Abstract
Abstract. Eastern Sicily is affected by earthquakes and tsunamis of local and remote origin, which is known through numerous historical chronicles. Recent studies have put emphasis on the role of submarine landslides as the direct cause of the main local tsunamis, envisaging that earthquakes (in 1693 and 1908) did produce a tsunami, but also that they triggered mass failures that were able to generate an even larger tsunami. The debate is still open, and though no general consensus has been found among scientists so far, this research had the merit to attract attention on possible generation of tsunamis by landslides off Sicily. In this paper we investigate the tsunami potential of mass failures along one sector of the Hyblean-Malta Escarpment (HME). facing Augusta. The HME is the main offshore geological structure of the region running almost parallel to the coast, off eastern Sicily. Here, bottom morphology and slope steepness favour soil failures. In our work we study slope stability under seismic load along a number of HME transects by using the Minimun Lithostatic Deviation (MLD) method, which is based on the limit-equilibrium theory. The main goal is to identify sectors of the HME that could be unstable under the effect of realistic earthquakes. We estimate the possible landslide volume and use it as input for numerical codes to simulate the landslide motion and the consequent tsunami. This is an important step for the assessment of the tsunami hazard in eastern Sicily and for local tsunami mitigation policies. It is also important in view of tsunami warning system since it can help to identify the minimum earthquake magnitude capable of triggering destructive tsunamis induced by landslides, and therefore to set up appropriate knowledge-based criteria to launch alert to the population.
Highlights
Earthquakes and tsunamis have often affected Eastern Sicily (Fig. 1) and several of them are reported as disastrous in coeval chronicles (Burgos, 1693; Boccone, 1697; Mongitore, 1743)
The EqLiMDL code, developed by Tinti and Manucci (2006, 2008) and modified by Paparo et al (2013), has the aim to establish the equilibrium state of a given slope cross-section under specified conditions using the Minimum Lithostatic Deviation (MLD) method, that is a variant of the Limit Equilibrium (LE) method
The mass is simplified as a chain of blocks and the code computes the motion of the centre of mass (CoM) of the blocks that move along a predefined path (Fig. 7) wing to the action of body forces, the bottom friction, the frontal drag and the block-block interactions
Summary
Earthquakes and tsunamis have often affected Eastern Sicily (Fig. 1) and several of them are reported as disastrous in coeval chronicles (Burgos, 1693; Boccone, 1697; Mongitore, 1743). One example of such occurrences is the 11 January 1693 earthquake (hereafter referred to as E1693). Our aims are (i) to examine the stability conditions of the HME segment facing Augusta and to estimate the Peak Ground Accelerations (PGAs) congruent with E1693 that could have induced a mass flow, (ii) in case of instability, to simulate the submarine landslide motion and the associated tsunami and (iii) to compare the tsunami simulation results with the observed effects of the T1693. Cient for those areas that could be affected by tsunamis produced by earthquake-induced landslides
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
