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geografic kids

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They can speed across the ocean as fast as a jet plane, swallow up islands and wipe out villages.

But what causes tsuamis...? Join National Geographic Kids and dive into our tsunami facts to find out!

What causes a tsunami?

Meaning " great harbour wave" in Japanese, tsunamis are sometimes called "tidal waves" but their strength has nothing to do with the tides. About four out of five tsunamis happen within the Ring Of Fire, a zone in the Pacific Ocean where earthquakes and volcanic eruptions frequently take place.

Giant slabs of the Earth's crust, called tectonic plates, grind together. Sometimes, though, the plates get stuck, the pressure builds up and they suddenly slam into a new position. This causes an earthquake. If an earthquake lifts or drops part of the ocean floor, the water above rises and starts spreading across the ocean, causing a tsunami. Underwater landslides or volcanic eruptions can also displace water (cause water to spread across the ocean) and may lead to a tsunami.

How big is a tsunami?

Out in the open ocean, tsunami waves are only about one-metre high because the water is deep. However, as the water becomes shallow, the waves slow down and begin to grow. They can rise 35m or higher - that's the same as a 10-floor block of flats! However, the scariest thing about a tsunami is its wavelength, as this determines how far inland it can travel. Whereas a large wave caused by a storm might have a wavelength of up to 150m, a tsunami could reach up to a fearsome 1,000km!

How fast is a tsunami?

A normal wind wave travels at about 90kmh, but a tsunami can race across the ocean at an incredible 970kmh! Sometimes, before a tsunami hits, there is a huge vacuum effect, sucking water from harbours and beaches. People can see the ocean floor littered with flopping fish and other sea animals. Then a wave blasts onto the shore minutes later, then another and another for two hours or more. There may also be up to one hour between each wave.

Can you predict when a tsunami is coming?

To save lives, scientists established the Pacific Tsunami Warning System, based in Hawaii, in the USA. Its network of detectors can track quakes that may cause a tsunami. These waves can race from one side of the Pacific Ocean to the other in less than a day, so people need to be warned in time to head for higher ground!

What do you think of these tsunami facts? Let us know by leaving a comment, below!

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Tsunami facts: check out the mighty wave! - National Geographic Kids

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They can speed across the ocean as fast as a jet plane, swallow up islands and wipe out villages. But what causes tsuamis...? Join National Geographic Kids and dive into our tsunami facts to find out! Meaning " great harbour wave" in Japanese, tsunamis are sometimes called "tidal waves" but their strength has nothing to do with the tides.

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info by national geographic

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Rare Video: Japan Tsunami | National Geographic

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tsunami   in japan
Rare Video: Japan Tsunami | National Geographic

June 9, 2011 - The March 11 earthquake and tsunami left more than 28,000 dead or missing. See incredible footage of the tsunami swamping cities and turning buildings into rubble. ➡ National Geographic: National Geographic is the world's premium destination for science, exploration, and adventure.
youtube

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by noaa natioal  wether sevice
exalmpe  of a warning for natrel disasters

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Please enable JavaScript. This page needs Javascript to function properly.

Event Magnitude 4.1 (Ml)
Depth 4 (kilometers)
Lat: 19.488 Lon: -155.464
Origin Time: 2023-03-24T03:04:00Z
view bulletin
Information
<![CDATA[ ...LOCAL TSUNAMI INFORMATION STATEMENT... ]]>

Note: Times are local to your browser, unless otherwise indicated See the map or table below for more information
Previous 40 Tsunami Messages

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Please enable JavaScript. This page needs Javascript to function properly. Event Magnitude 4.1 (Ml) Depth 4 (kilometers) Lat: 19.488 Lon: -155.464 Origin Time: 2023-03-24T03:04:00Z view bulletin Information Note: Times are local to your browser, unless otherwise indicated See the map or table below for more information Previous 40 Tsunami Messages

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national geographic

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Watch: Deadly Tsunami Hits Greenland | National Geographic

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A deadly tsunami hit a remote region of Greenland, leaving four people presumed dead. Dozens more were injured and 11 homes were washed away. The area near the small town of Nuugaatsiaq has a population of about 84.

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what do you do during a tsunami
video from sdcountyoes

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San Diego County used animated short film to educate kids about tsunamis. Animated Crab Teaches Students Valuable Tsunami Preparedness Information.