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On 24 August 2016, a Mw6.0 normal‐faulting earthquake struck central Italy, causing about 300 fatalities and heavy damage. A geological survey collected the coseismic effects observed at the surface in order to evaluate two competing hypotheses about their nature: surface faulting versus gravitational deformation. We find that the most significant geological effect is a 5.2 km long alignment of ground ruptures along the Mount Vettore Fault System. These ruptures are independent from lithology, topography, morphology, and change in slope and exhibit an average dip‐slip displacement of ~13 cm. Geometry, kinematics, and dimensional properties of this zone of deformation strongly lead us to favor the primary surface faulting hypothesis that fits well the predicted estimates from experimental scaling law relationships. Our study provides relevant hints for surface faulting in extensional domains, contributing to implement the worldwide database of the moderate earthquakes. Detailed documentation of subtle primary coseismic surface faulting induced by moderate magnitude earthquake masked by later seismic eventContribute to the worldwide database of the moderate earthquakes surface faulting events in extensional domains

Thirty-seven selected earthquakes which occurred in Phlegraean Fields from April to December 1983 are investigated from the focal mechanism point of view in order to attempt a preliminary representation of the stress pattern in the area. From 37 earthquakes, 15 reliable solutions were obtained. Ten mechanisms for events located around the Solfatara crater are of tensional type; 2 located in the Gulf of Pozzuoli seem to be compressive. No predominant orientation ofP andT axes seem to occur. Evidently, a more accurate analysis with a greater number of data — in particular for compressive events — is necessary in order to resolve a detailed map of stress pattern.

The interpretation of results from a 250 km long seismic refraction traverse recorded using ocean-bottom seismometers in the northwestern Ionian Sea and a fan profile recorded across southern Calabria have augmented previous studies by placing additional constraints on the Tyrrhenian Sea-Calabria-Ionian Sea transition. Overlapping branches of P nphases confirm the existence of a thinned crust (about 13 km) giving rise to the major Bouguer anomaly high of the central Ionian Basin. A low average crustal velocity is observed throughout the basin, in accordance with the very thick sedimentary cover exemplified by previous seismic surveys. A deepening Moho may be followed continuously from the centre of the basin to 40 km offshore from Calabria where a sudden depth decrease (30 to 20 km) is accompanied by a sharp change in the crustal velocity structure. The estimated depth of such a shallower Moho towards the northwest, confirmed by a shot recorded in a fan geometry across southern Calabria, is in accordance with that found earlier for the southernmost margin of the Tyrrhenian Basin.