Department of Biological, Geological and Environmental Sciences, University of Catania, Italy

Active normal faulting and uplifting, consistent with a WNW-ESE-oriented regional extension, dominate the Quaternary tectonics of the southern Calabrian Arc. The main tectonic structures of this extensional domain are considered to be the source of numerous historical and recent strong earthquakes, among which the 1783 seismic sequence (M 6.5–7) was one of the most destructive earthquakes ever recorded in Southern Italy. Previous works on the seismotectonic of the Calabrian Arc indicate a disagreement on the attitude (E-dipping vs W-dipping) of the main seismogenic sources slicing across southern Calabria, whereby the seismotectonic framework is still debated. Following a multidisciplinary approach, based on morpho-structural and seismological data, the geometry at depth of the most reliable sources (i.e., Cittanova and Serre faults) was first modelled in a 3D environment to retrieve information about their seismic potential. The GNSS data from the permanent stations of RING/RDN and TopNETlive Italy networks have been processed in order to estimate the velocity field affecting this area. Then, data inversion allowed us to document a predominant WNW-ESE active extensional strain orthogonally to the modelled faults, consistent with the regional dynamics. The reliability of the model was tested using empirical relationships and fault response modelling simulation. Furthermore, slip tendency analysis revealed the propensity to slip of the modelled planes by applying a remote stress state derived from the kinematic-structural survey on fault planes.

The MEV project is running for a long-term muography measurement at the North-East crater of the Etna Volcano, after the successful conclusion of the test phase in July 2017. Two sets of data were already acquired during 2017, during the last months of the summer, and 2018. Data analysis is currently ongoing in order to extract a two-dimensional density map of the target from the measured muon flux. But before, a major improvement on data pre-processing was required. It regards in particular the algorithm for event reconstruction and filtering and the introduction of a method to extract the telescope efficiency from data themselves. The main steps of this pre-analysis and their application to the test data set is described in this paper.

Recent works (Evelpidou et al., 2012) suggest that the modern tidal notch is disappearing worldwide due sea level rise over the last century. In order to assess this hypothesis, we measured modern tidal notches in several of sites along the Mediterranean coasts. We report observations on tidal notches cut along carbonate coasts from 73 sites from Italy, France, Croatia, Montenegro, Greece, Malta and Spain, plus additional observations carried outside the Mediterranean. At each site, we measured notch width and depth, and we described the characteristics of the biological rim at the base of the notch. We correlated these parameters with wave energy, tide gauge datasets and rock lithology. Our results suggest that, considering ‘the development of tidal notches the consequence of midlittoral bioerosion’ (as done in Evelpidou et al., 2012) is a simplification that can lead to misleading results, such as stating that notches are disappearing. Important roles in notch formation can be also played by wave action, rate of karst dissolution, salt weathering and wetting and drying cycles. Of course notch formation can be augmented and favoured also by bioerosion which can, in particular cases, be the main process of notch formation and development. Our dataset shows that notches are carved by an ensemble rather than by a single process, both today and in the past, and that it is difficult, if not impossible, to disentangle them and establish which one is prevailing. We therefore show that tidal notches are still forming, challenging the hypothesis that sea level rise has drowned them.