Three dimensional magnetotelluric modelling of Vulcano Island (Eolie,
Italy) and its implications for understanding recent volcanic unrest
Abstract
Resistivity imaging obtained by a short period magnetotelluric survey
identified the electrical resistivity patterns below Vulcano Island to a
depth of 2 km below sea level. In the 3D resistivity model, clear
contrasts generally characterized the caldera faults, whereas volcanic
edifices, craters, volcanic conduits, and/or eruptive fissures
corresponded to superficially high resistivity anomalies. Among the most
prominent detected structures, a resistive anomaly located below La
Fossa crater, which extends 2 km below the surface, likely represents a
“conduit” structure, along which magmatic fluids preferably ascend.
Other resistivity anomalies, mainly aligned in the N‒S direction,
characterized the island sector where considerable amounts of deep
subsurface fluids accumulate and mix with the ascending magmas related
to the most recent volcanic dynamics. The interpretation of the main
features reconstructed through the magnetotelluric investigation
significantly contributes to understanding the current unrest at
Vulcano.