Search

By examining the sedimentary records from two new cores collected from the Sabrina Coast slope, we have developed an age model spanning from the late Pliocene to the present. From multiproxy sediment analyses of the piston and kasten core, PC03, and KC03, collected during the IN2017_V01 survey on the Sabrina Coast (East Antarctica) offshore the Totten Glacier, we here present the outcomes derived within the seismostratigraphic record coupled with the sedimentological, geochemical paleomagnetic, and biostratigraphic contexts. Our results highlight that the area has been affected by recurrent sediment slides facilitated by siliceous deposits, both biogenic and from an unprecedented tephra layer, during some of the major paleoclimatological events of the late Pliocene. Diatoms contributed not only to the biostratigraphic and depositional environmental definition but also to the instability of the slope, together with the tephra layer, as documented offshore the Sabrina–Aurora Basin for the first time. [ABSTRACT FROM AUTHOR]

Here, we explore the complex seabed morphologies of the Gulf of Taranto in southern Italy including their connection to the geodynamic evolution of the region that began during the Neogene period when the Adria plate started subducting beneath the retreating Calabrian arc. We compiled the first Maps of the Geohazard Features of the Gulf of Taranto through comprehensive and collaborative high-resolution seabed surveys, integrating regional high-resolution multibeam sonar and sub-bottom profiling. Our findings indicate that the most significant marine geohazards identified are (i) the headwall of the shelf-indenting retrogressive canyon near Cirò Marina, situated close to the harbour, (ii) multiple landslide scarps on the steep slopes of intra-slope basins, along with buried stacked debris flow deposits at their base, indicating repeated mass movements, (iii) large-scale landslide scarps eroding the Apulian slopes (some controlled by faults). We propose that seismicity and tectonic tremor associated with slow slip events, represent potential triggers for geohazards in the Gulf of Taranto. The distinctive physiography of the Gulf creates a natural laboratory for studying and monitoring coastal and marine geohazards. Our study offers a resource for improving the understanding of marine geohazards along the Ionian Calabrian and Apulian margins in the Gulf of Taranto crucial for safeguarding coastal communities and marine infrastructures. [ABSTRACT FROM AUTHOR]

Analysis of multichannel seismic profiles collected on the continental rise off the Sabrina Coast, East Antarctica, has allowed the determination of the acoustic features that are indicative of major evolution steps of the East Antarctic Ice Sheet (EAIS) and highlights the role of meltwater that originated from Totten Glacier in shaping the margin architecture. The arrival of marine-terminating glaciers into the coastal region was recorded by an enhanced sediment input on the continental rise and the nucleation of channel-levees. Downslope sedimentary processes were dominant throughout the Late Cenozoic, testifying to the progressive growth of a highly dynamic, temperate ice sheet on the continent. The last evolutionary step marks the transition to when a full polar glacial regime occurred. The development of a prograding wedge with steeply dipping foresets on the continental shelf and slope exemplifies sedimentation at this time. Other sub-sea-floor observations indicate that downslope fluxes, triggered by glacial meltwater, were still able to deeply erode and deliver sediments to the rise area. This study's findings have led to the identification of expanded and well-preserved sedimentary successions, which we suggest should be considered as priority targets for future International Ocean Discovery Program deep drilling due to the sensitivity of the ice sheet in this area. [ABSTRACT FROM AUTHOR]

The Port of Trieste is an international hub for land and sea trade with the dynamic markets of central and eastern Europe. Thanks to its deep natural draft (about 18 m), the modern high‐capacity vessels can moor to the piers. In view of the foreseen increase in maritime traffic, this harbour is undergoing modernization in order to improve the commercial traffic capability. In this expansion plan, the container Trieste Marine Terminal, Pier VII, is seeking an extension by about 200 m. In support of this feasibility study, multidisciplinary data acquisition was conducted in order to characterize the seabed, the sub‐bottom sediments and the bedrock (flysch formation) in front of the Trieste Marine Terminal. The acquisition of high‐resolution swath bathymetry, side‐scan sonar and magnetometer data allowed a detailed analysis of the seabed conditions from an environmental and safety perspective. High‐resolution seismic reflection data enabled us to characterize the Plio‐Quaternary soft sediments and the underlying bedrock. A static underwater refraction survey was performed using hydrophone array deployed on the sea bottom to obtain seismic velocities and to achieve a reliable time‐to‐depth conversion of reflection seismic data by first‐arrival tomographic inversion. In addition to geophysical investigations, 11 offshore boreholes were drilled for detailed logging. In situ standard penetration tests were performed on core samples with the use of a pocket penetrometer and pocket vane in order to obtain uniaxial compressive strength, undrained shear strength and undrained cohesion values, and assess the cohesive soils. During drilling, 17 undisturbed samples and 12 semi‐disturbed samples were extracted to perform laboratory tests for the identification of the principal geotechnical parameters. The goal was to obtain a reliable geological/geotechnical model in front of the Trieste Marine Terminal – from the seabed to the bedrock. Below the seafloor, a sequence of about 20–30 m thickness, containing Plio‐Quaternary soft sediments, overlies the flysch, which locally presents alteration with rocks of reduced quality. The geophysical–geotechnical integrated approach allowed us to identify and map the top of the bedrock and provided valuable information for planning the pier extension project. [ABSTRACT FROM AUTHOR]

We present a high-resolution swath bathymetric and backscatter map of the entire sector of the Marine Reserve Area (MRA) of the Asinara Island, along with a geological and sediment thickness map derived from the interpretation of a large set of high-resolution seismic profiles, and an airborne-derived hyperspectral image of the Asinara Island. Acquired data show that most of the eastern marine sector of the Asinara Island is characterized by quite gentle bathymetric gradients, whereas the western coastline appears to be very indented, with an articulated and rough morphology of the seafloor, which deepens sharply towards the open sea. The maps presented in this study at the 1:50.000 scale do not only provide the first, high-resolution bathymetry of the MRA of the Asinara Island but also may furnish the base for the creation of a benthic habitat map and a more comprehensive maritime spatial planning of this protected area. [ABSTRACT FROM AUTHOR]