Exploring fault parameters impact on tsunami modelling on strike-slip faults off SW Iberia

The southwestern Iberian margin is one of the most seismogenic and tsunamigenic areas in Western Europe, witnessed through historical and instrumental catastrophic occurrences such as the 1755 Lisbon and 1969 Horseshoe events. This region, marked by the convergence of the African and Eurasian plates, undergoes structural deformation mainly accommodated by thrusts and strike-slip faults, which conform a 600 km-long and 300 km-wide deformation band named the SWIM Fault Zone. Previous studies that evaluated the sensitivity of tsunami impact on the SW Iberian coast to the fault geometry and slip distribution for local earthquakes, revealed that the SWIM strike-slip faults seem to be threatening faults for the Spanish coasts due to their orientation, extension and proximity to the shoreline.This study focuses on the two most prominent SWIM lineaments, the North (LNF) and South (LSF) strike-slip faults, to assess the effects of varying fault parameters on tsunami modelling. Parameters under scrutiny encompass fault dip, rake, seismogenic depth, and slip, with parameter ranges drawn from a comprehensive dataset comprising: a) multiscale multichannel seismic profiles and high-resolution bathymetry, enabling detailed characterization of the tectonic structures and fault plane construction; b) two regional wide-angle seismic sections spanning both faults, providing insights into the deep structure and physical properties along the fault planes, from which we derive slip values; and c) regional seismicity data, providing insight into the seismogenic depth and confirming seismic activity along both faults.This comprehensive investigation aims to deepen our understanding of how different fault parameters impact tsunami modeling, leveraging a robust dataset derived from multiple sources. The study's outcomes hold the potential to refine risk assessment methodologies and enhancing preparedness strategies for tsunami hazards along the southwestern Iberian coast.