Earthquake Early warning Strategies for on-site and network based systems

The main topic of this analysis is the development and testing of possible strategies to seismic risk mitigation through the declaration of alert massage, ongoing of earthquake, before that the strong sacking occur. With this aim, a single and multi-stations approach are investigated performing statistical test to proof the rapidity and reliability of alert. The first step of this study is explained in the chapter 1, where an on-site EEWS approach, called SAVE system, is implemented and tested. The system is a basic on-site single-station approach able to quickly characterize the earthquake in term of local intensity, magnitude and distance classification. The estimates provided by the system are affected by rather large uncertainties but the methodology is rapid, so to allow for an effective activation of automatic procedures for risk mitigation, also at the target sites very close to the source. The low computational cost of this algorithm makes it suitable for embedded solutions in a standalone seismic station, and a prototype was developed and described in the final chapter. In chapter 2, a refined and more accurate on-site system is proposed. Unlike the SAVE methodology, this P-wave based approach is aimed at providing a reliable overcoming prediction of the critical intensity level at recording site. The use of advanced data processing techniques, jointed with a multi-parameter approach, provides a more reliable prediction of maximum local intensity expected at site. This approach is useful for the rapid and strictly constrained local intensity prediction. Chapter 3 finally describes an integrated methodology aimed to interpolate the information obtained from the individual stations and map the potential damage zone (PDZ) in real time. Further details on this methodology, called Quake-up, are discussed in the same Chapter. In chapter 4, technical details about the project development of seismic station, called MOMA, and improvement of the spectral response of on-board geophone were provided