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

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

► We analyzed three leveling lines measured during the last 40 years.
► Leveling lines are located in eastern Sicily and southern Calabria (Italy).
► The analysis was carried out comparing elevation changes to reference benchmarks.
► The analysis allowed us to estimate very recent vertical movements.
► Elastic strain accumulation along tectonic structures is responsible for deformation.