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CDEMA Tsunami Preparedness - What Is A Tsunami
What Is A Tsunami?

A tsunami is a series of travelling ocean waves caused by a sudden disturbance of the ocean floor that displaces a large mass of water.  The waves spread outward in all directions from the disturbed area and can travel across entire ocean basins.

What a Tsunami is Not

Tsunamis are not the same as:

Regular ocean waves – these are caused by the forces outside of the earth’s sphere and the influence of gravity in relation to the moon, sun and planets. Tsunami waves are unrelated to regular ocean waves.


Tidal waves – A tidal wave is related to ocean tides whilst a tsunami is triggered by earthquakes, landslides or volcanic events.


Storm surge - Tsunami waves are different from storm surges.  Storm surges are temporary rises in the sea level characterised by large waves or surges which are pushed towards the shore due to the combination of low pressure and high winds associated with an oncoming storm, pushing on the ocean’s surface.


For more information:

What is a Tsunami, Generation of the Phenomena


Click here to watch Normal Wind driven wave and Tsunami Wave
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