Analysis of vertical movements in eastern Sicily and southern Calabria (Italy) through geodetic levelling data

The analysis of repeated high precision leveling observations during the last 40 years along lines of theItalian fundamental network allowed us to estimate very recent vertical movements in eastern Sicily andsouthern Calabria (Italy). The network is measured by the Italian Istituto Geografico Militare (IGM) and wehave analyzed three leveling lines. Because of the lack of an absolute reference datum, we have conductedthe analyses in terms of relative elevation changes compared to reference benchmarks. Although theprocessing of the different time series obtained from the high precision leveling has allowed us to estimateonly relative rates, their extreme accuracy, together with the large extension of networks, makes this typeof measurement fundamental for the estimate of recent vertical deformation. In addition, correlatinginstrumental and geological data makes it possible to identify active tectonic structures whose elasticstrain accumulation could be responsible for vertical deformation. In particular, vertical motion can berelated to the activity of a W-E trending fault separating the Catania Plain from the Hyblean Plateauin southeastern Sicily, a N-S trending normal fault occurring north of the Messina town and the NE-SWtrending Scilla normal fault in south-western Calabria. The last two are located on the sides of the MessinaStraits, an area of broad interest for the planning of the single-span bridge between Sicily and mainlandItaly.