they may topple over.
- Hold on until the shaking stops.
- If you are in the shower, do not run out. Drop, cover and hold and keep clear of objects that might fall over.
- If you are bound to a wheelchair or mobility device, lock your wheels and bend over and protect your head and neck. Remain seated until the earthquake is over.
- If you are in bed during an earthquake, stay in bed and grab a pillow to protect your head and neck.
- If you are in a place where there are lots of people (like stadiums or malls), avoid shelves or any other objects that might fall on you. Take cover and keep calm. Follow evacuation guidelines to avoid a stampede.
- Never use the elevators to exit a building.
When you are outdoors
- Stay away from buildings, power lines, lamp posts, trees, or overpasses to avoid any falling masonry or debris.
- If you can, move to open ground like parks or open spaces.
- If you’re in a car, stop the vehicle and wait for the quake to stop. Make sure you’re strapped in. Stay away from bridges that may sustain damage from the quake.
After an Earthquake
- Once the shaking stops, it’s important to assess the situation. If you are inside a building and have a clear way out, leave the building safely.
- Keep away from unsound structures that might give out. Be wary of exposed wires or leaking gas tanks.
- Unplug any electrical devices to reduce fire hazards.
- Do not light matches, candles, or lighters if you suspect a gas leak. Turn off gas valves if you know how to.
- Do not use the elevators.
- Be prepared for aftershocks as they can occur minutes, hours, or even days after a major quake.
- If you are trapped, do not make unnecessary movements. Keep calm and use any communication device with you (like a phone or a whistle) to ask for help.
- If you are on or near the coast during the quake, seek higher ground once it’s been deemed safe to do so. Tsunamis or seismic sea waves can occur after an earthquake. These waves cause significant damage to areas within a mile from the shore so move inland and to higher ground as soon as possible.
Earthquakes are so cataclysmic, ancient people thought the gods were tearing each other apart. In a way, they were right: this natural phenomenon is both dangerous and overwhelming.
When the ground beneath your feet starts to shake, it’s so easy to fall into panic and fear, so always keep a clear head on your shoulders. Know what to do and take the necessary precautions, especially if you live near a fault system. No one knows when a major earthquake would occur, so it’s also important to practice your drills and know what to do after the quake has passed.
What’s the strongest earthquake you’ve ever experienced and how did you survive it? Let us know in the comments below!