Geoscience Australia - ga.gov.au Tsunami are waves caused by sudden movement of the ocean due to earthquakes, landslides on the sea floor, land slumping into the ocean, large volcanic eruptions or meteorite impact in the ocean. Most tsunami are caused by large earthquakes on the sea floor when slabs of rock move past each other suddenly, causing the overlying water to move. The resulting waves move away from the source of the earthquake event. This animation shows how tsunamis are caused by large earthquakes. Tsunami caused by landslide: https://www.youtube.com/watch?v=feXCIfatJYo A Tsunami Scenario for Nuku’alofa: https://www.youtube.com/watch?v=tul1fR15UW4