Time-clustering of natural hazards

Natural hazards can be represented as point processes that are characterized by the occurrence times of the events and their intensities. It is crucial to investigate the correlation properties of these processes in order to gain a deep knowledge of the dynamical mechanisms which underlie hazardous phenomena. To this end, suitable methodologies must be developed to perform these correlation analyses on processes, which are described as point-like processes. The concept of time-clustering implies a time-structured organization of these processes, and is in direct opposition to the pure randomness typical of Poissonian processes in which the events are uncorrelated. This article reports several examples of natural hazards within the framework of time-clustering.