A tsunami, also called a tidal wave, is a massive wave
that causes extensive damage to land. A tsunami is started by earthquakes under
the sea.
An earthquake is caused by tectonic plates moving. They
float on top of the Earth’s mantle, so are not attached to anything. This means
that they move a LOT. When a plate moves, it causes an earthquake.
When an earthquake happens in the ocean, the energy from
it sends a rush of water up to the surface, which then sends waves in all
directions. Far away from the mainland, these waves are small – in fact, if you
are in a boat, you probably won’t feel them at all! But when the waves get
closer to land... the trouble begins.
In the shallower water, the waves create friction by
rubbing against the sea floor. This slows the wave down, making the waves
behind build up and creates a vast tsunami. It causes mass destruction on land.
Since tsunamis are created
by earthquakes, they act like
them. Earthquakes mostly happen near the edges of the tectonic plates, because
that is where two of them move apart or come closer together. So it makes sense
that a tsunami’s epicentre (the place where the earthquake is started) is near
the edge of the plates, right?
Tsunamis cause devastating damage. They flood EVERYTHING;
they pick up absolutely everything – cars, houses, people – and guess what?
When they pull back into the ocean (just like every other wave does) they pull
ALL the waste they picked up back in with them. This pollutes the sea like
crazy!
How do people predict these destruction machines? With buoys.
They float in the water near the coast, anchored in place, and detect
abnormally large waves. Most are positioned near the coastlines prone to
tsunamis, or the ones that are near the edges of the tectonic plates. Nowadays,
people can be warned when an earthquake is likely to occur.
