The Cruise MESC 2001 is part of the IGM-CNR research project 'Hazard evaluation of submarine geological processes in the Italian seas: earthquakes, tsunamis and slides' funded by the Italian group for protection from earthquakes (GNDT). The areas investigated during the survey (Fig.1), from the Messina Strait to the Malta escarpment, and around the Aeolian Volcanic edifices present a record of seismicity that goes back to historical times with events that seriously affected people and manufacts in the adjacent coastal area.
Active faulting of regional extent are affecting the slope of eastern Sicily and the adjacent Ionian basin. However, the complexity of the tectonic system in the region is far from being fully resolved, mainly because of the lack of a properly spaced seismic survey.
Published maps of active faults affecting the slope of eastern Sicily and the adjacent Ionian basin are currently based on a seismic grid that is loosely spaced ([1],[2],[3],[4]) and, therefore, both direction and extent of faults are only weakly constrained. Because a good knowledge of the architecture of a fault system is a pre-requisite to evaluate its hazard potential, we planned and carried out a seismic survey aiming at more closely mapping the active fault system of eastern Sicily offshore. The survey was planned upon a 5 nm spaced grid of reflection seismic profiles covering the Malta Escarpment and adjacent Ionian Basin; only towards the deeper Ionian Basin plain, away from the Malta Escarpment, spacing was enlarged to c.a. 10 nm.
The main objective was to better define the architecture of the active fault system affecting the eastern slope of Sicily. Firstly, the direction and continuity of fault segments should be better defined in plan view. Secondly, small sedimentary basins showing growth strata geometries have been originated by extensional faulting. Analysis of stratal geometries should help estimating amount of throw and relative age of activity of fault segments. Finally, the high resolution Chirp sonar profiles, acquired together with seismic data, could bring information on the occurrence of large mass movements along the slope. Such processes may play a role in trigger or modulate tsunamis in a tectonically active environment. An additional seismic survey, of limited extent, was planned also to be carried out in the sea surrounding the islands of Vulcano, Lipari and Salina with the aim of mapping the regional tectonic features controlling the evolution of the line of volcanoes and, eventually, the stability of the individual edifices.
