Operational earthquake forecast/prediction

The operational and decision-making problems related to earthquake forecast/prediction and seismic hazard assessment are nowadays a matter of significant debate, particularly on account of the very unsatisfactory global performance of Probabilistic Seismic Hazard Assessment at the occurence of most of the recent destructive earthquakes. While it is recognized that opera- tional tools must demonstrate their capability in anticipating large earthquakes and the related ground shaking by rigor- ous verification and validation process, only few methods proved effective so far. In view of the inherent uncertainties in predicting predictable, the usefulness of any forecast/ prediction method can then be judged taking into account the wide range of possible mitigation actions of different levels (from increased preparedness to evacuation). This paper aims to open a debate and complement the Summary and Recommendations by the International Commission on Earthquake Forecasting, established after the earthquake in L’Aquila (M = 6.3, 6 April 2009). The issues related with the definition, validation, and possible use of forecasting/ prediction methodologies, are addressed with special emphasis on existing operational practice in Italy.