An earthquake with a magnitude of 4 was felt on the boundary between Puy-de-Dôme and Allier (northwestern Auvergne-Rhône-Alpes) yesterday afternoon (May 9).
Residents of the village of Sainte-Christine dans les Combrailles to the north of Clermont-Ferrand felt the earth tremble, with one telling France 3 it was like: “A muffled noise coming from the ground and then a huge bang which made the house vibrate.
“Was it an earthquake? Am I the only one to have heard and felt it? It was not a plane because the sound was coming from the ground.”
Jean Battaglia of Auvergne’s earthquake detection network has confirmed that an earthquake did indeed occur, and that it was more powerful than those usually recorded.
“It would seem that there was an earthquake of 4.5 on the Richter scale, which is quite strong for Auvergne.
“It took place between Montaigut and La Celle dans les Combrailles.
“This is an area where there is a notable seismicity, it is actually the area of Auvergne with the most significant seismic activity.
“Normally, the [earthquakes detected] are little tremors which are not felt by the population. Normally, we have maximum magnitudes of 3.5. But this one of 4.5 magnitude is unusual.”
Despite being felt by the population, the earthquake was not dangerous for humans.
“It may have created some damage but it was not a huge earthquake, we have to put it in proportion,” Mr Battaglia said.
Earthquakes in Auvergne
An analyst from the BCSF Renass French earthquake tracking service has now confirmed the magnitude as being 4.
Mr Battaglia added that the 4.5 estimation is “A local magnitude, which can often be overestimated in comparison to the true magnitude, which is difficult to calculate. Often it will come down a bit. So, we could consider it a magnitude 4 earthquake, for example.
“The true estimation of magnitude is more complicated to obtain.”
Auvergne is a region where earthquakes often occur, and the historic and cultural region of the Combrailles is a particularly active zone.
Encyclopaedia Britannica states that it is only over 4 on the Richter scale that an earthquake will be felt by all and potentially cause objects to break, as it will become ‘light’ rather than ‘minor’.
There are approximately 500,000 earthquakes with a magnitude of more than 4 each year around the world.
You can find out more about earthquakes occurring in France on the BCSF Renass website,.