Geophysical Study of an Landslide in Northern Sicily

Abstract

The San Fratello area in the Nebrodi Mountains (northern Sicily) is a region of high instability. It has suffered many devastating occurrences, which have hit and destroyed the village of San Fratello. At present the area is still subject to a high landslide risk. A series of geophysical surveys have been carried out with the aim of determining the thickness and dimensions of the landslide body as well as some tectonic features, in order to gain insight into the evolution of the landslide. The following geophysical techniques have been used: borehole seismic tomography, i.e. down‐hole tomographic seismic soundings (DH TSS), time‐domain electromagnetic (TDEM) soundings and georadar profiling (GPR). An additional objective was to compare the efficiency of the geophysical methods used in real geological, morphological and logistic situations. The data obtained using seismic tomography outlined the shape and the thickness of the body of the landslide in the scar and track area, as well as some mechanical characteristics of the formations involved in the movement. TDEM soundings provided a little additional information on the upper 5–10 m. Georadar profiles supplied some information about the locations of some lateral lithological changes. Finally the information obtained with the various geophysical techniques was used to provide an outline of the history of the area.