Discover what causes tsunamis and how people living in areas at risk can protect themselves.
Underwater earthquakes can trigger a giant wave called a tsunami. Out at sea, the wave is barely noticeable from the surface but as it reaches shallower water it grows taller. When it reaches the shore it can cause massive destruction and flood inland for many kilometres.
Scientists and engineers have developed ways to deal with these dangers through defences, warning systems and building design. But even with the best plans in place, some communities can still be caught off guard.
Where do waves up to 30 metres in height come from?
How can you tell from the shoreline if a tsunami is on the way?
The DART system (Deep-ocean Assessment and Reporting of Tsunamis) warns countries of approaching tsunamis so that coastlines can be evacuated.
In 2011 an earthquake struck off the east coast of Japan, triggering a tsunami that caused widespread destruction and loss of life.