Tsunami (say tsoo-nah-me)
What is a tsunami?
A tsunami is a huge, long wave that comes suddenly and often without warning.

How is a tsunami caused?
When an earthquake or volcano occurs, the vibrations cause a drop in the sea bed and water floods into the gap. When the gap is full, water rushes back in the opposite direction and creates a long wave.

Movement of tsunami
At sea, a tsunami is only slightly higher than other waves. A tsunami moves at great speed, up to 800 km per hour. As it moves nearer to the coast, it slows down and can become higher than 50 metres.

Destruction
By the time the wave reaches the land, it is a high wall of moving water that crashes onto the land. The volume of water and the force of its impact causes huge devastation. It then draws back into the sea again, dragging with it anything in its path.

Word meaning
'Tsunami' is a Japanese meaning 'harbour wave'. They used to be called 'tidal waves', but this is an inaccurate term as they are not caused by tides.

The record
The highest tsunami ever recorded was 85 metres high, off the coast of Japan.

If you use any of this information in your own work, acknowledge this source in your bibliography like this:
Thomas, R. & Sydenham, S. Tsunami [Online] www.kidcyber.com.au 2009

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Updated April 2009 ©kidcyber