A tsunami is a series of powerful ocean waves caused by a sudden movement of ocean water. Usually after a big earthquake on the ocean floor.
Tsunami Quick Facts (Fast Answers)
- What is it? A series of waves (not just one).
- Most common cause: Large earthquakes at the ocean floor.
- Other causes: volcanic activity, landslides.
- How fast do tsunamis travel? Up to 500 miles per hour!
- What do they look like? A giant wall of water with strong currents.
What are Tsunamis? (Simple Definition)
A tsunami is a series of waves created when some big event (usually an earthquake) pushes a large amount of water up and down. These spread across the ocean and push dangerous waves to the coast.
What Causes a Tsunami?
Most tsunamis begin when an earth quake or other event causes the seafloor to move suddenly. This pushes the water above it causing waves.
Common causes are:
- Underwater earthquakes (most common)
- Underwater landslides
- Underwater volcanic activity
Is a Tsunami a Tidal Wave?
Technically, no. Because tides cause tidal waves, the normal ocean movement from the Sun and Moon’s gravity. Tsunamis are caused by external forces and happen randomly.
How Fast do Tsunamis Travel? How Big are They?
Tsunamis start out very fast near the point they were created. Sometimes going up to 500 miles per hour (as fast as a jet airplane)!
As they get closer to the coast, the ocean gets shallower so they slow down. But this means their waves grow taller!
Just because you make it through the first wave, don’t celebrate! The first wave is not always the biggest. And waves can keep arriving for hours.
Warning Signs: How Can You Tell a Tsunami Might be Coming?
Many countries have an official alert system. But sometimes there isn’t enough time to wait for this, or they are not working. Natural warning signs of a tsunami include:
- A strong earthquake
- Sudden rising or falling of the ocean levels
- Loud wave roars from the ocean
If you notice these signs, you should move to safety immediately.
What Should You do During an Official Tsunami Warning?
- Follow official local instructions
- Move to high ground and/or further inland
- Stay away from beaches and other large waters until given the all clear from officials
Here’s a guide of official alerts from the USA National Weather Service
10 Interesting Tsunami Facts for Kids and Students
- A tsunami is a series of waves, not just one
- Most tsunamis start as earthquakes under the ocean
- Some tsunamis start from underwater landslides or volcanoes
- A tsunami is not caused by tidal activity (not tidal waves)
- Tsunamis can travel as fast as 500 miles per hour
- They get taller as they approach the coast in shallower waters
- The ocean level changing rapidly is a sign of a tsunami
- The ocean may pull back before a tsunami arrives
- Tsunamis may last for hours with many waves
- Follow official local instructions if you are warned about a tsunami
Tsunami Facts for 5th Graders (Super Simple)
A tsunami is a series of waves that happen after an underwater earthquake. They may be very tall and happen for hours. If you are near the beach and feel an earthquake, go to higher ground and follow adults and local warnings.
When you think about a tsunami, what’s the first thing that comes to mind? Is it the huge waves that come crashing down on the shore, or the feeling of the earth shaking beneath your feet? Tsunamis are one of the most devastating forms of a natural disaster, and in this article, you’re going to learn more about them.
Keep reading to learn more about the origins of the word “tsunami,” how they are often connected to volcanoes, and why they often take place around the Pacific ocean.
6 Interesting Facts About Tsunamis for Kids
1. The word tsunami is Japanese in origin.
Did you know that the word “tsunami” is actually a Japanese word? In Japanese, the word means harbour wave. Although you can add the letter “s” to make the word plural in English, the pluralized word tsunami is different in Japanese.
2. Tsunamis are caused by underwater earthquakes.
When it comes to how the oceans are controlled, you probably know that waves are generated by wind and the tides. The waves are also controlled by the sun and moon’s gravitational pull. However, when a tsunami occurs, its huge waves are caused by underwater earthquakes that occur when the tectonic plates between the Earth shift. If a plate undernearth the ocean shifts suddenly, the water that is above the plate is suddenly displaced and causes the tsunami’s huge waves to rise.
3. The most devastating tsunami occurred in 2004 in India.
Although there have been several tsunamis that caused widespread disaster, the most devasting tsunami in recorded history was the 2004 tsunami that took place in India. It was caused by a 9.2 magnitude earthquake that occurred near Sumatra, Indonesia, and the earthquake itself was caused by a rupture in the fautlines between the Burma and India plate. Resulted in big flood.
The massive shift beneath the oceanbed caused waves that were around 100 ft high, and killed over 220,000 people in 14 countries. This earthquake was the second most powerful earthquake that has ever been recorded since the beginning of modern seismography in 1900.
4. Tsunamis can be caused by volcanoes.
Did you know that a volcano can cause a tsunami? They are called volcanic tsunamis or volcanogenic tsunami. It’s important to note that it’s not necessarily a volcanic eruption that causes a tsunami to occur, but various processes related to underwater volcanoes that causes them. For instance, they could be caused a volcanic earthquake, a caldera collapse, a submarine eruption, and even lava spillage in the sea.
5. Some zoologists believe that animals can sense a tsunami approaching. (Still Unproven)
Although this theory has been widely questioned and criticized, some zoologists are under the impression that certain animals have the ability to sense a tsunami approaching by sensing subsonic Rayleigh waves. The reason that scientists believe so strongly in this theory is because, if proven true, this theory can help researchers and weather experts with predicting and preventing natural disasters ahead of time.
Many media sources were of the impression that certain animals like elephants were able to hear the tsunami approaching and move to higher ground before the 2004 earthquake and tsunami hit in India.
6. Tsunamis commonly occur in areas in and around the Pacific Ocean.
The ocean basin in the Pacific Ocean is often referred to as the Ring of Fire. One of the most notable physical characteristics of this path are the various active volanoes and earthquakes that commonly occur there. The reason that so there are so many tsunamis, earthquakes, and active volcanoes located along this path is because there is a lot of movement near the tectonic plates. Some of these tectonic plates also overlap in parts, which causes the rock to melt and turn into magma. The magma, in turn, is extremely close to the surface of the earth, increasing the chances of a volcano erupting.
Conclusion
In this article, we took a closer look at some interesting facts about tsunamis. Although we knew that they were incredibly scary to witness and experience, we didn’t quite realize just how intense and scary these natural disasters are. We hope that you enjoyed reading this article, and that you learned something new from it.
Sources
- NOAA, U.S. Tsunami Warning System https://www.tsunami.gov/?page=tsunamiFAQ
- National Weather Service, About Tsunamis https://www.weather.gov/safety/tsunami-about
