Tsunami hazard in the Eastern Mediterranean: Strong earthquakes and tsunamis in the Corinth Gulf, Central Greece

The exhaustive review of a long number of historical documents, books, reports, scientific and press reports, instrumental recordings, previous catalogues and personal field observations, concluded with the production of a completely new tsunami catalogue for the Corinth Gulf, Central Greece, which is arranged in the format adopted by the GITEC group for the new European Tsunami Catalogue. The catalogue is presented in three sections: the Quick-Look Table, the Quick-Look Accounts File and the References File. An Appendix explains why some particular sea disturbances were not included in the new catalogue although they were considered as tsunami events by previous researchers. Past history clearly shows that most tsunamis in the Corinth Gulf are produced by strong (Ms greater than or equal to 5.5) offshore and near shore earthquakes. However, seismic or aseismic sliding of coastal and submarine sediments is a significant factor in tsunamigenesis. Calculations based on the random model indicate that the probability for at least one tsunami occurrence of intensity TI greater than or equal to 2 TI greater than or equal to 3 and TI greater than or equal to 4 within 50 years equals 0.851, 0.747 and 0.606, respectively. From the intensity-frequency relationship the mean return period of tsunami intensity TI greater than or equal to 2, TI greater than or equal to 3 and TI greater than or equal to 4 equals to 16, 40 and 103 years. The tsunami geographical distribution, however, is non-random with a clear trend for the tsunamigenesis to decrease drastically from west to east within the Corinth Gulf. In fact, the probability for a strong earthquake to cause a tsunami of TI greater than or equal to 3 in the Corinth Gulf considered as an entity is 0.35, while in the western part of the Gulf it goes up to 0.55. Therefore, the rapid and accurate determination of the earthquake focal parameters is of great importance in an algorithm of a real-time tsunami warning system in the Corinth Gulf.