The Eocene-Oligocene Transition at c. 34 million years ago (Ma) marked the global change from greenhouse to icehouse and the establishment of the East Antarctic Ice Sheet (EAIS). How the ice-sheet behaviour changed during interglacials across this climate transition is poorly understood. We analysed major, trace and rare earth elemental data of late Eocene interglacial mudstone from Prydz Bay at Ocean Drilling Program Site 1166 and early Oligocene interglacial mudstone from Integrated Ocean Drilling Program Site U1360 on the Wilkes Land continental shelf. Both sites have comparable glaciomarine depositional settings. Lithofacies and provenance at Site 1166 in Prydz Bay are indicative of a late Eocene glacial retreat in the Lambert Graben. Palaeoclimate proxies, including the Chemical Index of Alteration, mean annual temperature and mean annual precipitation, show a dominant warm and humid palaeoclimate for the late Eocene interglacial. In contrast, at Site U1360, in the early Oligocene, the provenance and interglacial weathering regime remained relatively stable with conditions of physical weathering. These results confirm that the EAIS substantially retreated periodically during late Eocene interglacials and that subglacial basins probably remained partially glaciated during interglacials in the earliest Oligocene.

In order to reconstruct past environmental conditions along the north-eastern Antarctic Peninsula, we documented changes in grain size, grain roundness, onlap as seen in ground-penetrating radar reflection profiles and ice-rafted debris on a set of 36 raised beaches developed over the last ~7.7 ± 0.9 ka on Joinville Island. The most pronounced changes in beach character occur at ~2.7–3.0 ka. At this time, there appears to have been a reintroduction of less rounded material, the development of stratification within individual beach ridges, an introduction of seaweed and limpets to the beach deposits, a change in clast provenance (although slightly earlier than the change in cobble roundness) and a shallowing of the overall beach plain slope. Prolonged cooling associated with the Neoglacial period may have contributed to these changes, as the readvance of glaciers could have changed the provenance of the beach deposits and introduced more material, leading to the change in roundness of the beach cobbles and the overall slope of the beach plain. This study suggests that late Holocene environmental change left a measurable impact on the coastal zone of Antarctica.

Antarctic soils provide an excellent setting to test biogeographical patterns across spatial and environmental scales given their relatively simple communities and the dominance of physical factors that create strong environmental gradients. Additional urgency is given by the fact that their unique terrestrial communities are the subject of conservation efforts in a rapidly changing environment. We investigated relationships of soil community assembly and alpha and beta diversity with climatic and environmental parameters across regional and local scales in Maritime Antarctica. We sampled from a regional gradient of sites that differ in habitat severity, ranging from relatively favourable to harsher physicochemical conditions. At the regional scale, bacterial community characteristics and microarthropod abundance varied along this severity gradient, but most measures of fungal communities did not. Microarthropod and microbial communities differed in which soil and climate parameters were most influential, and the specific parameters that influenced each taxon differed across broad and fine spatial scales. This suggests that conservation efforts will need to focus on a large variety of habitat characteristics to successfully encompass diversity across taxa. Because beta diversity was the result of species turnover, conservation efforts also cannot focus on only the most biodiverse sites to effectively preserve all aspects of biodiversity.

Ross seals (Ommatophoca rossii) travel away from the pack ice and spend most of their year foraging pelagically. Here, we augment the few existing records of Ross seal diving and haul-out behaviour, providing novel insights into how these are influenced diurnally and seasonally. We used biologging devices that recorded the dive behaviour (n = 5) and/or haul-out behaviour (n = 9) of Ross seals in the eastern Weddell Sea (2016–2019). Ross seals mostly dived between 100 and 200 m deep, often > 300 m, and for 5–12 min in duration, often > 20 min. During March–July, when Ross seals forage pelagically, diving metrics varied diurnally. The seals dived deeper during twilight and shallowest at night, while the number of dives and diving duration did not follow a clear diurnal pattern. Consequently, diving effort was highest during the night. Ross seals preferentially hauled out in the middle of the day during September, October, February and December, but not during the rest of the year. Three females that entered the pack ice during breeding season were hauled out continuously for 5–7 days, punctuated by water entries for 1–3 h during and/or after such continuous haul-outs over the breeding season. This behaviour might suggest that Ross seals alternate between capital and facultative income breeding.

The first recorded volcanic eruption in Antarctica occurred on Bridgeman Island (South Shetland Islands) in early 1821, < 2 years after Antarctica was discovered. However, the observations were disputed owing to a lack of physical evidence. A consensus arose that they probably referred to Penguin Island, a young volcano with a well-formed volcanic cone situated just 60 km to the west. However, a recent re-examination of the historical reports demonstrated that the event was undoubtedly located at Bridgeman Island. Our new study demonstrates that the eruption was explosive and lasted throughout 1821. The vent was situated in the sea ~500 m to the west of Bridgeman Island and the eruption was hydrovolcanic (Surtseyan). The new volcano constructed a tuff ring composed of unconsolidated lapilli and ash, which rapidly coalesced with nearby Bridgeman Island, similar to how the Capelinhos volcano joined with neighbouring Faial (Azores) in 1957–1958. The tuff ring had a very low profile and was rapidly removed by marine erosion. However, fumarolic activity persisted for a few decades. Because the eruption is only 200 years old, the underlying volcanic construct (Bridgeman Rise) should be regarded as dormant rather than extinct.

The natural environment in polar regions is being transformed, glaciers are melting and succession of microarthropods is being observed. We tested the hypothesis that habitat conditions, determined by the locality and character of the vegetation cover, play a significant role in such succession. The material for analysis was collected from four localities on King George Island in Antarctica: Arctowski Station, Demay Refuge, Republica del Ecuador Refuge and Comandante Ferraz Antarctic Station. From each locality, 30 samples (grasses, lichens, mosses) were collected and 310 508 microarthropod specimens were recorded, with 17 species (1 Mesostigmata, 9 Oribatida, 7 Collembola species) identified. Based on statistical analyses, it was shown that microarthropod communities differ both in individual localities and selected microhabitats. The greatest number of species was reported in the grass turf, while the greatest number of individuals was recorded in mosses. The dominant species at all the localities was Cryptopygus antarcticus antarcticus (299 203 individuals), which was found in greatest numbers in grasses and mosses. In turn, Tullbergia mixta (2485 individuals) was the dominant species of the lichens. Moreover, the following species, new to King George Island, were also identified: Flagrosuctobelba subcornigera, Liochthonius australis, Membranoppia ventrolaminata and Quadroppia monstruosa belonging to Oribatida as well as Archisotoma brucei belonging to Collembola.

Communication at the science-policy interface can be bewildering not only for early-career researchers, but also for many within the research community. In the context of Antarctica and the Southern Ocean, decision-makers operating within the Antarctic Treaty System (ATS) aspire to use the best available science as a basis for their decision-making. Therefore, to maximize the impact of Antarctic Treaty Parties' substantial investment in southern polar research, researchers wishing to contribute to policy and management must understand 1) how their work relates to and can potentially inform Antarctic and/or global policy and 2) the available mechanisms by which their research can be communicated to decision-makers. Recognizing these needs, we describe the main legal instruments relevant to Antarctic governance (primarily the ATS) and the associated meetings and stakeholders that contribute to policy development for the region. We highlight effective mechanisms by which Antarctic researchers may communicate their science into the policy realm, including through National Delegations or the Scientific Committee on Antarctic Research (SCAR), and we detail the key contemporary topics of interest to decision-makers, including those issues where further research is needed. Finally, we describe challenges at the Antarctic science-policy interface that may potentially slow or halt policy development.

Deciphering the sub-ice geology in the Wilkes Subglacial Basin region is important for understanding solid earth-ice sheet evolution and for assessing geological ties between East Antarctica and formerly contiguous Australia. We analyse marine sediment samples derived from drill site U1359 of Integrated Oceanic Drilling Program Expedition 318. Our study reports for the first time that the inland sediment source area comprises a complex mafic igneous terrain and a metamorphosed Precambrian subglacial basement. Pyroxene geochemical analyses confirm the presence of tholeiitic to calc-alkaline basalts. The high-grade part of the subglacial terrain contains upper amphibolite to granulite facies rocks that are comparable to Archaean to Palaeoproterozoic rocks exposed in the Terre Adélie Craton and the formerly adjacent Gawler Craton in Australia. Chemical Th-U-total Pb isochron method (CHIME) ages extracted from a subhedral monazite grain associated with the low-grade biotite-muscovite schist rock fragment provide a unimodal age of 799 ± 13 Ma. Rare occurrences of 800 Ma age in the Terre Adélie Craton and/or George V Coast provide evidence for the presence of at least one late Neoproterozoic magmato-metamorphic event in the interior of Wilkes Land. The affinity of the unexposed geological domains of Wilkes Land, East Antarctica, with their Australian counterparts is discussed in the context of the Rodinia supercontinent.

Antarctica is a continent dedicated to ‘peace and science’ and subject to international consensus-based governance through the Antarctic Treaty System. Through the Treaty, decision-making powers are reserved to Consultative Parties, which are those countries recognized as demonstrating ‘substantial scientific research activity’ in Antarctica. Türkiye acceded to the Antarctic Treaty in 1996. In its National Polar Science Program (2018–2022) it first declared a desire to attain consultative status to the Treaty. Here, we examine Türkiye‘s recent development across Antarctic science, policy and logistics. Since 2016, Türkiye’s national Antarctic scientific output has increased threefold, ranking seventh amongst the current 27 non-Consultative Parties, and this output is greater than some Consultative Parties. Türkiye has submitted more papers to the Antarctic Treaty Consultative Meetings than any other non-Consultative Party and is actively participating in the development of the Antarctic Protected Area system. To facilitate longer-term research goals, Türkiye is constructing an Antarctic research station (Horseshoe Island, Antarctic Peninsula), has joined several polar organizations, including the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP), and has developed scientific and logistical collaborations with many established Antarctic nations. The exceptionally rapid growth of Türkiye's Antarctic activities provides a firm foundation for the development of a future application for consultative status.

The changes implemented in 2005 in the development strategies of Antarctic science carried out by Chile have had a positive impact on the scientific productivity of the Chilean Antarctic Science Program (PROCIEN). We analysed scientometric indicators from between 2009 and 2019. The bibliographic data were extracted from the Web of Science database using search query keywords. We used multiple correspondence analysis to identify specific trends and also network analyses of international collaboration in VOSviewer. The number of Antarctic science publications in Chile has gradually increased from 21 in 2009 to 95 in 2019. The rise in the number of articles was higher in journals for the first impact factor quartile. Research lines showing increased first-quartile impact factor papers corresponded to Antarctic ecosystems, biotechnology and geosciences. The main geographical domains in which such research activities have been carried out corresponded to in the South Shetland Islands and the Antarctic Peninsula. Fieldwork data are the main sources for the production of scientific articles, and there are three science platforms within which most of these papers concentrate. The diversification of funding sources, the implementation of improvements in the selection process and Chile's alignment with Scientific Committee on Antarctic Research programmes have contributed to improving the science that Chile has developed in Antarctica.

More than 60 years since it entered into force in 1961, the Antarctic Treaty is experiencing significant challenges. These challenges also affect its associated instruments known as the Antarctic Treaty System (ATS). These are mostly external dynamics that are increasingly challenging the ATS from outside of the Antarctic region. They encompass a spectrum of issues relating to global legal regimes and to what extent they are applicable in the Antarctic context. Climate change appears to be the most significant of these challenges, as the tangible planetary impacts of global warming and the perception of its urgency and seriousness by states have prompted additional challenges to the ATS. The physical changes that continue to be scientifically unveiled in the Antarctic are manifesting severe impacts on a planetary scale, and this fact has underscored the need for broader and more rapid international engagement within the Antarctic governance discourse. Nevertheless, the existing decision-making mechanisms compounded by the adversarial atmosphere within the ATS due to external factors have become challenges of themselves. Such challenges call for the re-contemplation and reassessment of the legal regime of the Antarctic in general, and the ATS in particular, to find ways forward for an otherwise historically effective international legal system. This paper utilizes both scientific and legal lenses to underscore the urgent need to achieve better communication between the ATS generally, the Antarctic Treaty Consultative Meetings specifically and the UN Framework Convention on Climate Change and Intergovernmental Panel on Climate Change regimes and to overcome the multiple barriers that stand in the way of achieving that objective.

With the Antarctic region featuring more and more in discourse around anthropogenic climate change, understanding public support for research in the region is increasingly important. We examine public support for Antarctic science in Australia, drawing on findings from a nationally representative survey of just over 1000 adults conducted in 2021–2022. Key results reinforce earlier findings in other national contexts - for example, that older people and men are more likely to support Antarctic scientific research than younger people and women. They also reveal new information, including a correlation between particular sources of media coverage and support for Antarctic research. Our data have implications for where and how the public engagement efforts of government agencies and non-governmental organizations could most usefully be applied. While the survey is focused on Australia, it points to complexities around public support for Antarctic research that could be productively investigated in other national and in international contexts.

Subglacial melt has important implications for ice-sheet dynamics. Locating and identifying subglacial lakes are expensive and time-consuming, requiring radar surveys or satellite methods. We explore three methods to identify source regions for lakes using seven continent-wide environmental characteristics that are sensitive to or influenced by ice-sheet temperature. A simple comparison of environmental properties at lake locations with their continent-wide distributions suggests a statistical relationship (high Kolmogorov-Smirnov statistic) between stable lake locations and ice thickness and surface temperatures, indicating melting under passive conditions. Active lakes, in contrast, show little correlation with direct thermally influenced parameters, instead exhibiting large statistical differences with horizontal velocity and bedrock elevation. More sophisticated techniques, including principal component analysis (PCA) and machine learning (ML) classification, provide better spatial identification of lake types. Positive PCA scores derived from the environmental characteristics correlate with stable lakes, whereas negative values correspond to active lakes. ML methods can also identify regions where subglacial lake melt sources are probable. While ML provides the most accurate classification maps, the combination of approaches adds deeper knowledge of the primary controls on lake formation and the environmental settings in which they are likely to be found.

Antarctic research remains an enterprise in which people with certain backgrounds and identities have distinct career advantages over others. In this paper, we focus on barriers to women's participation and success in Antarctic research. Drawing on feminist social science literature on gender inequality in science, we identify two foundational, interrelated factors that have hampered progress across global Antarctic research. We propose that these barriers can be effectively addressed through intersectional approaches to change. We synthesize a broad range of multidisciplinary research on intersectionality in scientific workplaces and apply this literature to the unique institutional, historical and geographical contexts of Antarctic research. We argue that an intersectional lens improves understanding of persistent gender inequalities in Antarctic research, and we offer examples of how intersectionality can be practically applied within Antarctic institutions and communities. By embracing intersectional approaches to change, the Antarctic research community has the opportunity to lead in the advancement of equitable global scientific cultures and to fully realize Antarctica's potential as a place for peaceful, scientific collaboration by and for all humanity - not just a privileged few.

The COVID-19 pandemic and pandemic-related measures have impacted the lives and work-related activities of Antarctic researchers. To explore these impacts, we designed, piloted and disseminated an online survey in English, Russian, Spanish and Chinese in late 2020 and early 2021. The survey explored how the pandemic affected the productivity of Antarctic researchers, their career prospects and their mental wellbeing. Findings exposed patterns of inequities. For instance, of the 406 unique responses to the survey, women appeared to have been affected more adversely than men, especially in relation to mental health, and early-career researchers were disadvantaged more than their mid- or late-career colleagues. Overall, a third of the research participants reported at least one major negative impact from the pandemic on their mental health. Approximately half of the participants also mentioned that the COVID-19 pandemic had some positive effects, especially in terms of the advantages that working from home brought and opportunities to attend events, network or benefit from training workshops online. We conclude with a series of recommendations for science administrators and policymakers to mitigate the most serious adverse impacts of the pandemic on Antarctic research communities, with implications for other contexts where scientific activities are conducted under extreme circumstances.