Seismotectonics of the Ibero-Maghrebian region

Abstract A study of the seismotectonics of the Ibero-Maghrebian region is presented as deduced from main geological features, seismicity and focal mechanism data. The hypocentral distribution of shallow, intermediate-depth and deep earthquakes is analyzed. The direction of the stress distribution is inferred from the focal mechanism of 24 selected events. A seismotectonic framework summarizing these results together with the main geological features shows that a NW-SE general direction of horizontal compressive stresses is present in the region with a localized zone of horizontal tensions in the Betics and the Alboran Sea. The presence of intermediate-depth and deep earthquakes is tentatively explained as caused by two consecutive processes of subduction.

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