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A new System for Earthquake Detection and Source Parameters Determination in Italy S. Mazza , F. Mele, M. Olivieri, S. Pintore, M. Quintiliani, L. Scognamiglio, & G. Selvaggi. Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy. The Italian Seismic Network.
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A new System for Earthquake Detection and Source Parameters Determination in ItalyS. Mazza, F. Mele, M. Olivieri, S. Pintore, M. Quintiliani, L. Scognamiglio, & G. Selvaggi Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy
The Italian Seismic Network • About 200 ingv digital station with different seismometers, digitizers and trasmission media • ~30 from other Italian organizations • ~30 from foreign countries • ~60 accelerometers SP analog BB (Gaia-INGV Nanometrics) VBB (MedNet)
The Italian Seismicity Last 3 years only (from the Italian Bulletin) • Irregular Country shape • Inhomogeneous station distribution
Goal • Upgrade to compare with a modern network • Overcome the limitations of the old concept • Realize a robust and versatile system It is just a part, although the most sensible of a complex system for data acquisition, processing, archiving and distribution
EarthWorm Very many requirements: • Reliable • Unmanned • Self controlled • Major failures notifications • Rapid • rapid automatic information to face INGV commitment with the Italian Civil Protection • about all eqs in Italy with Ml > 2.5 with 2-5-30 minutes rule • about all eqs in the EuroMediterranean region with Ml > 5.0
EarthWorm • Efficient • to minimize the false alarms • to match the detection capacity of the old system • Versatile • Fulfilling multiple requirements • Integrate local network at different levels • Open • Development • Formats • Well documented
OS and HW • Solaris10 Sun Sparc box. • Reliability and Robustness • Completeness of Earthworm packages • Open source development tools available • Two identical processing machines • A third machine for development and tests
EW modules developped or modified to fit our needs. nmxptool arcto3g ingv_report Interactive tools Open development
Tuning some modules: Picker pick_ew Binder binder_ew Many configuration files: procedures to automatically create configuration files using our pre-existent Database. Difficulties
Three main differences between the two systems being compared: EW is unmanned We have imposed that EW has at least 4 stations to start a location EW does not include ~40 analog sp stations Results
Results: missed events Number of events Ml
Number of events Distance (km) Results: Epicentral comparison Each circle center is the manually revised epicenter, while radius is the distance to EW result Number of events for each beam of epicentral distance
Results: EW-only events Triangles are earthquakes detected only by Earthworm, In red false events, true ones in green. Green triangles in the Ionian Sea are not representative
Conclusions Work is in progress, but first results are very satisfactory. A good group is slowly growing to “nurse” the system. Some major improvements are already in the air. We already have a “backup” system for the present, limping one.
Thanks Thanks to Alfonso Mandiello, Valentino Lauciani, Remo Moro, Carlo Marcocci, Paul Frieberg and ISTI people, Alberto Michelini.