SOLLEVAMENTI A GRANDE SCALA E CONSEGUENTI FENOMENI GRAVITATIVI: L’ESEMPIO DEL VERSANTE ORIENTALE DELL’ETNA (SICILIA)

Abstract

Carveni P., Bella D., Benfatto S., Maniscalco R., Salleo Puntillo M. & Sturiale G., Regional uplift and consequent gravitational phenomena: the example of eastern slope of Mt Etna volcano. (IT ISSN 0394-3356, 2005).
Mt. Etna is the largest active volcano in Europe; it is a volcanic complex, formed by products of several eruptive centres, which were
active in different times. It is located on the margin of two main structural domains of Eastern Sicily: the Hyblaean Foreland and the
Apennine-Maghrebian Chain. The Hyblaean Foreland belongs to the northern part of the African Plate; it is formed by a very thick
Triassic to Pleistocene carbonate succession, with several intercalations of mafic volcanic rocks.
The Apennine-Maghrebian Chain consists of several thrust sheets, made up of structural units derived from different palaeogeographical domains; they were overthrusted upon each other during several tectonic phases from Eocene to Pleistocene.
Eastern Sicily is interested by a general uplift but a sector of the Etna volcanic building is characterized by lowering. Along the Ionian
Sea coast we recognized uplift movements between Catania and Aci Castello and subsidence between Stazzo and Torre Archirafi.
The lower eastern slope of Mt. Etna volcano is a high seismic hazard zone; it is characterized by superficial hypocentres earthquakes
with little mesoseismic area. Information is available about earthquakes which happened in this region during the last two centuries.
The seismic activity of three faults was studied in the time span between 1805 and 1989.
Tectonic movements also caused very important landscape variations, like waterfalls and river piracies.
Our studies demonstrate that the subsidence along the coast is the result of the total amount of displacement measured along the
fault planes (Moscarello, San Leonardello and Macchia-Stazzo Faults).
The analysis of the isoseismal lines suggests the presence of not yet known faults, whose existence is also testified on morphological
and geophysical bases.
The results of this paper agree with the data of literature related to the dynamics of the eastern slope of Mt. Etna; it is subject to a progressive sliding toward ESE.