Probabilistic Tsunami Hazard Analysis for Eastern Sicily (Italy)

San Francisco

We applied the method for Probabilistic Tsunami Hazard Analysis (PTHA), first introduced by Rikitake and Aida (1988), to the coasts of eastern Sicily (Italy), and focusing on important cities such as Messina, Catania, and Augusta. The method has been very recently improved by Gonzàlez et al. (2009) to explicitly include inundation. Our approach considers both far- and near-field sources. Based on the approach described by Lorito et al. (2008), we identified a few Source Zones (SZ), each of which is characterized by a Typical Fault (TF) floating within it and capable of generating the Maximum Credible Earthquake (MCE). Some of the MCE recall historical events such as the 1908 Messina, the 1693 Catania and the 365 AD Crete earthquakes. We calculated the combined probability for all considered SZs by assigning a recurrence interval to each of them and a Poisson distribution of the inter-event times. We performed the PTHA for different damage metrics, such as runup, current speed, momentum and Froude number, with probability of exceedance of given thresholds being evaluated for different time intervals.