Probability map of the next M ≥ 5.5 earthquakes in Italy

Abstract

[1] The main goal of this work is to provide a probability map for the next moderate to large earthquakes (M ! 5.5) in Italy. For this purpose we apply a new nonparametric multivariate model to characterize the spatiotemporal distribution of earthquakes. The method is able to account for tectonics/physics parameters that can potentially influence the spatiotemporal variability and tests their relative importance; moreover, it allows straightforward testing of a variety of hypothesis, such as Seismic Gap, Cluster, and Poisson hypothesis. The method has been applied to Italian seismicity of the last four centuries for earthquakes with M ! 5.5. Italy has been divided into 61 irregular zones representing areas with homogeneous tectonic regime resulting from active stress data. Besides the magnitude and the time of the earthquakes, the model includes information on the tectonic stress regime, the homogeneity of its orientation, the number of active faults, the dimension of the area and the homogeneity of the topography. The time distribution of the M ! 5.5 earthquakes appears clustered in time for a few years after an event, and then the distribution becomes similar to a memoryless Poisson process, leading to a time-dependent probability map. This map shows that the most likely regions where the next moderate to large earthquakes may occur are Friuli, UmbriaMarche, and part of Southern Apennines and the Calabrian arc.

Statistical analysis of the Central-Europe seismicity

“…Remarkably, a similar result has been found in previous studies on large time and magnitude scale by Kagan (1991); Kagan and Jackson (1991);Kagan and Jackson (2000); Cinti et al (2004) and Faenza et al, (submitted). Therefore, it seems that the clustering is a scale independent aspect with respect to the magnitude of the events (from low-medium to large) and spatial domain (for a regional to a global scale).…”

“…The application of this methodology to the Italian seismicity (Faenza et al, 2003;Cinti et al, 2004) and to the global (Faenza et al,in press) displays clustering behaviour for large events. In spite of the first order similarity with the time behaviour of aftershock sequences, described by the ETAS model (Ogata, 1988), it was found the empirical data show a longer clustering time that the ETAS activity .…”

Attenuation, source parameters and site effects in the Irpinia–Basilicata region (southern Apennines, Italy)

“…Today, seismicity is mainly concentrated within or close to the fault system associated with the 1980 IrpiniaBasilicata earthquake and several moderate-size events occurred in recent years, such as the 1990 and 1991 Potenza earthquakes (M 5.4 and 5.1, within the deeper strike-slip zone) and the 1996 event (M 4.9). This recent seismic activity provides clear indications that the Irpinia-Basilicata region still represents a region of high seismic risk, now and in the future (Cinti et al, 2004).…”

A prototype system for earthquake early-warning and alert management in southern Italy

“…Similarly, Cinti et al (2004) have provided a probability map of M > 5.5 earthquakes predicted over the next 10 years in Italy, and they indicate that the Campania-Lucania sector of the southern Apennines has one of the highest probabilities of occurrence.…”