This project was performed to investigate the evolution of Western ice sheet (WIS) in the Eastern Basin (Ross Sea), Antarctica. The Ross Sea is part of the West Antarctic Rift System that has three main depocenters as the Eastern Basin, the Central Basin and the Victoria Land Basin. The Eastern Basin contains a thick sedimentary sequence that tells about the WIS advance and retreat. DSDP cores were drilled in this area (Hayes and Frakes, 1975) gives knowledge about the stratigraphy and the depositional environment of the area from Upper Miocene to Pleistocene (Hayes and Frakes, 1975). Large erosional hiatuses and poor interpretations of DSDP cores, do not let to construct of the Eastern Basin depositional history and the evolution of the WIS (Hayes and Frakes, 1975; Denton et al., 1991). On the other hand, multichannel seismic studies in the Ross Sea gives more knowledge about the sedimentary sequences and unconformities (ANTOSTRAT, 1995). These studies show that Lower Pliocene is identified by a marked erosion surface, called RSU2 (De Santis et al., 1995; Brancolini et al., 1997), and is correlated with a large hiatus in DSDP 273 which is dated from 10.5 to 4 ma (Savage and Ciesielski, 1983). Horizon RSU2 corresponds to a sharp change in the structure and lithology of sediments, which may be interpreted as a major increase of the glacial influence. Thus, it is clear that RSU2 identifies a major, unique event in the depositional history at the Ross Sea. The explanation of this event is today largely hypothetical, based on progressive climatic cooling occurred during Pliocene and the consequent grow of the Antarctic ice sheet. For setting up reliable paleo-climatic models, however, we have to define precisely the extension and features of the ice sheet: thus, we proposed to carry out a detailed geophysical study in a specific area of the Ross Sea, for reconstructing dimensions and dynamics of the Eastern ice sheet during Pliocene, a period of large changes at a global level, anda also the most debated one for the history of the Antarctic ice sheet.

High-resolution multichannel seismic profiles have been collected in January–March 2017 by OGS on the continental rise off the Sabrina Coast (East Antarctica). The data were acquired as part of the Italian Program of Antarctic Research (PNRA) TYTAN “Totten Glacier dynamics and Southern Ocean circulation impact on depositional processes since the Mid- to Late Cenozoic” project (PI: F. Donda-OGS) during the Australian Marine National Facility survey IN2017-V01 on board the RV Investigator. TYTAN was embedded in to the Australian project "Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles” that aimed to understand the interaction of Totten Glacier and its ice drainage basin with the Southern Ocean during periods of warming and ice-sheet retreat in the Pleistocene and Holocene. In order to achieve these scientific objectives, three areas were identified for the geophysical and oceanographic survey: two on the continental slope and rise off Sabrina Coast and one on the continental shelf, which was not investigated because it remained covered by sea ice throughout the season. Expanded and well-preserved sedimentary successions imaged on the TYTAN seismic data highlight the potential of this region for deep ocean drilling, which will provide unprecedented history of the glaciers evolution in the Aurora Basin and their sensitivity to climate change under different background state conditions. In fact, TYTAN seismic data played a crucial role in the identification of potential drilling sites for the IODP 1002 Proposal “Totten Glacier Climate Vulnerability under varying Neogene climate conditions: Lessons for East Antarctic Ice Sheet climate sensitivity” (under review).

Complementary with the ODYSSEA project funded by PNRA, ANTSSS aimed at finding evidence for Late Pleistocene sedimentary signatures of major changes in the extent of grounded, marine based ice sheets in the Ross Sea, as preserved in slope/ rise drift deposits by means of seismic and oceanographic data. During the 2017 expedition, OGS Explora collected over 450 km of Single Channel Seismics (SCS), 1575 km2 of bathymetry, >500 km of sub-bottom, and oceanographic data, including Conductivity Temperature Depth (CTD), Acoustic Doppler Current Profiler (ADCP), Lowered-ADCP, Expendable Bathythermograph (XBT) and turbidity data. Part of the seismic data have been initially published in Gales et al. (2021) Role of dense shelf water in the development of Antarctic submarine canyon morphology. Geomorphology, 372, art. no. 107453. DOI: 10.1016/j.geomorph.2020.107453

High-resolution multichannel seismic profiles have been collected in January–March 2017 by OGS on the continental rise off the Sabrina Coast (East Antarctica). The data were acquired as part of the Italian Program of Antarctic Research (PNRA) TYTAN “Totten Glacier dynamics and Southern Ocean circulation impact on depositional processes since the Mid- to Late Cenozoic” project (PI: F. Donda-OGS) during the Australian Marine National Facility survey IN2017-V01 on board the RV Investigator. TYTAN was embedded in to the Australian project "Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles” that aimed to understand the interaction of Totten Glacier and its ice drainage basin with the Southern Ocean during periods of warming and ice-sheet retreat in the Pleistocene and Holocene. In order to achieve these scientific objectives, three areas were identified for the geophysical and oceanographic survey: two on the continental slope and rise off Sabrina Coast and one on the continental shelf, which was not investigated because it remained covered by sea ice throughout the season. Expanded and well-preserved sedimentary successions imaged on the TYTAN seismic data highlight the potential of this region for deep ocean drilling, which will provide unprecedented history of the glaciers evolution in the Aurora Basin and their sensitivity to climate change under different background state conditions. In fact, TYTAN seismic data played a crucial role in the identification of potential drilling sites for the IODP 1002 Proposal “Totten Glacier Climate Vulnerability under varying Neogene climate conditions: Lessons for East Antarctic Ice Sheet climate sensitivity” (under review).

SEDANO Project aim to understand the origin of the glacial depositional systems found offshore the Pacific margin of the Antarctic Peninsula. Four main glacial depositional systems have been identified. Geophysical surveys were carried out during these two projects The cores collected in this area characterise the sediment drifts as composed by fine-grained, poorly-sorted sediments, sourced from turbidity currents generated on the continental slope. To elucidate the role of dispersal and redistribution of sediments by bottom currents, three one-year long bottom current records in the area of the mound 7 were collected as well as nine CTD measurements collected in the same area . It is worthwhile noting the importance of this data set, constituting the first current measurements available in the Pacific margin of the Antarctic Peninsula. The aim of this work threefold: to infer which are the major large scale processes that govern bottom current regime, to understand the Bottom Boundary Layer (BBL) dynamics, and to assess the potential for resuspension induced by the measured currents.

High-resolution multichannel seismic profiles have been collected in January–March 2017 by OGS on the continental rise off the Sabrina Coast (East Antarctica). The data were acquired as part of the Italian Program of Antarctic Research (PNRA) TYTAN “Totten Glacier dynamics and Southern Ocean circulation impact on depositional processes since the Mid- to Late Cenozoic” project (PI: F. Donda-OGS) during the Australian Marine National Facility survey IN2017-V01 on board the RV Investigator. TYTAN was embedded in to the Australian project "Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles” that aimed to understand the interaction of Totten Glacier and its ice drainage basin with the Southern Ocean during periods of warming and ice-sheet retreat in the Pleistocene and Holocene. In order to achieve these scientific objectives, three areas were identified for the geophysical and oceanographic survey: two on the continental slope and rise off Sabrina Coast and one on the continental shelf, which was not investigated because it remained covered by sea ice throughout the season. Expanded and well-preserved sedimentary successions imaged on the TYTAN seismic data highlight the potential of this region for deep ocean drilling, which will provide unprecedented history of the glaciers evolution in the Aurora Basin and their sensitivity to climate change under different background state conditions. In fact, TYTAN seismic data played a crucial role in the identification of potential drilling sites for the IODP 1002 Proposal “Totten Glacier Climate Vulnerability under varying Neogene climate conditions: Lessons for East Antarctic Ice Sheet climate sensitivity” (under review).

During austral summer1996/97, the National Institute of Oceanography and Applied Geophysics - OGS, on board the research vessel OGS-Explora, conducted marine geological and geophysical surveys along the Antarctic Peninsula. During this cruise there were several research programmes; TENAP, BSR and SEDANO II. The TENAP (cenozoic Tectonic Evolutionof the Northem Antarctic Peninsula) programme was a geological and geophysical research project to study the Cenozoic tectonic evolution of the Antartic Peninsula and its borders; data were collected between longitude 59 and 66 degrees West, and latitude 61 and 64 degrees South. During this programme 702.5 km of 30-fold multichannel seismic reflection (MCS) data, 16 second records, 4 ms sample rate, were recorded on a SERCEL SN 358 DMX system. The source consisted of an airgun array with a total volume of 60.5 litres, using the Single Bubble methodology, fired every 50 meters into a 3000 m cable consisting of 120 hydrophone groups towed at an average depth of 12 m. A GPS + TRANSIT satellite receiver system was used for navigation. The Chief Scientists on this programme was: Giulio Pellis of the Dipartimento di Ingegneria Civile e Ambientale of the Università di Trieste, Piazzale Europa n. 1, 34127 Trieste, Italy. Processing of the data generally followed a conventional sequence: Reformat, Quality control, Amplitude recovery, Deconvolution, Velocity analysis, NMO corrections, Mute, Trace weighting, Stack, Mixing, Filter, Dynamic trace equalisation.

Complementary with the ODYSSEA project funded by PNRA, ANTSSS aimed at finding evidence for Late Pleistocene sedimentary signatures of major changes in the extent of grounded, marine based ice sheets in the Ross Sea, as preserved in slope/ rise drift deposits by means of seismic and oceanographic data. During the 2017 expedition, OGS Explora collected over 450 km of Single Channel Seismics (SCS), 1575 km2 of bathymetry, >500 km of sub-bottom, and oceanographic data, including Conductivity Temperature Depth (CTD), Acoustic Doppler Current Profiler (ADCP), Lowered-ADCP, Expendable Bathythermograph (XBT) and turbidity data. Part of the seismic data have been initially published in Gales et al. (2021) Role of dense shelf water in the development of Antarctic submarine canyon morphology. Geomorphology, 372, art. no. 107453. DOI: 10.1016/j.geomorph.2020.107453

During Austral Summer1990-91 the National Institute of Oceanography and Applied Geophysics - OGS conducted marine geological and geophysical surveys in the Ross Sea, over Weddel Sea and in the Balleny Zone of the MacQuarie Triple Junction. This cruise collected approximately 6036 km of multichannel seismic reflection (MCS) data. The surveys extended, in different areas, between longitudes 37 and 56 degrees west, and between latitudes 59 and 62 degrees south (Weddel Sea), between longitudes 171 east and 178 degrees west, and between latitudes 71 and 73 degrees south (Ross Sea), between longitudes 150 and 158 degrees east , and between latitudes 51 and 62 degrees south (Balleny). The surveys were carried out by the research vessel OGS Explora. The digital MCS data were recorded on a SERCEL SN 358 DMX system. The source consisted of an airgun array with variable configuration from a total volume of 45.16 litres fired approximately every 50 meters. A GPS + TRANSIT satellite receiver system was used for navigation. Processing of the data generally followed a conventional sequence: Reformat, Trace-sum with differential NMO, Quality control, Amplitude recovery, Deconvolution, Velocity analysis, NMO corrections, Mute, Trace weighting, Stack, Mixing, Filter, Balance.

During Austral Summer 1993-94 the National Institute of Oceanography and Applied Geophysics - OGS conducted marine geological and geophysical surveys over the Ross Sea, cruise IT91AR. During this cruise 581 km of 30-fold multichannel seismic reflection (MCS) data were collected in the Ross Sea, off the Cape Hallett, between longitudes 171 degrees East and 178 degrees West, and latitudes 71 and 73 degrees South. In 1993-94 the OGS completed the cruise IT94AR, with 852 km of 30-fold and 673 km of 3-fold multichannel seismic reflection data collected in the Ross Sea, off the coast of the McMurdo Island, between longitudes 168 degrees East and 181 degrees West, and latitudes 73 and 77 degrees South. The surveys were carried out by the research vessel OGS Explora. The digital MCS data were recorded on a SERCEL SN 358 DMX system. The source consisted of an airgun array with a total volume of 71.5 litres fired approximately every 50 meters into a 3000 m cable consisting of 120 hydrophone groups for the 30-fold profiles and every 250 meters into a 1500 m streamer for the 3-fold profiles. A GPS + TRANSIT satellite receiver system was used for the navigation. Processing of the data generally followed a conventional sequence: Reformat, Trace-sum with differential NMO, Quality control, Amplitude recovery, Deconvolution, Velocity analysis, NMO corrections, Mute, Trace weighting, Stack, Mixing, Filter, Balance.