A microtremor survey to define the subsoil structure in a mud volcanoes area: the case study of Salinelle (Mt Etna, Italy)

A microtremor survey aiming to obtain information on subsoil structure, was performed in the lower Southwestern Etnean flank (Sicily, Italy). The area is characterized by emissions of muddy and salty water which create specific pseudo-volcanic edifices. Recording sites were both randomly selected in the area and along two profiles. Horizontal to vertical noise spectral ratio, polarization and surface wave prospecting techniques were used. The spectral ratios results set into evidence different frequency ranges that appear interesting to infer information on the subsoil structure. The depth of the hydrocarbon reservoir was inferred through 1D modelling, by using the information coming from literature and experimental surveys. Moreover, a strongly directional effect, suggests the existence of a NNW-SSE oriented mud feeding dike.