GNGTS 2013 - Atti del 32° Convegno Nazionale

References Beccaluva L., Gabbianelli G., Lucchini F., Rossi P.L. and Savelli C.; 1985: Petrology and K/Ar ages of volcanic dredged from Eolian seamounts: implications for geodynamic evolution of the Southern Tyhrrenian basin. Earth Planetary Sciences Letters, 74, 187-208. Bruno P.P.G., Paoletti V., Grimaldi M. and Rapolla A.; 2000: Geophysical exploration for geothermal low enthalpy resources in Lipari Island, Italy. Journal of Volcanology and Geothermal Research, 98, 173-188. Capasso G., Favara R., Grassa F, Inguaggiato S. and Longo M.; 2005: On-line technique for preparing and measuring stable carbon isotope of total dissolved inorganic carbon in water samples (δ 13C TDIC). Annals of Geophysics, 48, 159-166. Capasso G., Favara R., and Inguaggiato S.; 1997 : Chemical features and isotopic composition of gaseous manifestations on Vulcano Island, Aeolian Islands, Italy: An interpretative model of fluid circulation . Geochim. Cosmochim. Acta, 61, 3425-3440. Capasso G. and Inguaggiato S.; 1998: A simple method for the determination of dissolved gases in natural waters. An application to thermal waters from Vulcano Island. Applied Geochemistry, 13, 631-642. Cavallaro C.; 1954: Le acque termo-minerali di S.Calogero di Lipari . Grafiche La Sicilia (Messina). Cortecci G., Dinelli E., Bolognesi L., Boschetti T. and Ferrara G.; 2001: Chemical and isotopic compositions of waterand dissolved sulfate from shallow wells onVulcano Island, Aeolian Archipelago, Italy. Geothermics, 30, 69-91. Craig H., 1961: Isotopic variations in meteoric waters . Science, 133, 1702-1703. Crisci G.M., De Rosa R., Esperanca S., Mazzuoli R. and Sonnino M.; 1991: Temporal evolution of a three component system: the island of Lipari (Aeolian Arc, southern Italy). Bulletin of Volcanology, 53, 207-221. Custodio E. and Herrera C.; 2000: Utilizacion de la relacion Cl/Br como trazador hidrogeoquımico en hidrologıa subterranea. Boletın Geologico y Minero, 111 (4), 49-67. Federico C., Capasso G., Paonita A. and Favara R.; 2010: Effects of steam-heating processes on a stratified volcanic aquifer: Stable isotopes and dissolved gases in thermal waters of Vulcano Island (Aeolian archipelago). Journal of Volcanology and Geothermal Research, 192, 178-190. Fischer P, Giggenbach W.F., Sano Y. and Williams S.N.; 1998: Fluxes and sources of volatiles discharged from Kudryavy,a subduction zone volcano, Kurile Islands . Earth and Planetary Science Letters, 160, 81-96. Grassa F., Capasso G., Favara R. and Inguaggiato S.; 2006: Chemical and isotopic composition of waters and dissolved gases in some thermal springs of Sicily and adjacent volcanic islands, Italy. Pure appl. Geophys., 163, 781-807. Inguaggiato S. and Rizzo A.; 2004: Dissolved helium isotope ratios in ground-waters: a new technique based on gas- water re-equilibration and its application to Stromboli volcanic system . Applied Geochemistry, 19, 665-673. Liotta M., Brusca L., Grassa F., Inguaggiato S., Longo M. and Madonia P.; 2006: Geochemistry of rainfall at Stromboli volcano (Aeolian Islands): Isotopic composition and plume-rain interaction. Geochemistry, Geophysics, Geosystems 7, 7. Liotta M., Grassa F., D’Alessandro W., Favara R., Gagliano Candela E., Pisciotta A. and Scaletta C.; 2013: Isotopic composition of precipitation and groundwater in Sicily, Italy. Applied Geochemistry, 34,199-206. Liotta M. and Martelli M.; 2012: Dissolved gases in brackish thermal waters: an improved analytical method. Geofluids, 12, 236-244. Longinelli A. and Selmo E.; 2003: Isotopic composition of precipitation in Italy: a first overall map. Journal of Hydrology, 270, 75-88. Peccerillo A.; 2005: Plio-Quaternary Volcanism in Italy. Editor Springer. Tranne C.A, Calanchi N., Lucchi F. and Rossi P.L.; 2000: Carta geologica schematica di Lipari, scale 1:10000. Edited by Agip. Space-time changes of seismic activity at Mt. Etna volcano (Italy) observed through statistical approaches S. Sicali 1,2 , M.S. Barbano 1 , S. D’Amico 2 , G. Lombardo 1 , F. Panzera 1,2 1 Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Catania, Italy 2 Osservatorio Etneo, Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Catania, Italy Introduction. Volcanic processes can locally modify the normal stress state of a volcano, which generally is connected to the regional stress field. Volcanic eruptions are often preceded by changes both in the rate and the location of local volcano-tectonic earthquakes so that a statistical approach can give a clue to investigate about precursors (Alparone et al. , 2011; Bell and Kilburn, 2012). The analysis of the space-time variations of the hypocentral distribution during pre-eruptive and inter-eruptive periods, could provide important constrains for a better understanding of the link between seismicity and eruptive processes (Lombardo and Cardaci, 1994; Vinciguerra et al. , 2001). Besides, some authors have pointed out that, in a volcano, the 277 GNGTS 2013 S essione 1.3