GNGTS 2019 - Atti del 38° Convegno Nazionale

GNGTS 2019 S essione 1.3 169 Gephart J.W. and Forsyth D.W.; 1984: An improved method for determining the regional stress tensor using earthquake focal mechanism data: Application to the San Fernando earthquake sequence . J. Geophys. Res., 89, 9305-9320. Gruppo Analisi Dati Sismici; 2019: Catalogo dei terremoti della Sicilia Orientale - Calabria Meridionale (1999- 2019) . Available at: http://www. ct.ingv.it/ufs/analisticatalogolist.php. Neri M., Casu F., Acocella V., Solaro G., Pepe S., Berardino P., Sansosti E., Caltabiano T., Lundgren P. and Lanari R.; 2009: Deformation and eruptions at Mt. Etna (Italy): a lesson from 15 years of observations . Geophys. Res. Lett., 36 , L02309. http://dx.doi.org/10.1029/2008GL036151. INNOVATIVE PERSPECTIVES FOR THE ASSESSMENT OF LOW-ENTHALPY GEOTHERMAL POTENTIAL IN VOLCANIC AREAS: A CASE STUDY FROM SALINA ISLAND (AEOLIAN ARC) G. Floridia 1 , M. Viccaro 1,2 1 Università di Catania, Dipartimento di Scienze Biologiche Geologiche e Ambientali - Catania, Italy 2 Istituto Nazionale di Geofisica e Vulcanologia – Sezione di Catania, Osservatorio Etneo - Catania, Italy Introduction. During the last years, the interest towards modern concepts of energy efficiency leads to the exploitation of alternative resources and innovative methods of energy production. In this regard, the interest toward geothermal resources is continuously increasing and entirely represents this new perspective. Sicily represents one of the most interesting geo- hydro-thermal sites of Southern Italy, which could offer exploitation of geothermal resources from low to medium-high enthalpy. The geological and hydrogeological setting of the island put into evidence how most of the territory is affected by a low-to-moderate thermal regime; it makes the area as one of the most suitable contexts where geothermal resources could have great potential to increase their whole usage. Furthermore, several active volcanic zones or areas at high hydrothermalism offer advantageous exploitation from low to high enthalpy geothermal resources. The case study is based on a detailed field survey providing information on lithostratigraphic features and on hydrogeological conditions of the area of Santa Marina Salina (Salina Island, Aeolian Island Arc) and is aimed at testing the thermal conductivity distribution at various depths by means of a theoretical model. Collected data become crucial for the definition of different conductivity gradient maps leading to the evaluation of the most suitable areas and their low-grade geothermal potential. Methodology. Objectives of the fieldwork are aimed at recognizing lithotypes and reconstructing the vertical stratigraphic successions of the first 100-150 meters in the area of the town hall of Santa Marina Salina. The presence of terrains belonging to four volcanic complexes has been established during the field survey: Rivi, Capo, Monte Fossa delle Felci and Porri. Although the investigated area was mainly affected by the activity of only two of the above-mentioned eruptive centres (i.e., the Rivi-Capo complex and Monte Fossa delle Felci), volcanic deposits belonging to the Porri volcano complex have been identified in some sectors. The chrono-stratigraphic reconstruction allowed a detailed interpretation of the volcano-tectonic mechanisms leading to the current morphology, together with a detailed definition of stratigraphic relationships.All this considered, a detailed geological map of the area has been outlined in order to define a geological model for the subsoil (Fig. 1). Despite the en2ironmental-friendly energy systems are solar thermal technologies, photovoltaic and wind power, other advantageous technologies exist, although they have not found wide development in countries such as Italy. Given the almost absent environmental impact and the rather favorable cost/bene t ratio,