We have investigated how the microbially-driven processes of carbon (C) mineralization (respiration) and nitrogen (N) mineralization/immobilization in a soil from the northern Maritime Antarctic respond to differences in water availability (20% and 80% water-holding capacity) and temperature (5°C and 15°C) in the presence and absence of different organic substrates (2 mg C as either glucose, glycine or tryptone soy broth (TSB) powder (a complex microbial growth medium)) in a controlled laboratory experiment over 175 days. Soil respiration and N mineralization/immobilization in the presence of a C-rich substrate (glucose) increased with increases in water and temperature. These factors were influential individually and had an additive effect when applied together. For the N-rich substrates (glycine and TSB), microbial responses to increased water or temperature alone were weak or not significant, but these factors interacted to give significantly positive increases when applied together. These data indicate that under the expected changes in environmental conditions in the Maritime Antarctic, where temperature and the availability of water and organic substrates will probably increase, soil microbial activity will lead to more rapid C and N cycling and have a positive feedback on these biogeochemical processes, particularly where or when these factors increase concurrently.

An ocean bottom seismometer (OBS) network was deployed for 1 month at Deception Island volcano, Antarctica, in early 2005. Although only two volcano-tectonic and three long-period events were observed, the three OBSs located > 2 km apart inside the caldera detected over 3900 events that could not be attributed to known volcanic or hydrothermal sources. These events are found on one instrument at a time and occur in three types. Type 1 events resemble impulsive signals from biological organisms while type 2 and type 3 events resemble long-period seismicity. The largest number of events was observed in a region of volcanic resurgence and hydrothermal venting. All three types occur together suggesting a common cause and they show evidence for a diurnal distribution. The events are most likely to be due to aquatic animals striking the sensors, but a geological source is also possible. In the first case, these signals indicate the presence of a biological community confined to the caldera. In the second case, they imply widespread hydrothermal activity in Port Foster. Future OBS experiments should bury the seismometers, include a hydrophone, deploy instruments side-by-side, or include a video camera to distinguish between biological and geological events.

The brooded embryos and/or juveniles of the sea stars Neosmilaster georgianus (Studer, 1885) and Lysasterias perrieri (Studer, 1885) and the isopod Glyptonotus antarcticus (Eights, 1853) were examined for their acceptability using the sympatric sea star Odontaster validus (Koehler, 1906) as a predator. Organic extracts were prepared from embryos of both sea stars and juveniles of Lyasterias perrieri and Glyptonotus antarcticus and tested in alginate food pellets to confirm whether lack of acceptability was chemically based. We found both intact whole embryos and juveniles of the sea star Neosmilaster georgianus were not acceptable to Odontaster validus. A methanol extract of the embryos was palatable. This could be the result of either the sequestration of deterrent chemicals within embryos or the presence of noxious compounds that were not extractable in methanol. Embryos and juveniles of the sea star Lysasterias perrieri were not acceptable to sea stars. Food pellets containing methanol extracts of unacceptable embryos were deterrent against sea stars, suggesting a chemical defence. Juvenile brooded isopods (Glyptonotus antarcticus) were also found to be unacceptable in sea star feeding bioassays. Significant rejection of alginate pellets containing a lipophilic dichloromethane methanol extract of juveniles indicated that this lack of acceptability was chemically based. Our study provides further support for chemical defences in the offspring of brooding lecithotrophic Antarctic marine invertebrates.

In Antarctica, the genus Bartramia has been restricted to a single polymorphic species, B. patens. Its status as a separate species or a subspecies of the Northern Hemisphere B. ithyphylla was debated. In the present paper, we combine analyses of chloroplast (trnS–rps4–trnT–trnL–trnF region) and nuclear ITS sequences with a reinvestigation of morphological characteristics to infer the identity of Antarctic Bartramia. Phylogenetic and Automatic Barcode Gap Discovery (ABGD) species delimitation analyses indicate that the species diversity of Bartramia in Antarctica has been underestimated, since two species were identified, both belonging to Bartramia sect. Pyridium. Of these, B. subsymmetrica is a new record of the species for Antarctica, as it has previously only been recorded from Livingston Island, South Shetlands. The other species is B. patens, which is separated from B. ithyphylla by newly inferred morphological characteristics and is a sister species to the latter in the molecular phylogenetic analyses. Consequently, we consider B. ithyphylla to be a Northern Hemisphere instead of a bipolar species. The suggested conspecificity of both taxa into one species in the ABGD analysis is considered to result from overlumping by this species delimitation method. The delimitation of the three species of section Bartramia (B. halleriana, B. mossmaniana and B. pomiformis) and the circumscription of the genus Bartramia are discussed.

Ice shelves fringing Antarctica are sensitive indicators of climate change due to the direct interface with the atmosphere and ocean. Meltwater induced by atmospheric warming percolates from the surface into hydrofractures and affects shelf stability. Surface melting reduces the microwave backscattering; thus backscatter data is useful in melt monitoring. The Ku-band scatterometer derived melting index (MI) was utilized to assess the decadal (2000–10) variability observed over Antarctic ice shelves. The low intensity melting observed over large ice shelves and high intensity melting observed over the Larsen, Amery, West and Shackleton ice shelves are discussed. A correlation of around 93% was observed between MI variation and rift propagation over Amery Ice Shelf. The El Niño and the Southern Oscillation (ENSO) correlation with MI was also investigated. The paper highlights that scatterometer derived information has the potential to assess meltwater production and rift propagation.

Measurement of pressure fluctuations provides the best means of detecting atmospheric internal gravity waves at the Earth's surface. We have developed an instrument which is sufficiently sensitive to detect the small pressure fluctuations associated with such waves yet robust enough for deployment in an Antarctic environment. The instrument incorporates several novel features, both in its design and in the method of deployment used. A prototype instrument has been successfully deployed at the British Antarctic Survey's Halley Station during 1989. The design of an experiment using an array of six improved instruments is briefly described.

A light, mining drill rig deployed from the stern of a research vessel has been used to carry out shallow drilling in 212 m water depth on the continental shelf in the eastern Weddell Sea. Penetration was 15 m below the seabed with 18% recovery in the 31 hours available for the experiment. The recovered glacigenic sediments are predominantly volcanic material of basaltic and andesitic composition with petrological characteristics and age similar to the continental flood basalts exposed in Vestfjella, about 130 km upstream from the drill site. The sediments include a reworked marine Miocene diatom flora. The material documents oscillations of the East Antarctic Ice Sheet over the past 30 ka. The lowermost diamicton probably represents a deformation till, and the grounding line retreated past the drill site 30 km from the shelf edge about 30 kyr BP. A readvance occurred during the Late Wisconsin Glacial Maximum. Assuming a reservoir correction of 1300 yr, marine conditions existed at the site between 10.1-7 kyr BP, and later at least between 2.8 and 2.5 kyr BP. The stratigraphy at the site has been disturbed by iceberg ploughing and/or contact between the ice shelf and the sea floor during local advances after 2.5 kyr BP.

Rates of tag-loss are determined for Dalton Jumbo Rototags applied to the hind flippers of 4343 (2208 males, 2135 females) southern elephant seal (Mirounga leonina) pups at Marion Island over an eight year period from 1983–1990 as part of a demographic study of the species. Loss rates were the lowest recorded to date for this species (range 0.0–9.1%). No significant relationship existed between age and rate of tag-loss, neither was there any sex or year related differences in age-specific tag-loss rates. The low rates of loss highlight the value of tagging as a marking technique, and allow for high levels of confidence in the reliability of the population parameters that are derived from the tagging data collected for the Marion Island population.

Six ichnocoenoses in the clastic Devonian Horlick Formation (max. 56 m) confirm the nearshore marine character of eight of the nine lithofacies present. Abasal sand sheet overlies a weathered granitic land surface (Kukri Erosion Surface) on Cambro–Ordovician granitoids. The level nature of this surface and the way it cuts across weathering profiles, suggests that the surface had been modified by marine processes prior to deposition. The basal sand sheet (Cross-bedded Sand sheet Lithofacies) contains tidal bundles, and at its top, abundant Monocraterion (Monocraterion Ichnocoenosis). The second sand sheet (Pleurothyrella Lithofacies) is heavily burrowed and shows alternating periods of sedimentation, burrowing, and erosion below wave base as the sea deepened (Catenarichnus Ichnocoenosis). With increasing transgression, finer sediments were deposited (Laminated Mudstone and Feldspathic lithofacies) in an unstable pattern of coarse sandbars and finer troughs (Cruziana-Rusophycus and Arenicolites ichnocoenoses) crossed by active longshore marine channels (Poorly-sorted Lithofacies, Spirophyton Ichnoocoenosis). Short-lived but powerful storms produced thin shelly tempestites (Shell-bed Lithofacies), whereas sporadic, very thin phosphate rich beds (Phosphatic Lithofacies) may have resulted from marine transgressions across the basin. The deepest water is probably represented by sediments of the Spirifer Lithofacies (Rosselia Ichnocoenosis). The Schulthess Lithofacies is regarded as fluvial, deposited in the lower reaches of a river draining a land area that lay towards Marie Byrd Land. Channels in the basal sand sheet indicate movement to the southwest, but orientation became more variable higher in the sequence. Four new measured sections are figured. The relationship of the Ohio Range to the rest of Antarctica during the Devonian is suggested.

Blue ice extent and its geographical distribution during the three years from December 1999–January 2003 have been mapped together with rock exposure areas for the entire Lambert-Amery glacial basin at an unprecedented level of spatial detail using Landsat ETM+ images. Various geometric and shape attributes for each blue ice patch have been derived. The total area of blue ice is estimated to be 20 422 km2, accounting for 1.48% of the glacial basin. We also found that the image texture information is helpful for distinguishing different types of blue ice: rough blue ice, smooth blue ice, and level blue ice. Rough blue ice areas are mostly associated with glacial dynamics and located in relatively low elevation regions, smooth blue ice areas are often related to nunataks and mountains, steep slopes and wind blows, and level blue ice areas are formed by melt-induced lakes in the margin of the ice shelf and melt-induced ponds on the ice shelf in low elevations. The elevation and surface slope properties of different types of blue ice area are characterized through regional topographical analysis with ICESat laser altimetry data. The effect of mountain height on the blue ice extent is also examined with local topographic profile analysis based on the ASTER global digital elevation model. The wide variation of the ratio of blue ice area length to mountain height indicates that the factors controlling the formation and extent of blue ice are more complicated than we previously thought.

Values of attenuation coefficient, Kd(λ), for five visible wavelengths are reported for 14 sites around South Georgia and the Bransfield Strait, in the Southern Ocean. The mean chlorophyll-plus-phaeopigment concentrations in the upper 30 m of the water column ranged from 0.32–6.633 mg m−3 with one particularly high mean value of 31 mg m−3. Partition of attenuation between chlorophyll (Kc) and other factors in the water column (Ko) indicated that the spectral character of Ko in the Bransfield Strait was consistent with absorption by non chlorophyll-like pigments (Gelbstoff). Values were significantly different between the two areas. Values of the specific attenuation coefficient due to pigment concentration (Kc) were small compared to temperate values. These data support other studies in suggesting that the application of remotely sensed ocean colour data to global biogeochemical surveys requires the development of regional algorithms.

The Ross Sea polynya is one of the most productive regions in the Southern Ocean. However, limited access and high spatio-temporal variability of physical and biological processes limit the use of conventional oceanographic methods to measure early season primary productivity. High-resolution observations from two Seagliders provide insights into the timing of a bloom in the southern Ross Sea polynya in December 2010. Changes in chlorophyll and oxygen concentrations are used to assess bloom dynamics. Using a ratio of dissolved oxygen to carbon, net primary production is estimated over the duration of the bloom showing a sensitive balance between net autotrophy and heterotrophy. The two gliders, observing spatially distinct regions during the same period, found net community production rates of -0.9±0.7 and 0.7±0.4 g C m-2 d-1. The difference highlights the spatial variability of biological processes and is probably caused by observing different stages of the bloom. The challenge of obtaining accurate primary productivity estimates highlights the need for increased observational efforts, particularly focusing on subsurface processes not resolved using surface or remote observations. Without an increased observational effort and the involvement of emerging technologies, it will not be possible to determine the seasonal trophic balance of the Ross Sea polynya and quantify the shelf’s importance in carbon export.

King George Island (South Shetland Islands, Antarctic Peninsula) is renowned for its terrestrial palaeoenvironmental record, which includes evidence for potentially up to four Cenozoic glacial periods. An advantage of the glacigenic outcrops on the island is that they are associated with volcanic formations that can be isotopically dated. As a result of a new mapping and chronological study, it can now be shown that the published stratigraphy and ages of many geological units on eastern King George Island require major revision. The Polonez Glaciation is dated as c. 26.64 ± 1.43 Ma (Late Oligocene (Chattian Stage)) and includes the outcrops previously considered as evidence for an Eocene glacial ('Krakow Glaciation'). It was succeeded by two important volcanic episodes (Boy Point and Cinder Spur formations) formed during a relatively brief interval (< 2 Ma), which also erupted within the Oligocene Chattian Stage. The Melville Glaciation is dated as c. 21–22 Ma (probably 21.8 Ma; Early Miocene (Aquitanian Stage)), and the Legru Glaciation is probably ≤ c. 10 Ma (Late Miocene or younger). As a result of this study, the Polonez and Melville glaciations can now be correlated with increased confidence with the Oi2b and Mi1a isotope zones, respectively, and thus represent major glacial episodes.

Cores acquired from the Ross Sea continental shelf and continental slope during the XXX Italian Programma Nazionale di Ricerche in Antartide (PNRA) were analysed and yielded interesting micropalaeontological, biostratigraphic diatom results and palaeoceanographic implications. These multi-proxy analyses enabled us to reconstruct the glacial/deglacial history of this sector of the Ross embayment over the last 40 000 years, advancing our understanding of the Last Glacial Maximum (LGM) environmental and sedimentological processes linked to the Ross Sea ice sheet/ice shelf fluctuations in a basin and continental-slope environment, and allowed us to measure some of the palaeoceanographic dynamics. The central sector of the Ross Sea and part of its coast (south of the Drygalski Ice Tongue) enjoyed open marine conditions in the pre-LGM era (27 500–24 000 years bp). The retreat of the ice sheet could have been influenced by a southward shift of a branch of the Ross gyre, which triggered early deglaciation at c. 18 600 cal bp with a significant Modified Circumpolar Deep Water inflow over the continental slope at c. 14 380 cal BP. We assume that a lack of depositional material in each core, although at different times, represents a hiatus. Other than problems in core collection, this could be due to the onset of modern oceanographic conditions, with strong gravity currents and strong High Salinity Shelf Water exportation. Moreover, we presume that improvements in biostratigraphy, study of reworked diatom taxa, and lithological and geochemical analyses will provide important constraints for the reconstruction of the LGM grounding line, ice-flow lines and ice-flow paths and an interesting tool for reconstructing palaeo-sub-bottom currents in this sector of the Ross embayment.

We have used data from the Ozone Monitoring Instrument (OMI) aboard NASA's Earth Observing System (EOS) Aura satellite over the period 2004–11 to describe the characteristics of surface ultraviolet (UV) irradiance at Escudero Station (62°12′S, 58°57′W). The station is located on King George Island (northern Antarctic Peninsula). Temperatures in summer are frequently above 0°C, and the surrounding ocean is typically ice-free. We found that the UV irradiance at Escudero is driven by the Antarctic ozone hole (which annually in spring leads to significant variations in the ozone) and by clouds (which are more frequent and have a larger optical depth compared with other Antarctic sites). The combined effect of ozone and clouds led to significant variations in the surface UV. The variability (taken as the standard deviation of the UV estimates retrieved from OMI) is typically greater than 30% at Escudero, but may reach values greater than 50% in spring. The consistency of OMI-derived data was checked by using ground-based spectral measurements carried out under controlled conditions in January 2011.

Human contamination of Antarctic environments is a sensitive issue and has been the focus of many research articles over the past 35 years. The majority of these studies have targeted waste materials and various hydrocarbons, with assessment of microbial contaminants being largely restricted to sewage outfalls. The present study aimed to detect bacteria of human origin in the area surrounding Halley research station. It was apparent from both molecular and culture methods that bacteria of human origin are extremely difficult to detect outside the immediate surrounding of the buildings, though recommendations are made for increasing the probability of determining the presence of organisms in the environment. The results also indicate that molecular methods are more sensitive than cultural techniques, in that the only evidence for organisms in the environment surrounding the buildings came from positive PCR reactions. PCR would appear to be a useful method for studying the microbial ecology of Antarctic environments.

The Cretaceous period is often regarded as one of "greenhouse" warmth, with perhaps its acme occurring in the late Albian stage (100 Ma ago). However, it is now apparent that, even at this time, there were significant meridional temperature gradients and distinct temperate biotas in the highest latitude regions. This is particularly so in the Southern Hemisphere, where an extensive Albian fossil record from Antarctica, Australia and New Zealand has revealed the presence of austral floras and faunas. With the recent improvements in stratigraphical correlations, it has become possible to trace the later Cretaceous palaeoenvironmental record in the Antarctic Peninsula region. Unfortunately, resolution of the early Late Cretaceous (Cenomanian–Coniacian stages) is still imprecise; there are some indications of strongly differentiated palynological assemblages, but studies of both macrofaunas and palaeotemperature estimates are incomplete. By the Santonian–Campanian, high-latitude biotas are well developed in the James Ross Island region and their enhancement through the final stages of the Cretaceous can be linked to a phase of global cooling. The persistence of low diversity temperate communities in high latitude regions may be of considerable ecological and evolutionary significance. For example, there is evidence to suggest that these communities may have been more resistant to mass extinction events; they may also have been important source regions for replacement taxa that arose after such events.

Fortyfour octopods from bottom trawls off Palmer Archipelago, south-eastern Argentina, south-eastern New Zealand, Crozet Islands and Showa Station were examined. Three species of Pareledone, three species of Graneledone and one species of Megaleledone were identified. All were characterized by having a single row of arm suckers. Mature males of P. harrissoni, P. adelieana and G. macrotyla were recorded for the first time. Hectocotylus and male reproductive organs of these species are described. On the basis of previously reported distributions and the present localities, P. charcoti, P. harrissoni and P. adelieana appear to have circumantarctic distributions. G. macrotyla was identified but the other two species of Graneledone could not be identified to species level because of the poor systematic state of this genus.

The Ross Sea is bordered by the Late Precambrian–Cambrian Ross–Delamerian Orogen of East Antarctica and the more Pacific-ward Ordovician–Silurian Lachlan–Tuhua–Robertson Bay–Swanson Orogen. A calcsilicate gneiss from Deep Sea Drilling Project 270 drill hole in the central Ross Sea, Antarctica, gives a U-Pb titanite age of 437 ± 6 Ma (2σ). This age of high-grade metamorphism is too young for typical Ross Orogen. Based on this age, and on lithology, we propose a provisional correlation with the Early Palaeozoic Lachlan–Tuhua–Robertson Bay–Swanson Orogen, and possibly the Bowers Terrane of northern Victoria Land. A metamorphosed porphyritic rhyolite dredged from the Iselin Bank, northern Ross Sea, gives a U-Pb zircon age of 545 ± 32 Ma (2σ). The U-Pb age, petrochemistry, Ar-Ar K-feldspar dating, and Sr and Nd isotopic ratios indicate a correlation with Late Proterozoic–Cambrian igneous protoliths of the Ross Orogen. If the Iselin Bank rhyolite is not ice-rafted debris, then it represents a further intriguing occurrence of Ross basement found outside the main Ross–Delamerian Orogen.

The ecological drivers underlying breeding performance are expected to differ across the geographical range of seabird species, but few studies have compared trade-offs between colonies with different local conditions. During chick-rearing (2000–01), we compared the foraging trips, diet and breeding parameters of two Adélie penguin colonies in the Ross Sea, at Edmonson Point (EdPo; ~2000 breeding pairs) and Inexpressible Island (InIs; ~24 000 breeding pairs). Penguins from InIs travelled farther and performed longer feeding trips. The quantity of food brought to the nest was the same for the two colonies, but penguins from InIs brought more fish and less krill. Eggs hatched earlier at EdPo. Breeding success did not differ, but chick weight during hatching–fledging was greater at InIs. Despite worse weather conditions at InIs, the larger proportion of high-energy food brought by penguins from InIs (i.e. fish) may explain their offspring‘s better performance. In addition, the persistence of fast ice at EdPo may have led to greater energy expenditure of breeding individuals, possibly reducing chick growth. The greater intraspecific competition expected at InIs may have been reduced by longer foraging trips and/or counteracted by the more nutritious diet. Our findings reveal complex trade-offs between foraging effort and environmental constraints in determining the breeding performance of Adélie penguins.