GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 Fig. 1 - f0 results of the 88 HVNSR performed in the Trasacco municipality (modifed from Famiani et al. 2022). The trend of the results suggests a deepening of the Quaternary Fucino basin towards east and the presence of a horst structure included between Secton 1 and 2 in red dashed lines. Results of HVNSR for all the measurements highlighted spatal variaton of f0 along some transects (Fig. 1) which could also be represented in contour plots (Fig. 2) remarking similar trends of the interpreted seismic lines in Patruno and Scisciani (2021). In consideraton of the availability of seismic statons, sometmes it was possible to perform several simultaneous recordings: in these cases the noise surveys acted as seismic arrays. It was then possible also to retrieve the dispersion characteristcs of the surface waves, in this case using cross-correlaton (CC) and FK analyses. For some sites with nearby borehole log data availability, the HVNSR curves were inverted around the fundamental resonance (f0) using the aforementoned dispersion curves as constraints. This analysis allowed us to reconstruct some 1D shear wave velocity profles and interpret results in terms of subsoil setng of geological features. Finally, we performed a rotatonal analysis of HVNSR for some specifc transects of statons, highlightng localized polarizaton efects that we interpreted as due to the presence of the hidden fault in those positons. This interpretaton was supported by available seismic refecton profles for the area. This case study shows that the low- cost HVNSR technique is able to give preliminary indicatons of anomalous behaviors when crossing fault lines (Fig. 2). These results are important for planning specifc geophysical surveys, requested to validate the preliminary fndings. Therefore, our approach can support microzonaton studies, especially in urban areas where fault zones are involved, or in places designated for future developments.