Fig. 4

Seismic sections from 45 stations of the network 3A. The sections for the three components of the ground motion are obtained ordering the local events, in the magnitude range 2.5–3.0 recorded by the 45 stations, by the epicentral-station distance. For each section a total number of 1253 events has been considered. Due to this large number, we stacked the normalized waveforms falling in windows of 50 m of distance from the epicenter.