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Concerning the seismic rupture
The rupture seems to have begun a few kilometers from the coast near the "Peñón de Alhucemas". These indications are corroborated by the epicenter obtained by the CNRM, the only one with data from stations close to the epicenter. The rupture seems to had propagate along 20 to 30km in a SSW direction, without having shown until now surface ruptures, although several fractures are found near the beach at the Club Mediterranée and in several places like at Ifassayenne.
Concerning the recording of strong aftershocks
It was possible to record more than a hundred of aftershocks in 2 accelerometers located near the seismic rupture, some of them having a strong magnitude. The preliminary analysis of the recordings of an aftershock with M=5.0 shows a strong amplification in the mountainous zone of Izmourenne due to the presence of quaternary sediments. These recordings will also be useful to accurately determine the location of the aftershocks, jointly with the data of other stations, and therefore the precise determination of the geometry of rupture.
Concernig the recording of microtremors
According to the first results obtained, the spectral relations between the horizontal and vertical components of the recordings of microtremors (Nakamura Method), seem to indicate strong amplifications in the zones of Ajdir and Izmourenne. The first results from the measurements done at Imzouren, do not show variations that can explain the differences in damages observed at different places visited.
Concernig destructive effects
Based on the damage observation and the different meetings with the architects from the Regional Urbanism Agency and the Emergency Architects the several following aspects can be commented:
- The auto-construction, which is constructing without design, seems to be the principal problem that can be mentioned on the observed damages, in particular, in the city of Imzouren. Although the existence of Constructive Normatives, many buildings are constructed by local constructors, without the intervention of any architect or calculation by engineers. In many cases the owner lives outside the country and the intermediates do not take care of the quality of the construction. This is a problem difficult to eliminate according to the Agency.
- The quality of the materials used: quality of the reinforced concrete, quality and quantity of the steel reinforcement, very few horizontal reinforcement, very small column sections even of 0.20m.
- Lack of legislation for the quality control and the existence of only one laboratory for the concrete quality control in the region.
- The responsibilities are diffuse in the legal texts.
