Environmental effects of the December 28, 1908, Southern Calabria-Messina (Southern Italy) earthquake

The review of all available contemporary documents, i.e., technical and photographic reports, newspapers, and other archive material, of the 1908, M 7.1, Messina-Reggio Calabria earthquake has allowed to recognize and classify a large number (365) of independent environmental effects of the earthquake and the subsequent tsunami. The effects have been categorized as slope movement, ground settlement, ground vertical movement and coastal retreat, liquefaction, ground crack, hydrological anomaly, gas emission, light, and rumble. No undisputable evidence of surface faulting has been pointed out. Nevertheless, the widespread and rather homogeneous subsidence of the coastal area of Messina (40-70 cm) might have been caused by slip along a NNE-SSW-trending, east-dipping fault, corresponding to the here proposed Messina Lineament. Likewise, slips along the Reggio Calabria, Armo and Motta San Giovanni faults, suggested by coastal subsidence and slides, ground cracks, and leveling data, cannot be ruled out. A large part of the achieved information has allowed to evaluate the epicentral intensity and local intensities at 74 sites, by applying the environmental seismic intensity scale ESI 2007. This study has led to the most comprehensive picture of the distribution and characteristics of coseismic environmental effects of that earthquake, a crucial knowledge to better estimate the future impact of a similar earthquake on a region that has seen a broad, and often poorly concerned, urban and infrastructural development since then.