Scenarios for earthquake-generated tsunamis on a complex tectonic area of diffuseuddeformation and low velocity: The Alboran Sea, Western Mediterranean

摘要

The tsunami impact on the Spanish and North African coasts of the Alboran Sea generated by several reliableudseismic tsunamigenic sources in this area was modeled. The tectonic setting is complex and a study of theudpotential sources from geological data is basic to obtain probable source characteristics. The tectonicudstructures considered in this study as potentially tsunamigenic are: the Alboran Ridge associated structures,udthe Carboneras Fault Zone and the Yusuf Fault Zone. We characterized 12 probable tsunamigenic seismicudsources in the Alboran Basin based on the results of recent oceanographical studies. The strain rate in the areaudis low and therefore its seismicity is moderate and cannot be used to infer characteristics of the major seismicudsources. These sources have been used as input for the numerical simulation of the wave propagation, basedudon the solution of the nonlinear shallow water equations through a finite-difference technique. We calculatedudthe Maximum Wave Elevations, and Tsunami Travel Times using the numerical simulations. The results areudshown as maps and profiles along the Spanish and African coasts. The sources associated with the AlboranudRidge show the maximum potential to generate damaging tsunamis, with maximum wave elevations in frontudof the coast exceeding 1.5 m. The Carboneras and Yusuf faults are not capable of generating disastrousudtsunamis on their own, although their proximity to the coast could trigger landslides and associated seauddisturbances. The areas which are more exposed to the impact of tsunamis generated in the Alboran Sea areudthe Spanish coast between Malaga and Adra, and the African coast between Alhoceima and Melilla.