French Polynesia sparked a Tsunami alert After the earthquake having struck the Kamchatka peninsula, in eastern Russia, as elsewhere other Pacific territories. Is France really exposed to the risk of tsunami? What regions are the most concerned And have already suffered waves of this type?
Overseas online in sight
Generally, we consider that The most risk regions of tsunami or tidal wave are located near subduction zoneswhere a tectonic plate plunges under another. 78% of tsunamis are thus caused by seismic activity10% by landslides and volcanic eruptions, the rest by other phenomena, meteorological for example.
Do you know signage in Tsunami risk areas?
The city of Deshaies in #Guadeloupe is a pioneer in the French Antilles with a specific display and an alert system, to reach the withdrawal areas in case of tsunami.#CaribeWave2023 pic.twitter.com/zyWedwNzxQ
– Ouragans.com (@ouragans) March 23, 2023
In our country, It is the overseas territories that are most threatenedbecause they are in areas at high risk of powerful earthquakes. Since 1690, at least 118 tsunamis occurred there, mainly in the Pacificwhere, moreover, 76% of fatal tsunamis took place, especially near the “belt of fire”, one of the most active seismic areas on the planet.
French Polynesia has undergone 16 tsunamis since 1837, In particular to the Marquesas Islands, of which 11 caused damage. In New Caledonia, 12 tsunamis have been identified since 1875, as in 2022 after the eruption of the Tonga volcano. In Reunion and Mayotte, the risk is lowerbut in 2004, the 2M wave from the Sumatra earthquake had caused more than a million euros in damage.
In the Caribbean, 75% of the Guadeloupe coast and 40% of the Martinican coast are exposed to the risk of tsunamiwhile these islands are at the convergence of several tectonic plates. For 400 years, more than 20 tsunamis have struck the small West Indiesas in 2004 after the earthquake in the islands of the Saintes: waves of 2 meters had reached the coast in 10 minutes.
Mediterranean and Atlantic not safe
Certainly less exposed, The metropolis is not fully spared by the risk of tsunamis: 68 have been there for 1500. The main threat lies in the Mediterranean, especially due to seismic activity along the Algerian coast and in Liguriain Italy. In the event of an earthquake, destructive waves can reach the French coast in 10 minutes to 2 hours.
This tsunami occurred on the other side of the world, but is such a phenomenon possible here in mainland France? On the western coasts, it is unlikely. On the other hand, in the Mediterranean, the risk is taken very seriously. The underwater activity is closely monitored. #jt20h pic.twitter.com/swZwbjHfqE
-Le20H-France Télévisions (@le20hfrancetele) July 31, 2025
It is the French Riviera which is particularly at risk : we remember in particular the 1887 After an earthquake of magnitude 6.2, or that of 4 meters in 1979 in Antibes after a landslide Near Nice Airport. In 2003, the Boumerdès earthquake in Algeria caused a tsunami having dropped sea level in certain ports with damage.
The coast between Ciotat and Toulon, the Côte des Maures, the Perpignan region and northwest Corsica are also affected by this significant risk. Within 30 years, UNESCO estimates the probability almost 100% that a tsunami strikes the Mediterranean. This is why some coastal cities, such as Cannes, set up alert systems and organize evacuation exercises.
The Atlantic facade is much less concernedin the absence of major subduction zones, but A tsunami is not impossible: it was the case in 1755after the terrible earthquake of Lisbon, Portugal, where the waves had reached the French coast.
Article reference:
The cross. Tsunamis: What are the most threatened French coasts?
