Tsunamis
A tsunami is a sea wavetriggered bya large-scale displacement of the sea floor. They are most commonly caused by earthquakes but can also be causedby major underwater (or 'submarine') landslides or volcanic eruptions. They can strike any coast at any time.Tsunamis can move as fast as a jet plane across the open ocean and can hit land with waves higher than 20 metres. Water canwash inland for several kilometres in flat lying areasand move up streams and rivers, destroying everything in its path. Waves may continue to strike the shoreline for many hoursand dangerous currents can continue for several days.Although a tsunami can't be prevented, its impact can be reduced when communities understand the risks, receive timely warnings and know how to respond.