{"id":672,"date":"2022-01-06T12:46:05","date_gmt":"2022-01-06T11:46:05","guid":{"rendered":"https:\/\/www.karibiodiv.net\/en\/?page_id=672"},"modified":"2025-09-18T15:36:49","modified_gmt":"2025-09-18T13:36:49","slug":"menaces-de-tsunamis-dans-la-caraibe","status":"publish","type":"page","link":"https:\/\/www.karibiodiv.net\/en\/patrimoine-naturel\/origine-et-evolution\/risques-naturels-en-territoire-caribeen\/menaces-de-tsunamis-dans-la-caraibe\/","title":{"rendered":"Tsunami threats in the Caribbean"},"content":{"rendered":"\n

One of the most destructive natural disasters in human history, a tsunami (from the Japanese tsu: port and nami: wave) also called “harbor wave” by the Japanese, is a series of giant and powerful waves that propagate across the ocean. They originate from a large quantity of water caused by a rapid and large-scale disturbance that originates in the ocean or large lakes generated following ground movements mainly due to earthquakes, an underwater volcanic eruption, a landslide or the impact of a meteor in the ocean.<\/p>\n\n\n\n

Tsunami waves move very quickly and can reach several meters in height. One of the visible signs of a tsunami is a drop in water level and a retreat of the sea, followed by a rise in water levels of one to several meters. It is important to remember that a tsunami is a very violent phenomenon that destroys everything in its path. The largest tsunamis known in human history reached an altitude of over 30 meters and are extremely destructive, causing numerous casualties.<\/p>\n\n\n\n

Tsunamis, origin and characteristics<\/strong><\/p>\n\n\n\n

A tsunami occurs when the seismic source is located at sea and has given rise to an earthquake of magnitude greater than 6.3 with a focus located less than 50 km deep. Its waves are generated by ground movements due mainly to underwater earthquakes. 85% of tsunamis recorded worldwide are due to earthquakes. A tsunami consists of several waves that will flood the coastline generally every 10 to 30 minutes, sometimes for several hours. The first wave is often not the largest. A rapid drop in sea level or the rapid retreat of the sea are natural warning signs of the imminent arrival of tsunami waves.<\/p>\n\n\n\n

Powerful waves can also occur following a landslide near the sea or a lake. A lava flow from a volcanic eruption or, more rarely, meteorite falls or other impacts on the sea surface can also cause a tsunami.<\/p>\n\n\n\n

Risk predictability, monitoring<\/strong><\/p>\n\n\n\n

The instrument used for tsunami forecasting and warning is called a tide gauge. It measures the change in sea level relative to a reference level. A tsunami warning can be given either by an earthquake, by the sudden rise or retreat of water levels, or by local authorities. At this point, the population has only a few minutes to move away from the shore to higher ground. In the event of a tsunami, people should avoid driving to avoid creating traffic jams, then stay away from the coast and move to higher ground.<\/p>\n\n\n\n

Some supporting links :<\/strong><\/p>\n\n\n\n