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Submarine landslides are very large events occurring across both active and passive continental margin. They are sediment transport processes caused by submarine slope’s instability and the result of both internal structure changes and external dynamic conditions. The genesis and evolution of slope failure is controlled by different geological factors which may be considered as predisposing factors (e.g., seafloor morphology, lithology, type of sediment, presence of fluid or weak layers) and triggering factors (e.g., earthquakes).The Italian continental margins provide an excellent playfield to study submarine landslides because they have been identified and mapped in different morpho-tectonic and sedimentary contexts (e.g., accretionary prism, volcanic edifices, foredeep continental slope, upper slope in front of large deltas…). Between the 2007 and 2013, in the framework of MaGIC project funded by the Italian Civil Protection (DPC) a detailed mapping program of seafloor morphologies and features including landslides was carried out. The morphological features identified during the Magic Project will be used as a base to create a geodatabase of the Italian submarine landslides. This will include a careful reclassification of the different features, extraction of morphometric parameters and identification of triggering and preconditioning factors for the different case studies. This work has been funded by PNRR GEOSCIENCES IR project, and aim at use statistical methods to better classify the landslides that are relate than to different geological settings, and constrain the relation between different parameters and the triggers. When a relation will be established, we may build a step towards a better geohazard assessment, and may be define the likelihood of submarine landslide occurrences across the Italian Continental Margins, even in the areas when the landslides did not occurred yet. In fact, landslide hazard assessment requires the estimation of where, when (or how frequently) and how large a given landslide event may be. In marine realm this is very difficult because the cost of direct analysis is higher than in the subaerial counterpart. Therefore, a geostatistical approach on very large number of features could probably be the most realistic approach to the problem.

The Ionian Calabrian and Apulian margins are severely incised by a dense network of submarine canyon systems, that have formed in response to ongoing km-scale uplift of Calabria over the last ca. 1Ma. Despite their young age (Pleistocene) they incise the continental shelf and slope over lengths of tens of kilometres, with thalwegs up to 2 km wide, walls higher than 200m and headwalls, that can extend over more than 50 km.Some of the canyon headwalls are very close to the coastline and in some cases, retrogressive features are observed from morphology and sub-bottom observations, representing a potential hazard for population and coastal infrastructures. Some of the canyons are isolated, others form hierarchic systems with five or more canyons merging into dendritic (cauliflower) systems that may or may not be connected to onshore drainage networks. They exhibit different characteristics in terms of headwall geometry, profile concavity and sinuosity.We present new information on their geomorphic attributes to gain new understanding about the dynamic and evolution of the different canyon systems in the last 1Ma. In addition, we aim at extracting information regarding the grain size and sediment type from vintage backscatter geophysical data and subbottom data, to analyse canyon headwall enlargement and their erosive activity. The overall purpose of my study is to bring new insights about the inception and evolution of the different canyon systems in relation to tectonic and sea level changes and thus be able to assess the potential geohazards that retrogressive canyon headwalls may represent today for coastal areas and infrastructures.

To ensure environmental and public safety, critical facilities require rigorous seismic hazard analysis to define seismic input for their design. We consider the case of the Trans Adriatic Pipeline (TAP), which is a pipeline that transports natural gas from the Caspian Sea to southern Italy, crossing active faults and areas characterized by high seismicity levels. For this pipeline, we develop a Probabilistic Seismic Hazard Assessment (PSHA) for the broader area, and, for the selected critical sites, we perform deterministic seismic hazard assessment (DSHA), by calculating shaking scenarios that account for the physics of the source, propagation, and site effects. This paper presents a DSHA for a compressor station located at Fier, along the Albanian coastal region. Considering the location of the most hazardous faults in the study site, revealed by the PSHA disaggregation, we model the ground motion for two different scenarios to simulate the worst-case scenario for this compressor station. We compute broadband waveforms for receivers on soft soils by applying specific transfer functions estimated from the available geotechnical data for the Fier area. The simulations reproduce the variability observed in the ground motion recorded in the near-earthquake source. The vertical ground motion is strong for receivers placed above the rupture areas and should not be ignored in seismic designs; furthermore, our vertical simulations reproduce the displacement and the static offset of the ground motion highlighted in recent studies. This observation confirms the importance of the DSHA analysis in defining the expected pipeline damage functions and permanent soil deformations.

The design of critical facilities needs a targeted computation of the expected ground motion levels. The Trans Adriatic Pipeline (TAP) is the pipeline that transports natural gas from the Greek-Turkish border, through Greece and Albania, to Italy. We present here the probabilistic seismic hazard analysis (PSHA) that we performed for this facility, and the deaggregation of the results, aiming to identify the dominant seismic sources for a selected site along the Albanian coast, where one of the two main compressor stations is located. PSHA is based on an articulated logic tree of twenty branches, consisting of two models for source, seismicity, estimation of the maximum magnitude, and ground motion. The area with the highest hazard occurs along the Adriatic coast of Albania (PGA between 0.8 and 0.9 g on rock for a return period of 2475 years), while strong ground motions are also expected to the north of Thessaloniki, Kavala, in the southern Alexandroupolis area, as well as at the border between Greece and Turkey. The earthquakes contributing most to the hazard of the test site at high and low frequencies (1 and 5 Hz) and the corresponding design events for the TAP infrastructure have been identified as local quakes with MW 6.6 and 6.0, respectively.

19 pages, 13 figures, 1 table, supplementary material https://doi.org/10.1016/j.margeo.2022.106739.-- Seismic reflection and bathymetric data collected during the MARLBORO and SARAS cruises are stored at SISMER repository (https://doi.org/10.17600/11480100, https://doi.org/10.17600/12450090, and https://campagnes.flotteoceanographique.fr/campagnes/12000010). Landslide parameters for MTDs mapped during this study are given in the appendix., Earthquakes are the most commonly cited cause of offshore slope failure, followed by high sedimentation rates and ensuing pore pressure build-up. In the South Alboran Sea, the moderate seismicity (Mw = 6.4) of the strike-slip Al Idrissi Fault Zone does not appear to control directly the landslides distribution. To provide a preliminary geohazard assessment, we characterized the spatial distribution, the volume and the ages of the submarine landslides from multibeam and seismic reflection data in the southern part of the Alboran Sea. Since the Quaternary numerous submarine landslide processes have affected the marine sedimentary cover with volumes of the mass transport deposits (MTD) estimated between 0.01 and 15 km3. West of the Al Idrissi Fault Zone, along the South Alboran Ridge's northern flank, the distribution of the MTD follows the SW-NE bank and ridge trend that correlates with blind thrusts and folds covered by a plastered contourite drift. A pockmark field, related to fluid escape, is visible near landslide scars where the contourite drift is relatively thicker. In this area, landslide scars occur on variable slopes (2–24°) and their associated MTDs show variable decompacted volumes (0.01-10 km3). East of the Al Idrissi Fault Zone, between the Alboran Ridge and the Pytheas Bank, the mapped MTDs have uneven volume. The smaller ones (10°), whereas those of the largest ones (3–15 km3) occur on gentler slopes (, This work was funded by the French programs Actions Marges, Défi Risques Naturels CNRS-IRD (MITI-ALARM) and UPMC-Emergence (ALARM project), the ALBAMAR JCJC ANR-17-03CE-0004, the EUROFLEETS program (FP7/2007-2013; n°228344), project FICTS-2011-03-01. Seismic reflection data were processed using the Seismic UNIX SU and Geovecteur© software. The processed seismic data were interpreted using Kingdom IHS Suite© software. This work also benefited from the DAMAGE (AEI/FEDER CGL2016-80687-R) and FAUCES (Ref CTM2015-65461-C2-R; MINCIU/FEDER) Projects financed by “Ministerio de Economía y Competitividad y al Fondo Europeo de Desarrollo Regional” (FEDER). This work acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation of ICM-CSIC (CEX2019-000928-S

This research has been funding by the Spanish projects: DAMAGE ( CGL2016-80687-RAEI/FEDER ) and FAUCES ( CTM2015-65461-C2-1-R ); and the Junta de Andalucía projects: RNM-148 (AGORA) P18-RT-3275 and PAPEL ( B-RNM-301-UGR18 ), We thank the UTM-CSIC technicians and the crew of the RV Sarmiento de Gamboa for their help in collecting data. We are grateful for the multibeam data we received from the Secretaria General de Pesca of the Ministry of Agriculture, Fisheries and Food (Spain). We also thank IHS for providing the Kingdom Suite™ licence. This work acknowledges to IGCP 640 - S4LIDE (Significance of Modern and Ancient Submarine Slope LandSLIDEs), and to the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)., We present a multidisciplinary study of morphology, stratigraphy, sedimentology, tectonic structure, and physical oceanography to report that the complex geomorphology of the Palomares continental margin and adjacent Algerian abyssal plain (i.e., Gulf of Vera, Western Mediterranean), is the result of the sedimentary response to the Aguilas Arc continental tectonic indentation in the Eurasian–Africa plate collision. The indentation is imprinted on the basement of the margin with elongated metamorphic antiforms that are pierced by igneous bodies, and synforms that accommodate the deformation and create a complex physiography. The basement is partially covered by Upper Miocene deposits sealed by the regional Messinian Erosive Surface characterized by palaeocanyons that carve the modern margin. These deposits and outcropping basement highs are then covered and shaped by Plio-Quaternary contourites formed under the action of the Light Intermediate and Dense Deep Mediterranean bottom currents. Even though bottom currents are responsible for the primary sedimentation that shapes the margin, 97% of this region's seafloor is affected by mass-movements that modified contourite sediments by eroding, deforming, faulting, sliding, and depositing sediments. Mass-movement processes have resulted in the formation of recurrent mass-flow deposits, an enlargement of the submarine canyons and gully incisions, and basin-scale gravitational slides spreading above the Messinian Salinity Crisis salt layer. The Polopo, Aguilas and Gata slides are characterized by an extensional upslope domain that shapes the continental margin, and by a downslope contractional domain that shapes the abyssal plain with diapirs piercing (hemi)pelagites/sheet-like turbidites creating a seafloor dotted by numerous crests. The mass movements were mostly triggered by the interplay of the continental tectonic indentation of the Aguilas Arc with sedimentological factors over time. The indentation, which involves the progressively southeastward tectonic tilting of the whole land-sea region, likely generated a quasi-continuous oversteepening of the entire margin, thus reducing the stability of the contourites. In addition, tectonic tilting and subsidence of the abyssal plain favoured the flow of the underlying Messinian Salinity Crisis salt layer, contributing to the gravitational instability of the overlying sediments over large areas of the margin and abyssal plain., DAMAGE CGL2016-80687-RAEI, FAUCES CTM2015-65461-C2-1-R, PAPEL B-RNM-301-UGR18, UTM-CSIC, Indian Health Service CEX2019-000928-S, European Regional Development Fund, Junta de Andalucía P18-RT-3275, RNM-148, Ministerio de Agricultura, Pesca y Alimentación

17 pages, 9 figures, 1 table, Submarine canyons are deep, large-scale incisions that occur on the continental shelf and slope of all ocean margins. These landforms serve as preferential particle-transport conduits that connect the coastal zone with the deep-sea. Canyons have been studied for decades and are among the most iconic submarine geomorphic features. Advances in marine technology are increasingly providing new understanding of the physical and biological processes that take place in canyons, which are also notoriously affected by the impact of anthropogenic activities. In this article we describe the main geomorphic characteristics of submarine canyons and synthesize the past and current knowledge on their formation, evolution, global distribution and hydrodynamical and ecological significance.

Introduzione all'Atlante dei lineamenti di pericolosità geologica dei mari italiani, alla legenda ed ai criteri interpretativi

Mud volcanoes (MVs) have been found in various geological settings on passive and active margins but are mostly known from collision zones on Earth. Mud volcanoes are well known to occur on land (e.g. in Azerbaijan), where at least 1000 MVs have been counted. The amount of submarine MVs is believed to be much larger and recent improvements in seafloor mapping led to the discovery of many MVs in all oceans. To contribute to the knowledge of submarine MVs, in particular the internal structure across Venere MV, we conducted a multi-geophysical imaging approach using high resolution multibeam bathymetry, (constraining seafloor expressions), multichannel, and wide-angle seismic data (constraining the internal structure and P-wave velocity distribution). Venere MV is located at the southern rim of the Crotone forearc basin of the Calabrian arc, offshore southern Italy, in a water depth of ~1500 m. The dimension of Venere MV from its bathymetric expression is ~10 km in the EW- and ~7 km in the NS-direction. Two circular cones of ~100 m elevation and ~1.5 km diameter are located in the center of Venere MV. The upper 200 m below the seafloor (bsf) consist of layers with seismic P-wave velocities gradually increasing from 1.53 to 1.7 km/s (sub-) parallel to the seafloor. A prominent reflection ~200 m bsf and a sudden increase of seismic P-wave velocities from 1.7 to 1.8 km/s mark a change with depth in the internal structure, where reflections dip, and seismic P-wave velocities laterally decrease towards the center of Venere MV. The MCS as well as seismic P-wave velocity structure indicate two separate feeder conduits of the two center cones of Venere MV. However, we do not map the roots of the MV, which are at depths beyond our data resolution. Reduced reflectivity occurs ~4 km across the center of the MV 200 m bsf and downwards. We mapped the chaotic reflections of the acoustic basement in depths varying from 500 m to 800 m bsf. Reduced reflectivity of the acoustic basement occurs beneath the center of the MV as well. Mapping of the fault system leads to the subseafloor dimension of Venere MV that exceeds its seafloor dimension by the factor of two.

Large-scale submarine gravitational land movements involving even more than 1,000 m thick sedimentary successions are known as megalandslides. We prove the existence of large-scale gravitational phenomena off the Crotone Basin, a forearc basin located on the Ionian side of Calabria (southern Italy), by seismic, morpho-bathymetric and well data. Our study reveals that the Crotone Megalandslide started moving between Late Zanclean and Early Piacenzian and was triggered by a contractional tectonic event leading to the basin inversion. Seaward gliding of the megalandslide continued until roughly Late Gelasian, and then resumed since Middle Pleistocene with a modest rate. Interestingly, the onshore part of the basin does not show a gravity-driven deformation comparable to that observed in the marine area, and this peculiar evidence allows some speculations on the origin of the megalandslide.

During the last 0.45 Ma, the Crotone Basin, a forearc basin located on the Ionian side of Calabria, southern Italy, experienced a phase of uplift that persists today. The transition from subsidence to uplift occurred close to the Marine Isotope Stage (MIS) 11 (ca. 0.4 Ma). The subsequent progressive emergence of the area was punctuated by several marine transgressions linked to high-frequency, high-magnitude glacio-eustatic changes, which are recorded as coastal terraces. These high-frequency sequences show a variable stacking pattern due to the interplay between glacio-eustasy, uplift and local physiography. In particular, a progressive SE-ward migration of the shoreline is documented in the study area since MIS 11. This trend was enhanced during the MIS 5.5 to MIS 2 time interval, due to the combined effect of uplift and lowering glacio-eustatic sea level until the Last Glacial Maximum. Moreover, the regional uplift also led to a physiographic change from relatively low-gradient to high-gradient settings between MIS 7.1 and MIS 5.5. A comparison between the late Quaternary geological record of the Crotone Basin and that of other basins is crucial to improve the present knowledge on past sea levels related to MISs. This ultimately will help to better understand the Holocene sea-level history and the human contribution to sea-level change, in order to predict future scenarios.

The Crotone Basin is a Neogene-Quaternary depocenter developed along the Ionian margin of Calabria, southern Italy. The basin opening was concomitant with the onset of spreading of the Tyrrhenian backarc Basin during late Serravallian and the subduction of the Ionian lithosphere below the Calabrian Arc. The adoption of modern sequence stratigraphic principles to subdivide the basin fill into stratigraphic sequences of different rank, bounded by subaerial unconformities, has allowed cycles of creation and loss of accommodation mainly related to tectonics to be recognized. In particular, an alternation between phases of basin subsidence, concomitant with spreading of the Tyrrhenian backarc Basin and forward migration of the Arc, and phases of compressional or transpressional tectonics, accompanied by basin uplift and stopping of Arc migration, are well recognizable in the basin fill, in particular for the late Messinian to late Pleistocene part of the succession. The present study highlights the effectiveness of the sequence stratigraphic method in basin analysis to decipher the effects of large-scale tectonic events on sedimentation and ultimately to reconstruct the geodynamic evolution of the central Mediterranean.

Amblas, David ... et al.-- 22 pages, 8 figures, 1 table, Submarine canyons are deep incisions observed along most of the world’s continental margins. Their topographic relief is as dramatic as that of any canyon or river valley on land but is hidden beneath the surface of the ocean. Our knowledge of canyons has therefore come primarily from remote sensing and sampling, and has involved contributions from various oceanographic disciplines. Canyons are a critical link between coastal and shelf waters and abyssal depths; water masses, sediment, nutrients, and even litter and pollutants are carried through them. Advances in technology continue to provide new insights into canyon environments by pushing the frontier of deep marine observations and measurements. In this chapter we describe the main geomorphic features of submarine canyons and what is known about their formation and the processes that shape them. We also consider submarine gullies, which are small valleys commonly found within or alongside submarine canyons on the continental slope and may represent an incipient stage of canyon development, This work was supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 658358 (D. Amblas)

Three regional unconformity surfaces typify the Plio-Pleistocene fill of the onshore to offshore basins of the Calabrian Arc, an arcuate terrane migrating to the SE above the NW subducting Ionian lithosphere, between the southern Apennines and Sicily. These unconformity surfaces formed in the mid-Pliocene (late Zanclean to early Piacenzian), the early Pleistocene (intra-Gelasian) and the mid-Pleistocene (late Calabrian). Their expression varies significantly across the area, so that from one to three unconformities may be recognized within any given basin. Several lines of evidence suggest that the spatially variable development of the unconformities across the Arc records interruptions of subsidence by phases of uplift and deformation, related to the extent and nature of successive tectonic events linked to episodic subduction zone retreat and slab fragmentation during the Plio-Pleistocene interval. In particular, the mid-Pliocene unconformity is associated with uplift and deformation on the Ionian flank of the Calabrian Arc that interrupted a phase of basin subsidence coeval with opening of the Vavilov back-arc basin, and may record either interference of the Arc with the Apulian microplate, or an episode of out-of-sequence tectonic thickening within` the advancing accretionary wedge. The two Pleistocene unconformities bracket a phase of basin collapse in northern Calabria that coincides with the ultra-fast opening of the Marsili backarc basin, and are associated with uplift and contractional–transpressional deformation that record interference of the subducting slab with adjacent microplates. The recognition of a synchronous development of unconformities in the Calabrian basins provides key references for further studies of the geodynamic evolution of the central Mediterranean.

‘Cold’ seeps (or cold vents) are seafloor manifestations of fluid migration through sediments from the subsurface to the seabed and into the water column, and may reach the atmosphere. They are an important but not fully understood process in our oceans that has important repercussions on human society and on the climate. Modern sonar systems can obtain seafloor images of cold seep features from tens to thousands of meters wide with metric resolution, providing key information on the formation and evolution of the various seabed expressions of cold seeps. In this chapter we attempt to address cold seep systems with an emphasis on their origin, evolution, form, and occurrence, approaching them primarily from their morphologies and the acoustic character of the seafloor and near bottom erupted sediments. We address morphological characteristics of mud volcanoes, pockmarks, carbonate-related structures including MDAC, AOM and giant carbonate mounds and ridges, offering various examples mainly from recent discoveries in Mediterranean region which are among the most spectacular and most frequently cited examples. Detailed focus on topics such as acoustic backscatter, brine pools, etc. have been described in separate gray boxes of text with the aim to highlight their particular significance. Finally, gaps in knowledge and key research questions on cold seep studies have been outlined with the aim of orienting young researchers and students towards those topics that deserve the highest attention as they are still unresolved., Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Italia, FREMER Laboratoire Aléas géologiques et Dynamique Sédimentaire Centre Bretagne, Francia, Área de Geología Marina, Instituto Geológico y Minero de España, España, Lyngby Marine Geophysical Research, Países Bajos

Anthropogenic trace metal concentrations were studied in sediments of the South Adriatic basin. This study shows that in some Anthropogenic trace metal concentrations were studied in sediments of the South Adriatic basin. This study shows that in some Mediterranean sedimentation systems, the anthropogenic trace metal contamination is affecting not only the coastal areas and continental shelf, but is transferred to some extent also in the adjacent continental slope and deep basin. Complex morphology and sedimentary processes are responsible for the spatial differences in trace metal concentrations between different sub-areas of the South Adriatic. Historical trace metal profiles show trends that were increasing in the 20 century and decreasing in the last 30 years.

Zn and Pb are well known for having a large anthropogenic component in the Adriatic Sea. These trace elements were measured along with OC and mud content in sediments to distinguish their trends among three sectors within the western Adriatic Sea (North, Central and South). The highest concentrations were found in the North within to the Po river prodelta. Discriminant analysis results showed the separation of the North from the Central and the South due to Zn, OC and mud content. Pb did not display a specific trend probably being more associated to the clay fraction of sediments.