GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 1.3 271 showing the clear role of tectonic elements in the ascent of fluid and confirming the hypothesis of strict relation to both the stratigraphic and structural setting (Della Seta et al. , 2015). The main structural control of Mt. Nuovo gravitational slope deformations can be attributed to mayor fault lines. Preferential paths for fluid rising may have played a dual role in controlling the pore- pressure distribution and inducing the localization of hydrothermal alteration in the rock mass. The thermo-fluid dynamic model fits the temperature log-profile measured in deep wells (Fig. 1) and outputs the thermal- baric field within the Mt. Nuovo slope. Perspectives. The preliminary results obtained so far encourage further numerical modelling, in order to evaluate the mechanical response of the slope system with respect to transient hydrothermal conditions and to estimate long-term effect of thermal anomalies on rock mass creep process (Chigira et al. , 1992). The here proposed numerical modelling will be enriched by specific laboratory physical and mechanical data derived by thermo-mechanical investigation on Mt. Epomeo Green Tuff. The obtained results constitute a starting point for studies focused on the dynamics and mechanics of the gravity-induced slope evolution affecting the Mt. Nuovo area, providing the thermo-baric range which controls the evolution of the gravitational deformations. Thermo-mechanical modelling of the Mt. Nuovo slope will be implemented to quantify the landslide hazard and infer possible paroxysmal scenarios toward general collapse. Aknowledgements. This research was funded by “Sapienza” University of Rome in the frame of the project “Influence of geothermal systems and related thermal regime variations on the onset and development of large slope instabilities in the island of Ischia” (2015 - prot. C26A15FH3L - P.I. Dr. Carlo Esposito). References AGIP; 1987: Geologia e geofisica del sistema geotermico dei Campi Flegrei . Technical report. Settore Esplor. e Ric. Geoterm.-Metodol. per l’Esplor. Geotermica. San Donato Milanese, Italy, pp. 1-23. Bächler D., Kohl T., Rybach L.; 2003: Impact of graben-parallel faults on hydrothermal convection-Rhine Graben case study . Physics and Chemistry of the Earth, 28 , pp. 431–441. Bozzano F., Gaeta M., Lenti L., Martino S., Paciello A., Palladino D.M., Sottili G.; 2013: Modeling the effects of eruptive and seismic activities on flank instability at Mount Etna, Italy . Journal of Geophysical Research: Solid Earth, 118 : 5252-5273. Carlino S., Somma R., Troiano A., Di Giuseppe M.G., Troise C., De Natale G.; 2014: The geothermal system of Ischia Island (southern Italy): critical review and sustainability analysis of geothermal resource for electricity generation. Renewable Energy, 62 , pp. 177-196. Fig. 1 – a) Plot of defined domains in the 2D numerical model according to Carlino et al. , (2014) and Della Seta et al. , (2015). b) Temperature vs. depth results from Ischia deep wells. A comparison with the output of performed simulation is here proposed.