Valutazione della performance dilocalizzazione della RSNC-INGVtramite simulazione numerica

A properly organized seismic network is a valuable tool formonitoring seismic zones and seismic risk assessment. This paperproposes a method for evaluating the performance in hypocenter location of a seismic network by numerical simulation(SNES, SeismicNetwork Evaluation through Simulation). The SNESmethod needs as input: the location of the stationsthat make the network and their noisiness, the velocity model used in the location routine and a law that allows to estimate thevariance in the time residuals. This method gives, as function of magnitude, hypocentral depth and confidence level, the spatialdistribution of: number of active stations in the location procedure and relative azimuthal gaps and confidence intervals inhypocentral parameters regarding both the geometry of the seismic network and the use of an inadequate velocity model.In recent years, the RSNC-INGV (Rete Sismica Nazionale Centralizzata dell’Istituto Nazionale di Geofisica e Vulcanologia,Italy) has been greatly increased. In fact, since 2009 it receive signals from 305 seismic stations with 258 wideband threecomponentsensors. Following the description of the SNES method and of the algorithms used, the results of its application toRSNC-INGV will be given.This application has allowed to indentify the noisiness of the RSNC-INGV and to evaluate the goodness of the velocity modelused it the location routine. Furthermore, the SNES method has allowed to quantify the location performance of the RSNCINGVand to identify some seismogenic areas on the national territory that are currently not enough covered. The upgradingof the network in these areas could be optimized using the SNES technique.