Bouguer Anomaly of the Solfatara Hydrothermal Plume, Campi Flegrei

Solfatara tuff cone is the most hydrothermally active area within Campi Flegrei caldera, a resurgent nested caldera near Naples, Italy. Hydrothermal gases and fluids are released most vigorously here and at Pisciarelli nearby. Models explaining the measured fumarole emissions and deformation require a plume of ascending hot water vapour and CO2 from depth. Here we present preliminary findings from a new gravity survey which aims at i) creating a high precision Bouguer anomaly map of Solfatara and ii) imaging the hydrothermal plume. We carried out a high spatial density gravity survey of Solfatara and the surrounding area using a Scintrex CG5 gravimeter and simultaneous benchmark localisation using a GNSS system. We created a dense grid of 51 stations within Solfatara crater, and a reduced density network of 37 further stations outside the crater to 3km distance. Other geophysical techniques such as electromagnetism, electrical resistivity, and active seismic imaging have resolved the subsurface architecture to depths between a few hundred meters to 3km depth. Our coverage and spacing should capture the details of the plume under Solfatara and have resolution to approximately 3km depth.