An integrated geodynamic analysis of seismic sources in the Eastern Rif: Insights from geological, seismological, gravimetric, and aeromagnetic data

The Rif’s belt is characterized by low to moderate seismic activity resulting from the continental collision between the African and Eurasian plates. This seismic activity, which involves devastation and human losses, requires an in-depth study of its origins and mechanisms. This study aims to identify the geological structures responsible for seismic activity in the eastern Rif by adopting an integrated methodological approach. The methodology relies on the use of a Geographic Information System (GIS) to process and analyze multiple geological, seismological, and geophysical datasets. Various filters were applied to magnetic and gravimetric data (vertical derivatives) to characterize the subsurface. The analysis of earthquake focal mechanisms helped identify active faults. The results show that the seismicity, with a NW-SE orientation, is localized within a fragile depression south of the city of Selouane. The final geological model highlights a system of faults and strike-slips oriented NE-SW and NW-SE. A significant spatial correlation is observed between epicenters and Messinian-aged NW-SE strike-slips, suggesting their reactivation. The analysis indicates that a system of dextral strike-slips is likely the source of this seismic activity. The proposed geodynamic model represents a major advancement in understanding local seismic activities and serves as an essential reference for future studies. These results significantly contribute to the assessment and management of seismic risks, thereby enhancing the safety and resilience of populations in this high-risk area.

KEYWORDS: Geodynamic model; Seismotectonic; Focal mechanism; Magnetic; Gravimetric; ·
Eastern Rif.