Abstract The European Marine Observation and Data Network (EMODnet) Project provides freely available data on European seas. The main purpose of EMODnet is to overcome the fragmentation and dishomogeneity of the available data, providing access to a harmonized and interoperable database. The EMODnet Geology Lot includes information at multiple scales on the seabed and its substrate ( http://www.emodnet-geology.eu/ ). The dataset on ‘Geological events and probabilities’ collects information on landslides, earthquakes, volcanic structures, active tectonics, tsunamis and fluid emissions. The Geological Survey of Italy, which coordinates the collation of ‘Geological events and probabilities’ data, provided guidelines to compile layers complemented by comprehensive and detailed patterns of attributes for each feature in order to characterize each type of geological event. Occurrences of events are often associated with each other, particularly in tectonically active areas. Geological events affect both submerged and coastal environments. Data gathered by EMODnet Geology provide a good basis for further studies, contributing to the outlining of different tectonic settings and providing support to the use of marine resources, as well as to the management of marine-coastal areas particularly regarding the identification and assessment of geological and environmental hazards.

ABSTRACT The Pliocene–Quaternary igneous record of the Tyrrhenian Sea area features a surprisingly large range of compositions from subalkaline to ultra-alkaline and from ultrabasic to acid. These rocks, emplaced within the basin and along its margins, are characterized by strongly SiO 2 -undersaturated and CaO-rich to strongly SiO 2 -oversaturated and peraluminous compositions, with sodic to ultrapotassic alkaline and tholeiitic to calc-alkaline and high-K calc-alkaline affinities. We focused on the different models proposed to explain the famous Roman Comagmatic Region, part of the Quaternary volcanism that spreads along the eastern side of the Tyrrhenian area, in the stretched part of the Apennines thrust-and-fold belt. We reviewed data and hypotheses proposed in the literature that infer active to fossil subduction up to models that exclude subduction entirely. Many field geology observations sustain the interpretation that the evolution of the Tyrrhenian-Apennine system was related to subduction of the western margin of Adria continental lithosphere after minor recycling of oceanic lithosphere. However, the lateral extent of the subducting slab in the last millions of years, when magmatism flared up, remains debatable. The igneous activity that developed in the last millions of years along the Tyrrhenian margin is here explained as originating from a subduction-modified mantle, regardless of whether the large-scale subduction system is still active.

Abstract A marine sediment core from the western Mediterranean provides a new high-resolution 4500 year record of palaeomagnetic secular variation and relative palaeointensity. In 2013, the 7.1 m C5 core was recovered from the Tyrrhenian Sea as part of the NextData climate data project. The coring site, 15 km offshore from the Volturno river mouth, is well located to record combined marine and terrestrial palaeoclimatic influences, and the fine-grained, rapidly deposited sediments are effective palaeomagnetic recorders. We investigate the palaeomagnetic field direction and strength recorded in the core, which provide a valuable high-resolution record of Holocene geomagnetic variation in the area. Using rock magnetic techniques, we constrain the magnetic mineralogy of the studied sediments and confirm their suitability for palaeomagnetic analysis. Palaeomagnetic declination and inclination records were determined by stepwise alternating-field demagnetization, and relative palaeointensity estimates were obtained based on normalization to anhysterestic and isothermal remanent magnetization and to magnetic susceptibility. The age of the core is well constrained with a tephra and biostratigraphic age model, and its magnetic records are compared with relevant core and model data for the region, demonstrating that our record is compatible with previous results from the area. An automated curve matching approach is applied to assess the compatibility of our data with the existing secular variation path for the Mediterranean area.

Abstract The southern Tyrrhenian continental margin is the product of Pliocene–Recent back-arc extension. An area of approximately 30 km 2 of gentle (about 1.5°) lower slope of the last glacial outer shelf sedimentary wedge in water depths of between 200 and 300 m failed between 14 and 11 ka BP. We approached the landslide by multibeam and sub-bottom profiler surveying, high-resolution multichannel seismics, and coring for stratigraphic and geotechnical purposes. With regard to a slope-stability analysis, we carried out an assessment of the stratigraphic and structural setting of the area of the Licosa landslide. This analysis revealed that the landslide detached along a marker bed that was composed of the tephra layer Y-5 ( c. 39 ka). Several previously unknown geological characteristics of the area are likely to have affected the slope stability. These are the basal erosion of the slope in the Licosa Channel, a high sedimentation rate in the sedimentary wedge, earthquake shaking, the volcanic ash nature of the detachment surface, subsurface gas/fluid migration, and lateral porewater flow from the depocentre of wedge to the base of the slope along the high-permeability ash layers. A newly discovered prominent structural discontinuity is identified as the fault whose activity may have triggered the landslide.

Abstract The collection of high-resolution multibeam bathymetry off the tectonically controlled Tyrrhenian Calabrian margin (southern Tyrrhenian Sea) allowed us to recognize several mass-wasting processes, including shelf-indenting canyons and several landslide scars ranging over different spatial scales. In this paper, we aim to characterize two large submarine landslides (S1 and S2) affecting an area of c. 7 and 14 km 2 , respectively; both scars occur within water depths of 700–1000 m on slope gradients of 1.5−3°. S1 is interpreted as a disintegrative landslide, because most parts of the related landslide deposits were evacuated from the scar and are not recognizable on the present-day bathymetry, whereas the landslide deposits of S2 are well-preserved and mostly confined within the scar, indicating a different post-failure evolution. Based on the integration of multibeam bathymetry and single-channel seismic profiles, both the landslides are interpreted as translational failures, whereas their different post-failure behaviour has been associated with differences in material properties (inferred by headscarp morphology), depth of their failure plane and frontal confinement. We also suggest that thick contourite deposits recognized in the area may represent an important preconditioning factor for the development of these landslides, similarly to that observed in the nearby Capo Vaticano scar complex.