We present an improved rendition of the geodetic velocity and strain fields in Sicily and southern Calabria obtained through the analysis of 18 years of GPS observations from continuous and survey station networks. The dense spatial coverage of geodetic data provides precise quantitative estimates of previously established first‐order active kinematic features, including: i) a narrow east‐west‐elongated belt of contraction (∼1–1.5 mm/yr) extending offshore northern Sicily from Ustica to Stromboli across the Aeolian Islands; ii) a narrow east‐west‐trending contractional belt located along the northern rim of the Hyblean Plateau in southern Sicily, with shortening at up to 4.4 mm/yr; iii) right motion (∼3.6 mm/yr) on the Aeolian‐Tindari‐Letojanni fault (ATLF) system, a main shear zone extending from the Aeolian Islands to the Ionian coast of Sicily, with significant transpression and transtension partitioned between discrete sectors of the fault; iv) transtension (∼1 mm/yr) across the Sicily Channel between Sicily and North Africa. We use geodetic observations coupled to geological constraints to better elucidate the interplay of crustal blocks revealed in the investigated area. In particular, we focus on the ATLF, which forms the primary boundary between the Sicilian and Calabrian blocks. The ATLF juxtaposes north‐south contraction between Sicily and the Tyrrhenian block with northwest‐southeast extension in northeastern Sicily and Calabria. Contraction between Sicily and Tyrrhenian blocks probably arises from the main Europe‐Nubia convergence, although Sicily has a component of lateral motion away from Nubia. We found that convergence is not restricted to the northern offshore, as commonly believed, but is widely accommodated between the frontal belt and the northern rim of the Hyblean foreland in southern Sicily. Geodetic data also indicate that active right shear on the ATLF occurs to the southeast of the mapped fault array in northern Sicily, suggesting the fault cuts through till the Ionian coast of the island. The small geodetic divergence between the Hyblean and Apulian blocks rimming on both sides the Calabria block and subjacent Ionian slab, coupled with marine geophysical evidences in the Ionian Sea lends credit to the proposed deep root of the ATLF and to a fragmentation of the Ionian domain.

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The continuous GPS network operating on Mt. Etna with its 36 stations is currently one of the largest worldwide. The aim of this network is the evaluation of volcanic hazard and the modelling of the active sources. In this paper, we propose an in‐depth analysis and modelling of continuous GPS data collected at Mt. Etna from May 2008 to December 2010. The analyzed period has been divided into four different coherent phases: 1) 14 May 2008–02 August 2008 (deflation of the entire GPS network); 2) 02 August 2008–14 June 2009 (deflation of the summit area and inflation at lower heights); 3) 14 June 2009–21 May 2010 (inflation of the entire GPS network); 4) 21 May 2010–31 December 2010 (inflation at medium and low heights and end of the inflation in the summit area). Analytical models indicate a non‐uniform deformation style revealing spaced sources acting at different time on different segments of a multi‐level magma reservoir. The Etnean plumbing system imaged here is depicted as an elongated magma reservoir that extends from the volcano body downwards to about 6.5 km below sea level (b.s.l.), sloping slightly towards the North‐West, with storage volumes located at about 6.5, 2.0 and 0.0 km (b.s.l.). The changes in position of the modelled pressure sources during the analyzed time intervals indicate that, throughout the 2008 eruptive period, the deformation field was mostly driven by the upward migration of magma. On the other hand, the pattern of deformation recorded after the end of the eruption strongly suggests a significant contribution of the magma overpressure generated by the gas boiling, thus outlining the importance of volatiles content in magma.

Starting off from a review of previous literature on kinematic models of the unstable eastern flank of Mt. Etna, we propose a new model. The model is based on our analysis of a large quantity of multidisciplinary data deriving from an extensive and diverse network of INGV monitoring devices deployed along the slopes of the volcano. Our analysis had a twofold objective: first, investigating the origin of the recently observed slow-slip events on the eastern flank of Mt. Etna; and second, defining a general kinematic model for the instability of this area of the volcano. To this end, we investigated the 2008-2013 period using data collected from different geochemical, geodetic, and seismic networks, integrated with the tectonic and geologic features of the volcano and including the volcanic activity during the observation period. The complex correlations between the large quantities of multidisciplinary data have given us the opportunity to infer, as outlined in this work, that the fluids of volcanic origin and their interrelationship with aquifers, tectonic and morphological features play a dominant role in the large scale instability of the eastern flank of Mt. Etna. Furthermore, we suggest that changes in the strain distribution due to volcanic inflation/deflation cycles are closely connected to changes in shallow depth fluid circulation. Finally, we propose a general framework for both the short and long term modeling of the large flank displacements observed.

The tectonic deformation of the Lipari–Vulcano complex, one of the most important active volcanic areas of the Mediterranean region, is studied here through the analysis of 10 years (1996–2006) of GPS data from both three permanent and 13 non‐permanent stations. This area can be considered crucial for the understanding of the interaction between the Eurasian and African plates in the Mediterranean area, and, in general, this work emphasizes a methodological approach, already applied in other areas worldwide (J. Geophys. Res., 1996, 101, 27 957; J. Geodyn., 1999, 27, 213) where geodetic data and strain parameters maps of critical areas can help to improve our understanding of their geodynamical aspects. In this framework, this study is aimed at providing a kinematic deformation model on the basis of the dense geodetically estimated velocities of the Lipari–Vulcano complex. In particular, the observed deformation pattern can be described by a combination of (1) the main N–S regional compression and (2) a NNE–SSW compression with a small right‐lateral strike slip component acting along a tectonic structure trending N°40W between the two islands. This pattern was inspected through a simplified synthetic model.

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For decades, many authors have attempted to define the location, geometry and kinematics of the causative fault for the 1908 December 28, M 7.1 earthquake that struck the Messina Straits between Sicily and Calabria (southern Italy). The coseismic displacement caused a predominant downwarping of the Straits and small land uplift away from it, which were documented by levelling surveys performed 1 yr before and immediately after the earthquake. Most of the source models based on inversion of levelling data suggested that the earthquake was caused by a low angle, east-dipping blind normal fault, whose upper projection intersects the Earth surface on the Sicilian (west) side of the Messina Straits. An alternative interpretation holds that the causative fault is one of the high-angle, west-dipping faults located in southern Calabria, on the eastern side of the Straits, and may in large part coincide with the mapped Armo Fault. Here, we critically review the levelling data with the aim of defining both their usefulness and limits in modelling the seismogenic fault. We demonstrate that the levelling data alone are not capable of discriminating between the two oppositely dipping fault models, and thus their role as a keystone for modellers is untenable. However, new morphotectonic and geodetic data indicate that the Armo Fault has very recent activity and is accumulating strain. The surface observations, together with appraisal of macroseismic intensity distribution, available seismic tomography and marine geophysical evidence, lends credit to the hypothesis that the Armo and possibly the S. Eufemia faults are part of a major crustal structure that slipped during the 1908 earthquake.