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Abstract

Probabilistic tsunami risk is assessed using a procedure that allows including mixed data from the instrumental part of tsunami catalogs, and data from the highly incomplete and uncertain pre-instrumental part. Such a model was used successfully for hazard assessment of earthquakes (Kijko et al., 2016) and tsunamis (Smit et al., 2019), considering seismic magnitude and tsunami height as metrics of the respective hazards. We applied this technique using catalogs for the basins of the Mediterranean and connected seas. Wave impact (destructiveness) is expressed in terms of tsunami intensity, K, i.e., a risk metric on the Papadopoulos-Imamura 12-degree scale. Risk level is assessed in terms of probabilities of exceedance and return periods of certain intensity levels in specific time frames. Tests and sensitivity analysis showed that using complete data sets generally provided more realistic results than using entire data sets. Our results indicated that the risk level depended on the seismicity level and not on the size of the investigated basin. The highest tsunami risk level was found in the eastern Mediterranean, with a significantly lower risk in the western Mediterranean. In the Marmara Sea, the tsunami risk was low, and the lowest was in the Black Sea. The risk in the Corinth Gulf in Central Greece was comparable to that of WM. The return period of damaging tsunamis was 22 years in the entire Mediterranean basin and from 31 to 1 660 years in the various sub-basins.