Not so long ago I was sure we’d witnessed an earthquake. We were walking up our drive when there was an incredibly loud crunching sound. Now, I’d heard something very like that before, many years ago, when there’d been a very short earthquake in Washington, Tyne and Wear. I’d been doing an audit on a firm on an industrial estate there when it happened. Everyone had come rushing out of the factory units to see what was going on. Great excitement.
At first we thought our mystery noise must have been a sonic boom as there was no record of an earthquake in our area on that day. An earthquake is ‘tremblement de terre’ or ‘séisme’ in French. Our nearest seismic movement monitoring and measuring station is at Toulx Ste Croix, about 20 km away. This is one of 40 automatic stations that send signals in real time to the central database for Seismic activity at Bruyères le Châtel. Every time we come down from the panoramic tower there, we go and jump up and down just outside the seismic monitoring device which is next to it. But so far, I don’t think our efforts have been recorded! However, supposing a worrying reading was sent from there, one of the team of scientists who man Bruyeres 24 hours a day would be alerted, and if it was a sign that something dreadful was about to happen, they in turn would alert the relevant authorities – police, army, government departments. France also has 4 seismic stations abroad and 12 stations monitoring possible tsunamis.
There are hundreds of minor tremors in France every year, but only a few notable ones i.e. of 4 or more on the Richter scale. The major French earthquake zones are Guadaloupe and Martinique, the Auvergne, Isere, Savoie, Alpes Maritime, Haut Rhin and Loiret.
To find out the latest on earthquakes in France, log onto the website of the Réseau National de Surveillance Séismique at http://www.franceseisme.fr/donnees/intensites/carte.php. This had plenty of fascinating facts and figures. Another good earthquake website, but which unfortunately hasn’t been updated since 1 January this year, is at http://www.sisfrance.net/. And another at http://www.alertes-meteo.com/tremblement_de_terre/terre_sommaire.htm gives historic and general information on earthquakes. An English language site on earth tremors in France is at http://www-tamaris.cea.fr/html/en/notions/activity.php.
So our noise wasn’t an earthquake and it wasn’t a sonic boom. What was it? In Nouzerines, a couple of kms away, a large chunk of an old house had collapsed. A farmer had been storing hay bales in it, and one of these had fallen and broken a crucial beam in the roof. Down came half the old building with an awful lot of noise and dust. Mystery solved!