Operational earthquake forecasting comprises procedures for gathering and disseminating authoritative information about the time dependence of seismic hazards to help communities prepare for potentially destructive earthquakes. Seismic hazards are known to change with time, in part because earthquakes release energy and suddenly alter the conditions within fault systems that will lead to future earthquakes. Statistical and physical models of earthquake interactions have begun to capture many features of natural seismicity, such as aftershock triggering and the clustering of seismic sequences. These models can be used to estimate future earthquake probabilities conditional on a region's earthquake history.At the present time, earthquake probabilities derived from validated models are too low for precise short-term predictions of when and where big quakes will strike; consequently, no schemes for "deterministic" earthquake prediction have been qualified for operational purposes. However, the methods of probabilistic earthquake forecasting are improving in reliability and skill, and they can provide time-dependent hazard information potentially useful in reducing earthquake losses and enhancing community preparedness and resilience.This report summarizes the current capabilities of probabilistic earthquake forecasting in Italy and elsewhere. It offers recommendations about how to validate and improve operational forecasting procedures and how to increase their utility in civil protection. A. Charge to the CommissionThe International Commission on Earthquake Forecasting for Civil Protection ("the Commission" or ICEF) was authorized by Article 6 of Ordinanza del Presidente del Consiglio dei Ministri no. 3757, issued on 21 April 2009. The Commission was appointed by Dr. Guido Bertolaso, head of the Dipartimento della Protezione Civile (DPC), with the following statement of charge:1. Report on the current state of knowledge of short-term prediction and forecasting of tectonic earthquakes.

No abstract

Summary We investigated precursory seismicity in and around the epicentral zone of the Mw= 7.4 1999 August 17 Izmit (Turkey) earthquake, by applying a statistical method—the RTL (Region–Time–Length) algorithm—to earthquake catalogues derived from that for the period 1981–1999 of Kandilli Observatory and Earthquake Research Institute (KOERI). The derived catalogues are complete for events MD≥ 3 in most of western Turkey. After declustering aftershocks, we investigated the seismicity patterns preceding the Izmit event at local (Izmit tectonic zone) and national (Turkey) scales. The RTL parameter indicates that a period of seismic quiescence started at the end of 1995 and reached a minimum in December 1996. An activation phase lasting about three months followed. The main shock in Izmit and vicinity did not occur when the seismicity returned to its background level, but occurred with a delay of nearly 2.5 yr. We present a new parameter to quantify the spatial distribution of seismic quiescence. The results from both catalogues indicate that a significant quiescence anomaly appeared in 1996 around the epicenter of the Izmit earthquake. The primary characteristics of the seismicity patterns prior to the Izmit earthquake are similar to those obtained for large events in Russia and Japan. The variations of seismicity patterns revealed by the RTL algorithm may offer better understanding of the physical nature of seismo‐tectonics and provide useful information for seismic hazard estimation. The varying characteristics of the Izmit and other events may reflect the difference between seismo‐tectonics in Turkey and in other regions such as Russia and Japan.

No abstract

Abstract. Many factors complicate earthquake sequences, including the heterogeneity and self-similarity of the geological medium, the hierarchical structure of faults and stresses, and small-scale variations in the stresses from different sources. A seismic process is a type of nonlinear dissipative system demonstrating opposing trends towards order and chaos. Transitions from equilibrium to unstable equilibrium and local dynamic instability appear when there is an inflow of energy; reverse transitions appear when energy is dissipating. Several metastable areas of a different scale exist in the seismically active region before an earthquake. Some earthquakes are preceded by precursory phenomena of a different scale in space and time. These include long-term activation, seismic quiescence, foreshocks in the broad and narrow sense, hidden periodical vibrations, effects of the synchronization of seismic activity, and others. Such phenomena indicate that the dynamic system of lithosphere is moving to a new state -catastrophe. A number of examples of medium-term and short-term precursors is shown in this paper. However, no precursors identified to date are clear and unambiguous: the percentage of missed targets and false alarms is high. The weak fluctuations from outer and internal sources play a great role on the eve of an earthquake and the occurrence time of the future event depends on the collective behavior of triggers. The main task is to improve the methods of metastable zone detection and probabilistic forecasting.