Attenuation parameters for Friuli region from strong-motion accelerogram spectra

Abstract By using the accelerometric data obtained during the heaviest earthquakes that occurred in Friuli in 1976, an attempt was made to obtain a law of attenuation in the northeastern Po river area as dependence on the frequency. The study was carried out by comparison of power spectra of entire accelerograms at different distances. In the frequency range of 0.1 to 10 Hz, a Q value was found which was proportionally dependent on the frequency as f n , with n = 1.1. This result can be considered valid for that region and for distances of up to about 200 km from the epicentral area.