GNGTS 2015 - Atti del 34° Convegno Nazionale

or trapping of SH-waves, while the dip in terms of a shallow shear-wave velocity inversion, i.e. the same that in Favignana due to the interface between the stiff grainstones and the plastic clays. The shift of the stratigraphic response to higher frequencies at Cala Rossa Bay when compared to Anchor Bay could be related to the different thickness or depth of the clayey deposits. Based on estimated shear-wave velocities and thicknesses, the peak observed in the HVSR curves is compatible with the stratigraphy of Cala Rossa Bay. However, further in-site characterization will be surveyed for future analyses. The HVSR peak generally is visible on the unstable blocks and this could be related to the weakening of the clays in the landslide zone that is responsible for an increasing of the local impedance contrast with the underlying bedrock. Fig. 3 – Comparison between amplitude spectrum and HVSR results for the A3 station in Cala Rossa Bay (on left) and the station 11 in Anchor Bay (on right). GNGTS 2015 S essione 3.2 61