When an earthquake occurs under the sea, it can trigger a tsunami . A tsunami is a huge tidal wave that moves very quickly towards the shore. These waves can cause a huge amount of damage along the coastline and can result in many deaths. See figure 3 for how a tsunami happens.
3 1
An undersea earthquake disturbs the seabed and causes powerful waves to move out very quickly in all directions.
A tsunami can devastate low-lying coastal areas.
2
3. How a tsunami happens
The sea waves become much higher
as they approach shallow waters near the coast. They can be up to 30 metres high – as they crash onto the shore. That's as high as a 10-storey building!
Staying well
On 11 March 2011 the Great Sendai Earthquake, with a magnitude of 9, struck off the coast of Japan, triggering a series of large tsunami waves.
First, locate Japan using an atlas or Google Maps. Then study this photograph for two minutes.
Imagine that you are a local business owner who lived in one of the homes destroyed in this picture. Write a paragraph to explain what you are feeling and how this has impacted on you, your family and your business. When finished, swap with a classmate and read their work.