Killer Waves
Listen to the story about dangerous tides
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The words
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Word
Meaning
Tsunami (n.)
A powerful ocean wave that carries huge energy. Example: The tsunami moved fast and surprised the people on the beach.
Coastline (n.)
The place where land meets the sea. Example: Many towns sit close to the coastline.
Destructive (adj.)
Something that causes great damage. Example: The storm had a destructive effect on the village.
Volume (n.)
The amount of space something takes up. Example: A large volume of water rushed toward land.
Surface (n.)
The top layer of something. Example: The water surface looked calm before the wave arrived.
The story
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Killer Waves
In 2004, a tsunami killed 283,000 people. In 2011, a tsunami hit Japan’s seashore. It killed 18,000 and destroyed a nuclear power station. What are tsunamis and where do they come from?
A tsunami is a wave with lots of energy. It’s different from regular waves, called tidal waves. Tidal waves are usually 150 meters wide. A tsunami can stretch out for 100 km.
Tidal waves move surface water. A tsunami moves surface water and water below the wave all the way down to the sea bottom.
Wind makes tidal waves. A tsunami is created when a large volume of water is moved in a short period of time. The most common cause is an undersea earthquake. It pushes a lot of water up into the air. When it falls back into the sea, a big splash is created. That splash sends out long waves.
As a tsunami moves close to land, it begins to slow down. Way out in the deep sea, a tsunami travels 700 km per hour, which is similar to a jet plane. Near land, its speed falls to 60 km per hour.
Close to land, the wave grows higher, but a huge wall of water is not common. If a tsunami reaches land, it can destroy buildings and lift cars.
Often, the first wave that hits land will pull back into the sea. It looks like the tsunami is over. Minutes or hours later, more waves hit the coastline, causing more damage and death.
Let’s return to the original question: what’s a tsunami?
It’s a series of waves usually created by an undersea earthquake. It moves a lot of water below the surface. When it gets close to land, it slows down. It can destroy cities and kill. It is one of nature’s most destructive forces.