GNGTS 2015 - Atti del 34° Convegno Nazionale

Although the seismic array was deployed not so far from the accelerometric station location, it lays on a different geological unit with respect this one, so an adjustment of the obtained seismo-stratigraphical profile (Tab. 2) was necessary, in order to better represent the subsoil beneath the accelerometric station. As the sole information in this last site is provided by HVSR curves, the best quality one of themwas chosen as representative of this place. After removed the shallowest layer, this adjustment involved changes in layer thickness and velocity values. These values were changed by hand, by using a surface-wave model (which is used in the inversion Fig. 1 – Inversion results for the accelerometric station of Peglio: blue lines represent the experimental data, red lines mark the best profile (the minimum misfit one), green line describe the profiles whose misfit is no higher than the double of the minimum one, black lines mark the variability range of the results and cyan line is the reference velocity of 800 m/s. Tab. 2 - Geological interpretation of the best-profile shallow strata obtained beneath the array position: for each layer, depth, thickness, S-wave velocity, type of material and corresponding geological formation are reported. depth (m) thickness (m) V S (m/s) lithology geological unit 2 2 116 debris MUSa 11 9 241 marl and clay marls (Colombacci) FCO 38 27 571 gypsum GES 70 32 952 marl FAM1c 144 74 995 sandstone and marl FAM1 152 GNGTS 2015 S essione 2.2