Analysis of the recent Plio-Quaternary deformation and the correlation with the focal mechanisms of the significant earthquakes in the Bokoya, Ras Tarf (Eastern Rif)

Université Mohammed V, Faculté des sciences Département sciences de la terre, Unité de recherche GEORISK et LGRN, 4 Avenue Ibn Battouta Rabat-Agdal, BP 1014, Rabat, Maroc.

Abstract

Relative movements of microplates developed between the African and Eurasian plate characterize the continuity of the tectonic movements in Westerner of the Mediterranean Sea. The convergence movements between these plates, at the origin of the current structuring in oriental Rif. The recent tectonics in the south ripple of Alboran Sea, translated by an important seismic activity, In the North of Morocco, exactly in the Al Hoceima region, considered as zone of plates border with important seismicity. The structural analysis made in this paper and the interpretation of focals mechanisms earthquakes characteristics in the Al Hoceima region, has allows to deduct the main directions of faults, which we compared with the results of the satellite images. This study we has provides to demonstrate the directions of faults which are able to generate earthquakes in the future. The direction NE-SW represents the overall faults dominant in oriental Rif, this major direction coincides with the breaks of surface. A reduced number of faults shows a generall direction NNE-SSO to N-S through the Quaternary formations in the NO of Al Hoceima city, the direction NO does not show a good correlation with the directions of surface rupture, as well as with the deducted directions from focals mechanisms. This study drives us to propose that faults of direction NNE-SSO to NE-SO, represent the major directions of the faults in the Al Hoceima region, which represents the main cause of the seismic activity in the region.