A tsunami is a series of powerful waves caused by a sudden movement of the sea or lake floor, or by something falling into water - like the ripples created when a stone is thrown into a pond, but bigger.
Most tsunamis are caused by underwater earthquakes, but they can also be caused by volcanic eruptions or underwater landslides.
Tsunami evacuation zones and warnings
Tsunami evacuation zones show the areas that you should move out of if you feel a long or strong earthquake, or if there is an official tsunami warning.
Canterbury's tsunami hazard
A tsunami is a series of waves that move through the ocean (or a lake) caused by a sudden movement of the sea floor or by something falling into the ocean.
Mackenzie Basin lake tsunamis
Tsunamis only happen in the ocean, right? Actually, tsunamis can happen on lakes too.