Survive an Earthquake

Survive an earthquake – published on July 10, 2021

The key factors:

1. Almost 80 percent of all earthquakes occur around the perimeter of the Pacific Ocean.
2. In America, the entire west coast is vulnerable to major seismic events.
3. When and where your home was built will determine how earthquake resistant it is.
4. Earthquakes don’t kill people directly; falling debris and buildings collapsing are the cause of almost all injuries and deaths.

How you can survive an earthquake

We are going to briefly cover how earthquakes work and then jump right into how to survive an earthquake. See these sections below:

1. The three things to do immediately when the shaking starts.
2. How to handle situations like when you are driving, sleeping, or in the bathroom when the big one hits.
3. What to do when the shaking stops.
4. How rescuers will go about finding you if are trapped.
5. Five simple things you can do right now to tip the odds in favor of your survival.
6. Other earthquake hazards that can impact your home besides the shaking.

An earthquake is the result of two pieces of the earth rapidly slipping (grinding) past each other. The earth’s crust is composed of different “plates” that move according to the theory of plate tectonics. The surface where these two pieces slip is called a fault. The specific location of where the earthquake originates is called the epicenter.

How earthquakes are rated

The Richter Scale was used for decades, but has been mostly supplanted by the Moment Magnitude Scale. It’s a similar logarithmic scale with no limit on the upper end. Each whole number (6, 7, 8 …) represents a ten-fold increase in magnitude. Going from a 6 to a 7? You just increased the magnitude by 10 times. People generally have a hard time wrapping their heads around the exponential increases in the rate of growth caused by logarithmic magnitude scales. The graphs look like a path of a fighter jet when it takes off, hits the afterburner, and goes almost vertical:

The graph above shows an example of a magnitude 5 earthquake. It has a 100,000 micron amplitude deviation above and below the baseline. The amplitude is the ground motion measured by a seismograph. 100,000 microns equals ten centimeters – almost 4 inches of ground movement for a level 5 quake. The amplitude height on a magnitude 6 earthquake is ten million microns which is one thousand centimeters – almost 400 inches of ground movement. Let that sink in – the difference between four inches and four hundred inches in earth movement is one point on the scale. Things get big very fast on a logarithmic scale.

A magnitude 8 earthquake is one hundred million microns. A magnitude 9 is one thousand million microns, also known as a trillion. The 2011 earthquake and subsequent tsunami in Japan killed 19,747 people. It was a magnitude 9 undersea megathrust earthquake with an epicenter 70 miles out to sea. There is a similar fault line just off the coast of America and Canada. It runs for seven hundred miles along the coastlines of northern California, Oregon, Washington, and Vancouver Island. It’s known as “the really big one.”

The really big one

When geologists look around the world at potential earthquake zones in fault lines, the granddaddy of them all is the Cascadia Subduction Zone. In 2015 New Yorker Magazine published a well-researched article about it called The Really Big One. The subtitle of this article is: “An earthquake will destroy a sizable portion of the coastal Northwest. The question is when.”

The Cascadia Subduction Zone

Subduction is the process of one tectonic plate diving beneath an adjacent plate on a geological time scale (1 to 3 inches per year). This creates tension that has energy potential. When these plates reach their breaking point, energy is released. In the case of the Cascadia subduction zone, the Juan de Fuca plate is diving under the North American plate:

The “really big one” has hit many times

The Oregon Office of Emergency Management, has looked to the past to predict the future:

There have been 41 earthquakes in the last 10,000 years within this fault that have occurred as few as 190 years or as much as 1200 years apart. The last earthquake that occurred in this fault was on January 26, 1700, with an estimated 9.0 magnitude.

The Cascadia Subduction Zone has not produced an earthquake since 1700 and is building up pressure where the Juan de Fuca Plate is subsiding underneath the North American plate. Currently, scientists are predicting that there is about a 37 percent chance that a megathrust earthquake of 7.1+ magnitude in this fault zone will occur in the next 50 years.

The duration of an earthquake

From The Really Big One:

“Seismologists know that how long an earthquake lasts is a decent proxy for its magnitude. The 1989 earthquake in Loma Prieta, California, which killed sixty-three people and caused six billion dollars’ worth of damage, lasted about fifteen seconds and had a magnitude of 6.9. A thirty-second earthquake generally has a magnitude in the mid-sevens. A minute-long quake is in the high sevens, a two-minute quake has entered the eights, and a three-minute quake is in the high eights. By four minutes, an earthquake has hit magnitude 9.0 (like in Japan in 2011).

Let that sink in: a magnitude 9 earthquake can shake the earth for four minutes. That is longer than you can hold your breath. The long duration adds another dangerous dimension to high magnitude earthquakes.

What will kill you first

Next we’ll look at the two things that cause the most injuries and deaths in an earthquake. Not on the list is being swallowed up by the earth splitting open and then closing back up. That doesn’t happen outside of Hollywood. Another thing not on this list is a tsunami caused by an earthquake. That is for a future article. These are the two things that kill the most people in an earthquake:

Falling objects

If you live in a seismic hazard zone that has a history of earthquake building codes, then falling objects are probably what will kill you first. Earthquake building codes mandate that human occupied structures are built to resist the forces generated in an earthquake. To stop falling objects, you need to find overhead cover. In the military term, “cover” is something that will stop incoming bullets. The same goes for earthquake shrapnel – whatever is on the ceiling, walls, and shelves needs to be stopped. But you will probably not have ideal positions of cover to choose from, unless you plan ahead.

We are not just looking at overhead objects falling straight down. When the earth violently shifts sideways in an earthquake, its energy can “throw” objects laterally. A kitchen cupboard full of dishes will burst out horizontally and try to occupy the same space as you are.

Collapsing structures

The second thing that can kill you first is the structure above you failing and collapsing down on you. If you are in a typical home, right now you have many thousands of pounds of ceiling, trusses, and roofing directly above you. They are all tied together in a self-supporting matrix. The upside is that this matrix increases their strength and resistance to external forces tremendously. The downside is that this matrix can resist these external forces until it collapses entirely.

There are two kinds of force that can be applied to a structure: static and dynamic. An example of a static force is a snow load on the roof of a house. It is a constant force that increases slowly as the snow accumulates. This force is applied to the structure in the same direction as gravity. Gravity is the original static load in the universe. An earthquake is a dynamic force that can violently shift the earth sideways. This puts lateral forces on structures. Unless these structures were built specifically to resist these forces, they will collapse.

Earthquake building codes

If you live in an area that has a history of quakes, the local building codes will mandate that structures are built to resist the forces of an earthquake, especially these lateral forces. In 1964 a 9.2 magnitude earthquake shook Alaska for 4 minutes and 38 seconds. There were thousands of aftershocks that lasted for months – including 11 of them in the first day that were over 6.0 in magnitude. Many homes and buildings collapsed:

After this major quake, the building codes were revised to include more earthquake resistance. In 2018 a 7.1 magnitude earthquake hit Alaska with much less damage and no loss of life. Some of this was due to the lesser magnitude, but the building codes were highly cited as a major reason why there was so little infrastructure failure compared to the 1964 quake. PBS laid it all out in their article Strict building codes helped anchorage withstand quake:

ANCHORAGE, Alaska — The magnitude 7.0 earthquake that rattled Alaska’s largest city cracked roads and collapsed highway ramps, but there were no reports of widespread catastrophic damage or collapsed buildings. There’s a good reason for that. A devastating 1964 Alaska earthquake — the most powerful on record in the United States — led to stricter building codes that helped structures withstand the shifting earth Friday. “Congratulations to the people of Alaska for being really prepared for this earthquake,” U.S. Geological Survey Geophysicist Paul Caruso said Saturday. “Because a magnitude 7.0 in a city like that, you know, it could have been significantly worse.”

A seismic expert said Alaska and California use the most stringent standards to help buildings withstand earthquakes.

Seismic hazard zones

Geologists use regional geology (the physical structure of the earth) and seismology (the history of earthquakes) to determine the likelihood of future quakes. Local planning departments determine the building codes based on this information. Here is a map of the known seismic hazard zones in the United States:

Note the high hazard zones shown in purple. They include almost the entire west coast, including southern Alaska and the Big Island of Hawaii. Also at the highest hazard is the New Madrid Seismic Zone that borders Arkansas, Missouri, Kentucky, and Tennessee.

Your chances of surviving an earthquake go way down when you are inside a structure that collapses. Many structures fail during aftershocks, but a magnitude 9 earthquake that lasts four minutes doesn’t need aftershocks to collapse your home. Finding out what the building codes for earthquakes were when your home or apartment was built is number one on our earthquake preparation steps below.

Next we’re going to look at what you should do when an earthquake hits:

Immediate action drill

The earthquake page on the US Government’s disaster preparedness website (ready.gov) instructs us to drop, cover, and hold on:

This is good advice when you are inside your home or workplace. When you feel the earth shake, do this immediately. But bear in mind the structure that you are in. If you have a choice between immediately getting outside or taking cover inside, outside is usually the best option. Now we’ll look at what to do to survive an earthquake when you are in other places:

Actively survive an earthquake

Places you might be and what is usually the best immediate option:

1. Driving a car – safely pull over and stop the vehicle someplace without any structures like an overpass above you. Set the parking brake, and stay buckled up. Keep the windows rolled up. They will resist impacts if the earth throws things at you. Watch out for falling power lines, other vehicles, and anything that can impact your vehicle. This is an excellent time to put down your phone and develop acute situational awareness.
2. In the bathroom – crouch down beside the sink cabinet or get in the bathtub and assume the fetal position. Shower curtains block air so you should open it completely to one side. You don’t want it falling on top of you. Being trapped in a collapsed structure is bad enough, having plastic wrapped over the top of you makes it much worse.
3. Sleeping – roll out of bed onto the floor next to the bed. See the section below on the Triangle of Life where we discuss the best locations to shelter inside a structure that might collapse.
4. Outside – if you can move, get to a spot where nothing can fall on you and get down on the ground. See the video at the bottom of this article of how Japanese pedestrians in a city respond to an earthquake. They give an excellent example on how to calmly move to safe open spaces to survive an earthquake.

These are things to tuck into the back of your mind for when the shaking starts. Always be aware of what is above you.

What to do when the shaking stops

Now that you’ve survived your first real earthquake, you need to stay safe:

1. Move to a safer place, being mindful of aftershocks.
2. Watch out for disrupted utilities like downed power lines and ruptured gas lines.
3. Start calling out for people. This is the time to locate anyone in your immediate area. You may have a window of time before they lose consciousness. Do not walk or crawl onto any collapsed structures.
4. Turn off all utilities if you can do it safely. Do not go into damaged structures.

Your survival response will make the first two items happen without much thought. Remember to find your tribe and shut down all incoming electricity, water, and natural gas. Broken water lines can flood areas where survivors are trapped. Shut everything down.

If you are trapped

Let’s look at it from the rescuers perspective. They are presented with a collapsed building that could have survivors. The first rule is to not make it worse. The best way is to establish communication with a survivor using sound. They shut down all external noises and hit the ground or structure in a rhythm that a survivor will recognize as being made by humans. The two questions being asked by this simple communication are: “Are you alive? and “Where are you.” They will call for absolute silence and do this repeatedly as they carefully remove the debris looking for the voids where survivors are found.

This brings up the Triangle of Life. It is a theory that when you are in an earthquake, you should seek out places that will become voids if the structure collapses. Instead of getting under a bed, the theory is that you should get down on the floor next to the stout dresser in your bedroom. Proponents of this theory believe the ceiling, trusses, and roofing will land on the dresser, shear off at that point, and then leave a triangular void. This logo represents a person on each side of an object with a roof beam broken over the top. It shows a triangular void on each side of the object with a survivor in them:

The American Red Cross has weighed in on the Triangle of Life with this statemenmt:

“Drop, cover, and hold on!” is a U.S. based recommendation based on U.S. Building Codes and construction standards. Much research in the United States has confirmed that “Drop, Cover, and Hold On!” has saved lives in the United States. Engineering researchers have demonstrated that very few buildings collapse or “pancake” in the U.S. as they might do in other countries.

The question is: “Do you think falling objects will kill you before the roof comes down and crushes you?” If I lived in a concrete apartment building in Turkey, I would be a total believer in the Triangle of Life and shelter in place next to a stout object. If I lived in a modern home in Seattle or San Francisco, I would drop, cover, and hold on (under the bed). Different building codes and construction methods may require different ways to survive an earthquake.

Now, we will jump back in time to today. You are at home or work and you are reading this article. These are some things you can do right now to improve your chances in an earthquake:

Prepare for an earthquake

Five easy things to do right now:

1. Find out what the local earthquake building codes were when your home or apartment was built. This information can be found at the county building code department. They may have this information online, but you will probably have to contact them. The question to ask is “my home is XX years old, were there earthquake specific building codes in effect at that time?” Building codes are usually re-assessed after major seismic events. If you want to dig deeper, you need to know the largest quake in your area and if the codes were implemented or revised after that quake. Wikipedia has a list of worldwide earthquakes broken down by state and country. If you know this information, you will know that your home should be able to withstand that magnitude of earthquake.
2. Find out about other earthquake hazards in your area. See the list below.
3. Store combustible liquids in a separate structure from your home. Fire accelerants like fuel, oil, solvents, paint, etc.
4. Join an Earthquake warning system. Your phone can warn you when an earthquake is about to happen. Here is the state of California’s website featuring the MyShake apps for Android and iPhone. They have recently expanded the coverage to include Oregon and Washington. Another option is Early Warning Lab’s QuakeAlertUSA that also covers California and Oregon and also has apps for Android and iPhone.
5. Find out how (and tool up) to shut off your utilities – electricity, water, natural gas, etc. Some of these require special tools. Here are some tools at Amazon that will allow you to shut off your utilities:

Full disclosure: as an Amazon Associate I earn from qualifying purchases. The convenient links below will take you directly to the items on Amazon and help support this website. Thank you very much!

Sillcock key – One of the major challenges after a major quake is finding clean water. If you are anywhere near urban or industrial areas, you should have a sillcock key to tap into municipal water or even the water that is inside a building’s internal plumbing. This small tool features four sizes of square sockets to handle all of the wall hydrants you are likely to encounter. Here’s an affordable two pack: DURATECH 4 Way Sillcock Key Set

Gas shut off wrench – If you have natural gas at your home, you need a gas shut off wrench. When the gas valve handle on your meter is in line with the pipe, the valve is open, when the valve handle is 90 degrees across the pipe, the valve is shut. This one from Amazon is also a pry bar and has a wrench to shut off the curbside main water valve into your home: 4 in 1 Emergency Tool: Gas & Water Shut Off, Pry Bar, Non Sparking, Emergency earthquake Gas Shut Off Valve

If you do not have natural gas, but you do have municipal water, this tool will allow you to shut off the main water pipe into your home at the curbside water meter: Water Meter Key 12 Inch – Contractor Grade Enforced Steel T-Handle – Tool for Curb Main Water Shutoff

And don’t get caught without a fire extinguisher. Here is a pair of class ABC dry chemical extinguishers: Amerex B500, 5lb ABC Dry Chemical Class A B C Fire Extinguisher (2 pack)

And a bonus download: FEMA’s earthquake safety preparedness checklist (PDF).

Other earthquake hazards

Besides falling objects and collapsing structures, there are

1. Fires are a major hazard after an earthquake. Ignition sources like woodstoves and gas appliances can start fires in homes. The fire hazard scales upward in cities and industrial areas where large amounts of fuel are stored and transported.
2. Transportation infrastructure failures – even if roads, bridges, subways, and airports are still standing, they will be shut down until they can be inspected.
3. Electrical system failure – most electrical infrastructure is built to codes for the seismic zone they are located in. But the grid going down is one way that a distant earthquake can affect your home. Be sure and see our comprehensive article on preparing for a power outage.
4. Landslides – moving masses of earth, rock, and debris down a slope.
5. Tsunamis – if you live on the coast, this is another way that a distant earthquake under the ocean can affect your home. these will be discussed in a future article.
6. Tsunamis caused by landslides caused by volcanoes – not an earthquake, but we don’t want the east coast of the United States to feels left out. The island of La Palma in the Canary Islands off of the west coast of Africa has a mass of earth all teed up and ready to slide into the sea, causing a tsunami to travel across the Atlantic Ocean and impact the eastern coastlines of North and South America.
7. Soil liquefaction – solid ground that quickly turning into something that resembles quicksand:

Soil liquefaction occurs when partially or fully water saturated soil is shaken during an earthquake. It behaves like a liquid and can be very dangerous. It is the one earthquake phenomena that can swallow large objects like cars or people. But it’s most likely effect is to undermine the foundation of structures. Heavy objects like your home or car will sink into earthquake liquefaction. Here is a video from Japan showing sidewalks and roads moving due to soil liquefaction underneath them:

Note the excellent example of how the people calmly move to safe places and get low to the ground. Japan has lost many lives to earthquakes for centuries. They have heavily invested in earthquake and tsunami education and conduct extensive earthquake drills for their population.

The Takeaway

Knowledge is the key. Earthquakes hit with short notice and you must act immediately to actively survive an earthquake. Simple preparations like finding out the building codes when your home was built or downloading an app will increase your knowledge and allow you to keep your tribe alive. Stay safe!

Next article: The ideal wildfire shelter

At Amazon: Best Sellers in Safety and Security Full disclosure: as an Amazon Associate I earn from qualifying purchases. The convenient links below will take you directly to the items on Amazon and help support this website. Thank you very much!