Convulsive geological events in the Alborán seahazardous and sedimentological consequences

Abstract

Convulsive geological events are natural processes of a destructive nature characterized by a sudden, highly energetic release of regional or global extent. These processes are extraordinary in nature and their impact, although it may be significant, is not well known in the geological record, especially in the marine environment. In this Ph. D. Thesis, two cases of convulsive events in the Alborán Sea, a geodynamic active area located at the Eurasian-African plate boundary have been analysed, one of a tsunamigenic type associated with faults and the other the controversial Zanclean megaflood that put an end to the Messinian Salinity Crisis. The central question of this thesis comprises several research questions: given the historical and sedimentary evidence of tsunamis in the Alborán Sea, what is their genesis; being most of the faults in this area strike-slip, can they generate tsunamis; and in relation to the megaflood, what is the evidence in the sedimentary record that shows that it existed? To address these research questions, geological analysis through seismic profiles of different resolutions, commercial and scientific wells, and multibeam bathymetry with mathematical modelling have been combined. This approach allows to identify, characterize and map, as well as better understand the geological evidences in order to improve the interpretation of convulsive processes.