GNGTS 2013 - Atti del 32° Convegno Nazionale

Integration of stratigraphic data with HVSR measures for studies of seismic microzonation: the case of Oliveri (ME) P. Di Stefano, D. Luzio, P. Renda, R. Martorana, P. Capizzi, A. D’Alessandro, N. Messina, G. Napoli, M. Perricone, S. Todaro, G. Zarcone DiSTeM Department, University of Palermo, Italy Introduction. The seismic microzoning is a technique of analysis of a territory which aims to recognize, at a small scale, the local geological and geomorphologic conditions that may significantly affect the characteristics of the seismic motion, generating stress on structures that could produce permanent and critical effects. In other words, this technique has the objective to predict and evaluate possible site effects as a result of an earthquake. The first phase of the seismic microzoning is the detailed partition of the territory in homogeneous areas with respect to the expected behavior of soils during an earthquake. The seismic micro-zoning is a tool for prevention and reduction of seismic risk particularly effective when used already in the process of planning. The present paper focus on a recent study applied to the Oliveri, a coastal village settled on a coastal plain in north-eastern Sicily. Geological setting (Tectonic outline of the urban area of Oliveri). The area of Oliveri is part of the Peloritani Mountains, a segment of the Maghrebian chain that is mainly constituted by a pile of tectonic units consisting of Hercynian metamorphic rocks and their Meso-Cenozoic sedimentary covers. According to Giunta et al. (1998), the tectonic pile of the Peloritani Mountains is formed by the Longi-Taormina Unit, Fondachelli Unit, Mandanici Unit, Mela Unit and Aspromonte Unit. These units are overlapped by Oligo-Miocene siliciclastic turbidites pertaining to the Stilo-Capo d’Orlando Fm. upward follow, by a tectonic contact, the Antisicilide Units, represented by the Argille Variegate, that are capped unconformably in turn by the Floresta Calcarenites (Lower Miocene). In the Peloritani Mountains different deformation steps related to the Alpine orogeny follow the Hercynian ductile deformations. The Oligo-Miocene contraction has been characterized by Fig. 1 – Distribution of epicenters of instrumental earthquakes located by the INGV between 1981 and 2011. 235 GNGTS 2013 S essione 2.2