Methods for Determining the Most Dangerous Seismic Areas

For the purposes of this study, we analyzed regional seismicity distributed near the epicenters of numerous major earthquakes that occurred in various regions of the world. In particular, the analysis of clusters near strong earthquakes shows that, prior to major events, seismic activity follows specific spatial patterns, with a hi frequency of strong earthquakes near seismic clusters and along the connecting zones between them. In addition to seismic clusters, other patterns were analyzed, such as pre-seismic quiescence in the epicentral area, and various patterns (doughnut-shaped, arc-shaped, arrow-shaped, and epicenter alignments), foreshocks, and seismic belts. The models described show that approximately 98% of the 218 strong earthquakes occur in areas of higher density where seismic belts consist of segments connecting two consecutive epicenters or alignments of three or more epicenters. This represents a statistical feature in the distribution of earthquakes; when correlated with the phenomenon of their local clustering, it allows us to guide the interpretation of epicentral distributions and to assess the significance of alignments along different directions. Therefore, the analysis of the spatio-temporal distribution of clusters and earthquakes using our retrospective models has enabled a better identification of the most hazardous areas where the occurrence of a strong event is most likely.