Showing 11332 items
1 January, 2011 by Hilmar Gudmundsson
The response of ice streams to ocean tides is investigated. Numerical modelling experiments are conducted using a two-dimensional flow-line model of coupled ice-stream and ice-shelf flow. The model includes all…Read more on Ice-stream response to ocean tides and the form of the basal sliding law
1 January, 2011 by Richard Phillips
Navigational control of avian migration is understood, largely from the study of terrestrial birds, to depend on either genetically or culturally inherited information. By tracking the individual migrations of Atlantic…1 January, 2011 by Katrin Linse
The marine ecosystem on the eastern shelf of the Antarctic Peninsula was surveyed 5 and 12 years after the climate-induced collapse of the Larsen A and B ice shelves. An…Read more on Biodiversity change after climate-induced ice-shelf collapse in the Antarctic
1 January, 2011 by Jaume Forcada
The interactions among diet, ecology, physiology, and biochemistry affect N and C stable isotope signatures in animal tissues. Here, we examined if ecological segregation among animals in relation to sex…1 January, 2011 by Philip Leat
New 40Ar–39Ar ages of 5.6 to 1.3 Ma for lavas from the fossil Phoenix Ridge in the Drake Passage show that magmatism continued for at least 2 Ma after the…1 January, 2011 by Victoria Peck
In order to monitor the evolution of the British-Irish Ice Sheet (BIIS) and its influence in surface ocean structure during marine isotopic stages (MIS) 2 and 3, we have analyzed…1 January, 2011
Recent research has raised concerns about the potential influence of rapid climate change on the stability of major ice sheets. The behaviour of glaciers is determined largely by the processes…1 January, 2011 by Teal Riley
The results of the first attempt to use Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data for the purposes of lithologic mapping on the Antarctic Peninsula are presented for…1 January, 2011 by Vsevolod Afanasyev
We used light-level archival geolocators to track five Veeries (Catharus fuscescens) for one annual cycle as they migrated from Delaware to South America and back. Southward migration commenced in late…1 January, 2011 by Richard Phillips
Seabirds and other marine animals are at risk from anthropogenic activities that target them directly and those that can harm them incidentally. We integrate year-round tracking and vessel studies to…1 January, 2011 by Claire Allen
Major deepwater masses upwell and reach the surface in the Southern Ocean, forming an important conduit supplying nutrients and micronutrients to the surface and playing a key role in the…1 January, 2011 by Mervyn Freeman
Meteor wind data from the first year of operation of the Falkland Islands SuperDARN radar (52° S, 59° W) are used to characterize the atmospheric tides and background winds in…1 January, 2011 by Ed King
Despite significant advances over the past decades, our understanding of drumlin formation and associated ice-bed processes is still incomplete. In this paper, we present the integrated use of geomorphological, sedimentological…1 January, 2011 by Kevin Newsham
For the past 50 years there has been rapid warming in the maritime Antarctic1, 2, 3, with concurrent, and probably temperature-mediated, proliferation of the two native plants, Antarctic pearlwort (Colobanthus…1 January, 2011 by Kevin Newsham
Most nitrogen (N) enters many Arctic and Antarctic soil ecosystems as protein. Soils in these polar environments frequently contain large stocks of proteinaceous organic matter, which has decomposed slowly due…1 January, 2011 by Kevin Newsham
Nitrogen is a key regulator of primary productivity in many terrestrial ecosystems. Historically, only inorganic N (NH4+ and NO3-) and L-amino acids have been considered to be important to the…1 January, 2011 by Richard Hindmarsh, Richard Hindmarsh
A recent paper by Reference CalovCalov and others (2010) presents an intercomparison of several numerical ice-sheet models where the development of large-scale thermo-viscous instabilities is compared. In all but one…1 January, 2011 by Jaume Forcada, Susie Grant
Emerging Bayesian analytical approaches offer increasingly sophisticated means of reconstructing historical population dynamics from genetic data, but have been little applied to scenarios involving demographic bottlenecks. Consequently, we analysed a…Read more on Bayesian inference of a historical bottleneck in a heavily exploited marine mammal
1 January, 2011 by Andrew Clarke, Katrin Linse, Lloyd Peck
Life-history characteristics exert a profound influence upon the population structure of many marine organisms. However, relatively few genetic studies have compared direct with indirect-developing species in the same ecosystem or…1 January, 2011 by Andrew Clarke, Katrin Linse, Lloyd Peck
Although studies of population genetic structure are commonplace, a strong bias exists toward species from low latitudes and with relatively poor dispersal capabilities. Consequently, we used 280 amplified fragment length…1 January, 2011 by David Barnes, Huw Griffiths, Oliver Hogg
We attempt to quantify how significant the polar archipelago of South Georgia is as a source of regional and global marine biodiversity. We evaluate numbers of rare, endemic and range-edge…1 January, 2011 by Eric Wolff
The complex cyclical nature of Pleistocene climate, driven by the evolving orbital configuration of the Earth, is well known but not well understood. A major climatic transition took place at…Read more on The Mid-Brunhes Event and West Antarctic Ice Sheet stability
1 January, 2011 by Eric Wolff
Rapid, or abrupt, climate change is regarded as a change in the climate system to a new state following the crossing of a threshold. It generally occurs at a rate…Read more on Rapid climate change: lessons from the recent geological past
1 January, 2011 by Andrew Fleming, Kevin Hughes, Peter Fretwell
Globally, areas categorically known to be free of human visitation are rare, but still exist in Antarctica. Such areas may be among the most pristine locations remaining on Earth and,…Read more on Untouched Antarctica: mapping a finite and diminishing environmental resource
1 January, 2011 by Kevin Hughes
To understand fully the risk of biological invasions, it is necessary to quantify propagule pressure along all introduction pathways. In the Antarctic region, importation of fresh produce is a potentially…1 January, 2011 by Richard Phillips
The long breeding period and high reproductive investment of seabirds make use of resource-rich foraging areas pivotal both during and between breeding seasons. We tracked adult Australasian Gannets (Morus serrator)…1 January, 2011 by David Barnes, Peter Convey
The available literature on marine debris and its impacts in the sub-Antarctic Islands, the Antarctic Peninsula and on the coasts of Antarctica was organized and interpreted here. A total of…Read more on Plastics in the Antarctic environment: Are we looking only at the tip of the iceberg?
1 January, 2011 by Joanne Johnson, Stephen Roberts
The northeast Antarctic Peninsula (NEAP) region is currently showing signs of significant environmental change, evidenced by acceleration of glacial retreat and collapse of both Larsen-A and -B ice shelves within…1 January, 2011 by Anna Jones, Eric Wolff
Measurements of a suite of individual NOy components were carried out at Halley station in coastal Antarctica as part of the CHABLIS campaign (Chemistry of the Antarctic Boundary Layer and…1 January, 2011 by Michael Rose
This paper details the design of a novel thermoelectric energy harvesting device, capable of powering sea-ice instrumentation during the polar winter, when other sources of energy are either unavailable or…Read more on Powering sea-ice instrumentation via the Seebeck Effect
1 January, 2011 by Thomas Bracegirdle
On the basis of ERA40 and NCEP/NCAR Reanalysis (NNR) and simulations from CCCma, CCSM, CSIRO, HadCM3, MIROC-MEDRES and GFDL, which support the Intergovernmental Panel on Climate Change (IPCC) 4th Assessment…1 January, 2011 by David Barnes, Huw Griffiths
The Antarctic continental slope spans the depths from the shelf break (usually between 500 and 1000 m) to not, vert, similar3000 m, is very steep, overlain by ‘warm’ (2–2.5 °C)…Read more on Is there a distinct continental slope fauna in the Antarctic?
1 January, 2011 by Richard Hindmarsh, Richard Hindmarsh
The water-ice-rich north polar layered deposits (NPLD) of Mars play a key role in the Martian climate through an active exchange of water vapor with the atmosphere. Conditions are not…1 January, 2011 by David Vaughan
Sea level rise, especially combined with possible changes in storm surges and increased river discharge resulting from climate change, poses a major threat in low-lying river deltas. In this study…1 January, 2011 by Ed King
The Antarctic Ice Sheet loses mass to the surrounding ocean mainly by drainage through a network of ice streams: fast-flowing glaciers bounded on either side by ice flowing one or…Read more on Ice stream or not? Radio-echo sounding of Carlson Inlet, West Antarctica
1 January, 2011 by Hilmar Gudmundsson, Keith Makinson
We report on three GPS records of flow of the Larsen C Ice Shelf, spanning 2 months to 2 years. Variations in speed are evident at periods from a few…Read more on Nonlinear interaction between ocean tides and the Larsen C Ice Shelf system
1 January, 2011 by Amelie Kirchgaessner
A recent study on cloud observations reports an increase in total cloud cover at Faraday/Vernadsky since 1960 in the annual and wintertime data. The aim of this present study is…Read more on An analysis of precipitation data from the Antarctic base Faraday/Vernadsky
1 January, 2011
Migratory land birds perform extreme endurance flights when crossing ecological barriers, such as deserts, oceans and ice-caps. When travelling over benign areas, birds are expected to migrate by shorter flight…Read more on Great flights by great snipes: long and fast non-stop migration over benign habitats
1 January, 2011 by Jonathan Shanklin
The Antarctic ozone hole of 2010 is reviewed from a variety of perspectives, making use of various data and analyses. Based on total column ozone metrics, the 2010 ozone hole…1 January, 2011 by Richard Phillips
Seabirds in seasonal environments are often long-distance migrants and, for many species and populations, their ranges throughout the non-breeding period are unknown. As conditions during the non-breeding season often affect…1 January, 2011 by Peter Convey
Various microbial groups are well known to produce a range of extracellular enzymes and other secondary metabolites. However, the occurrence and importance of investment in such activities have received relatively…1 January, 2011 by Lloyd Peck, Simon Morley
Factors determining thermal niche separation of two sympatric infaunal bivalves (Laternula truncata and L. boschasina) occurring in a Singapore mangrove were examined by comparing experienced microhabitat temperature with the thermal…1 January, 2011 by Richard Phillips
Knowledge of the dynamics of long-distance migrations of pelagic seabirds is limited. Recent advances in tracking technology have yielded detailed, continuous accounts of the movements of individual seabirds over large…Read more on Dynamics of seasonal movements by a trans-Pacific migrant, the Westland petrel
1 January, 2011 by Eric Wolff
We have compiled 37 ice, marine and terrestrial palaeoclimate records covering the last 800 000 years in order to assess the pattern of glacial and interglacial strength, and termination amplitude.…1 January, 2011 by Jean-Baptiste Sallee
This study examines the subduction of the Subantarctic Mode Water in the Indian Ocean in an ocean–atmosphere coupled model in which the ocean component is eddy permitting. The purpose is…1 January, 2011
Snow distribution is a dominating factor in sea-ice mass balance in the Bellingshausen Sea, Antarctica, through its roles in insulating the ice and contributing to snow-ice production. The wind has…1 January, 2011 by Anna Jones, Eric Wolff, Louise Sime
We know from the ice record that the concentration of atmospheric methane, [CH4], at the Last Glacial Maximum (LGM) was roughly half that in the pre-industrial era (PI), buthow much…1 January, 2011 by Anna Jones, Eric Wolff, Louise Sime
The ice-core record of the carbon-13 content of atmospheric methane (δ13CH4) has largely been used to constrain past changes in methane sources. The aim of this paper is to explore,…1 January, 2011 by Neil Brough
The Greenland Summit Halogen-HO(x) (GSHOX) Campaign was performed in spring 2007 and summer 2008 to investigate the impact of halogens on HO(x) (= OH+HO(2)) cycling above the Greenland Ice Sheet.…1 January, 2011 by Thomas Bracegirdle
The sensitivity of the intensity of polar lows to changes in the sea-surface temperature (SST) is investigated. This is done by using an axisymmetric non-hydrostatic numerical model. It is found…Read more on Limited polar low sensitivity to sea-surface temperature
1 January, 2011 by Hua Lu
We have studied the characterization of the 11-year solar cycle (SC) signals in the Southern Hemisphere (SH) during the winter and spring using European Centre for Medium-Range Weather Forecasts (ECMWF)…1 January, 2011 by Philip Leat
Electron microprobe analyses are presented for phenocrysts and matrix glass in peralkaline, silica-oversaturated trachytes from the Menengai volcano, Kenya Rift Valley. The dominant phenocryst assemblage is alkali feldspar–hedenbergite–fayalite–titanomagnetite–apatite. Aenigmatite, amphibole…1 January, 2011 by Janet Silk, Richard Phillips, Vsevolod Afanasyev
Despite the recent burgeoning in predator tracking studies, few report on seabird activity patterns, despite the potential to provide important insights into foraging ecology and distribution. In the first year-round…1 January, 2011 by Adrian Jenkins, Keith Makinson, Keith Nicholls, Paul Holland
An isopycnic coordinate ocean circulation model is applied to the ocean cavity beneath Filchner-Ronne Ice Shelf, investigating the role of tides on sub-ice shelf circulation and ice shelf basal mass…Read more on Influence of tides on melting and freezing beneath Filchner-Ronne Ice Shelf, Antarctica
1 January, 2011
In October 2003 a campaign on board the Australian icebreaker Aurora Australis had the objective to validate standard Aqua Advanced Microwave Scanning Radiometer (AMSR-E) sea-ice products. Additionally, the satellite laser…1 January, 2011 by Chester Sands, Sandra McInnes, Sandra McInnes
We assessed the available morphological evidence to see if this corroborates the paraphyly in the Parachela (Tardigrada) as suggested by recent molecular data. We reconcile molecular phylogenetics with alpha morphology,…Read more on Phylum Tardigrada: A re-evaluation of the Parachela
1 January, 2011 by Gareth Marshall
This study examines regional atmospheric circulation changes associated with a reversal in the sign of the relationship between the Southern Annular Mode (SAM) and near-surface temperatures at Halley station, East…1 January, 2011 by Louise Sime
The sensitivity of interglacial Greenland temperature to orbital and CO2 forcing is investigated using the NorthGRIP ice core data and coupled ocean-atmosphere IPSL-CM4 model simulations. These simulations were conducted in…1 January, 2011 by Louise Sime
We compare the present and last interglacial periods as recorded in Antarctic water stable isotope records now available at various temporal resolutions from six East Antarctic ice cores: Vostok, Taylor…Read more on A comparison of the present and last interglacial periods in six Antarctic ice cores
1 January, 2011
Lubchenco challenges scientists to: ‘‘ address the most urgent needs of society, in proportion to their importance; communicate their knowledge and understanding widely in order to inform decisions of individuals…1 January, 2011 by Peter Convey
The springtail Gomphiocephalus hodgsoni (Arthropoda: Collembola) has been the focus of extensive ecophysiological and molecular genetic work and is now arguably the most well-studied of the continental Antarctic springtails. Here,…1 January, 2011 by Povl Abrahamsen, Hugh Venables, Michael Meredith
Antarctic Bottom Water (AABW), the densest water in the global overturning circulation, has warmed in recent decades, most notably in the Atlantic. Time series recorded within the boundary currents immediately…1 January, 2011 by Keith Nicholls, Michael Meredith
A serendipitous > 8-month time series of hydrographic properties was obtained from the vicinity of the South Orkney Islands, Southern Ocean, by tagging a southern elephant seal (Mirounga leonine) on…1 January, 2011
The ecology of Earth's first large organisms is an unsolved problem in palaeontology. This experience report discusses the determination of which ecosystems could have been feasible, by considering the biological…1 January, 2011 by Lloyd Peck, Melody Clark, Simon Morley
The limpet, Nacella concinna, collected from the Antarctic Peninsula (67 S), was incubated at -0.3 degrees C and 2.9 degrees C for 9 months to test if the previously reported…1 January, 2011 by Peter Convey
It has long been maintained that the majority of terrestrial Antarctic species are relatively recent, post last glacial maximum, arrivals with perhaps a few microbial or protozoan taxa being substantially…1 January, 2011
Delayed sleep phase (and sometimes free-run) is common in the Antarctic winter (no natural sunlight) and optimizing the artificial light conditions is desirable. This project evaluated sleep when using 17…1 January, 2011 by David Newnham, David Maxfield, Mark Clilverd, Richard Horne
We report the first ground-based passive microwave observations made from Troll station, Antarctica, which show enhanced mesospheric nitric oxide (NO) volume mixing ratio reaching levels of 1.2 ppmv, or 2–3…1 January, 2011 by Kevin Newsham
P>Dark septate endophytes (DSE) frequently colonize roots in the natural environment, but the effects of these fungi on plants are obscure, with previous studies indicating negative, neutral or positive effects…Read more on A meta-analysis of plant responses to dark septate root endophytes
1 January, 2011 by Kevin Newsham
Previous studies have shown the leafy liverwort Cephaloziella varians to associate consistently with fungi, typically the ericoid mycorrhizal symbiont Rhizoscyphus ericae, across a wide latitudinal gradient in the maritime and…1 January, 2011
Radar studies of firn on the ice sheets have revealed complex folds on its internal layering that form from the interplay of snow accumulation and ice flow. A mathematical theory…1 January, 2011 by Melody Clark, Simon Morley
Animal physiology, ecology and evolution are affected by temperature and it is expected that community structure will be strongly influenced by global warming. This is particularly relevant in the tropics,…Read more on Upper temperature limits of tropical marine ectotherms: global warming implications
1 January, 2011 by Vsevolod Afanasyev
Ten geolocators (light-level data loggers) were attached to Common Terns (Sterna hirundo) at a breeding site in the northeastern USA in 2007 and 2008; six were retrieved (five with useful…Read more on Migrations and winter quarters of five common terns tracked using geolocators
1 January, 2011 by David Barnes, Lloyd Peck, Melody Clark, Simon Morley
The Antarctic intertidal zone is one of the world's most extreme marine environments. As well as having a typically high annual temperature variation (~ 30 °C), it is affected by…Read more on Antarctic intertidal limpet ecophysiology: a winter-summer comparison
1 January, 2011 by Stephen Roberts
Quantitative climate reconstructions are fundamental to understand long-term trends in natural climate variability and to test climate models used to predict future climate change. Recent advances in molecular geochemistry have…1 January, 2011 by Lloyd Peck
There is great concern currently over environmental change and the biotic responses, actual or potential, to that change. There is also great concern over biodiversity and the observed losses to…Read more on Organisms and responses to environmental change
1 January, 2011 by Dominic Hodgson, Peter Convey
Cultivation techniques were used to study the heterotrophic bacterial diversity in two microbial mat samples originating from the littoral zone of two continental Antarctic lakes (Forlidas Pond and Lundstrom Lake)…1 January, 2011 by Richard Phillips
Considerable attention has focused on inter- and intraspecific variation in trophic niches of marine predators. Although this has revealed evidence for sexual segregation in distribution in some species, few studies…1 January, 2011 by Richard Phillips
Gadfly petrels are strictly oceanic seabirds that range very far from their breeding grounds. Foraging movements outside the breeding season are poorly described. We used global location sensing (GLS) to…1 January, 2011 by Michael Meredith
Antarctic coastal waters undergo major physical alterations during summer. Increased temperatures induce sea-ice melting and glacial melt water input, leading to strong stratification of the upper water column. We investigated…1 January, 2011 by Alistair Crame
We report on the discovery of a new outcrop of fossiliferous Neogene sediments on northern James Ross Island, northern Antarctic Peninsula. Approximately 100 specimens of the pectinid bivalve Austrochlamys anderssoni…1 January, 2011 by Geraint Tarling
We study the composition and biophysical properties of wax esters extracted from the Antarctic copepod, Calanoides acutus, to explore if these factors adjust buoyancy in diapausing copepods. Levels of wax…Read more on Phase transitions of wax esters adjust buoyancy in diapausing Calanoides acutus
1 January, 2011 by Peter Ward
Fatty acid biomarker analysis of the Cyclopoid copepods Oithona similis and Oithona frigida sampled from the Southern Ocean during the austral summer has indicated differences in diet between the two…Read more on Importance of diatoms for Oithona in Antarctic waters
1 January, 2011 by Roger Worland
The Arctic springtail Megaphorura arctica (Tullberg, 1876) employs a strategy known as cryoprotective dehydration to survive winter temperatures as low as -25 degrees C. During cryoprotective dehydration, water is lost…1 January, 2011 by Martin Collins
We review information from scientific trawl surveys carried out between 1977 and 2002 in the Porcupine Seabight and Abyssal Plain area of the Northeast Atlantic (240-4865 m water depth). Since…1 January, 2011 by Andrew Fleming, Hamish Pritchard
Satellite remote sensing has come to dominate the measurement of glacier and ice-sheet change. Three independent methods now exist for assessing ice-sheet mass balance and we focus on progress in…Read more on Understanding ice-sheet mass balance: progress in satellite altimetry and gravimetry
1 January, 2011
Diatom-rich sediments are common in several oceanic regions, especially the Southern Ocean. Some of these are strongly affected by bottom currents and are expected to be sorted by the flow.…1 January, 2011 by Roger Worland, Melody Clark
Cold hardiness in the Arctic Collembola Megaphorura arctica (Tullberg), formerly Onychiurus arcticus, has been the subject of extensive studies over the last decade. This species employs an unusual strategy known…1 January, 2011 by Hilmar Gudmundsson
The determination of basal properties on ice streams from surface data is formulated as a Bayesian statistical inference problem. The theory is applied to a flowline on Rutford Ice Stream,…1 January, 2011 by Richard Phillips
Pelagic seabirds are highly mobile, reducing the likelihood of allopatric speciation where disruption of gene flow between populations is caused by physically insurmountable, extrinsic barriers. Spatial segregation during the non-breeding…1 January, 2011 by Claus-Dieter Hillenbrand, Robert Larter
Sediment cores from cross-shelf troughs on the NE Antarctic Peninsula shelf recovered tills with variable shear strengths that represent different subglacial depositional regimes. In addition to detailed qualitative micromorphological descriptions,…1 January, 2011 by Claus-Dieter Hillenbrand, Robert Larter
Acoustic sub-bottom profiler surveys on the northeast Antarctic Peninsula shelf indicate that parts of the seabed are underlain by an acoustically transparent layer that is thin on the inner shelf…1 January, 2011 by Anje-Margriet Neutel
Global and regional climate models, such as those used in IPCC assessments, are the best tools available for climate predictions. Such models typically account for large-scale land-atmosphere feedbacks. However, these…Read more on Local ecosystem feedbacks and critical transitions in the climate
1 January, 2011 by David Vaughan, Hugh Corr
We assess basal roughness beneath Pine Island Glacier (PIG), West Antarctica, based on a recent airborne radio-echo sounding dataset. We identify a clear relationship between faster ice flow and decreased…Read more on The basal roughness of Pine Island Glacier, West Antarctica
1 January, 2011
The diets of Antarctic toothfish Dissostichus mawsoni and Patagonian toothfish Dissostichus eleginoides were examined around the South Sandwich Islands in the Southern Ocean, one of few regions with overlapping populations…1 January, 2011 by Dominic Hodgson, Stephen Roberts
The recent disintegration of Antarctic Peninsula ice shelves, and the associated accelerated discharge and retreat of continental glaciers, has highlighted the necessity of quantifying the current rate of Antarctic ice…