The 1783 Calabrian earthquake - 3

Among the most impressive effects on the landscape of the eathquake-affected areas there were landslides, huge masses detachments from hills, collapses and liquefaction phenomana. Particularly devastating effects were observed near the Aspromonte and in the Gioia Tauro Plain: entire hills collapsed and filled the valleys, while the landslides blocked a large number of waterways giving rise to lakes. Giovanni Vivenzio reported on such phenomena and pointed out that about fifty lakes arose as a consequence of the seismic shocks. In the report of the seismological commission chaired by Michele Sarconi, some plains were described as covered with circular hollows, mainly with the typical size of carriage-wheels, with a concave or convex surface and filled with dry sand. Upon digging down, they were found to be funnel-shaped, with the moist loose sand at the center marking the source of outgoing water (fig. 1). The same phenomenon was vividly accounted for by the volcanologist, archeologist and diplomat William D. Hamilton, who traveled to explore the devasted areas: “Just before we arrived at Rosarno, near a ford of the river Mamella we passed over a swampy plain, in many parts of which I was shewn small hollows in the earth, of the shape of an inverted cone: they were covered with sand, as was the soil near them. I was told that, during the earthquake of the 5th of February, from each of these spots a fountain of water mixed with sand had been driven up to a considerable height. I spoke to a peasant here, who was present, and was covered with the water and sand; but assured me, that it was not hot, as had been represented. Before his appearance, he said, the river was dry; but soon after returned and overflowed its banks. I afterwards found, that the same phenomenon had been constant with respect to all the other rivers in the plain during the formidable shock of the 5th of February” (W.D. Hamilton, 1783, p.180).

___Salvatore Esposito & Adele Naddeo