Earthquake‐generated tsunamis in the Mediterranean Sea: Scenarios of potential threats to Southern Italy

Abstract

[1] We calculated the impact on Southern Italy of a large set of tsunamis resulting from earthquakes generated by major fault zones of the Mediterranean Sea. Our approach merges updated knowledge on the regional tectonic setting and scenario-like calculations of expected tsunami impact. We selected three potential source zones located at short, intermediate and large distance from our target coastlines: the Southern Tyrrhenian thrust belt; the Tell-Atlas thrust belt; and the western Hellenic Arc. For each zone we determined a Maximum Credible Earthquake and described the geometry, kinematics and size of its associated Typical Fault. We then let the Typical Fault float along strike of its parent source zone and simulated all tsunamis it could trigger. Simulations are based on the solution of the nonlinear shallow water equations through a finite difference technique. For each run we calculated the wavefields at desired simulation times and the maximum water elevation field, then produced traveltime maps and maximum wave-height profiles along the target coastlines. The results show a highly variable impact for tsunamis generated by the different source zones. For example, a large Hellenic Arc earthquake will produce a much higher tsunami wave (up to 5 m) than those of the other two source zones (up to 1.5 m). This implies that tsunami scenarios for Mediterranean Sea countries must necessarily be computed at the scale of the entire basin. Our work represents a pilot study for constructing a basin-wide tsunami scenario database to be used for tsunami hazard assessment and early warning.

Scenarios for earthquake-generated tsunamis on a complex tectonic area of diffuse deformation and low velocity: The Alboran Sea, Western Mediterranean

“…The characteristics of the sources are taken from known events in similar tectonic environments; for example, the Forecast Propagation Database of the NOM (http://nctr. pmel.noaa.gov /propagation-database.html), that replicates typical subduction events, or the sources proposed for the Mediterranean by Lorito et al (2008) with typical characteristics based on the tectonic environment. However, in tectonically complex areas such defining generic sources are difficult and risky, given the implications for the planning of local warning systems.…”

Probabilistic tsunami hazard in the Mediterranean Sea

“…Therefore, only a qualitative comparison to the results of previous studies will be given in the following. Lorito et al [2008] considered the tsunami hazard in Southern Italy due to most credible scenarios from three tsunamigenic earthquake sources. Their findings are in general agreement with our results: The largest tsunami hazard in Southern Italy is found to be due to earthquakes in the Eastern Hellenic Arc where tsunami waves up to $4 m can affect Sicily.…”

“…[4] Tsunami hazard has traditionally been studied by simulating the effect of "worst-case" or "most credible" scenario events with little emphasis on the probability of the scenario events [e.g., Tinti and Armigliato, 2003;Hébert et al, 2005;Paulatto et al, 2007;Lorito et al, 2008;Shaw et al, 2008]. Although such scenarios can be extremely useful for response planning, knowledge of the probability of occurrence of an event is crucial for planning risk mitigation efforts (especially when considering multiple hazards), for defining building design specifications and for insurance pricing.…”

Simulation of tsunami generation, propagation and coastal inundation in the Eastern Mediterranean

“…The generation and propagation of tsunamis in the Eastern Mediterranean has been numerically studied by relatively few researchers, especially in comparison to the geotectonic regime of the area. One may refer to the work of Tinti et al (2005), for scenarios of tsunamis of tectonic origin from the Algerian earthquake of 1980, the Eastern Sicily Arc and the Western/Eastern Hellenic Arc; Salamon et al (2007), for tsunamis generated from landslide and/or earthquake scenarios impacting the coasts of Syria, Lebanon and Israel; Lorito et al (2008) for earthquake-generated tsunamis from the Algeria-Tunisia, Southern Tyrrhenian, and Hellenic Arc source zones; as well as of Yolsal et al (2007) and Periáñez and Abril (2014), covering all generation mechanisms (geological faults, landslides, entry of pyroclastic flows into the sea and the collapse of a volcano caldera). However, the adequate representation of nearshore dynamics and coastal inundation remains an issue in all relevant attempts for the area.…”