Modello di velocità 1D e distribuzione della microsismicità nell’area dei Monti Tiburtini-Prenestini e Simbruini (Appennino centrale).

Abstract

We analyzed the seismicity of the Tiburtini, Prenestini and Simbruini Mountains region, whose seismic importance is related with the nearness to the town of Rome. It has been carried out an analysis of the seismicity of the region using the data recorded by the permanent stations belonging to the Italian National Seismic Network (RSNC) from 2000, and subsequently integrated with data of local seismic network from 2003 to 2007. The increase of the number of stations in the last years allow us to obtain better quality earthquake localization as before done. We have produced a large database of re-picked events collecting arrival times of P and S waves of local earthquakes with magnitude larger than 2.0, belonging to the 2000-2007 period. We computed an average Vp/Vs ratio using a modified Wadati method (Chatelain, 1978) obtaining a value of 1.85. To better constrain the hypocentral depths we performed an analysis to find the best P-wave one-dimensional (1D) velocity model for the crustal seismic structure of the study area, using the VELEST algorithm (Kissling et al., 1995).