Tsunamis are one of nature’s most brutal forces. These powerful waves are often generated by strong earthquakes or volcanic eruptions and have the ability to destroy nearly anything in their path. These massive waves move quickly and can travel thousands of miles across oceans before crashing onto the shore. Tsunamis have captured the attention of awestruck people for centuries, and may even be a source of inspiration for many famous ancient legends.
These massive waves are unlike any others. Unlike the regular waves that roll into the shoreline on a regular and consistent basis, these towering waves require specific conditions in order to be created. No shoreline is perfectly safe from tsunamis, but some areas are more vulnerable than others. Scientists have been working for decades on perfecting systems that can predict and warn people when a tsunami is imminent, but nature’s unpredictability has made this difficult. While we may never know exactly when or where the next tsunami will strike, science has uncovered how they’re formed and how they may have even shaped the history of the world.
Take a look at these 25 amazing facts about one of nature’s most powerful forces.
Many people picture a single, giant wave when they hear the word tsunami, but that’s not actually the case. They consist of a series of waves, a phenomenon that’s commonly referred to as a “wave train.” According to National Geographic, the initial wave isn’t usually the strongest. The largest and most powerful waves often don’t occur until the fifth or sixth wave. These waves don’t always roll in in rapid succession - they can hit the shore in anywhere from a few minutes to two hours apart.
The gradual increase in wave power and the unreliable timing of tsunamis is often the cause of many related fatalities. After the initial wave hits, people are quick to run outside to assist others that couldn’t get to safety before the first wave. These good Samaritans are then caught in the subsequent waves that they can’t predict.
Saying that tsunamis are big waves don’t really begin to cover it. The massive waves regularly reach 100 feet in height and hit the shore with thousands of times the power of a regular wave. For comparison, even during intense sea storms, average waves don't usually grow taller than 30 feet in height.
The waves aren’t only tall, they’re incredibly long. They can be as long as 60 miles. The Indian Ocean tsunami of 2004 was able to hit 11 separate countries because of its size. They also have very large wavelengths, sometimes reaching hundreds of kilometers.
Tsunamis move fast. Waves have been recorded traveling as quickly as 600 mph - which is nearly the speed of a jet plane. Average beach waves that are generated by wind typically only travel between 2 to 60 mph depending on the strength of the wind.
Their incredible speed is the reason so many people are caught off guard and unable to get to safety before the waves hit the shore. Even once a warning has been put out following an earthquake, many people don't have the time or transportation to get out of harm's way on higher ground. Because of this limited time-frame, areas vulnerable to tsunamis prepare for the event.
The term tsunami literally translates to “harbor wave” in Japanese. Japan is particularly susceptible to tsunamis because of its position in the Pacific Ocean. They’re also commonly called killer waves because of the destruction they bring.
Tsunamis hit Japan more than any other country in the world, and the country has also seen some of the most destructive tsunamis ever recorded. The 2011 tsunami in Japan was amongst the worst the world has ever seen. According to CNN, over 20,000 people lost their lives, and over 2,000 people are still listed as missing.
Sometimes, the ocean offers an eerie warning sign that a tsunami is imminent. Around a half hour before the tsunami strikes, the ocean will drain away from the shore leaving land exposed which is usually covered by water, even during low tides. Scientists call this phenomenon a drawback. The space left by water that is pulled into the sea serves as the trough of the wave.
Drawbacks can cause some serious confusion and panic across beaches once they appear. Some people just aren’t aware of what the strange sight means, while those who are aware understand just how important it is that they get to safety as soon as possible.
Not all tsunamis are caused by the same forces. Most are caused by strong earthquakes, but volcanic eruptions, landslides, and rapid changes in atmospheric pressure have also been responsible. Scientists believe that on a few occasions, giant meteors landing in the ocean may have also been the cause.
No one has ever actually witnessed a tsunami that was caused by a meteor landing in the ocean, a popular theory among scientists is that around 3.5 billion years ago one of these tsunamis was responsible for wiping out life on earth.
The first written account of tsunamis is found in History of the Peloponnesian War which was penned by Greek historian Thucydides in 431 BCE. He was the first to write about the relationship between underwater earthquakes and tsunamis.
Scientists can now predict tsunamis with incredibly precise accuracy. But they can also go back and study past tsunamis to better understand them. For example, scientists now believe that an asteroid hit the Indian Ocean about 4800 years ago, generating a massive tsunami. They think the resulting waves might have reached heights of 600 feet.
Roughly 90% of all Tsunamis occur in an area of the Pacific Ocean known as The Ring of Fire, where many underwater earthquakes occur. On the other hand, very few tsunamis have ever hit the European coastline - one struck the Mediterranean coast in 1530 B.C., and another struck Lisbon, Portugal in 1755.
Tsunamis that are formed by earthquakes are the result of a lighter tectonic plate being forced above a heavier plate. This causes sudden rises and dips of the ocean floor, resulting in the water above it being displaced. The tsunami is then generated by the rapidly changing ocean level. When the tectonic plates slide apart or past each other, tsunamis generally don’t form.
Tsunamis are capable of causing massive amounts of damage to coastal towns. Sometimes, the effects of them are so devastating that they impact communities for years to come. In addition to the initial damage caused by the massive waves, the salt that washes up on the shore can dehydrate the land and cause ongoing damage to the soil for years.
The 2011 Tsunami in Japan is estimated to be the world’s most costly natural disaster. According to World Vision, the direct economic loss of the disaster was estimated at $360 billion. Despite the fact that Japan is one of the world’s leading countries in disaster preparedness, an international response was needed to assist the people of Japan.
On the off chance that you’re ever actually caught in a tsunami, experts do have some tips to help you survive the experience. First up - don’t try to swim. In a tsunami, there’s nowhere to go. The waves are so massive that you’re going to be caught in them no matter how strong of a swimmer you are. The current will always be pulling you away from the coast, so when you try to swim away from them, you’re wasting valuable energy that you’ll need later on.
So if you shouldn’t swim, what should you do? Experts say you should simply float. If you’re able to find a buoyant object to hold onto, grab onto that and don’t let go. If you can’t find an object, do your best to stretch out and use your body to stay on top of the water. You’ll want to allow the current to do the rest of the work for you as you ride it into shore.
Most waves that you encounter are at their strongest when in the deep sea. As they roll towards the shore, they lose energy and are at their weakest once they finally break and crash onto the beach.
This isn’t the case with tsunamis. Once they’re formed, they travel through the ocean at full speed and lose very little energy on their way to the shore. Deep at sea, tsunami waves may only be a few feet high and appear no more threatening than other waves to ships that pass over them.
Palm trees are often planted near coasts because of their sturdy trunks and durability. The long and strong trunks are well adapted to the sometimes brutal coastal conditions and have earned a reputation for enduring tsunami waves totally intact.
Other plants and structures don't have the same luck when a tsunami hits the shore. Most plant life isn't durable enough to withstand the powerful waves and even massive trees can be destroyed by the impact. Even strong buildings are often ruined in the aftermath. Japan is attempting to build strong concrete walls on some shores in an attempt to mitigate tsunami damage.
Tsunamis don’t always hit the shore just because its close to the site of the earthquake. They can travel for miles, hitting the coasts of faraway places that would never even be close to feeling the earthquake.
In 1960, one of the largest earthquakes ever recorded at a 9.5 magnitude occurred roughly 100 miles off the coast of Chile. It only took 15 minutes for a tsunami to strike the Chilean coastline with 80-foot waves. But it didn’t stop there. Roughly 15 hours after the earthquake, tsunami waves struck the coast of Hawaii. And about 22 hours after the earthquake, waves hit the coast of Japan which is over 10,000 miles away from the site of the earthquake.
While tidal waves and tsunamis are both ocean waves, the similarities end there. The USGS defines a tidal wave as “a shallow water wave caused by the gravitational interactions between the Sun, Moon, and Earth.” Since these gravitational interactions have nothing to do with the formation of tsunamis, referring to them as tidal waves is incorrect.
Tidal waves can still be large and move quickly, but they’re predictable and a regular occurrence in many places. The largest tidal waves are found in the Canadian province of New Brunswick, where waves have been known to reach 50 feet tall.
Much has been said about animal’s instinct in predicting natural disasters before they happen. There may be no better proof of this than the animals that were in the areas affected by the Indian Ocean tsunami in 2004.
In the hours leading up to the tsunami, people throughout the area reported strange animal behavior. Zoo animals refused to leave their shelters during their normal schedules, dogs didn’t want to go outside, and elephants and flamingos were seen fleeing to higher ground. This instinct likely saved many animal lives as an extremely low number of animals were claimed by the tsunami.
Ancient legends hold many unexplained phenomena that live on today as a mystery. But researchers believe that some of these legends may actually be tsunamis. People in ancient times didn’t have the technology to study tsunamis, so they believed they were signs from God.
Stories like the great biblical flood that wiped out nearly all civilization, the parting of the Red Sea during the Israelites exodus from Egypt, as well as the complete destruction of the Minoan civilization that was on the island of Crete may all be the result of tsunamis.
Most waves, those caused by wind as well as tidal waves break and curl as they hit the coast. But tsunamis don’t follow this pattern. Instead, they come towards the shore in what's known as a bore. These large, steep waves look like a giant wall of water.
As tsunamis rush towards the shore, they slow down rapidly. The water that was once traveling at the same speed as a jet plane approached the beach at about 25mph. Because it’s slowing down, the water begins to pull up and reach huge sizes. Many of these walls of water are the size of 10 story buildings by the time they hit land.
Because tsunamis can appear so suddenly and so quickly, it can be difficult to find a way to safety. The first instinct many people have is to get in the car and drive to safety, but research shows that this isn’t always the best idea. People who try to escape in their cars are often caught in traffic jams, meaning they are stuck close to shore and more likely to be swept up in a wave. It’s better to escape on foot, climbing to higher ground as soon as possible.
People who live in areas where tsunamis are common often have evacuation routes and instructions specific to their location. In addition to regular fire drills, Japanese schools even practice what to do in the case of a tsunami.
Hawaii’s location in the Pacific Ocean makes it particularly vulnerable to tsunami waves. They occur almost annually and they usually see a severe tsunami about once every seven years. Because of this, they are well prepared for the event. Hawaii has evacuation routes in place and residents are well-informed on what to do when they occur.
The largest tsunami to hit Hawaii was in 1946. The coast of Hilo, located on the northeastern side of the island of Hawaii, was hit with 30-foot tall waves.
In 1958, a mega-tsunami hit Alaska and caused the largest waves ever recorded. The massive waves reached 1,700 feet - that’s roughly the size of a 157-story skyscraper. As was the case in Lituya Bay, most mega-tsunamis are the result of landslides. But Alaska isn’t the only place in the United States at high-risk for tsunamis. California, Hawaii, Oregon, and Washington are all susceptible to being hit by waves.
Scientists actually believe that the next mega-tsunami could have a huge impact on the United States. Studies have predicted the next mega-tsunami will occur near the Canary Islands and that the waves could devastate coastal cities like Boston and New York when they travel across the Atlantic Ocean.
Scientific developments have given us the ability to predict tsunamis. Early alerts can be instrumental when it comes to getting people out of harm’s way. But of the major oceans, only the Pacific Ocean has a multinational warning system. Many people have wondered how many lives might have been saved if there was one in the Indian Ocean at the time of the 2004 tsunami.
Japan has the most advanced warning system in the world. Their tsunami warning system consists of more than 1,500 seismometers and more than 500 water-level gauges. According to the BBC, this intricate system costs nearly $20 million dollars a year to run.
After a tsunami crashes onto the shore and spreads across the land, it washes back into the ocean. Sometimes the water can rush back with nearly the same force it had coming in. Because of this, the water often washes objects into the ocean which can turn up months later on distant shores.
After the 2011 tsunami in Japan, a soccerball traveled all the way across the Pacific to Alaska. A local man found the ball on a beach and posted it on his blog. The post circulated and Misaki Murakami recognized it as his own. The ball was mailed back to Murakami, whose house and belongings were destroyed by the tsunami.
Tsunamis are usually associated with oceans, but they can actually occur in any body of water around the world. They are generally caused by the same earth movements that cause ocean tsunamis - earthquakes, volcanic eruptions, and rock avalanches have all been known to cause tsunamis in lakes.
To date, no extremely destructive tsunamis have occurred in lakes, but there have been several recorded instances. Some scientists are pushing for more research on these tsunamis, stating that they could be incredibly destructive to beachgoers and surrounding towns.
The Indian Ocean tsunami of 2004 is one of the most famous and most destructive tsunamis of all time. But one astounding fact about the tsunami is often overlooked by the media. It was so powerful that it actually uncovered ancient relics from the lost city of Mahabalipuram.
Mahabalipuram was the capital port city of the powerful kingdom about 1,500 years ago. This kingdom was well known for being a trade partner with Egypt, Arabia, Roma, Greece, and China."As the tsunami waves receded, they scoured away sand deposits that had covered these sculptures for centuries," said Alok Tripathi, an underwater archaeologist in an interview with Down to Earth.
Tsunamis are actually quite common in deep ocean waters. Earthquakes are frequent in the ocean, but they usually occur far from land. These earthquakes are still capable of setting off a tsunami, but that doesn’t mean they’ll do damage on shore. These are the tsunamis that generate smaller, 1-3 foot tall waves that are barely noticeable by sailors.
According to National Geographic, on average two tsunamis will do damage near the source every year. Larger, destructive tsunamis tend to happen every 15 years.
The damage tsunamis are capable of causing in only a mere matter of minutes has earned them the reputation of being one of the world’s most destructive natural disasters. Over the past 2,000 years, roughly 500,000 people have lost their lives to tsunamis in the Pacific region. The 2004 Indian Ocean tsunami claimed over 250,000 lives alone.
The most destructive tsunamis typically occur in the Pacific Ocean. These extremely powerful tsunamis are usually caused by strong earthquakes that displace large amounts of water at once.
Sources: National Geographic, CNN, NBC News, BBC