Аннотация:We describe the characteristics of crustal wave propagation in eastern Sicily by using the background seismicity of the area. We follow the approach de- scribed by Malagnini, Hermann, and Di Bona (2000) and Malagnini et al. (2002). Our data set consists of 106 earthquakes recorded by nine three-component digital seismic stations between 1994 and 2001. We used only crustal events (depths shal- lower than 25 km), with local magnitudes ranging from 1.0 to 4.3, and hypocentral distances from 10 to 130 km. Peak ground velocities from 1311 narrow bandpass-filtered waveforms are mea- sured in thefrequency range 1.0-16.0 Hz,and regressedtodefinecrustalpropagation, excitation, and site characteristics, with respect to a reference station. A subsequent modeling effort is carried out, through the use of random vibration theory (RVT), for obtaining a quantitative evaluation of the apparent geometrical spreading g(r), and of the crustal quality factor Q(f). An attenuation parameter, j0, is also evaluated relative to a reference rock site. The attenuation and source parameters estimated in this study are used through the RVT in order to predict the peak horizontal ground acceleration (PGA), and the 5% damping pseudoacceleration spectra (PSA).
