Site features responsible for uneven seismic effects in the historical centre of Melfi (Basilicata, Southern Italy)

The study deals with a multi-disciplinary set of tools aimed to identify the factors controlling the seismic effects caused by an earthquake of the past in a historical town. To this end we illustrate a case study based on the analysis of the damage caused by the 1930 Irpinia earthquake (Me=6.7) in a town of Southern Italy. To understand the anomalies of damage, we used an integrated approach that combines geological and geophysical surveys with the analysis of archive sources. Geological surveys were integrated by geo-electrical prospecting and drillings. Moreover, the influence of the soil profile on Peak Ground Acceleration and Housner Intensity was investigated by 1D numerical modelling and the earthquake slope response to seismic shaking was characterised by the azimuthal variation of Noise Standard Spectral Ratio. Finally, a combination among all these data allowed to create a complete picture of the possible causes of uneven damage.