The Integrated Seismic Monitoring System in Italy

In the past 5 years the Italian monitoring system, managed by the Istituto Nazionale di Geofisica e Vulcanologia (INGV) has been strongly improved, thanks to support from the National Dept. of Civil Protection (DPC). Basic goals of the network are the rapid evaluation of earthquake parameters and the acquisition of high quality data for seismological research on earthquake source and deep structure. Particular emphasis has been given to real- time data transmission, network robustness and redundancy, multisensor remote stations. Presently, data from more than 250 stations are received in real-time at the INGV acquisition system in Rome, mostly through satellite links (about 100) and terrestrial digital lines (about 100), while other data are received through radio links and Internet. Our stations are equipped with either commercial (mostly Nanometrics) or INGV- produced digitizers (GAIA2). MedNet data in Italy and EuroMed regions are also used for real time monitoring. MedNet data are shared in real-time with ORFEUS and IRIS, while data from the National Seismic network are presently distributed for triggered events a few minutes after an earthquake. Data latencies are mostly in the range 0-10 s, with the upper limit (constrained by satellite channel sharing) presently being reduced down to 3 s. Most of the stations are equipped with either Trillium 40s, 120s or 240s, or STS2 seismometers, coupled with Episensor accelerometers. In about 100 sites, continuous GPS's send stream data in real time to the INGV centres, at 1s or 30s sampling rate. Data from GPS receivers are available at http:ring.gm.ingv.it for a subset of the network. A few dense dial-up local networks in central Italy contribute to the monitoring system. Beside a centralized acquisition in Rome, data from wide regions covered by the network are transmitted in real time to other INGV centres (Grottaminarda, Catania) to guarantee redundancy and disaster recovery. In volcanic areas, such as Etna and Vesuvio, dense multiparametric networks are operated in real time from INGV centres in Napoli and Catania. Present targets of the national network, which is still under development, include off-shore monitoring through OBS development and connection, integration with strong motion national network, Shake Maps rapid computation (http:earthquake.rm.ingv.it/shakemap/shake/), early warning for targeted areas.