Calibrated (in unit of solar disk brightness) measurements of the sky brightness at DOME C as obtained by the ESCAPE experiment during the campaign 2019-2020

Here we present the surface snow samples collected along the international EAIIST project traverse, which took place in 2019-2020 Antarctic Campaign. We report the number of surface samples (upper 10 cm and integrated 1m samples) collected and their geographic information.

We present here the final 100-meter cell size grid projection EPSG:9354 and metadata from the ISOBatA PNRA project, shared with the Alfred Wegener Institute (AWI) as part of the International Bathymetric Chart of the Southern Ocean (IBCSO). This dataset was collected by the ISOBatA project team using the Kongsberg EM304 multibeam system installed on the R/V Laura Bassi. The dataset processed and quality-controlled using QPS Qimera software and corrected for sound velocity using XBT and CTD data (courtesy of the MORSEA project), has been provided to AWI (IBCSO) and is archived here to ensure traceability, wide dissemination, and future usability. The PNRA-funded project ISOBatA (Italian Southern Ocean Bathymetry from consistent exploitation of opportunistic seafloor datasets in the Antarctic region and surrounding areas) introduced an innovative approach to optimize the collection of acoustic (mainly bathymetric) and magnetometric data. The primary objective of the project was to improve the bathymetric understanding of the Southern Ocean by collecting multibeam echosounder data during the Laura Bassi expeditions, focusing on previously unexplored areas in the Ross Sea and in the region between the Macquarie Triple Junction (MQ TJ) and the Emerald Fracture Zone (EMZ). The operational phase of ISOBatA spanned three expeditions: XXXVII (2021-2022), XXXVIII (2023), and XXXIX (2024) of the Laura Bassi in Antarctica. In the first two years (XXXVII and XXXVIII), the project benefited from dedicated ship time, which enabled efficient data collection through strategic speed reductions during transfers and route adjustments along pre-identified corridors. Data collection was planned based on pre-existing metadata, such as IBCSO coverage, the Seismic Data Library (SDL), Italian Mooring Sites, and Italian Coring and Box Coring Sites. This also included transit routes through the Southern Ocean along the MQ and EMZ, as well as unmapped areas in the Ross Sea, such as the Italian MORSEA Mooring Sites. In the third year (XXXIX), no dedicated ship time was available. Nevertheless, ISOBatA managed to collect data under two conditions: 1) without changing the ship's course or speed and 2) by simultaneously collecting acoustic data for other projects, which affected the spatial resolution of the data collected with EM304. Despite the challenges posed by rough seas, ice, ship speeds, and the lack of tide gauges, ISOBatA proved the feasibility of opportunistic acoustic data collection, particularly in the Ross Sea. This was achieved by utilizing downtime during mooring maintenance, support for supply vessels, medical evacuation (MEDEVAC), and sheltering during standby weather conditions. Onboard data sharing fostered valuable collaborations with other research teams, enhancing the overall scientific results. We acknowledge the MORSEA project for providing real-time of XBT and CTD data, which enabled the application of accurate sound velocity profiles. We also thank to the PNRA Program for funding and support, to ISOBatA project partners: OGS (PI D. Accettella, P. Diviacco), UniMIB (A. Savini), IGAG-CNR (M. Cuffaro), and INGV (F. Muccini), as well as the Laura Bassi research teams for their scientific contributions and collaborations. Keywords: Southern Ocean, Bathymetry, ISOBatA, Laura Bassi, Antarctica, IBCSO.

Here we present the firn cores collected along the international EAIIST project traverse, which took place in 2019-2020 Antarctic Campaign. We report the number of firn cores collected, the depth of the samplings and their geographic information.

Below the results obtained by the HOT ANTARCTICA project are presented. Results regarding geochemistry of crustal melts Main results obtained by the most prominent samples are described separately for each of the investigated terranes (Napier Complex, Lützow Holm Complex, Rauer Islands and Schrimacher Hills). The methodology employed during the work is also listed below: 1) Samples interrogated in this project were previously collected from Napier Complex (provided by the collaboration with Prof. Simon Harley, University of Edinburgh), Lützow Holm Complex (provided by the collaboration with Prof. Satish-Kumar, University of Niigata), Rauer Islands (provided by the collaboration with Prof. Simon Harley, University of Edinburgh and in collaboration with Zhao Liu, Northwest University ,China) and Schrimacher Hills (provided by the Museo Nazionale dell’Antartide, Siena, Italy). 2) Microstructural and petrographic study were done in all samples to identify equilibrium assemblages, melting reaction microstructures and occurrence of nanogranitoids (i.e. crystallized inclusions), melt and fluid inclusions. 3) Microstructural characterization of inclusions using Field Emission-Scanning Electron Microscope (FE-SEM) analyses were done: i) to identify the submicrometric phases within nanogranitoids and ii) to verify the homogeneity of remelted nanogranites and preserved glassy melt inclusions. 4) Experimental remelting of crystallized melt inclusions was performed to overcome the problem of MI decrepitation and volatile loss. The remelting of nanogranitoids was performed at high pressure with a piston cylinder apparatus using a QUICKpress piston cylinder apparatus produced by Depths of the Earth (installed at the Dipartimento di Geoscienze, UniPd). 5) Analysis of the major and trace elements contents of melt inclusions was carried out using i) an electron microprobe at the at University of Milan and ii) a LAICPMS at University of Perugia. 6) Thermodynamic modeling of anatectic conditions: the evaluation of P-T-X parameters and of P-T paths in the different geologic contexts were carried out using the software Perple_X. 7) Micro-Raman spectroscopy: characterization of fluid inclusions coexisting with melt inclusions was done using a HORIBA LabRam HR (high resolution) Raman microspectrometer at the University of Pavia. 8) Cross-comparison of data: during the development of this research project all collected data were analyzed by cross-comparing the information from the different geological contexts, with the aim to highlight similarities and differences. 9) Data discussion and evaluation: all data was analyzed and discussed in tight collaboration with the researchers involved in this project. 10) Synthesis and dissemination of results: dissemination of results was done with oral and poster presentations in several international conferences (see list on the appropriate section - Atti). Presentations include invited keynote presentations by the PI, Bruna Borges Carvalho at Goldschmidt (France, 2023) and Hutton Symposium (Italy, 2023). Invited seminars were also given in several important universities around the world [University of Bern, Switzerland; University of Cambridge, UK; University of Niigata, University of Kyoto, Japan]. Furthermore, a total of two research papers have been published in journals of high impact factor, and other two articles are in preparation. Here we also provide mineral, geochemical and geochronological data of studied areas at Rundvagshetta and Rauer Islands. Preprinted versions of two published article where the data is explained are also provided. Carvalho, B.B., Bartoli, O., Cesare, B., Satish-Kumar, M., Petrelli, M., Kawakami, T., Hokada, T., Gilio, M. (2023). Revealing the link between A-type granites and hottest melts from residual metasedimentary crust. Geology 51, 845-849. https://doi.org/10.1130/G51097.1 Liu, Z., Carvalho, B.B., Li, W., Tong, L., Bartoli, O., Li, C., Chen, L., ,Yan, Q, Wu, H. 2023. Into the high to ultrahigh temperature melting of Earth’s crust: Investigations of melt and fluid inclusions within Mg–rich metapelitic granulites from the Mather Peninsula, East Antarctica. Journal of Petrology 64, egad051. https://doi.org/10.1093/petrology/egad051 Results regarding petrology and geochronology of granulites In northern Victoria Land, the presence of two contrasting P-T paths suggests the possibility that high-grade complexes could have experienced a different metamorphic evolution both in space and time. Geochronological data of the Granite Harbour Intrusives support a prolonged magmatic activity (540-480 Ma), with multiple igneous pulses. This could imply the existence of magmatic underplating triggering the development of monometamorphic granulites during the Ross Orogeny. On the other hand, structural and PT evolution suggest the presence of a polymetamorphic granulitic belt that could be remnant of older orogeny as the Panafrican (ca. 600-500 Ma) (Lombardo et al., 1987; Palmeri, 1997; Talarico and Castelli, 1995). In order to discriminate mono- from poly-metamorphic evolution, metasedimentary granulite complex from the Deep Freeze Range has been investigated. Among all available granulite samples, a detailed petrographical study has been conducted to select the most representative and suitable HT granulite-facies rocks: four samples have been individuated for petrological and geochronological analyses (Opx-Grt and >30 µm Zrn/Mnz bearing), fifteen for geochemistry (absence of leucosome). In the Deep Freeze Range, HT granulites consist of Grt-Opx±Bt±Crd±Spl±Crn gneisses characterized by the presence of numerous Opx±Grt leucocratic segregations. Geochemical results confirm that analyzed granulite protholites have sedimentary origin, being comparable to Post Archean Australian Shale (PAAS; Taylor and McLennan, 1985), and they have been deposited in an orogenic setting (active continental margin). Petrographical, microstructural and mineral chemistry analyses show a metamorphic evolution including three different stages: Pl-Grt1-Spl-Crn-Ilm medium-P granulite facies (M1), Qtz-Pl-Opx-Grt1-Crd-Ilm-Kfs low-P granulite facies (M2), and Qtz-Pl-Grt2-Kfs-Bt-Ath low-P amphibolite (M3). Preliminary petrological results indicate that evolving metamorphic parageneses describe an initial isothermal decompression (exhumation event) followed by isobaric cooling; further thermodynamic modeling by software Perple_X will allow to better define P-T-X conditions. Geochronological studies involved the observation and analysis of monazites and zircons on four selected granulite thin sections. Investigations included X-ray mapping carried out under the electron microscope, CL-BSE imaging (zircons), and trace element analysis and U-Pb dating using LA-ICP-MS. Acquired data are still under review and will have a fundamental role in the reconstruction of the P-T-t path, thus making it possible to discriminate between mono- and poly-metamorphic hypotheses. References Lombardo et al 1987. Memorie della Società Geologica Italiana 33, 99-130. Palmeri R. 1997. Lithos 42, 47-66. Talarico and Castelli D. 1995. Precamb. Res. 75, 157-174. Taylor and McLennan S.M. 1985. Blackwell, Oxford, 312 p.

The larval stages can be considered as the link from plankton to benthos. In order to study larval recruitment from zoobenthos, 40 tiles were placed at each of the four sites outlined in the project: Tethys Bay (control), Rod Bay (area subject to anthropogenic impact), Faraglione (control) and Adelie Cove (area subject to natural impact, linked to the presence of a penguin house). Due to adverse environmental factors all the tiles from Faraglione were lost and from Tethys Bay only half were found. The tiles were analysed with the help of a binocular, which enabled better visualisation of the organisms and, consequently, better identification.

Antarctic ecosystems have a high number of species, that are closely linked to the presence of sea ice and seasonal cycles. This biodiversity is subject to anthropogenic and natural influences. Zooplankton communities can provide a static snapshot of the health of the ecosystem. Zooplankton samples were collected with a 200 μm mesh net at 3 different sampling points at 80 m depth.

The raw SeaSpy magnetometer data presented here were collected in the Southern Ocean (SO) as part of the ISOBatA PNRA project during the XXXVII and XXXVIII Italian Antarctic expeditions on board the icebreaker Laura Bassi. The ISOBatA project (Italian Southern Ocean Bathymetry from consistent exploitation of opportunistic seafloor datasets in the Antarctic region and surrounding areas) aimed to improve the understanding of the Southern Ocean through a novel approach that systematically integrates the collection of bathymetric and magnetometric data during the Laura Bassi voyages in poorly charted regions between the Macquarie Triple Junction – MTJ and the Emerald Fracture Zone n-EFZ. This dataset spans two field campaigns (2021-2022 and 2023) collected through optimized navigation strategies, including reducing vessel speed during transits and following pre-planned corridors to enhance data quality and spatial coverage. The project was a collaboration between OGS (PI D. Accettella), UniMIB (A. Savini), IGAG-CNR (M. Cuffaro) and INGV (F. Muccini). The work was supported by the Programma Nazionale di Ricerca in Antartide - PNRA and benefited from the joint efforts of the Laura Bassi research teams on board. Keywords: Southern Ocean, Bathymetry, ISOBatA, Laura Bassi, Antarctica, IBCSO.

We will collect stool samples from the volunteers at the Mario Zucchelli Station at different time points. The samples will be analysed by shotgun metagenomic sequencing, considering only the microbial component.

Calibrated (in unit of solar disk brightness) measurements of the sky brightness at DOME C as obtained by the ESCAPE experiment during the campaign 2018-2019