GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 1.2 GNGTS 2023 The reconstructed 3D model provides an image of a single vertical geothermal system fed by deep fluids forming a gas plume feeding the Solfatara and Pisciarelli fumarole fields. This plume of gas in the upper part of the S-PHS rises to the surface, mainly along the external eastern flank of Solfatara Volcano. These developed mainly along faults breaking hydrothermally altered layer, about 300-500 m thick, that serves as a cap for the S-PHS in correspondence mainly with the Solfatara crater. Sections and maps extracted by the model highlight the presence of sharp resistivity contrasts that can be correlated to volcano-tectonic features that interest both shallow and deep sectors of the investigated subsurface. Faults and fractures recognized in the field correspond well with resistivity discontinuity. Earthquake hypocenters have occurred in the area since 2000 compared with the resistivity anomaly, and structural features provide a helpful indication of the relationship between fluid circulation mechanism and volcanic structures. The current MT imaging indicates the central role of the S-PHS system in the actual evolution of the caldera unrest. References Di Giuseppe, M.G., Troiano, A., Carlino, S., 2017. Magnetotelluric imaging of the resurgent caldera on the island of Ischia (southern Italy): inferences for its structure and activity. Bulletin of Volcanology 79, 85. https://doi.org/10.1007/s00445-017-1170-4 Di Giuseppe, M.G., Troiano, A., Fedele, A., Caputo, T., Patella, D., Troise, C., De Natale, G., 2015. Electrical resistivity tomography imaging of the near-surface structure of the Solfatara crater, Campi Flegrei (Naples, Italy). Bulletin of Volcanology 77. https://doi.org/10.1007/s00445-015-0910-6 Isaia, R., Di Giuseppe, M.G., Natale, J., D’Assisi Tramparulo, F., Troiano, A., Vitale, S., 2021. Volcano‐tectonic setting of the Pisciarelli Fumarole Field, Campi Flegrei caldera, southern Italy: insights into fluid circulation patterns and hazard scenarios. Tectonics. https://doi.org/10.1029/2020tc006227 Isaia, R., Di Giuseppe, M.G., Troiano, A., Avino, R., Caliro, S., Santi, A., Vitale, S., 2022. Structure and Present State of the Astroni Volcano in the Campi Flegrei Caldera in Italy Based on Multidisciplinary Investigations. Geochem Geophys Geosyst. https://doi.org/10.1029/2022GC010534 Isaia, R., Vitale, S., Di Giuseppe, M.G., Iannuzzi, E., Tramparulo, F.D.A., Troiano, A., 2015. Stratigraphy, structure, and volcano-tectonic evolution of Solfatara maar-diatreme (Campi Flegrei, Italy). Bulletin of the Geological Society of America 127, 1485–1504. https://doi.org/10.1130/B31183.1 Troiano, A., Di Giuseppe, M.G., Patella, D., Troise, C., De Natale, G., 2014. Electromagnetic outline of the Solfatara-Pisciarelli hydrothermal system, Campi Flegrei (Southern Italy). Journal of