E' possibile osservare online il funzionamento di un prototipo di sistema di early warning sismico che implementa metodi sviluppati anche in ambito ReLUIS. Il link è questo (password: 'ergoii'). Per i dettagli sul sistema si veda qui.
The EaRly warninG demo (ERGO II) was developed to test the potential of Perfoemance-BAsed Earthquake Early Warning (PBEEW). ERGO II processes in real-time the accelerometric data provided by a sub-net (6 stations) of ISNet and is it installed in the main building of the school of engineering of the University of Naples Federico II, in Naples, which is the target site of the EEW. It is able to perform structural response analysis prediction before the earthquake reaches the building in the case of potentially dangerous events occurring in the southern Appennines region.
ERGO II is composed of the following four panels (figure below).
• 1. Real-time monitoring and event detection: In this panel two kind of data are given: (a) the real-time accelerometric signals of the stations, shown on a two minutes time window; and (b) the portion of signal that, based on signal-to-noise ratio, determined the last trigger (i.e., event detection) of a specific station (on the left). Because it may be the case that local noise (e.g., traffic) determines a station to trigger, the system declares an event (M larger than 3) only if at least three station trigger within the same two seconds time interval.
• 2. Estimation of earthquake parameters: This panel activates when an event is declared. If this condition occurs, the magnitude and location are estimated in real-time as a function of evolving information from the first panel. Moreover, on a map where also the stations are located, it is shown the estimated epicenter and the available lead-time .
• 3. Local seismic sensors: This panel shows signals recorded at the base of the building at four depths (0m; -7m; -15m; -30m). These sensors are not part of the EEW systems, yet they are indended as a benchmarck for the recorded ground motion a the building site with respect to what predicted by the EEWs.
• 4. RTPSHA and PBEEW: This panel performs RTPSHA for the site where the system is installed based on information on magnitude and distance from panel 2. In particular, it computes and shows real-time evolving PDFs of Peak Ground Accelration (PGA) at the site. This panel also computes predicted structural response in terms of: peak floor acceleration (PFA), Peak Floor Displacement (PFD), and peak Interstory Drift (ID) for three floors of the building.