Exploratory seismic site response surveys in a complex geologic area: a case study from Mt. Etna volcano (southern Italy)

摘要: A preliminary study targeting to evaluate the local seismic response was performed in eastern flank of Mt. Etna (southern Italy) using ambient noise measurements. The obtained spectral ratios were subdivided through cluster analysis into different classes fundamental frequency permitting draw an iso-frequency contour map. set evidence extreme heterogeneity lava sequences, which makes difficult identify a single bedrock formation. Another important outcome, concerning effects terms and azimuth, is role played by fracture fields associated with main structural systems area. existence two zones strong directional striking WNW–ESE NW–SE, nearly orthogonal orientation fields, corroborate such hypothesis.