Earthquake Early Warning Systems, P. Gasparini et al. editors, Springer, 2007
Iunio Iervolino, Vincenzo Convertito, Massimiliano Giorgio, Gaetano Manfredi and Aldo Zollo
Earthquake Early Warning Systems (EEWS), based on real-time prediction of ground motion or structural response measures, may play a role in reducing vulnerability and/or exposition of buildings and lifelines. In fact, recently seismologists developed efficient methods for real-time estimation of event’s magnitude and location based on limited information of the P-waves; therefore, when an event is occurring, estimates of magnitude and source-to-site distance are available, and the prediction of the structural demand at the site may be performed by Probabilistic Seismic Hazard Analysis (PSHA) and then by Probabilistic Seismic Demand Analysis (PSDA) conditioned to the EEWS measures. Such of an approach contains higher level of information with respect to the traditional seismic risk analysis and may be used for real-time risk management. However, this kind of prediction is performed in very uncertain conditions which may affect the effectiveness of the system and therefore have to be taken into proper account. In the present study the performance of the EWWS under development in the Campanian region (southern Italy) is assessed by simulation. The earthquake localization is formulated in a Voronoi cells approach, while the magnitude estimation refers to a Bayesian method. Simulation has an empirical basis but do not require any recorded signals. Results, in terms of hazard analysis and false/missed alarm probabilities, lead to conclude that the PSHA conditioned to the EEWS improves significantly the seismic risk prediction at the site and it is close to the one can produce if magnitude and distance would be deterministically known.