Spatial variations in the ion composition were studied in 55 surface snow samples collected along three transects in the Ingrid Christensen Coast of East Antarctica. The sea-salt ion constituents revealed a drastic reduction from the ice edge to inland sites. The computed sea-salt sodium and non-sea-salt calcium concentrations suggest that while sea spray primarily contributes to the Na+, the crustal contribution dominates the Ca2+ in snow samples. The Cl-/ssNa+ ratios of the snow samples from the Larsemann transect varied between 4.7 and 1.05, indicating that additional Cl- sources like soil dust are important in the inland sites. The enrichment factors (Ef) confirm a dominant crustal source for Ca2+ in all transects. The Ef(K+) values indicate a dominant sea spray source for K+ in the coastal stations of the Larsemann and Publications transects. The Ef(Mg2+) values indicate the absence of any significant Mg2+ enrichment compared to seawater values. Secondary sulphur species (nssSO42- and MSA) within the snow samples suggest that both vary independently of each other, possibly influenced by the local biological activities. The nssSO42- data revealed that several summer snow deposits in the study region are significantly fractionated, apparently related to the sea ice existence during summer.

Landforms with the appearance of cryoplanation terraces were studied on Alexander Island in an attempt to better understand their formation and growth. Developed on sub-horizontal sedimentary rocks, with 360° exposure around a nunatak, the terraces show a distinct equatorward orientational preference and an increase in terrace size with elevation. Available data fail to indicate any evidence of freeze-thaw weathering and information relating to present-day debris transport is singularly absent. Thermal data from the rock exposures showed variability that could cause thermal fatigue but no rates of change of temperature commensurate with thermal shock were recorded. Terrace development appears to be connected with lithological differences in the local sandstones, with growth along sedimentary junctions. Although presently in a permafrost environment, the available information on these landforms does not appear to be compatible with that generally accepted for cryoplanation terraces.

The relationships between vegetation patterns and periglacial features and their underlying ecology are still poorly understood and lack specific investigations in Antarctica. Here we present the results of vegetation colonization of different types of sorted patterned ground and gelifluction features (lobes and terracettes) at four sites in northern Victoria Land. This paper aims to understand the relationships between vegetation and the most widespread periglacial features in Victoria Land, discuss the role of periglacial features and vegetation in determining the ground surface temperature, and assess whether periglacial features provide ecological niches for vegetation colonization and development. Vegetation patterns are influenced by the feature type, mainly relating to patterned ground and debris island versus gelifluction features. The relations between vegetation and the periglacial features investigated in continental Antarctic are similar to those described for the Arctic, although in this part of the Antarctic vegetation is exclusively composed of cryptogams. Frost heave, ground texture and relief associated with different types of periglacial features provide a range of ecological niches sustaining vegetation biodiversity. Our data confirm the importance of periglacial features in shaping flora and vegetation biodiversity, as previously assessed only for the soil fauna in continental Antarctic.

Three models were used to look at the Southern Ocean Ross Sea sector circulation and hydrography. Two were climate models of low (1°) to intermediate resolution (1/3°), and one was an operational high resolution (1/10°) ocean model. Despite model differences (including physics and forcing), mean and monthly variability aspects of off-shelf circulation are consistently represented, and could imply bathymetric constraints. Western and eastern cyclonic gyral systems separated by shallow bathymetry around 180°E redistributing water between the wider Southern Ocean and the Ross Sea are found. Some model seasonal gyral transports increase as the Antarctic Circumpolar Current transport decreases. Model flows at 900 m at the gyral eastern end compare favourably with float data. On-shelf model depth-averaged west–east flow is relatively consistent with that reconstructed from longline fishing records. These flows have components associated with isopycnal gradients in both light and dense waters. The climate models reproduce characteristic isopycnal layer inflections (‘V’s) associated with the observed Antarctic Slope Front and on-shelf deep water formation, and these models transport some 4 Sv of this bottom water northwards across the outer 1000 m shelf isobath. Overall flow complexity suggests care is needed to force regional Ross Sea models.

Metasedimentary rocks constitute an important but comparatively poorly understood part of the Antarctic Peninsula. Herein we report single-grain U-Pb detrital-zircon ages from samples of the Trinity Peninsula and Botany Bay Groups of north-western Graham Land. All studied samples are dominated by a large and narrowly defined population of late Palaeozoic zircons. Significant early–middle Palaeozoic and minor Neoproterozoic and Mesoproterozoic sub-populations constitute the majority of pre-Carboniferous grains. These detrital-zircon age populations are consistent with sediment derivation entirely from western Gondwana sources. Despite the clear Gondwana signatures, our data suggest that the Trinity Peninsula Group province was either a parautochthonous peri-Gondwanan terrane later accreted to the Antarctic Peninsula, or a significant topographic barrier precluded voluminous sediment contributions from the interior of Gondwana. Statistical comparisons with similar metasedimentary complexes of southern South America, the South Shetland Islands and eastern New Zealand indicate a diversity of sediment provenance not previously recognized, but may provide a means to better determine the pre-break-up configuration of western Gondwana. Although insufficient to definitively restore Antarctic Peninsula components adjacent to South American complexes, some Trinity Peninsula Group samples exhibit robust affinities to the Miers Bluff Formation in the South Shetland Islands and the Duque de York and Main Range Metamorphic Complexes of the Patagonian Andes.

Seasonal variation of temperature, pressure, snow accumulation, winds, and their harmonic analysis are presented by using the data from Zhongshan Station and three Automatic Weather Stations deployed between the East Antarctic coast and the summit of the ice sheet at Dome A for the period 2005–07. Results show that: 1) temperature, snow accumulation and specific humidity decrease with increasing elevation and distance from the coast, with snow accumulation decreasing from 199 mm water equivalent (w.e.) yr-1 at LGB69 (180 km from the coast) to 31 mm w.e. yr-1 at Dome A, 2) Dome A experiences an extremely low minimum temperature of -82.5°C with the monthly mean temperature below -50°C for eight months in contrast to Zhongshan Station which does not show any monthly mean temperatures below -20°C, 3) mean surface wind speed increases from the coast to the escarpment region, and then reduces rapidly towards the interior plateau with the strongest winds occurring at katabatic sites with the greatest surface slopes, 4) temperature and pressure all shows a distinct biannual oscillation with a main minimum in spring and a secondary minimum in autumn, differing slightly from station to station, and 5) winter temperature corelessness increases as a function of elevation and distance from the coast, from 0.260 at the coastal Zhongshan Station to 0.433 at Dome A.

Permian and Triassic lacustrine and fluvial-system deposits in the Beardmore Glacier area of the Transantarctic Mountains preserve a superb record of continental environments and evidence of life on extensive bedding plane exposures. They yielded the first invertebrate trackways reported from continental Permo-Triassic deposits of Antarctica, here assigned to the ichnogenera Diplichnites and Diplopodichnus, which were probably produced by myriapodous arthropods. A resting trace is compared to Orbiculichnus and interpreted as generated by a jumping insect. Plant life is represented by leaf impressions, fossil forests and peat, vertebrates by body and trace fossils, and invertebrate shallow infauna by near surface burrows. The small number and diversity of trackways recovered from the large bedding plane exposures suggest that trackway-producing arthropods were rare at these high southern palaeolatitudes.

The first articulated skeleton of a penguin from the late Eocene of Antarctica is described. MLP 96-I-6-13 comes from the upper Submeseta Allomember (La Meseta Formation) of Isla Marambio (locality DPV 10/84). The significance of this finding in the context of the Anthropornis nordenskjoeldi biozone is discussed. An osteologic description of the recovered elements and a brief discussion of its systematic determination are provided. MLP 96-I-6-13 is the first articulated skeleton with sure specific assignment to Palaeeudyptes gunnari (Wiman, 1905), a species previously known only through isolated tarsometatarsi and included in the groups of Wiman.

At monthly and annual timescales, the zonally asymmetric circulation over the Southern Ocean is dominated by two quasi-stationary anticyclones: a western anticyclone approximately located south of New Zealand, and an eastern anticyclone located over the Drake Passage region. In this research their influence on late 20th century Antarctic sea ice is explored. During early winter, sea ice in the Weddell, Amundsen and Bellingshausen seas is influenced by the location of the east anticyclone. During late winter, the strength and location of the west anticyclone influences sea ice primarily in the Ross and Amundsen seas. The anticyclones have some effect on wind-driven sea ice motion, but the primary mechanism explaining their link to sea ice appears to be meridional atmospheric thermal advection. A western shift in the west anticyclone may be partly responsible for observed increases in ice cover in the Ross Sea over the late 20th century, but there is little evidence in existing data to support a link between the east anticyclone and observed sea ice trends.

Hyper-arid deserts present extreme challenges to life. The environmental buffering provided by quartz and other translucent rocks allows hypolithic microbial communities to develop on sub-soil surfaces of such rocks. These refuge communities have been reported, for many locations worldwide, to be predominantly cyanobacterial in nature. Here we report the discovery in Antarctica’s hyper-arid McMurdo Dry Valleys of three clearly distinguishable types of hypolithic community. Based on gross colonization morphology and identification of dominant taxa, we have classified hypolithic communities as Type I (cyanobacterial dominated), Type II (fungal dominated) and Type III (moss dominated). This discovery supports a growing awareness of the high biocomplexity in Antarctic deserts, emphasizes the possible importance of cryptic microbial communities in nutrient cycling and provides evidence for possible successional community processes within a cold arid landscape.

During two consecutive reconnaissance surveys in 2004 and 2005 and a revisit in 2008, the glaciological and meteorological conditions in the vicinity of the new Belgian Princess Elisabeth Station (71°57′S; 23°20′E) on Utsteinen Ridge were investigated. We set up an automatic weather station, measured the ice thickness around the Utsteinen Ridge, and established a mass balance stake network. These baseline investigations show that Utsteinen Ridge is a relatively sheltered spot from the main katabatic winds. Furthermore, winter temperature conditions are rather mild, confirming the coreless winter conditions of the Antarctic ice sheet. Mass balance is generally low (near zero) with a small accumulation to the east and relatively little ablation to the west of Utsteinen Ridge. Ice flow in the vicinity of the station is also minimal, since the Sør Rondane Mountains upstream of the station block most of the ice flow, a feature that is most apparent in the area where the station is situated. Measurements of the surface topography separated by four years show that the construction of the station seems to have a limited effect on the redistribution of snow around it. In view of the sheltered and safe ice conditions, the area is an ideal place for deploying field activities.

A surface energy balance model is forced by 13 years of high-quality hourly observations from the Antarctic coastal station Neumayer. The model accurately reproduces observed surface temperatures. Surface sublimation is significant in summer, when absorbed solar radiation heats the surface. Including a first order estimate of snowdrift sublimation in the calculation more than triples the total sublimation, removing 19% of the solid precipitation, indicating that snowdrift sublimation is potentially important for the mass balance of Antarctic ice shelves. Surface melt occurs at Neumayer in all summers, but all the meltwater refreezes. In two-thirds of the cases, the refreezing is quasi-instantaneous (within the model timestep of 6 min), so that no liquid water remains in the snow. For all other events, the occurrence of liquid water in the snowpack at Neumayer agrees well with satellite-based liquid water detection.

We report and describe two new small diamictite outcrops on Isla Marambio (Seymour Island), Antarctic Peninsula. These rocks rest on an erosional unconformity on top of the Eocene La Meseta Formation and are unconformably covered by glaciomarine rocks of the ?Pliocene–Pleistocene Weddell Sea Formation. The lithology, fossil content and isotopic ages obtained strongly suggest that the rocks belong to the Hobbs Glacier Formation and support a Late Miocene age for this unit. Additionally, the dated basalt clast provides the oldest age (12.4 Ma) for the James Ross Island Volcanic Group recorded up to now. The here described diamictite cannot be confidently correlated with a glaciomarine unit previously assigned to the Late Eocene–Lower Oligocene taken as proof that initial expansion of ice on Antarctica encompassed the entire continent synchronously in the earliest Oligocene. However, it is now evident that there are likely to be more, short but important, stratigraphic sequences of key regional and Antarctic wide interest preserved on the plateau of Isla Marambio.

We examined sequence variation of ITS and phy2 for Bryum argenteum from Antarctica, sub-Antarctic, New Zealand and Australia to understand better taxonomic delimitations and resolve relationships between these geographic regions. Bryum argenteum has been recorded as two species, B. argenteum and B. subrotundifolium, in all four regions with the latter now referred to as B. argenteum var. muticum. We found disagreement between taxon delimitations (based on morphology) and molecular markers. All continental Antarctic specimens consistently formed a monophyletic sister group that consisted of both morphologically identified B. argenteum varieties, separate to all non-Antarctic specimens (also consisting of both varieties). We suggest, contrary to previous records, that all continental Antarctic (Victoria Land) populations are referable to B. argenteum var. muticum, while sub-Antarctic, Australian and New Zealand populations included here are B. argenteum var. argenteum. Additionally, since there was less genetic diversity within Victoria Land, Antarctica, than observed between non-Antarctic samples, we suggest that this is, in part, due to a potentially lower rate of DNA substitution and isolation in northern and southern refugia within Victoria Land since the Pleistocene.

The French-Italian Concordia (CCD) seismological station at Dome C is one of two observatories setup on the ice cap in the interior of the Antarctic continent. We analysed the seismic signal due to ambient noise at this station and at three temporary stations 5 km away from Concordia, in order to specify the ice properties beneath them. A method based on the horizontal to vertical (H/V) spectral ratio, commonly used to analyse soil response in seismic regions, was applied to the Antarctic stations. The main peak in the spectral ratios is observed at frequencies 6.7–8 Hz at the Dome C stations, but it is not observed at another station on the ice cap, QSPA, where the sensor is buried at 275 m depth. This peak can be explained by a 23 m thick unconsolidated snow or firn layer with a low S-wave velocity of 0.7 km s-1, overlying a consolidated layer with S-wave velocity 1.8 km s-1. Despite the non-uniqueness of the solutions obtained by fitting the H/V spectra, this model is preferred because the depth of the velocity contrast coincides with the density at which ice particles arrange themselves in a continuous, dense lattice. A small variability of this structure is observed around Dome C.

The results of lithological mapping using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data for the Wright Peninsula region of Adelaide Island, Antarctic Peninsula are compared with existing geological maps and recent field observations to assess the potential of multispectral remote sensing to undertake lithological mapping on the Antarctic Peninsula. The Wright Peninsula comprises calc-alkaline intrusive rocks ranging from granite to gabbro, volcanic rocks of acidic to intermediate composition, and arc-related sediments. The reflective and thermal bands of a single ASTER image were analysed with reference to reflectance spectra of rock samples from the study area. Assessment of the ASTER mapping outcomes was undertaken with a newly compiled geological map of Adelaide Island and observations made during recent fieldwork. The results demonstrate that ASTER can uniquely discriminate granitoid intrusive rocks and altered rhyolitic volcanic rocks that display distinctive spectral properties. The results are more ambiguous at discriminating more intermediate/mafic rocks such as diorite/gabbro, andesite/basalt and chlorite-bearing sediments due to the similarity in spectral properties. These results demonstrate that although ASTER data are limited in their ability to uniquely discriminate lithologies they can provide important lithological information in support of geological mapping on the Antarctic Peninsula.

While ocean current and winds certainly play a major role in guiding the trajectories of free-floating icebergs, the direct effect of atmospheric surface pressure gradients can also have an important influence on the trajectories of large icebergs whose horizontal dimensions are sufficiently great to span synoptic systems. This effect is examined as a way of understanding why icebergs B15A, B15J, B15K, and C16 became “trapped” in a limited region immediately north of Ross Island for a period of several years, without being grounded. This limited region is otherwise flushed annually by summer surface winds and currents; thus the delay of the northward drift of the large icebergs (particularly B15A and B15J) defied expectation. The best explanation for this unexpected iceberg behaviour is that the large volcanic massifs on Ross Island create a quasi-permanent surface pressure anomaly patterned as a dipole, with high pressure in the area upwind of the island (an area appropriately called Windless Bight), and low pressure in the downwind area of the iceberg parking lot. The surface pressure regime experienced by two icebergs B15A and B15K is estimated using Automatic Weather Station observations and Global Positioning System receivers deployed on their surfaces to explain why they remained trapped. Breakdown of the atmospheric pressure gradients allowed them to eventually escape from the region to the north-west.

Nowadays it is well accepted that background aerosols in the boundary layer over remote oceans are of marine origin and not aged continental. Particularly in the Atlantic sector of the Southern Ocean at least four main important regions exhibit significant ocean primary productivity. They are the Bellingshausen–Amundsen Sea, the Weddell Sea, the southern Argentinean shelf and the southern Chilean coast. In this work, we have combined ground-based continuous atmospheric sampling of aerosol number concentration (ANC), over-sea dimethyl sulphide (DMS) measurements, chlorophyll a (chl a) concentration provided by Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite images, in situ meteorological data and monthly regional NCEP-NCAR re-analysis wind fields in order to investigate the relative contribution of each of the above regions to the apportionment of the ANC at King George Island (KGI), South Shetland Islands. Our results suggest that, at least during the period from September 1998–December 1999, the southern Argentinean shelf acted as the main contributor to the ANC measured in KGI.