No less than 15–20 sedimentary basins are now known on the Antarctic continental landmass and surrounding continental shelves. Reconstruction of their tectonic and stratigraphic evolution is a specialized task. Owing to the polar position of the continent, the Pacific and Atlantic global geostructures are closely spaced there and the interplay between them is strong enough to result in hybridization of the characteristic tectonic features of the various basins. The present morphostructure of the southern polar region of the Earth is characterized by a prominent circumpolar zoning. Therefore, the sedimentary basins form a gigantic ring along the continental margin, including both the shelf proper and the edge of the continent. Within the ring, the basins are associated with different types of margins successively replacing each other, from the Mesozoic magmatic are in the Pacific segment to the classic passive margin off East Antarctica. The formation of the sedimentary basins in the Antarctic segment of the Pacific mobile belt was a part of a single process of geosynclinal development, whereas on the craton flank the process was superposed on the continental structures by rifting during Gondwana fragmentation. During post-break-up tectonism, continental glaciation played an important part in the formation of the sedimentary basins.

We report the first formal record of the Indian meal moth Plodia interpunctella from a location within the Antarctic Treaty area, with the capture of a live adult male within the Brazilian Comandante Ferraz research station on King George Island, South Shetland Islands. This species is a well-known pest of stored products and is widely recorded in synanthropic situations such as food stores globally. No other adults or immature stages have been observed on the station. While there is no suggestion that P. interpunctella could survive or establish in the natural environment beyond the station, this observation highlights the ever-present threat of unintended anthropogenically assisted transfer of non-Antarctic species into human facilities on the continent, with some such species proving extremely difficult to eradicate if they successfully establish within these facilities.

It is well established that the reaction of HO2 with NO plays a central role in atmospheric chemistry, by way of OH/HO2 recycling and reduction of ozone depletion by HOx cycles in the stratosphere and through ozone production in the troposphere. Utilizing a photochemical box model, we investigate the impact of the recently observed HNO3 production channel (HO2+NO → HNO3) on NOx (NO + NO2), HOx (OH + HO2), HNO3, and O3 concentrations in the boundary layer at the South Pole, Antarctica. Our simulations exemplify decreases in peak O3, NO, NO2, and OH and an increase in HNO3. Also, mean OH is in better agreement with observations, while worsening the agreement with O3, HO2, and HNO3 concentrations observed at the South Pole. The reduced concentrations of NOx are consistent with expected decreases in atmospheric NOx lifetime as a result of increased sequestration of NOx into HNO3. Although we show that the inclusion of the novel HNO3 production channel brings better agreement of OH with field measurements, the modelled ozone and HNO3 are worsened, and the changes in NOx lifetime imply that snowpack NOx emissions and snowpack nitrate recycling must be re-evaluated.

Pseudochaenichthys georgianus is a member of the unique Channichthyidae family of fishes, which lack haemoglobin. The distribution, length-frequency and summer diet are described from 14 bottom trawl surveys undertaken in the summers between 1986 and 2006. Pseudochaenichthys georgianus (50–590 mm TL) were caught throughout the South Georgia shelf from depths of 76–370 m, but very few specimens (< 1%) were caught on the Shag Rocks shelf. Multiple cohorts were present during each survey and length-frequency analysis of these cohorts suggests that growth is fast during the first 3–4 years. Stomach contents analysis (2005 & 2006) indicated that P. georgianus is a pelagic or semi pelagic predator, with the summer diet dominated by Antarctic krill (Euphausia superba). Fish (channichthyids and notothenids) were also taken, but were a relatively minor part of the diet.

Simultaneous acoustic Doppler sodar and tethersonde measurements were used to study some of the characteristics of the unstable boundary layer at Dumont d'Urville, Adélie Land, East Antarctica during the summer 1993–94. A description of the convective boundary layer and its behaviour in connection with the wind regime is given along with the frequency distribution of free convection episodes. The surface heat flux has been evaluated using the vertical velocity variance derived from sodar measurements. The turbulent exchange coefficients, estimated by coupling sodar and tethered balloon measurements, are in strong agreement with those present in literature for the Antarctic regions.

We assessed the content of some major and trace elements and lichen compounds as well as antioxidant activity in eight lichen species representing four families collected in areas > 1 km distant from Bellingshausen (King George Island) and > 1 km distant from Molodezhnaya (Thala Hills, Enderby Land) research stations. Content levels of Cu, Pb, Cd, Zn and As in Physcia caesia, Physconia muscigena, Umbilicaria aprina, Umbilicaria decussata and Usnea aurantiaco-atra thalli were similar to or lower than previously reported for these species in the Maritime and Continental Antarctic, as well as from reference sites. The first data on the contents of 15 elements in Ramalina terebrata and Thamnolecania brialmontii thalli from the Maritime Antarctic are reported. Our analyses confirmed the presence of the main photosynthetic pigments in the species examined (chlorophyll a and b, phaeophytin a and b, neoxanthin, violaxanthin, lutein and β-carotene). We identified protolichesterinic acid in T. brialmontii thalli for the first time. Antioxidant activity varied from 190 μg/g dry weight (U. decussata) to 14,740 μg/g dry weight (T. brialmontii). The data obtained complement previous research while also providing new baseline data that will have utility in monitoring and identifying future change.

During summer (2 December 1999–23 January 2000) an Ocean Surface Current Radar (OSCR-II) was used to provide surface current measurements within the Terra Nova Bay polynya, one of the most important coastal polynyas of the Ross Sea. This represents an important step towards a continuous monitoring of the area. Useful information is now available as a basis for future work in this field, although the two radar sites, necessary to calculate the total current vector, did not work together throughout the whole period of the experiment as one of the units was damaged. The results demonstrate the feasibility of this kind of measurement and suggest that very important dynamical characteristics of the polynya could be deduced from long term deployment of such a system.

Due to its geographic isolation and relatively limited human impact, Antarctica is a promising location to study the eco-physiology of natural halogen cycles. Anaerobic sediments from Antarctic melt ponds on Ross Island and on the McMurdo Ice Shelf near Bratina Island were tested for activity of microbial reductive dehalogenation. Anaerobic enrichment cultures were established with potential electron donors and tetrachloroethene, trichloroethene, 2-bromophenol, 2-chlorophenol, 3-bromobenzoate, or 3-chlorobenozoate, as model halocarbon electron acceptors. Dechlorination of aromatic compounds was limited, whereas 2-bromophenol was debrominated in seven of the eight sediments and one site also showed debromination of 3-bromobenzoate. A most probable number estimate with 2-bromophenol at one site revealed 103–104 cultivatable debrominators per gram of sediment (wet weight). Chloroethene dechlorination was slow and primarily produced trichloroethene from tetrachloroethene, although both cis- and trans-dichloroethene were detected in certain enrichments upon extended incubation. These results demonstrate the presence of reductive dehalogenating activity in anaerobic, Antarctic melt-pond sediments and expand the known metabolic diversity of Antarctic microorganisms.

Three temporary Automatic Weather Stations measured summertime surface layer climate over the Darwin–Hatherton Glacial system. These data were used to test a Polar optimized Weather Research and Forecasting model (Polar-WRF) simulation for December as a case study. Observations show differences in hourly averaged solar and net all-wave radiation between white ice and blue ice areas (BIAs). Although the down-welling solar radiation is higher over the white ice region, the net all-wave energy is higher over the BIA. Derived albedo for each surface type confirms that the blue ice areas have lower albedo. Also, the hourly averaged temperatures are higher at lower elevation stations, creating a gradient towards the Ross Ice Shelf. Analysis shows that there is a diurnal oscillation in strength and intensity of the katabatic wind. The two lower stations register a distinct reversal of wind direction in the early afternoon due to intrusion of an anabatic circulation. Anabatic winds are not prevalent further up the Darwin Glacier. A high-resolution Polar-WRF simulation as a case study shows good agreement with observations. The December 2008 case study is characterized by a strong south-westerly katabatic wind over Hatherton, whereas the flow over Lower Darwin was diurnally reversing. Polar-WRF shows that the katabatic front advanced and retreated periodically between Hatherton and Lower Darwin.

The new genus and species Bicoloromyces kyffinensis is described as new to science from a sterile crustose lichen, perhaps Lecanora fuscobrunnea or Lecidella sp. from Ebony Ridge of Mount Kyffin, Antarctica. The fungus recalls superficially the lichenicolous species referred to Taeniolella, but differs in having semi-macronematous conidiophores, tissues encrusted with calcium oxalate, aeruginose to blue-black colouration under the microscope, and conidia which are distoseptate and formed in basipetal chains. Energy dispersive spectroscopy established that the encrustations were of calcium oxalate. Differences from genera of rock-inhabiting fungi described from the Antarctic are discussed. This appears to be the furthest south any lichen-inhabiting fungus has been reported.

We set out to document the diversity and distribution of bryophytes in Admiralty Bay and thereby enable the identification of patterns in local diversity and their possible drivers. Combining data extracted from different sources and recent collections, we documented the presence of 63 species. Similarity analyses of moss species diversity in relation to underlying geology and ornithogenic influence identified an identical cophenetic correlation coefficient of 0.744 for both factors. The Sørensen index was < 0.6, indicating that the groups share < 60% of the species recorded. The data showed that the selected filters (ornithogenic soils, non-ornithogenic soils and different geological extracts) did not underlie consistent species groupings, and we conclude that other environmental and topographical factors are likely to be responsible for shaping the moss community structure in Admiralty Bay. To enable effective management of Antarctic Specially Managed Area (ASMA) No. 1 and Antarctic Specially Protected Area (ASPA) No. 128, robust assessments of the local ecosystem and biodiversity are necessary to assist in the decision-making processes mandated under the Antarctic Treaty System, one of whose founding principles is the preservation of the Antarctic ecosystem.

Polar subglacial hydrologic systems have garnered much interest since the recognition of Lake Vostok in 1996. In Antarctica, these environments are hydrologically diverse, including isolated lakes of different sizes, river–lake flow-through systems, “swamps” and groundwater (Siegert 2016). The refreezing of subglacial meltwater is also an important process beneath a large portion of the East Antarctic Ice Sheet (Bell et al. 2011). As subglacial water refreezes it exsolves salts, potentially leaving behind saline and hypersaline brines. Brines thought to derive from this cryoconcentration process have been observed in the northern polar permafrost regions and in the McMurdo Dry Valleys (MDVs) region of Antarctica. Additionally, sediments in the Victoria Land Basin have diagenetic signatures produced by brine movement dating from 3–11 m.y.a, suggesting hypersaline brines have existed in the McMurdo region since at least this time (Staudigel et al. 2018).

Variations in atmospheric conditions can be important factors influencing temperature dynamics within the active layer of a soil. Solar radiation and air temperature can directly alter ground surface temperatures, while variations in wind and precipitation can control how quickly heat is carried through soil pores. The presence of seasonal snow cover can also create a thermal barrier between the atmosphere and ground surface. This study examines the relation between atmospheric conditions and ground temperature variations on a deglaciated island along the Western Antarctic Peninsula. Ground temperatures were most significantly influenced by incoming solar radiation, followed by air temperature variations. When winter months were included in the comparison, the influence of air temperature increased while solar radiation became less influential, indicating that snow cover reflected solar radiation inputs, but was not thick enough to insulate the ground. When ground temperatures were compared to atmospheric conditions of preceding weeks, seasonal temperature peaks 1.6 m below ground were best related to seasonal air temperature peaks from the previous two weeks. The same ground temperature peaks were best related to seasonal solar radiation peaks of seven weeks prior. This difference was a result of temperature lags within the atmosphere.

The perennial ice-covered lakes of the Antarctic McMurdo Dry Valleys harbour oligotrophic microbial communities that are separated geographically from other aquatic systems. Their microbiomes include planktonic microbes as well as lift-off mat communities that emerge from the ice. We used the ShortBRED protein family profiler to quantify the antibiotic resistance genes (ARGs) from metagenomes of lift-off mats emerging from ice and from filtered water samples of Lake Fryxell and Lake Bonney. The overall proportion of ARG hits was similar to that found in temperate-zone rural ponds with moderate human inputs. Specific ARGs showed distinct distributions for the two lakes and for mat vs planktonic sources. Metagenomic taxa distributions showed that mat phototrophs consisted mainly of cyanobacteria or Betaproteobacteria, whereas the water column phototrophs were mainly protists. An enrichment culture of the Betaproteobacterium Rhodoferax antarcticus from a Lake Fryxell mat sample showed an unusual mat-forming phenotype not previously reported for this species. Its genome showed no ARGs associated with Betaproteobacteria but had ARGs consistent with a minor Pseudomonas component. The Antarctic lake mats and water showed specific ARGs distinctive to the mat and water sources, but overall ARG levels were similar to those of temperate water bodies with moderate human inputs.

Lake Untersee is a perennially ice-covered Antarctic lake that consists of two basins. The deepest basin, next to the Anuchin Glacier is aerobic to its maximum depth of 160 m. The shallower basin has a maximum depth of 100 m, is anoxic below 80 m, and is shielded from convective currents. The thermal profile in the anoxic basin is unusual in that the water temperature below 50 m is constant at 4°C but rises to 5°C between 70 m and 80 m depth, then drops to 3.7°C at the bottom. Field measurements were used to conduct a thermal and stability analysis of the anoxic basin. The shape of the thermal maximum implies two discrete locations of energy input, one of 0.11 W m-2 at 71 m depth and one of 0.06 W m-2 at 80 m depth. Heat from microbial activity cannot account for the required amount of energy at either depth. Instead, absorption of solar radiation due to an increase in water opacity at these depths can account for the required energy input. Hence, while microbial metabolism is not an important source of heat, biomass increases opacity in the water column resulting in greater absorption of sunlight.

Recently Ricci et al. (1993) proposed a series of general guidelines for the naming of igneous and metamorphic rocks in Antarctica, based on discussions held by the SCAR Working Group on Geology. Ricci et al. (1993) suggested that names for igneous and metamorphic rock units should comprise an appropriate geographic name and simple lithological field term. However, they also suggest that names should not include terms that indicate the form or structure of a rock unit, such as dyke, pluton or batholith.

Erect bryozoans are extremely abundant and diverse in polar waters and individual species may span a wide range in latitude and bathymetry. A number of aspects of lifestyle, including polypide recycling, embryo production, distribution, growth form and epibiosis were compared in three species of erect byozoans. These were collected from two locations; Signy Island (60°S) and Rothera Point, Adelaide Island (68°S) and a variety of depths. All three species were in similar stages of polypide cycling within and between the two sites. In the species Isosecuriflustra rubefacta and Nematoflustra flagellata the rate of brown body production (polypide generations) was slower at Signy Island than at Rothera Point. There was little difference between localities (within species) in the pattern of embryo production and no change in embryo size with depth. Embryos of I. rubefacta, however, were significantly larger at Rothera Point than at Signy Island. The proportion of the community occupied by each species changed with depth, but all three species occurred in shallower water at Rothera Point than at Signy Island. Fouling by epibionts decreased with increasing depth and from Signy Island to Rothera Point, both in terms of per cent cover and number of colonizing taxa. Possible trends with depth and latitude are compared with other studies involving bryozoans. The literature on Antarctic benthic taxa, in general, is also considered to determine whether trends within the Bryozoa are reflected in other groups.