Engineering Earthquake Early Warning via Regional Networks

Significant investments are undergoing internationally to develop earthquake early warning (EEW) systems. So far, reasonably, the most of the research in this field was driven by seismologists as the issues to determine essential feasibility of EEW were mainly related to the earthquake source. Many of them have been brilliantly solved, and the principles of this discipline are collected in the so-called real-time seismology. On the other hand, operating EEW systems rely on general-purpose intensity measures as proxies for the impending ground motion potential and suitable for population alert. In fact, to date, comparatively little attention was given to EEW by earthquake engineering, and design approaches for structure-specific EEW are mostly lacking. Applications to site-specific systems have not been extensively investigated and EEW convenience is not yet proven except a few pioneering cases, although the topic is certainly worthwhile. For example, in structure-specific EEW the determination of appropriate alarm thresholds is important when the false alarm may induce significant losses; similarly, economic appeal with respect to other risk mitigation strategies, as seismic upgrade, should be assessed. In the paper the least issues to be faced in the design of engineering applications of EEW are reviewed and some work done in this direction is discussed. The review presented intends to summarize the work of the author and co-workers in this field illustrating a possible performance-based approach for the design of structure-specific applications of EEW.