M. Bezzeghoud and E. Buforn
Source parameters of the 1992 Melilla (Spain, M _w = 4.8), 1994 Alhoceima (Morocco, M _w = 5.8), and 1994 Mascara (Algeria, M _w = 5.7) earthquakes and seismotectonic implications
Bulletin of the Seismological Society of America (April 1999), 89(2):359-372

Abstract:
Source mechanisms of the Melilla, Alhoceima, and Mascara earthquakes, including fault-plane solutions, waveform modeling, and spectral analysis, are presented. Strike-slip solutions have been obtained for the Melilla and Alhoceima earthquakes and reverse faulting for Mascara. Teleseismic P-wave inversion, using broadband data, show a complex mechanism for the Alhoceima earthquake formed by two subevents at very shallow depth (7 and 8 km) and scalar seismic moments of 1.1X10e+17 N-m and 4.8X10e+17 N-m. The Mascara earthquake was a single event, with a shallow depth (4.5 km) and a scalar seismic moment of 3.3X10e + 17 N-m. Results of the Alhoceima, Melilla, and Mascara earthquakes, together with 53 focal mechanisms in the region, show a regional stress regime that corresponds to horizontal compression in a NW-SE direction, associated with the convergence between Eurasia and Africa. A change of the stress regime in the plate boundary of the Ibero-Maghrebian region has been found.