2023-06-19 14:17:37
June 19, 2023
5.3 to 5.8 on the Richter scale for the first tremor, measured at 6:38 p.m. across much of western France on Friday. Then 4.6 for the first aftershock, which occurred a few hours later, in the middle of the night. A major earthquake therefore occurred a few days ago, and, as often, it was felt very differently.
There are those who believed in an explosion, those who saw their floors warp, those who saw the walls of their house crack or collapse, as in La Laigne, a small town in Charente-Maritime heavily affected by the major earthquake last Friday. And then there are the others, who saw nothing, heard nothing, or even felt anything.
To explain this variation in impressions, many factors come into play. The magnitude and distance to the focus of the earthquake, in the first place: that of Friday seems to have originated on a fault located a few hundred meters below the town of Cram-Chaban, near Mauzé-sur-le-Mignon, between La Rochelle (Charente-Maritime) and Niort (Deux-Sèvres). The greater the magnitude, and the closer you are to the focus and the epicenter of the earthquake (the point on the surface of the ground closest to the focus), the more likely it is to have felt it. However, people located hundreds of kilometers away very clearly perceived the tremors, but not their immediate neighbors…
Multiple factors
This is probably because other factors come into play. For example: the height of the buildings in which you are (the higher you are, the greater the oscillations will be), and the soils on which they are built (the soils near watercourses are more sensitive to seismic waves than more compact soils).
The differences in feelings are also and above all explained by what you were doing at the time of the earthquake: this is what can be read on the blog of researcher Austin Elliott, American scientist specializing in earthquakes at the Institute of United States Geological Surveys. In a 2017 post titled “Who Feels Earthquakes? “, he explains that one of the main causes of these differences is explained by the fact that non-sensitive people “are within the perceptible radius of the earthquake, but do not pay sufficient attention to it”.
Thus, below a certain threshold, “earthquakes can go unnoticed by people on the move or in noisy environments.” A l’inverse, “being at rest, and of course in a quiet room or space, obviously increases the odds; being indoors rather than outdoors, where there are many objects generating rattling noises, increases the likelihood of noticing a small earthquake or distinguishing it from just a passing truck”.
To note : Beyond the physical feeling of the earthquake, there are also its psychological consequences. Friday’s earthquake only injured two people, but many residents expressed their distress in the areas most affected by the material damage. A psychological unit was quickly set up in Mauzé-sur-le-Mignon. Many studies have shown that about a quarter of people who have experienced an earthquake are at risk of developing post-traumatic stress disorder.
1687225014
#Earthquake #feel #it.. #dont