Tsunamis
Awareness, Education & Support
A tsunami (stoo-NAH-mee) is an ocean wave or series of waves caused by a sudden disturbance of the sea floor that displaces a large amount of water. These powerful waves can travel as fast as a jet plane, as much as 800km/hr, within the ocean. At the coast, they have been recorded at heights of up to 30 metres and have travelled several hundreds of metres inland.
The word ‘tsunami’ comes from two Japanese words meaning ‘harbour’ (tsu) and ‘wave’ (nami). They are sometimes referred to as tidal waves but this is misleading. Tsunamis are NOT tidal waves as tidal waves are related to ocean tides while tsunamis are triggered by earthquakes, submarine landslides, volcanic events or by large meteorite impacts in the ocean.
Tsunami Risks
Tsunami waves are different from large waves brought by storms. Most tsunami waves do not break like normal surf waves at the beach that curl over as they approach shore rather they come in much like a very strong and very fast wall of water. Those that do break often form vertical walls of turbulent water called bores.
People caught in the path of a tsunami are at extreme risk from being crushed or struck by debris, or drowning. Children and the elderly are particularly at risk, as they often have less mobility, strength and endurance to evade or resist the onslaught.
