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In this paper we present the seabed maps of the shallow-water areas of Lampedusa and Linosa, belonging to the Pelagie Islands Marine Protected Area. Two surveys were carried out ("Lampedusa 2015" and "Linosa 2016") to collect bathymetric and acoustic backscatter data through the use of a Reson SeaBat 7125 high-resolution multibeam system. Ground-truth data, in the form of grab samples and diver video-observations, were also collected during both surveys. Sediment samples were analyzed for grain size, while video images were analyzed and described revealing the acoustic seabed and other bio-physical characteristics. A map of seabed classification, including sediment types and seagrass distribution, was produced using the tool Remote Sensing Object Based Image Analysis (RSOBIA) by integrating information derived from backscatter data and bathy-morphological features, validated by ground-truth data. This allows to create a first seabed maps (i.e. benthoscape classification), of Lampedusa and Linosa, at scale 1:20 000 and 1:32 000, respectively, that will be checked and implemented through further surveys. The results point out a very rich and largely variable marine ecosystem on the seabed surrounding the two islands, with the occurrence of priority habitats, and will be of support for a more comprehensive maritime spatial planning of the Marine Protected Area. [ABSTRACT FROM AUTHOR]

A previously unknown submerged volcanic field offshore western Sardinia (western Mediterranean Sea), has been identified based on swath bathymetric data collected in 2009, 2010 and 2013, and high-resolution seismic profiles collected in 2011 and 2013. About 40 conical-shaped volcanic edifices (maximum width of about 1600 m and maximum height of about 180 m) and several lava outcrops (up to 1,200 m wide) were recognized at 20 to 150 m water depth over an area of 800 km. The volcanic edifices are mainly eruptive monogenic vents, mostly isolated with a rather distinct shape, or grouped to form a coalescent volcanic body in which single elements are often still recognizable. High-resolution seismics enabled identifying relationships between the volcanic bodies and continental margin successions. The edifices overlie a major erosional surface related to the margin exposure following the Messinian salinity crisis, and are overlain by or interbedded with an early Pliocene marine unit. This seismo-stratigraphic pattern dates the volcanic activity to the early Pliocene, in agreement with the radiometric age of the Catalano island lavas (4.7 Ma) reported in earlier studies. The morphometry of the volcanic bodies suggests that cone erosion was higher at shallow water depths. Indeed, most of the shallow edifices are strongly eroded and flattened at 125 to 130 m water depth, plausibly explained by recurrent sub-aerial exposure during Pleistocene sea-level lowstands, whereas cones in deeper water are much better preserved. Volcanic vents and lava deposits, hereafter named the Catalano volcanic field (CVF), are emplaced along lineaments corresponding to the main directions of the normal fault system, which lowered the Sinis Basin and the western Sardinia continental margin. The CVF represents a volumetrically relevant phase of the late Miocene - Quaternary anorogenic volcanic cycle of Sardinia, which is related to the first stage of the extensional tectonics affecting the island since the late Miocene. [ABSTRACT FROM AUTHOR]

The late Quaternary evolution of the Sele River coastal plain (Salerno Gulf, southern Italy) was investigated through integrated stratigraphical, chronological and palaeoecological analyses. The main environmental changes were ascribed to glacio-eustatic variations leading to rapid ingressions alternating with coastal progradations. The marked marine ingression of MIS 5.5 is testified by palaeoridges now cropping out 4 km inland at 11/13 m a.s.l. (Gromola palaeoridge). The eustatic minimum of MIS 2 is testified by lower shoreface deposits in the offshore core record and in the seismic profiles at 120/130 m below sea level. This prolonged sea-level fall was interrupted by at least three rapid sea-level rises, probably related to MIS 5.3, 5.1 and 3. The evidence of the first two sea level rises are represented by shoreface deposits in the inland S1 core (30 m thick, 3 m a.s.l., 1.5 km inland). The highstand of MIS 3 was identified by seismic profiles as onlapping marine deposits. The shore deposits at 100 m b.s.l were tentatively attributed to the lowstand of MIS 4. After the lowstand of MIS 2, the Sele Plain was newly flooded due to the rapid Post Glacial sea-level rise. This ingression caused the inland migration of a barrier-lagoon system and stopped at approximately 5.5 ky BP. From that moment the shoreline started prograding up to the present position probably due to the decrease in the sea-level rise rates and to the volcaniclastic supplies from the Neapolitan volcanoes, especially from the AD 79 Vesuvius eruption, also recorded in the subbottom chirp profiles. [ABSTRACT FROM AUTHOR]

A complementary data set consisting of sedimentological, petrophysical, geochronologic and seismo-stratigraphic analysis was used to detect the sedimentary changes in the inner shelf record in a mostly stable region, over the last 3 ky cal BP, that is since the sea level attained its present day position. This study has been carried out within the VULCOST project on the Salerno Gulf (south-eastern Tyrrhenian Sea, Italy), to learn more about the impact of minor morpho-climatic changes and anthropogenic disturbances on the shelf sedimentary record. Some decimeter-thick sandy beds deposited on the inner shelf, off the Sele river mouth, in the time span corresponding to the Little Ice Age (LIA), despite the fact that, at the time, the coastline at that time was farther inland with respect to its present day position. Since the beginning of the 20th century, mainly fine grained sediment settled, possibly owing to the restoration of mild climatic conditions, changes in the rivers' regime and land-use. The analysis of the marine cores, collected off the coast, also reveals a litho-stratigraphic mismatch among coeval intervals, possibly driven by the different response of the catchments to the morpho-climatic variations. High resolution seismic data shows that the sediment bypass area, shaped by wave action, is much deeper than the estimated limit, if computed on the base of fair-weather wave length and sedimentologic analysis. Indeed, toplap terminations of reflectors are recognizable as deep as 25 m in the southern sector of the Gulf and suggest an intense reworking of the seabed over long periods, much deeper than the outer limit of the beach. This evidence is also supported by the state of pyroclastic layers in the core record, which proves sediment reworking in the marine setting, down to 24 m of depth. The high resolution sedimentologic and stratigraphic reconstructions point to a non linear relation between depth, distance from the coast and sand deposition over the time. This suggests a complex picture of coastal dynamics within the same basin, with a remarkable outcome regarding the wave-cut terraces as proxies of sea level stands. [ABSTRACT FROM AUTHOR]

The Bulgheria canyon-fan system in the eastern Tyrrhenian Sea displays well-developed, small-scale, fluvial-like features and has formed alongside the northern slope of the Sapri peri-Tyrrhenian basin. This study reveals, for the first time, the morphology and course of the present-day system as well as the buried elements based on a Digital Terrain Model and high-resolution seismic profiles interpretation. Two adjacent canyons (Infreschi and Luna) originate in the Cilento outer shelf at a short distance from each other and feed an intraslope basin fan through two main sub-parallel channels that run about 12 and 8 km, respectively. Channel and levee development seems to be controlled primarily by the local slope gradient and by Coriolis forces that induce a faster vertical growth of the right-side features, as is often observed in the Northern Hemisphere. Centrifugal forces, on the other hand, have induced episodic flow-stripping at the meander loops and bends, causing local destruction of the main channel levees rather than new levee growth at the outer bends. Overbank deposits are associated with overspill turbidite deposition in the mid fan where a topographic constraint occurs, whereas large-sediment, low-angle wave fields are mainly developed on the outer fan. Buried features and relict morphologies suggest that the Infreschi channel experienced at least two phases of re-incision since the final stages of the middle Pleistocene. Local re-adjustment of outer lobe growth due to channel avulsion and meander abandonment is possibly a consequence of relative base-level fluctuations. The sedimentary record of the mid and outer fan includes outrun mass wasting deposits from extensive failures of the Sapri slope. Indeed, a marked scar is present on the eastern side of the modern outer lobe that indicates the persistency of mass flow passages up to recent times. In addition to the environmental factors that are currently considered to cause canyon formation on the shelf margin, this study proposes the possibility that the head canyon branch close to the mainland was incised by massive and persistent underground freshwater flow from the adjacent aquifer when the sea-level was lower than at present. [ABSTRACT FROM AUTHOR]