Joint inversion of receiver functions and surface wave dispersion velocities to investigate the crustal structure of north of Morocco: case of Rif domain

Based on three-component seismograms of teleseismic events, the receiver function (RF) and surface wave dispersion approaches are well-confirmed tools for exploring crustal and upper mantle structures of northern Morocco. In addition, providing new data to better constrain and understand the geodynamic evolution and the Earth’s interior structure under the Rif Mountain is crucial. This study aimed to investigate the crustal complexities and the mohogeometry beneath the study area and to detect the possible high velocity. In addition, the depth of basement rocks and the thickness of the sedimentary cover under the surface of the study area are retrieved. A database of teleseismic events digitally recorded by 35 broad-band seismic stations from the TopoIberia, Picasso and CNRST located in Northern Morocco is used. Results show that the crustal structure of northern Morocco is filled by a sequence of sediments that differs in thickness across the region. The crustal thickness differs from West to East and reaches a maximum value of about 45 km in the Central Rif and a minimum of about 18 km in the Eastern Rif. The obtained Vp/Vs ratio varies between 1.7 and 1.8 in northern Morocco. The areas with a somewhat noticeable increase in the Vp/Vs ratio may represent geothermal areas, which could be exploited as renewable energy sources in the north of Morocco. The shear wave velocity model delineates a low seismic velocity zone in the upper crust at Central Rif and is observed at depths ranging from 5 to 12 km. This low-velocity zone may be attributed to the presence of weak fault zones. Compared with previous studies, the current study covers most of northern Morocco and provides new information about the tectonic evolution and crustal structure for those regions. The crustal models inferred from the RFs are consistent with previous studies, especially at stations located in the same areas.