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Abstract

The study of tsunami hazard is frequently approached from numerical modelling in a deterministic or probabilistic way. When probabilistic assessments are developed, epistemic and aleatory uncertainties are taken into account and incorporated into logic-tree and Monte Carlo approaches. Our approach is based on the use of physics-based earthquake simulators, developed in recent decades to overcome the temporal limitation of the instrumental seismic catalogue in probabilistic seismic hazard assessment (PSHA). Recent development of numerical codes based on the rate-and-state constitutive law for fault slip and frictional behaviour (RSQSim) allows also the modelling of the short-term rupture process based on a quasi-dynamic physical approximation. We have applied this model to the Eastern Betic Shear Zone, where one of the major faults of the western Mediterranean is present, the Carboneras Fault. This fault is a left-lateral transpressive structure oriented with a length of ∼150 km, most of them offshore, and a slip rate of 1.3 mm/yr. This fault has been proposed as source of the 1522 Almeria earthquake (Int. VIII-IX) possibly related to a local tsunami. We present tsunami simulations from seismic ruptures of a 1 Myr synthetic seismic catalogue generated with RSQSim, consistent on 773,893 events with magnitudes Mw 3.3 - 7.6. The Carboneras Fault has the capacity to generate locally damaging tsunamis. The frequency - magnitude distribution of the seismic catalogue departs from the classical Gutenberg-Richter potential relation showing a bell-shaped distribution for the bigger events. The inter-event times for the maximum earthquake magnitudes are between 2000 and 6000 years.