Abstract:
On January 19th, 1992, at 20h 31mn UT, the village of Rouina (El Asnam, Algeria) was struck by a seismic event of magnitude 5.2. This event was the biggest one recorded in the region since the El Asnam earthquake of October 10th 1980, M=7.3. The seismic crisis corresponding to this event was for the first time in Algeria monitored by means of the stations of the ASTN (Algerian Seismological Telemetred Network). According to the ASTN data we can see that this event was preceded by a series of foreshocks which began at 12h 25mn UT, with two events of M=4.7 and M=4.3. These two events, in our minds, announced in a certain way the occurrence of the main shock. We thought that such an example could be considered in certain seismogenic zones as a warning system, although of course we have to keep in mind that the density of the stations and their spatial coverage must be good.