Site response estimation and ground motion spectrum scenario in the Catania area

A realistic definition of seismic input for the Catania area is obtained us ing advanced modeling techniques that allow us the computation of synthetic seismograms, containing body and surface waves. With the modal summation t echnique, extended to laterally heterogeneous anelastic structural models, we create a database of synthetic signals which can be used for the study o f the local response in a set of selected sites located within the Catania area. We propose a ground shaking scenario corresponding to a source spectr um of an earthquake that mimics the destructive event that occurred on 11 J anuary 1693. Making use of the simplified geotechnical map for the Catania area, we produce maps which illustrate the spatial variability of the SH wa veforms over the entire area. Using the detailed geological and geotechnica l information along a selected cross section, we study the site response to the SH and P-SV motion in a very realistic case, adopting and comparing di fferent estimation techniques.