Imaging Near Surface Migration Paths of Volcanic Gases on Vulcano Island (Italy) with IP Tomography, 3D Thermal Mapping and Drone Photogrammetry

Abstract

The island of Vulcano (Aeolian Islands) is an active volcano north of Sicily, Italy. It is considered one of the most active volcanoes in the Mediterranean, has been marked by frequent eruptions and seismic activity in the past, and is closely monitored today. The Fossa crater on Vulcano Island houses a fumarole field that constantly emits volcanic gases. These emissions can be harmful to human health if inhaled in large amounts. The intensity of the fumarole field’s emissions fluctuates on a scale of hours to several years, indicating the level of volcanic activity and the current meteorological conditions. In combination with other indicators, the fumarolic activity can be used for the hazard risk assessment. Understanding migration and rock fluid interactions in volcanic terrain is therefore important for establishing reliable early warning systems and making informed decisions about alert levels. In June 2022, when the presented field campaign took place, Vulcano Island exhibited a phase of particularly strong volcanic activity. We utilized drone photogrammetry, high-resolution infrared thermal imaging and induced polarization (IP) tomography to study the fumarole field at the Fossa crater. The electrical resistivity and polarization data revealed significant contrasts in the shallow subsurface, reflecting the complex interactions between mineralization, water, and reactive gases. We present the results of the multimethod field survey, including the methodology and outcome of integrating high-resolution surface information with the 3D inversion results of the IP tomography.