Olivier Bouc unit is responsible for seismic and volcanic risks of Geological and Mining Research Bureau (BRGM). He returns to the 5.2 magnitude earthquake that occurred Thursday morning between La Rochelle and Rochefort
The Point.fr. Are the frequent earthquakes in Charente
Olivier Bouc: the Charente is considered a moderate risk area for earthquakes, just behind the Pyrenees, the Alps and the south of Alsace. The place of France where the earthquake risk is by far the strongest, is the Caribbean. The earthquake occurred Thursday morning in one of the flaws of the so-called system of Oléron. This is a very old seismic region, the relatively regular activity. The last earthquake of the fault goes back to 1972. It was a magnitude of 5 and had not died.
How does it feel when ‘ a 5.2 magnitude earthquake occurs? What kind of damage can it cause?
The measurement of magnitude is not enough to estimate the damage and sensations that causes an earthquake. The magnitude assesses the amount of energy released, but other parameters are involved such as the depth of the rupture, the soil composition, population density or the quality of infrastructure. That is why we are trying to gather as much evidence about these events in order to truly assess its impact. For the earthquake Thursday morning, we just we reported cracks on the walls this time.
Can s ‘expect aftershocks, even a small tsunami?
the movement of the mechanism in the basement because it is always possible to observe replicas in the hours, days or even months to come. For the earthquake that occurred in the region in 1972, had felt new tremors four or five months after the first earthquake. There was a slightly lower intensity, with a magnitude of about 4.5. Generally, the replicas are lower than the initial earthquake. Of course, one can never exclude a stronger response, but on this specific case, it seems unlikely to me. As for the tsunami, it is estimated that a minimum of 6 magnitude earthquake to cause. Ultimately, such as an earthquake Thursday morning may cause a wave of a few centimeters, to observable sentence. This is absolutely incomparable with what could happen in Japan in 2011.