Fluid migration along the active submarine hydrothermal system of Panarea: preliminary results from passive hydroacoustic and geodetic data

Stromboli and Panarea Islands are located in the eastern sector of the Aeolian Arc, a geologically active region where deep subduction processes, crustal tectonic activity and volcanism coexist. A set of recent studies have demonstrated a consistent temporal correlation between seismic tremor variations within the Panarea hydrothermal system and soil degassing rates measured close to the Stromboli’s summit area. These findings would suggest a shared magmatic source and fluid migration along a common tectonic structure. However, the temporal and physical relationships between changes in the Panarea hydrothermal system, soil degassing rates at the Stromboli summit area, and transient ground deformation recorded by GNSS remain poorly constrained. To further investigate these complex dynamics, we propose a multidisciplinary approach that combines passive hydroacoustic and geodetic monitoring to explore the dynamics of fluid ascent. The Panarea Volcanic complex, characterised by one of the most active hydrothermal fields in the Mediterranean Sea, represents an ideal site to evaluate the potential of integrating these techniques. By analysing the multiparametric time series recorded between 2016 and 2018, we focus on specific time windows characterised by intensified submarine hydrothermal venting at Panarea. Specifically, this preliminary analysis compares the high-frequency bands (100-2000 Hz) of sound associated to bubbles’ plume, recorded by a hydrophone deployed permanently within the so-called “Black Point” hydrothermal spring area and related to gas flow rate, with transient ground deformation captured by the nearby GNSS stations (CPAN, IPAN). The result of this preliminary analysis allows us to identify and quantitatively estimate analogous trends, detecting both synchronous variations and time-lagged signals across the datasets. This work provides new insights into the local cause-effect relationship between hydrothermal fluid migration and crustal deformation. Furthermore, it highlights the potential of an integrated methodological approach to better understand the role of fluids and their interaction with local tectonic structures in complex volcanic settings.