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Terrestrial Tremors

Updated: Nov 19, 2023



It’s 10:00 in the morning and you’re scrolling on your phone, mindlessly consuming the various pieces of media being thrown at you when you feel a sharp, sudden rumble. You pass this off as your imagination or your dad walking down the stairs, but then it happens again. That’s odd. The last time you checked, the earth randomly shaking is not a normal occurrence, right? Suddenly, your mind flashes back to 8th grade Earth Science when you learned about tectonic plates and… earthquakes.


Of course, earthquakes, those spontaneous natural disasters that wreck the land, crumble buildings like coffee cake, and kill thousands upon thousands of people. An impending sense of doom crashes down on you, putting you in a state of petrification. But this is no time to stand idle, waiting for the disaster to strike. You must take action, but how?


You remember the boy from 8th grade sitting next to you saying that the safest place to be in an earthquake is under a doorway, since it’s the strongest part of the house. As you grab your two cats and cower under your bedroom door frame, you thank that 8th grade boy under your breath. You can feel the ground shaking, plates crashing to the ground and the wood of the walls creaking under pressure. It’s okay though, because you’re safe and sound under your doorway, right?


Nope! Congratulations! You are dead! The door frame cracked and the walls caved in on you, burying you under the rubble of your home. In your final moments, you curse that 8th grade boy as your consciousness fades away.


Movies and TV shows, as well as false facts and “survival tips,” have skewed our perception of what earthquakes really are. These misconceptions can be extremely dangerous, and if you don’t learn about the proper precautions for earthquake safety, then you may find yourself in a shaky situation one day.


 

What are Earthquakes?


This answer may seem obvious to you. You might think an earthquake is just the ground rumbling. While this isn’t technically wrong, this explanation is quite elementary and leaves out a lot of details.


Earthquakes are sudden shakes in the ground caused by a release of energy within the earth's crust, which are known as seismic waves. This energy is usually released when the tectonic plates of the earth’s crust shift and move past each other, while the immense heat of the molten rock they lay on distorts and shifts the plates. This causes the surface of the earth to move.


Think of it like a jigsaw puzzle, shaped to piece together perfectly. If these pieces were to be jumbled up, it would ruin the picture. While earthquakes can occur anywhere in the world, they are most common in places with major fault lines. This is why earthquakes are common in California, as it is located on a fault between the Pacific and North American plates.


Measuring the Size of an Earthquake


Like most things in life, not all earthquakes are created equal. Tectonic plates don’t shift the exact same amount every time an earthquake happens, so how do scientists determine the size of an earthquake?


The size, or magnitude, of an earthquake is measured using a seismograph. A seismograph draws zig-zagged lines on a piece of paper to replicate how much the tectonic plates have shifted. The higher the line is drawn, the bigger the magnitude is on the Richter scale, which ranges from 0.0–10.0.


Smaller earthquakes that have Richter scale magnitudes of 0.0–2.5 are generally not felt by people, nor are they big enough to really do anything. Depending on the magnitude, the destruction can vary from some fallen items to the deaths of thousands.


Take, for example, the mini earthquakes in California versus an earthquake such as the Tohoku earthquake in Japan in 2011. Since California resides on top of fault lines, a good number of earthquakes occur, usually many per day. These are considered minor earthquakes, only having a magnitude of 0.0–2.5, and are often not even felt by people.


However, Japan’s Tohoku earthquake of 2011 caused absolute devastation, with a magnitude of 9.1. In some cases, an earthquake under the sea can become the catalyst for a tsunami, which is exactly what happened here. The waves caused by the tsunami reached heights of up to 40m tall, displacing 450,000 people and killing over 18,000. The tsunami destroyed thousands of structures, such as houses, roads, and railways. It even caused three nuclear reactors to malfunction in the Fukushima Daiichi Nuclear Power Plant, releasing radioactive materials into the environment and forcing people to evacuate.


Earthquake Myths


Earthquakes have the capability to be catastrophic, so it is important to be able to keep yourself safe if you are unfortunate enough to experience one. But, for a natural disaster so spontaneous and unpredictable, how can you protect yourself? What earthquake facts are real, and not just exaggerations and false claims from the media?


Common misconceptions

1. Major earthquakes only occur early in the morning.

Earthquakes can occur during any time of day, in any part of the world. While many major earthquakes happen in the early morning, they are not exclusive to that time slot. The Imperial Valley earthquake occurred around 9:00 p.m., and Japan’s Tohoku earthquake happened at 2:46 p.m.


2. Earthquakes can cause the ground to split in two, big enough to swallow humans, and even tall buildings.

This is the depiction of earthquakes most seen in the media, (such as in the 2013 animated movie, Croods), but fortunately for us, it is inaccurate. Earthquakes are caused by the grinding of tectonic plates against each other, moving the ground across its fault, not away from it. The friction caused by the collision of plates is what causes earthquakes, so nothing would happen if they were to spread apart. Earthquakes can cause minor cracks in the ground, but it’s highly doubtful that they are big enough for people to worry about falling through. Also, no, there is no lava at the bottom of these cracks.


3. The safest place to be in an earthquake is underneath a door frame.

Your doorway is about as safe as any other part of your house. There isn’t any magical reinforcement spell cast on it that would make you any safer, and, if anything, the door would probably just break your bones as it wildly swings around. Instead, you would likely be safer ducking under a sturdy object such as a table or a desk.

In short, don’t listen to that 8th grade boy.


4. It’s safer to be outside than inside during an earthquake.

Unless you live in a barren desert, then it would be better to just stay put. Theoretically, it seems to make sense, since you wouldn’t have a roof to collapse over your head and furniture to crush your skull. Still, most injuries during earthquakes usually occur when people are moving within a structure or trying to get out. It’s better to just stay put under a solid piece of furniture instead of taking that risk, especially since there are still other buildings and structures outside that can hurt you, and, unlike being inside, you have no extra furniture to protect you. Until you are certain that the shaking has stopped and it is safe to exit, stay put and wait it out.


5. Earthquakes only happen during hot, dry weather.

Unlike most other natural disasters, earthquakes don’t have anything to do with weather, since everything happens below the earth’s surface. Whether it’s snowing, raining, or an arid summer day, an earthquake can happen at any time.


6. The aftershocks aren’t as dangerous as the mainshocks.

Aftershocks are just as dangerous as the mainshock, if not more. An earthquake has a foreshock, a mainshock, and an aftershock. While it’s true that foreshocks are smaller than mainshocks and aftershocks, people usually assume that the aftershock is also smaller, which isn’t true. Aftershocks have the same magnitude as the mainshock, and can be equally, or even more, destructive. It’s even possible for them to trigger even larger tremors, which can blur the line on which was a foreshock, mainshock, and aftershock. Aftershocks can occur hours, days, months, and even years after the initial earthquake.


7. Earthquakes can be avoided.

There is nothing we can really do to stop an earthquake once it starts, other than to take the proper precautions to keep ourselves safe and evacuate the area if an earthquake is predicted to occur. Unfortunately, earthquakes can be difficult to predict, and since everything happens below ground, it’s hard to notice the signs of an upcoming earthquake. The best thing to do is to know how to prepare for an earthquake if it ever does come.


8. We can’t do anything to lessen earthquakes, since they’re natural disasters.

For the most part, yes, earthquakes do occur naturally without any human influence. However, the frequencies of most natural disasters are increasing due to humans and our contributions to climate change.


Mining causes a large number of man-made earthquakes, with the sudden removal of the earth’s contents making the ground unstable. Fracking can also cause earthquakes. Fracking is the process of injecting liquids into the earth at high pressure to extract oil or gasses. The pressure from fracking causes earthquakes to occur.


Some of the deadliest earthquakes by far have been caused by dams, whether it’s the dams breaking or just the pressure from that amount of water being held in one area. In 2008, the Great Wenchuan earthquake in Sichuan, China, was caused by the large weight of water that was being held in a reservoir over a fault line, about 320 million tons. This caused an earthquake with a magnitude of 7.9 and the deaths of an estimated 80,000 people.


How to Stay Safe During an Earthquake


To reduce the chances of earthquake damage, the best course of action would be to reduce the number of earthquakes. Obviously, the naturally occurring earthquakes are out of our control, but the man-made ones are not. Governments have been implementing stricter regulations on industrial activities to prevent disasters like the Sichuan earthquake. Stronger infrastructure is required, as well as being more aware of the faults under the ground before building anything that could potentially trigger an earthquake.


To keep yourself safe, in case you do find yourself in an earthquake, the basic steps to follow are “drop, cover, and hold on.”


Drop: Drop down to your hands and knees before the earthquake causes you to stumble. This will prevent you from falling while also allowing you to have enough mobility to move if needed.


Cover: Find a sturdy piece of furniture like a table or desk and hide under it. If your entire body won’t fit under it, prioritize your head and neck. If there is nothing you can hide under, duck down next to a wall that doesn’t connect to the outside, or next to low furniture that you’re sure won’t fall on you. Then, cover your head and neck with your arms and hands.


Hold on: Hold on to your shelter until the quake is over. There is a possibility that your shelter will move, so be prepared to move with it.


If you are in a car: Stop quickly in a safe place with no overpasses, poles, wires, or buildings if possible. Make sure to stay in your car until help arrives or it is safe to drive again.


If you cannot drop to your knees: Try to sit down. If you can’t do either, you still must cover your head and neck with your arms.


If you are outside: Stay outside. Trying to move around too much during an earthquake is very dangerous. If you find yourself outside then find an open area without trees, poles, buildings, or any other structures that could potentially fall on you.

 

Recap

Earthquakes are extremely dangerous natural disasters that occur due to the shifting of tectonic plates against one another. They are ranked in severity from 0–10 on the Richter scale. Strong earthquakes have the potential to kill tens of thousands of people and decimate entire cities.


If you ever find yourself stuck in an earthquake, always remember to drop, cover, and hold on.

It’s important to always stay informed about natural disasters because you never know if one will come your way. If you liked this blog and want to learn more about other natural disasters then check out our most recent blogs.


Stay updated and active by following the Environmental Defense Initiative on Medium and all of our social media platforms!






Author: Ina Sabarre

Editor: Charlotte Wang


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