Reconstructing Hydrothermal Fluid Pathways and Storage at the Solfatara Crater (Campi Flegrei, Italy) Using Seismic Scattering and Absorption

Imaging of fluid pathways is crucial to characterize processes taking place in hydrothermal systems, a primary cause volcanic unrest and associated hazards. The joint imaging seismic absorption scattering an efficient instrument map flow at crustal scale, specifically volcanoes; however, this technique has so far been applied image volcanoes systems the kilometre scale. Here, we use data from meter-scale, active survey inside shallow structure Solfatara crater obtain first frequency-dependent near-surface model system. used monitor historic Campi Flegrei caldera (Italy), high-risk volcano under continuous surveillance due its closeness densely populated area. Improving part system broaden understanding that are progressively characterizing other portions eastern caldera. contrasts highlight structural feature, fault separating plume zones CO 2 saturation nearing fumaroles. While high-absorption anomalies mark high soil temperatures fluxes, low-absorption indicate very upflow caused by between liquid-rich vapour-rich fluids coming mud pools fumaroles, respectively. All maps show SW-NE trend consistent with fluid-migration towards results provide constraints clarify mechanisms migration crater. techniques offer complementary geophysical images interpretation prove attenuation measurements suitable heterogeneous media detailed