The earthquake that shook the Pacific on July 30th didn't just spark concern in French Polynesia. In mainland France, the event served as a reminder that the French coast, while less exposed, is not immune to the risk of tidal waves. Measures are in place, but the threats remain very real. In Polynesia, the waves remained modest, with no significant damage. But the quake, which occurred off the coast of Russia, triggered an alert across the entire Pacific basin. In mainland France, the alarm reached Cannes, where the risk of a tsunami has been anticipated for several years.
In the Mediterranean, faults under close surveillance
In the Alpes-Maritimes region, the city of Cannes has installed nearly forty loudspeakers throughout the commune and marked evacuation routes on the ground. This organization is not insignificant: the Mediterranean coast, although seemingly calm, is bordered by active seismic faults, some of which are in close proximity to the shores. Among them, the Ligurian fault, off the Italian coast, tops the list of risk areas. Others, more distant, such as those located in Algeria, are also monitored, as they are likely to generate powerful tsunamis. For Quentin Bletery, a geophysicist at the French Institute for Research and Development, the proximity of these faults justifies increased vigilance across the entire Mediterranean arc.
The Atlantic is also exposed, but differently
On the Atlantic coast, the danger also exists, even if the probabilities are lower. Since 2012, a National Tsunami Warning Center located in the Paris region has been continuously monitoring earth movements that could affect the French coasts. According to its director, Hélène Hébert, the expected heights in the event of a tsunami would be around one meter, but the effects could last for several hours, particularly in the event of aftershocks. Contrary to popular belief, the two French coasts therefore present comparable risk levels. The difference is more due to the frequency of earthquakes than to their potential intensity.
A risk culture still in its infancy
While systems exist, as in Cannes, their widespread adoption remains tentative. Few cities today have clearly identified evacuation plans or effective warning systems. Yet, when faced with unpredictable natural phenomena, responsiveness remains the best defense. This reminder from the Pacific underscores an uncomfortable truth: France, even continental France, is not immune to a tidal wave. It remains to be seen whether awareness, this time, will overcome fleeting emotion.
