So what is a Tsunami?
A tsunami is a flood of water that can cause a huge destruction when it hits a coastline.
Tsunamis are caused from underwater earthquakes. Underwater earthquakes happen when the oceanic and continental templates push into each other and build up pressure. The pressure builds up until the oceanic templates slips under the continental plate releasing all of the pressure and energy.
If an underwater earthquake is large enough, the ocean floor will make destructive movements, therefore the water above the sea floor must move too.
The ocean water is pushed upward causing a large ripple that begins to travel through the ocean. This large ripple, which becomes the tsunami travels at a very fast speed of up to 600 miles per hour.
The tsunami that followed the earthquake in Japan caused massive destruction and loss of lives. Japan has moved 4 metres closes to South America as a result of the earthquake.