The origin of Tsunamis

The events of the tsunami

This uncertainty, of geological origin, should not be confused with the phenomena of swell or strong waves caused by abnormal weather conditions, such as the wind. It is therefore possible that a tsunami is formed when there is good weather.

Most tsunamis are caused by underwater earthquakes. These earthquakes, when they are powerful, make it vibrate a large amount of water. The waves propagate in all directions. Other events may also move a large amount of water and create tsunamis by domino effect. For example, a large landslide into the sea or an underwater volcanic eruption.

The warning signs of a tsunami

• The earth can shake, but you don't feel it necessarily.
• The sea may suddenly recede, exposing the seabed.
• Some animals may have a strange behavior (excitation, flight to the heights).
• We can hear a rumbling or strange noises coming from the sea.

Source : Booklet teacher-cycle 4 – Project "Pare pa Pare" – French Red Cross – 2024

For more information :

Caribbean | Tsunami Programme – UNESCO. The member states concerned by the tsunamis, the measures of prevention, the regional exercises, and the role of the centres of alert. (English)

Tsunamis – CDEMA – Agency caribbean management of emergency situations in the event of a disaster. Practical resources to understand tsunamis and prepare before, during, and after their passage. (English)

Tsunamis – UWI – University Of The West Indies. Explanations on tsunamis, the formation of tsunamis in the Caribbean, how to protect themselves. (English)

Risk coastlines – Geohazards – French Government. Resource to understand what a tsunami is, its risks, the useful actions to protect oneself, and the available French subsidies. (French)