Earthquakes in France: Haute-Savoie and Savoie among the areas most at risk

This week, the earth shook several times in France. Monday October 7, the north of France was hit by a magnitude 2.7 earthquake whose epicenter was located in Cambes-en-Plaine, a few kilometers from Caen. While this Wednesday, it was the Côte d’Azur which recorded a magnitude 2.3 earthquake then an aftershock of magnitude 2.9. The epicenter was in the Mediterranean Sea, about twenty kilometers from Nice.

The tremors could be felt by some residents, but did not cause any damage. These events are not unusual: Normandy is located in a seismic zone of low intensity but with regular activity. It is common for earthquakes of this force to occur, but their depth generally makes them imperceptible, geophysicist Daniel Amorese told France Bleu Normandie. The Alpes-Maritimes are partly located in an area with “average” seismic activity (4/5). Here, around ten seismic episodes are recorded every day, but are not felt by the population.

Haute-Savoie and Savoie in zone 4

What about elsewhere in France? Five seismicity zones exist, determined by article D. 568-81 of the environmental code, ranging from very low to high. Outside of the Antilles, no area is classified as a strong zone (level 5). Some territories, on the other hand, are in zone 4, corresponding to “average” activity.

This is the case for almost all of Haute-Savoie and a large part of Savoie (apart from Tarentaise – Vanoise). The Pays de Gex and the Pays Bellegardien are in zone 3, corresponding to “moderate” activity. This risk is determined using a probabilistic approach based on the frequency and intensity of earthquakes in the area concerned.

Also read | Seismic risk in Haute-Savoie: on board the seismotruck, an earthquake simulator

In Haute-Savoie, the last shock felt dates back to June 7. The village of Digny-Saint-Clair, near Annecy, was the epicenter of an earthquake measuring 3.3 on the Richter scale. Before that, residents remember the 1996 earthquake in Annecy. With a magnitude of 5.3, it caused a lot of damage – without causing any casualties.