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\u2019Aquila (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

Stabilizing intermediate-term medium-range earthquake predictions

A new scheme for the application of the intermediate- term medium-range earthquake prediction algorithm M8 is proposed. The scheme accounts for the natural distribution of seismic activity, eliminates the subjectivity in the positioning of the areas of investiga- tion and provides additional stability of the predictions with respect to the original variant. According to the retroactive testing in Italy and adjacent regions, this improvement is achieved without any significant change of the alarm volume in comparison with the results published so far

Earthquake recurrence and seismic hazard assessment: a comparative analysis over the Italian territory.

Rigorous and objective testing of seismic hazard assessments against real seismic activity are a necessary precondition for any responsible seismic risk assessment. The reference hazard maps for the Italian seismic code, obtained with the classical probabilistic approach (PSHA) and the alternative ground shaking maps based on the neo\uaddeterministic approach (NDSHA) are cross-\uad compared and tested against the\ua0real seismicity for\ua0the territory\ua0of\ua0Italy. NDSHA is\ua0a\ua0methodology\ua0that allows\ua0for\ua0the\ua0sound definition of\ua0credible\ua0scenario events, based on the realistic physical modelling of ground motion from a wide set of possible earthquakes. The flexibility of NDSHA permits to account for earthquake recurrence and allows for the generation of ground motion maps at specified return periods that permits a straightforward comparison between the NDSHA and the\ua0PSHA maps

Intermediate-term prediction of earthquakes in Italy: algorithm M8

Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal