Stromboli Island (Italy): Scenarios of Tsunamis Generated by Submarine Landslides

Abstract

Stromboli is an Italian volcanic island known for its persistent state of activity, which leads to frequent mass failures and consequently to frequent tsunamis ranging from large (and rare) catastrophic events involving the entire southern Tyrrhenian Sea to smaller events with, however, extremely strong local impact. Most of tsunamigenic landslides occur in the Sciara del Fuoco (SdF) zone, which is a deep scar in the NW flank of the volcano, that was produced by a Holocene massive flank collapse and that is the accumulation area of all the eruptive ejecta from the craters. Shallow-water bathymetric surveys around the island help one to identify submarine canyons and detachment scars giving evidence of mass instabilities and failures that may have produced and might produce tsunamis. The main purpose of this paper is to call attention to tsunami sources in Stromboli that are located outside the SdF area. Further, we do not touch on tsunami scenarios associated with gigantic sector collapses that have repeat times in the order of several thousands of years, but rather concentrate on intermediate size tsunamis, such as the ones that occurred in December 2002. Though we cannot omit tsunamis from the zone of the SdF, the main emphasis is on the elaboration of preliminary scenarios for three more possible source areas around Stromboli, namely Punta Lena Sud, Forgia Vecchia and Strombolicchio, with the aim of purposeful contributing to the evaluation of the hazard associated with such events and to increase the knowledge of potential threats affecting Stromboli and the nearby islands of the Aeolian archipelago.The simulations show that tsunami sources outside of the SdF can produce disastrous effects. As a consequence, we recommend that the monitoring system that is presently operating in Stromboli and that is focussed on the SdF source area be extended in order to cover even the other sources. Moreover, a synoptic analysis of the results from all the considered tsunami scenarios leads to a very interesting relation between the tsunami total energy and the landslide potential energy, that could be used as a very effective tool to evaluate the expected tsunami size from estimates of the landslide size.

Integrating geologic fault data into tsunami hazard studies

“…Parameters of sample fault ruptures (see Fig. 6a) Lorito et al, 2008;Tiberti et al, 2008;Tinti et al, 2008;Tang et al, 2009). However, while the scenario based approach is being progressively replaced by PTHA, it can be still useful in many circumstances such as the construction of infrastructure design scenarios, or for an order-of-magnitude estimate in particularly complex tectonic settings (Løvholt et al, 2012b).…”

Hydrogeology of Stromboli volcano, Aeolian Islands (Italy) from the interpretation of resistivity tomograms, self-potential, soil temperature and soil CO2 concentration measurements

“…In the case of volcanic islands, such giant landslides can in turn generate tsunamis. Stromboli is a prime example (Tinti et al . 1999, 2000, 2003, 2006, 2008; Tibaldi 2001; Bonaccorso et al .…”

Historical tsunamis and present tsunami hazard in eastern Indonesia and the southern Philippines

“…Tsunami hazard analysis has traditionally been scenario‐based [ Tinti and Armigliato , 2003; Løvholt et al , 2006; Okal et al , 2006; Okal and Synolakis , 2008; Lorito et al , 2008; Tinti et al , 2008; Tang et al , 2009; Okal et al , 2011]. More recently, however, a Probabilistic Tsunami Hazard Analysis (PTHA) approach has been developed and put to practical use [ Annaka et al , 2007; Geist and Parsons , 2006; Thio et al , 2007; González et al , 2009; Blaser et al , 2012].…”