The 1783 Calabrian earthquake - 1

Among the longest and disruptive seismic events occurring in Italy, there was the sequence of earthquakes that in 1783 hit Calabria and north-east Sicily. Its main features were the displacement of epicenters from Messina towards the North-North-East direction and a very shallow focal zone. Thus many physical changes were clearly visible on the Earth’s surface, ranging from large block collapses to massive landslides and wide crack openings (fig. 1). With reference to the Fra Ramondo and Covalo area, the geologist Charles Lyell wrote: “A small valley, containing a beautiful olive-grove, called Fra Ramondo, underwent a most extraordinary revolution.
Innumerable fissures first traversed the river-plain in all directions, and absorbed the water until the argillaeous substratum became soaked, and a great part of it was reduced to a state of fluid paste. Strange alterations in the outline of the ground were the consequence, as the soil to a great depth was easily moulded into any form. In addition to this change, the ruins of the neighbouring hills were precipitated into the hollow; and while many olives were uprooted, others remained growing on the fallen masses and inclined at various angles. The small river Caridi was entirely concealed for many days; and when at length it reappeared, it had shaped for itself an entirely new channel” (C. Lyell, 1830, p. 425).
The wide range of effects produced by the seismic sequence attracted many Italian and European scholars, interested in studying the event in detail and understanding the underlying phenomenology. Among them there were Giovanni Vivenzio, Déodat de Dolomieu and William D. Hamilton.
For the first time, a seismological commission led by Michele Sarconi was set up in Naples by the Reale Accademia delle Scienze e Belle Lettere, appointed by the Bourbon government to carry out systematic investigations of earthquake’s effects and estimate the damage producted. Interestingly, Sarconi’s final report (fig. 2) is accompanied by an atlas of pictures, drawn by the architects Pompeo Schiantarelli and Ignazio Stile. This exceptional document testifies the disruptive power of an earthquake that forever changed the environment and the characteristics of those regions.

___Salvatore Esposito & Adele Naddeo