Seismic Activations in Italy in the 15th–21st Centuries, from Historical Data

Abstract

The article is an attempt to trace the seismic regime (temporal recurrence and grouping of strong earthquakes) in the central and southern Apennines during the historical period, beginning from the 13th century. The special attention is paid to consideration of seismic events of 2009–2017 in Italy in the context of the spatiotemporal regularities of the regional strong seismicity in the past. The analysis of data on historical and modern seismic catalogs enabled to identify eight seismic activations within the central and southern Apennines since the 15th century. These are both general activations, covering the central and southern Apennines, and those that occurred only within the central or predominantly southern Apennines. The identified activations included from three to seven strong earthquakes and continued from 3 to 20 (?) years. The last activation of 1997–2017 is characterized by concentration of seismic events (with no extreme values of magnitudes and intensity) only in the central Apennines and by considerable duration. The role of historical sources (in this case, the Saint Petersburg Vedomosti newspaper) in reconstructing a more complete timeline of past seismicity is emphasized.