Tsunami 101: How to Survive a Tsunami

Picture this. 

Giant ocean waves engulf entire towns and skyscrapers, leveling everything in their path as helpless people look on, awaiting their impending doom.

You’ve seen it in every movie made about the apocalypse ever. Bet the thought of it makes your skin crawl. 

As a prepper, you probably know having a bug out bag prepared isn’t gonna cut it in a catastrophe like that. Luckily, there’s more ways than one to prep for these kinds of disasters.

Stick around because this blog will cover everything you need to know about how to survive a tsunami.

To get started, let’s discuss the science behind tsunamis first.

What Causes a Tsunami?

A tsunami happens when a large volume of water is suddenly displaced, causing water to surge onto land. This water displacement can be caused by earthquakes, landslides, volcanic activity, and even asteroids and meteorites. 

Let’s explore these tsunami triggers one by one. 


Undersea earthquakes are the most common cause of tsunamis. When tectonic plates shift on the ocean floor, massive forces of energy radiate through the ocean, creating long waves that grow in height as it moves through shallow waters. 

These waves can travel up to 500 miles per hour in deep waters or about the speed of a commercial jet. If it ever crossed your mind before, the answer is no. You can’t outrun a tsunami! As it nears the shore, these waves slow down only to grow vertically up to heights of 10 to 100 feet.

Most experts say that tsunamis look more like rising floods than regular waves. So if you’ve ever thought about surfing a tsunami wave, that’s not happening either. That’s because tsunami waves are propelled by large forces of energy and don’t close in on themselves like regular waves do. If you try to surf through a tsunami wave, you’ll likely just drown.

The deadliest tsunami in recorded history was actually triggered by an undersea earthquake. The 2004 Indian Ocean Earthquake claimed 230,000 lives after an undersea megathrust caused a magnitude 9.3 earthquake that produced 100-foot tall waves just 20 minutes after the seismic activity was registered.

No formal warnings were issued when the deadly quake happened, leaving people with little to no chance of escaping. Many foreign tourists enjoying their post-Christmas vacations by the beach died as a result. 

Some tourists and residents in the affected coastal areas reportedly didn’t even feel the quake’s tremors as it occurred. 

Video footage of the Boxing Day Tsunami shows tourists pointing at the waves rolling in from a distance, unaware of their sheer size. By the time they realized what was happening, it was too late.


Like earthquakes, landslides along the coast or even under the sea can cause massive and sudden water displacement, resulting in tsunamis.

Imagine a pebble being dropped into a glass of water. The force of the pebble hitting the water causes water inside the glass to shoot up and spill out. 

The same principle happens with landslides, but instead of a tiny pebble, it’s a massive chunk of land displacing tons upon tons of water. In fact, it was actually a landslide that triggered the largest tsunami in recorded history.

A giant chunk of land—we’re talking a whole darn mountain peak—fell off and dropped 2,000 feet into Lituya Bay, Alaska, on July 9, 1958, generating the largest tsunami ever recorded. It soared up to heights of over 1,700 feet and cleared hundreds of thousands of trees in its wake. 

To give you a better perspective, the Empire State Building in New York stands at only 1,250 feet. Now, imagine a wave large enough to engulf that building.

Those apocalyptic movie tsunamis don’t seem so ridiculous now, do they?

Miraculously, since the area wasn’t heavily populated, only 5 unlucky folks perished that day.

Volcanic Activity

Apart from earthquakes and landslides, both land and underwater volcanic eruptions can also generate tsunamis due to explosions, caldera collapses, or tectonic movements spawned by volcanic activity. 

Although only 5% of tsunamis are caused by volcanic activity, the force of volcanic eruptions can still trigger catastrophic tsunamis for nearby coastal areas.

Case in point, the 1883 eruption of Krakatoa caused over 36,000 deaths and generated 130-foot tall waves after the volcano collapsed into a caldera.

It’s said that because of the sheer destructive force of the eruption, the sound waves following the explosion circled the globe seven times!

Asteroids and Meteorites

Meteor and asteroid impacts are rare incidents compared to the previous tsunami triggers discussed. In fact, no tsunamis have ever been caused by asteroids and meteorites in human history. 

However, asteroids and meteorites can still cause tsunamis that are disastrous, if not worse, than the ones produced by earthly tsunami catalysts.

Perhaps, it’s not your first time hearing about the asteroid that caused the dinosaur extinction, but did you know that the 6-mile wide giant space rock that turned the dinos into fossils, also triggered huge global tsunamis following its impact?

Experts who’ve studied the Chicxulub impact crater believe that the initial tidal wave shot up a whopping 5,000 feet into the air, causing “smaller” ripples afterward.

If you’re not quite registering that information, we’re talking massive destruction on a Biblical scale, much like the floods that drowned everything except for Noah’s Ark. 

A tsunami of this magnitude would be what experts refer to as a mega tsunami.

Where Do Most Tsunamis Occur? 

For most tsunami triggers, there’s no telling when one will present itself at any given moment, but with the help of modern science, we can now map out where most tsunamis occur.

The best preppers ought to know that about 80% of the world’s tsunamis happen in the Pacific Ocean, along the Ring of Fire. Large displacements of water in the Pacific travel outwards in all directions, forming tsunamis in the bordering countries.

The following are some countries along the Pacific Ring of Fire that experience the most earthquakes and tsunamis:

  • Indonesia 
  • New Zealand 
  • Papua New Guinea
  • Philippines 
  • Japan
  • United States
  • Chile
  • Canada
  • Guatemala
  • Russia
  • Peru

If you reside in coastal areas in any of these countries, you might wanna round up your earthquake kit for the next big quake. 

In the United States, cities along the West Coast—Los Angeles, San Diego, San Jose, San Francisco, Sacramento, Portland, Seattle, Anchorage, and Honolulu—are the most vulnerable to tsunamis.

With these in mind, it’s in your best interest to know the telltale signs of an incoming tsunami if you’re planning a visit to any of these tsunami-prone sites.

How To Know When a Tsunami Is Coming?

In the event of a tsunami, seconds can mean the difference between life and death. It is imperative that individuals and communities have the necessary knowledge and skills to quickly recognize the signs of an incoming tsunami and take appropriate action. 

In this section, we’ll discuss how to interpret the different levels of tsunami alerts and how to identify nature’s own tsunami warning signs. 

Tsunami Alert 

The National Oceanic and Atmospheric Administration (NOAA) works together with the United States Geological Survey to help determine when and where to issue tsunami alerts. 

Currently, the National Weather Service (NWS) has four levels of tsunami alerts: 

  • Warning – Dangerous coastal flooding and powerful currents possible
  • Advisory – Strong currents and waves possible
  • Watch – Distant tsunami possible
  • Information Statement – No threat or very distant threat

Check out their safety diagram to learn how to react accordingly to each tsunami alert.

When a tsunami is imminent, warnings are disseminated through multiple channels including local radio and TV broadcasts, wireless emergency alerts, and NOAA Weather Radio. 

Information can also be obtained from local authorities, text messages, and phone notifications. Additionally, relevant updates can be found on websites such as Tsunami.gov, also maintained by NOAA. Outdoor sirens will also sound alarms in critical danger zones. 

That said, keep in mind that while tsunami alerts help, they’re not always infallible. Partly the reason why the 2004 Indian Ocean tsunami turned out to be the deadliest of all time, was because people in the area never received any tsunami alerts to begin with.

In the absence of tsunami alerts, there are tsunami warning signs you can look out for especially if you happen to be near the ocean before the onset of a tsunami.

Tsunami Warning Signs

More often than not, nature has its own way of telling us to get the f*** out before an impending disaster. If you ever find yourself at the beach on an unsuspecting day, look out for these tsunami warning signs:

  • Shake – If you feel a large earthquake lasting more than 20 seconds, you’re likely close to the quake’s epicenter. Shorelines near the epicenter may be hit by a tsunami within a few minutes to a few hours.
  • Drop – A rapid and unexpected drop in water levels may be the only sign of an approaching tsunami in coastal areas that are too far from the epicenter to have felt the quake’s tremors. If you’re by the beach and noticed the water receding oddly fast, it’s a good sign to run inland.
  • Roar – Tsunami survivors and people living in coastal areas commonly report a loud roaring sound coming from the ocean right before an impending tsunami. If that’s not a clear enough warning for you, we don’t know what is.

How to Survive a Tsunami

As you may have guessed, knowing what tsunami warning signs to look out for isn’t gonna be enough. After all, surviving a tsunami is no easy feat. 

To brace yourself, check out the tips we’ve laid out below on how to survive a tsunami before, during, and after it hits.


Disaster experts say that earthquakes leave more people injured than tsunamis, only because anyone in the path of a tsunami almost certainly dies.

But there’s gotta be something you can do, right? 

Hell yeah! By all means, seasoned preppers would agree that knowing what to do in advance can spell the difference between life and death.

With that, here are some things you can do to gear up before a tsunami hits.

Pack Your Disaster Kit

Packing for something that might never happen can be a pain in the butt, but when the ground’s shaking and the tide’s rising, you’ll thank yourself for getting it done in the first place.

Here are the top things you’ll need to consider when packing your disaster kit:

  • Food – Opt for non-perishable food items like canned goods, dried fruits, nuts, granola bars, and whole wheat crackers. 
  • Water – For long-term storage, try to find stainless steel containers that can store 2-5 gallons of water. For emergencies when water is scarce, try to source emergency water pouches in advance. The US Coast Guard suggests drinking two pouches per person per day.
  • First Aid Kit – Some basic items to include in your first aid kit are emergency plasters, sterile gauze dressings, disposable gloves, alcohol, antibacterial wipes, tweezers, medical scissors, antibiotic cream, and your own prescription medication. In packing a first aid kit, tailor it to your specific needs first. 

Opt for a satellite phone or an emergency radio. If not, whistles, flashlights, and flare guns are some useful tools for signaling for help.

For more comprehensive lists, check out our articles on flood preparedness, earthquake and first aid kits, emergency communication devices, and tips on storing water for SHTF.

Know the Topography and Natural History of Your Location

Whether it’s the place you’re living in, consider moving to, or just visiting, it helps to know the topography and weather patterns of your location. Why?

For one, low-lying coastal cities will be devastated by a tsunami. In inclement weather, you’ll be safer in towns located further inland. 

On the other hand, regions that have previously been wrecked by a tsunami may have better disaster response and infrastructures in place than towns that have never experienced one before.

In any case, it pays to do your research in advance because it just might save your life.

Talk to Locals and Authorities 

Learn the evacuation routes and tsunami alerts in your own hometown and in foreign locations by approaching locals and authorities. This will help you determine how prepared the local community is for natural disasters.

If you’re living along a coastal region, we suggest observing whether high or low tides are common to the area. Notice the shoreline receding unusually fast on a particular day? It helps to know if it’s a normal occurrence or not.

You can rest easy knowing it’s not new to the area, but your internal alarms should start ringing if it’s the latter, given that this is a natural tsunami warning sign.

Look Out for Tsunami Alerts and Tsunami Warning Signs

For tsunami warning signs, remember Shake, Drop, and Roar. If you experience volatile shaking, notice a drop in water levels, or hear a roaring sound from the ocean, it’s your best bet to leave immediately.

As soon as you’ve noticed the natural tsunami warning signs and received a tsunami alert from NOAA, you only have a few minutes to an hour to evacuate. This will vary depending on how near or far you are from the coast. Whatever the case, there’s no time to lose.


All your alarms have set off and you’re certain there’s an incoming tsunami. If you’ve been a diligent prepper, this is when all your preparations are gonna pay off. 

Now, in the face of Poseidon’s wrath, what else can you do to keep yourself alive?

Below, we’ve laid out some valuable tips on how you can stay safe during a tsunami.

Head for Higher Ground

Heading for higher ground is the single most important thing you can do for your survival in a tsunami. 

A tsunami comes with the force of the whole ocean behind it and will sweep off anything in its path as though it were nothing. Remember, you have no chance of outrunning it.

Even if you were an Olympic swimmer, you wouldn’t be able to swim through its violent waves. On the off chance you could, you’d still be thrashed against debris and killed.

Your absolute best option is finding higher ground inland. 

The roads will likely be congested, so if you’re inside a car and end up stuck in traffic, get out of the car and run. You’ll have better chances of surviving on foot if you can find higher ground. 

Find a Steel-Reinforced Concrete Building

If you can’t go inland, your next best option is to find the tallest building in your area. 

Try to find a steel-reinforced concrete building that’s at least four stories high. Use the stairs when you go up, and stay away from large windows.

Hide in an area of the building that’s facing inland so you won’t be hit by the brunt of the tsunami’s force.

Hold On

The waves will likely take any sort of debris with them. To reduce your odds of getting injured, run to a place that’s away from cars and other large structures. 

If you’re unable to get to high ground or hide out in a tall building, find anything sturdy to hold on to. It can be a roof or a tall tree. Hold on for dear life until the crisis abates.

During the 2004 Boxing Day Tsunami, a pregnant Indonesian woman survived by clinging to a palm tree for five whole days. Now that’s a true survivor’s spirit!

Sail Towards the Open Sea if You’re in a Boat

This might sound like the last thing you’d want to do in the face of a looming tidal wave, but you’ll have better chances of making it out alive by sailing further out to sea if you’re stuck in a boat during a tsunami. 

This is because the shallow waters near the shore amplify the height and power of the tsunami waves, making it more dangerous and life-threatening to be on the coast. Sailing out to open sea minimizes the impact of the waves and increases your chances of survival. 

This requires clear and calculated judgment, as well as an understanding of tidal and oceanic conditions, to effectively navigate the waters and reach a safe haven.

Still don’t believe us?

A father and his son enjoying a fishing trip managed to survive the Lituya Bay tsunami after maneuvering their boat to ride out the waves instead of heading to shore.

Talk about keeping a clear head when S hits the fan!


Say you’ve managed to survive the onslaught of the tides. Don’t rejoice just yet, because your trials aren’t over. The aftermath can be just as ugly, if not worse. Expect blocked roads, washed-up cars, and possibly even dead bodies.

Stay on guard and observe these tips in the aftermath of a tsunami.

Look Out for Tsunami Aftermath Hazards

The tides have withdrawn, but in their place is a cesspool of washed-up gunk and other types of rubbish you can’t possibly make out. 

If you ever find yourself in this situation, here are some dangers you need to look out for:

  • Contaminated flood waters
  • Broken power lines
  • Gas leaks
  • Floating debris
  • Collapsing buildings
  • Landslides
  • Mudflows
  • Fire hazards

Find Shelter and Wait for Rescue

Once you’re through the thick of it, get on elevated ground and signal for help with whatever items you have at your disposal. Resist the urge to take shelter inside affected structures since they’re at risk of collapsing. 

Help might take a while to arrive due to blocked roads, so try your best to get out of the water and stay dry.

Stay Tuned for Emergency Alerts and Local Updates

If you hear reports about the waves retreating, beware. This isn’t an invitation to go back. 

Tsunamis can last for hours, sometimes even days, and the first wave is rarely the most powerful.

The Boxing Day Tsunami that took 230,000 lives in 2004 lasted a total of seven hours.

As a general rule, don’t attempt to go back to the coast until authorities officially declare the “all clear”.

Final Thoughts

Most folks live their entire lives thinking there’s no way they’ll ever encounter a tsunami.

Until they do. And by then, it’s too late.

Don’t be one of those people. 

Now that you know the basics of how to survive a tsunami, you have one more survival skill up your sleeve, and you’re one step closer to being the sensible hero that makes it out of those dystopian movies alive. 

Of course, this is easier said than done. Like all skills, survival skills need to be honed and constantly refreshed.

Have other tsunami survival tips you can share? Let us know in the comments!

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