We present the results of the seismic deaggregation in 15 of the most important cities with the greatest seismic hazard in the south and west of the Iberian Peninsula (Spain and Portugal). The deaggregation was carried out based on the calculation of the seismic hazard in the zone, taking into account the peak horizontal acceleration with 10% probability of exceedance in 50 years (return period of 475 years). We first performed a deaggregation study in terms of magnitude and distance in order to subsequently carry it out in azimuth. The aim of both studies is to determine the relative contribution of the different seismic foci and sources to the seismic hazard in a given location. Due to the lack of enough seismotectonic data in the study region, we could not obtain information about the contribution of specific active faults and we have not been able to include a characteristic earthquake model. However, by starting from a calculated hazard using smoothed background seismicity, it is possible to determine the contribution of the different seismic foci of the region to the seismic hazard at each location. The results reveal that there are cities where the hazard is entirely, or almost entirely, due to the local seismicity (e.g., in Portugal: Lisbon, 87%; Coimbra, 82%; in Spain: Almerı·a, 99%; Co· rdoba, 99%; Granada, 99%). We have also determined that there are cities where seismic foci at 200 km away or more can be the most important or at least contribute significantly to the hazard (e.g., Beja and Faro in Portugal and Ca·diz and Huelva in Spain).

Understanding active tectonics and seismicity in extensional settings requires the analysis of high‐angle normal faults (HANFs) and the transfer of deformation at depth. The debate surrounds the role of low‐angle normal faults (LANFs) in triggering high magnitude earthquakes. The central Betic Cordillera is an active seismic zone affected by the NNW‐SSE Eurasia‐Nubia convergence and orthogonal extension. The seismicity and present‐day stress determined by earthquake focal mechanisms reveals the activity of a NE‐SW extensional system in the shallowest 12 km of the Granada Basin. The structure of the sedimentary infill, as derived by geological field and gravimetric techniques, suggests the formation of a half‐graben tilted to the N‐NE. Seismologic data suggest the activity of HANFs above 6–7 km depth and a LANF zone around 6–12 km depth, with related earthquakes of up to Mw 4.0 and 20° to 30° fault dips. High‐precision leveling lines highlight the importance of the Granada Fault in the system, with average vertical displacement rates of 0.35–1.1 mm/yr. These data suggest creep fault behavior at the surface and increased seismicity at depth. The upper crustal extension in the collisional Betic Cordillera is accommodated by a top‐to‐the‐WSW extensional detachment related to westward motion and rollback in the Gibraltar Arc and the gravitational collapse of the cordillera, in a framework of NNW‐SSE shortening. This comprehensive study draws a new scenario that advances understanding of relationships between HANFs and LANFs.