Optimizing the automatic location of the real-time Antelope® system in north-eastern Italy

North-eastern Italy is one of the most seismically active areas of Italy, being affected in the past by eight destructive earthquakes. This area is densely populated and heavily industrialized, hence its seismic monitoring is crucial for Civil Defense purposes. This task is managed by the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), through its Centro Ricerche Sismologiche (CRS), that performs the automatic real-time locations through the Antelope® BRTT software package. An accurate choice of the Antelope® setting parameters is necessary to ensure the best performance of the real-time system, that means the most accurate location for the earthquakes with magnitude ML≥2.5 (the alarm threshold), avoiding any false event. This goal was pursued by testing different parameters on a data set built with 295 earthquakes representative of the local seismicity. The tuned parameters were then validated on the earthquakes which occurred in the monitored area in 2011: all events with ML≥2.5 were correctly detected and located with a median epicentral distance difference of 2 km with respect to the OGS catalogue. The OGS real-time system was tuned with these parameters that have been operating successfully since 2012.