Relatore: Aldo Zollo, Professore ordinario DSF-UniNa (seminario presso IPGP - Institut de Physique du Globe de Paris)
Earthquake early warning systems (EEWS) are real-time monitoringinfrastructures that are able to provide rapid notification of thepotential damaging effects of an impending earthquake. The final aim is topredict the expected damage and losses at critical infrastructures, tens ofseconds before the occurrence of the strong ground shaking produced by theearthquake.
The operability and reliability of an EEWS thus depends on the fasttelemetry and processing of data from dense instrument arrays deployed inthe source region of the event of concern or surrounding the target site.For a regional EEWS, the relevant source parameters (event location andmagnitude) are estimated from the early portion of recorded signals in thenear-source region. They are used to predict, with a quantified confidence,a ground motion intensity measure at a distant site where a target structureof interest is located.
Recently, robust and effective algorithms for the real time and evolutionaryevent location have been developed to provide in few seconds the informationabout the hypocenter location. On the other hand the feasibility of areal-time earthquake magnitude determination using the information carriedout in the initial portion of recorded P- and S-signals is matter ofinvestigation and debate.
In this seminar we shall review the principles, methods and technologicaldevelopments related to the feasibility and implementation of a regionalearly warning system with a special focus on the seismic alert managementsystem under construction in Campania region, southern Italy. We shall describe a probabilistic, evolutionary approach for the real timelocation and magnitude estimation based on a general strategy, where thecomputation starts when few seconds of data from a small number of recordingstations are available, and the source parameters estimates along with theiruncertainties are progressively updated with time. The method testing andvalidation is illustrated through the analysis of and application toEuro-Mediterranean and Japanese earthquake records.