Nowaday urbanization. White curves represent the Tiber valley with its tributary lateral velleys, both form the Holocene hydrographic network of the city. Black curve represents the Aurelian Walls (275 AD) where the historical center is located. White rectangle represents the area where ground shaking has been modeled. White square in the upper part of the rectangle indicates the place where the 3D permanent array of seismic stations is installed, near the S. Paolo Cathedral (red square) in the southern part of the city.

(Upper panel) Epicentres (small circles) of the April 2009 seismic sequence in central Apennine. The main shock (shown by the small white circle) is about 100 km far from Rome, its focal mechanism is from Herrmann and Malagnini [2009]. (Middle panel) Map of the study area of Rome where seismological stations (red circles) are installed since 2008. (Lower panel) Cross-section of the Tiber valley where a 72-m deep borehole station (BRH) is operating since 2008. Records of VSC, GRB, and BRH are analyzed in this study.

Stratigraphy of the site under study (white rectangle) made by three layers: topography, recent alluvium and gravel.

Using ArcGis (http://www.esriitalia.it/) we have digitized and linked together the three lithologies of the previous figure in order to get a georeferenced site ready for being put on the computetional grid

Top panel: synthetic seismogram of the W-E component at the array site in the Tiber valley (white square in the bottom panel). Bottom panel: snapshot of the velocity field on the free surface of the area under study. The borders of the Tiber valley are represented by the yellow curves. Colours represent the normalized amplitude of the velocity field as indicated by the vertical colorbar on the right.