Showing 11880 items
1 May, 2014 by Claus-Dieter Hillenbrand, James Smith, Robert Larter
Recent palaeoglaciological studies on the West Antarctic shelf have mainly focused on the wide embayments of the Ross and Amundsen seas in order to reconstruct the extent and subsequent retreat…1 May, 2014 by Mark Clilverd, Neil Cobbett, Paul Breen
Sub-ionospheric radio-wave data from an AARDDVARK receiver located in Churchill, Canada, is analysed to determine the characteristics of electron precipitation into the atmosphere over the range 3 30 keV precipitation fluxes of…1 May, 2014 by Andrew Clarke, David Barnes, Huw Griffiths, Lloyd Peck, Peter Convey, Simon Morley
Patterns of environmental spatial structure lie at the heart of the most fundamental and familiar patterns of diversity on Earth. Antarctica contains some of the strongest environmental gradients on the…Read more on The spatial structure of Antarctic biodiversity
1 May, 2014 by Will Goodall-Copestake
The identification of salp species by morphological features alone can be challenging. This study combined morphological and molecular approaches to characterize different salp reproductive forms (oozooids and blastozooids) collected from…1 May, 2014 by Paul Holland
Unlike the rapid sea-ice losses reported in the Arctic, satellite observations show an overall increase in Antarctic sea ice concentration over recent decades. However, observations of decadal trends in Antarctic…1 May, 2014 by Anna Jones, Howard Roscoe, Neil Brough
Tropospheric BrO was measured by a ground-based remote-sensing spectrometer at Halley in Antarctica in spring 2007, and BrO was measured by satellite-borne remote-sensing spectrometers using similar spectral regions and similar…1 May, 2014 by Geraint Tarling, Sally Thorpe
Antarctic krill are known to have strong swimming capabilities, but direct observations of the speed and direction of krill-swarm movement within their natural environment are rare. We identified and examined…Read more on Instantaneous movement of krill swarms in the Antarctic Circumpolar Current
1 May, 2014 by Emma Woodfield, Richard Horne, Sarah Glauert
The intense inner radiation belt at Jupiter (>50 MeV at 1.5 RJ) is generally accepted to be created by radial diffusion of electrons from further away from the planet. However,…1 May, 2014 by Philip Trathan
Many animals migrate between breeding and wintering areas; however, whether each animal behaves consistently in space and time between consecutive years is less well understood. Furthermore, previous breeding state (successful…Read more on Individual consistency in migratory behaviour of a pelagic seabird
30 April, 2014 by Emilie Capron
During the last glacial cycle, Greenland temperature showed many rapid temperature variations, the so called Dansgaard-Oeschger (DO) events. The past atmospheric methane concentration closely followed these temperature variations, which implies…29 April, 2014 by Paul Holland
An ocean mixed-layer model has been incorporated into the Los Alamos sea ice model CICE to investigate regional variations in the surface-driven formation of Antarctic shelf waters. This model captures…Read more on Sea ice and the ocean mixed layer over the Antarctic shelf seas
28 April, 2014 by Richard Horne
We investigate the temporal evolution and the spatial distribution of electromagnetic ion cyclotron (EMIC) waves during the 8–11 June 2001 geomagnetic storm, one of the storms selected for study by…24 April, 2014 by Peter Convey
This study provides the description of the complete mitochondrial genome of the Antarctic collembola Folsomotoma octooculata. Since mitogenomic data are extensively used for phylogenetic reconstruction, we also provide a phylogenetic…24 April, 2014 by Mark Clilverd
Variation in solar irradiance is considered an important factor in natural climate forcing. Variations in the solar UV in particular are now regarded as a major source of decadal variability…22 April, 2014 by Ed King
The collapses of the Larsen A and B ice shelves on the Antarctic Peninsula in 1995 and 2002 confirm the impact of southward-propagating climate warming in this region. Recent mass…Read more on Marine ice regulates the future stability of a large Antarctic ice shelf
20 April, 2014 by Adrian Jenkins, Paul Holland
A laboratory experiment is constructed to simulate the density-driven circulation under an idealized Antarctic ice shelf and to investigate the flux of dense and freshwater in and out of the…Read more on The effect of geometry on ice shelf ocean cavity ventilation: a laboratory experiment
17 April, 2014 by David Jones, Hilmar Gudmundsson
The British Antarctic Survey's Halley Research Station is located on the Brunt Ice Shelf, Antarctica, where it is potentially vulnerable to calving events. Existing historical records show that the Brunt…Read more on Halley Research Station, Antarctica: calving risks and monitoring strategies
16 April, 2014 by Fausto Ferraccioli
Wilkes Land is a key region for studying the configuration of Gondwana and for appreciating the role of tectonic boundary conditions on East Antarctic Ice Sheet (EAIS) behavior. Despite this…Read more on The subglacial geology of Wilkes Land, East Antarctica
16 April, 2014 by Mark Clilverd
A summary is presented of experimental optical observations at 4278 Å from close to a powerful (~150 kW) VLF transmitter (call-sign JXN) with a transmission frequency of 16.4 kHz. Approximately…15 April, 2014 by Adrian Jenkins, Jan De Rydt, Paul Holland, Pierre Dutrieux
Observations beneath the floating section of Pine Island Glacier have revealed the presence of a subglacial ridge which rises up to 300 m above the surrounding bathymetry. This topographic feature…Read more on Geometric and oceanographic controls on melting beneath Pine Island Glacier
15 April, 2014 by Peter Convey
Climate change has played a critical role in the evolution and structure of Earth’s biodiversity. Geothermal activity, which can maintain ice-free terrain in glaciated regions, provides a tantalizing solution to…Read more on Geothermal activity helps life survive glacial cycles
10 April, 2014 by Carlos Martin Garcia
We use a full-Stokes thermo-mechanically coupled ice-flow model to study the dynamics of the glacier inside Scharffenbergbotnen valley, Dronning Maud Land, Antarctica. The domain encompasses a high accumulation rate region…3 April, 2014 by Kevin Hughes
Annex V to the Protocol on Environmental Protection to the Antarctic Treaty (the Protocol) establishes a framework for designating Antarctic Specially Protected Areas (ASPAs) and Antarctic Specially Managed Areas (ASMAs).…Read more on Specially protected and managed areas in Antarctica (updated)
2 April, 2014 by Richard Phillips
Individual wintering strategies and patterns of winter site fidelity in successive years are highly variable among seabird species. Yet, an understanding of consistency in timing of movements and the degree…2 April, 2014
Viruses from extreme environments are still largely unexplored and may harbor unseen genetic potential. Here, we present a first glance at the morphological diversity of virus like particles (VLPs) from…1 April, 2014 by Martin Black
This paper presents an investigation of image texture approaches for mapping sub-pixel fluvial grain-size features from airborne imagery, allowing for the rapid acquisition of surface sand and coarse fraction (>1.41…Read more on Mapping sub-pixel fluvial grain sizes with hyperspatial imagery
1 April, 2014 by Jennifer Jackson
Right whales (Eubalaena spp.) were the focus of worldwide whaling activities from the 16th to the 20th century. During the first part of the 19th century, the southern right whale…1 April, 2014
Cenozoic opening of the central Scotia Sea involved the tectonic translation of crustal blocks to form the North Scotia Ridge, which today is a major topographic constriction to the flow…1 April, 2014 by Lloyd Peck
This study examined high temperature survival and heat shock protein 70 (Hsp70) responses to temperature variation for two marine invertebrate species on sub-Antarctic Marion Island. The isopod Exosphaeroma gigas Leach…1 April, 2014 by Dominic Hodgson, Huw Griffiths, Stephen Roberts
We present multibeam swath bathymetric surveys of the major fjords surrounding the sub-Antarctic island of South Georgia to characterise the glacial geomorphology and to identify the relative timings and extent…1 April, 2014 by Hugh Corr, Richard Hindmarsh, Richard Hindmarsh
Isolated areas of high basal drag, or ‘sticky spots’, are important and poorly understood features in the force balance and dynamics of West Antarctic ice streams. Characterizing sticky spots formed…1 April, 2014 by Dominic Hodgson, Peter Convey
With direct meteorological data on the Antarctic Peninsula only dating back to the 1950s, scientists must search elsewhere for climate change records of the distant past. A series of expeditions…1 April, 2014 by Andrew Clarke
Living organisms on Earth are characterized by three necessary features: a set of internal instructions encoded in DNA (software), a suite of proteins and associated macromolecules providing a boundary and…1 April, 2014 by Alistair Crame, Jane Francis, Vanessa Bowman
In an effort to improve understanding of faunal evolution and its relationship to climate change, the PALEOPOLAR project is challenging existing theories about the Early Cenozoic era using an integrated,…1 April, 2014
The cold ice shelf water (ISW) that formed below the Filchner–Ronne Ice Shelf in the southwestern Weddell Sea, Antarctica, escapes the ice shelf cavity through the Filchner Depression and spills…Read more on On the Seasonal Signal of the Filchner Overflow, Weddell Sea, Antarctica
1 April, 2014 by Katrin Linse
The cold stenothermal nature of the Southern Ocean, and highly adapted fauna living within, raises the question of how much intra-specific variation there is among invertebrate populations, and how variation…1 April, 2014
Bryophytes are unable to control tissue water content although physiological adaptations allow growth in a wide range of habitats. Carbon isotope signals in two mosses (Syntrichia ruralis and Chorisodontium aciphyllum)…1 April, 2014 by Lloyd Peck, Melody Clark
Many early life-stage response studies to ocean acidification utilize gametes/offspring obtained from ambient-sourced parents, which are then directly introduced to experimentally altered seawater pH. This approach may produce a stress…1 April, 2014
We have recently suggested that the warming in the sea surface temperature (SST) since 1900, did not occur smoothly and slowly, but with two rapid shifts in 1925/1926 and 1987/1988,…Read more on Evidence for two abrupt warming events of SST in the last century
1 April, 2014
Long records of the latitude and speed of the North Atlantic eddy-driven jet stream since 1871 are presented from the newly available Twentieth Century Reanalysis. These jet variations underlie the…Read more on Twentieth century North Atlantic jet variability
28 March, 2014 by Jane Francis
General Circulation Model simulations of the mid-Pliocene warm period (mPWP, 3.264 to 3.025 Myr ago) currently underestimate the level of warming that proxy data suggest existed at high latitudes, with…27 March, 2014 by Hua Lu, Thomas Bracegirdle, Tony Phillips
This study provides a mechanistic explanation of why the Holton-Tan (HT) effect, a phenomenon in which the strength of northern stratospheric winter polar vortex synchronizes with the equatorial quasi-biennial oscillation…Read more on Mechanisms for the Holton-Tan relationship and its decadal variation
24 March, 2014 by Jennifer Jackson, Katrin Linse
The skeleton of a natural whale fall discovered in the Southern Ocean at 1,445 m was densely covered by one small, janirid isopod. Jaera tyleri sp. nov. is the first…21 March, 2014 by David Newnham
This paper describes the stratospheric and mesospheric ozone profiles retrieved from spectral measurements of the 249.96 GHz O3 line, using the British Antarctic Survey's ground-based Microwave Radiometer at Troll (BAS-MRT),…17 March, 2014 by Peter Convey
Mosses, dominant elements in the vegetation of polar and alpine regions, have well-developed stress tolerance features permitting cryptobiosis. However, direct regeneration after longer periods of cryptobiosis has been demonstrated only…Read more on Millennial timescale regeneration in a moss from Antarctica
17 March, 2014 by Vsevolod Afanasyev
Scaly-sided Mergansers Mergus squamatus breed on freshwater rivers in far eastern Russia, Korea and China, wintering in similar habitats in China and Korea, but nothing was known of their moulting…15 March, 2014 by Jean-Baptiste Sallee
Low levels of iron limit primary productivity across much of the Southern Ocean. At the basin scale, most dissolved iron is supplied to surface waters from subsurface reservoirs, because land…Read more on Surface-water iron supplies in the Southern Ocean sustained by deep winter mixing
11 March, 2014 by Michael Thorne
Proxy measures of genome-wide heterozygosity based on approximately 10 microsatellites have been used to uncover heterozygosity fitness correlations (HFCs) for a wealth of important fitness traits in natural populations. However,…Read more on High-throughput sequencing reveals inbreeding depression in a natural population
11 March, 2014 by Pierre Dutrieux
Large sectors of the Antarctic ice sheet are vulnerable to increases in melting at the bases of fringing ice shelves, with melt rates depending on ocean temperatures and circulations in…Read more on Export and circulation of ice cavity water in Pine Island Bay, West Antarctica
7 March, 2014 by Jane Francis
Evidence suggests that the early Eocene was a time of extreme global warmth. However, there are discrepancies between the results of many previous modelling studies and the proxy data at…Read more on Investigating vegetation-climate feedbacks during the early Eocene
3 March, 2014 by Geraint Tarling
The formation of two vertically discrete layers (bilayers) at night-time is a commonly observed phenomenon in zooplankton and is regularly found in Gullmarsfjord, a fjord with a 50 m sill…3 March, 2014 by Richard Phillips
We studied the year-round distribution and at-sea activity patterns of the sibling species, northern giant petrel Macronectes halli and southern giant petrel M. giganteus. Loggers combining light-based geolocators and immersion…1 March, 2014 by Kevin Hughes
Despite considerable research on biological invasions, key areas remain poorly explored, especially ways to reduce unintentional propagule transfer. The Antarctic represents a microcosm of the situation, with the numbers of…1 March, 2014 by Richard Phillips
Pelagic longline fisheries in the southwest Atlantic are a major conservation concern for several threatened seabirds, including four species of great albatrosses: wandering albatross (Diomedea exulans), Tristan albatross (Diomedea dabbenena),…1 March, 2014 by Paul Holland
Ice-shelf fractures frequently terminate where they encounter suture zones, regions of material heterogeneity that form between meteoric inflows in ice shelves. This heterogeneity can consist of marine ice, meteoric ice…Read more on The structure and effect of suture zones in the Larsen C Ice Shelf, Antarctica
1 March, 2014 by Richard Phillips
We hypothesized that changes in southeastern Bering Sea foraging conditions for black-legged kittiwakes (Rissa tridactyla) have caused shifts in habitat use with direct implications for population trends. To test this,…26 February, 2014 by Victoria Peck
Characterised by long term cooling and abrupt ice sheet expansion on Antarctica ~14 Ma ago, the mid Miocene marked the beginning of the modern ice-house world, yet there is still little…Read more on Deep ocean carbonate ion increase during mid Miocene CO2 decline
21 February, 2014 by James Smith, Joanne Johnson, Robert Larter
Pine Island Glacier, a major outlet of the West Antarctic Ice Sheet, has been undergoing rapid thinning and retreat for the past two decades. Here we demonstrate, using glacial-geological and…Read more on Rapid thinning of Pine Island Glacier in the early Holocene
15 February, 2014
Increased loads of land-based pollutants through river plumes are a major threat to the coastal water quality, ecosystems and sanitary heath. Identifying the coastal areas impacted by potentially polluted freshwaters…14 February, 2014 by Louise Sime
The evaluation of ice sheet models is one of the pressing problems in the study of ice sheets dynamics. Here we examine the question of how much isochronous information is…Read more on Isochronous information in a Greenland ice sheet radio-echo sounding dataset
12 February, 2014 by Markus Frey
Snow in the environment acts as a host to rich chemistry and provides a matrix for physical exchange of contaminants within the ecosystem. The goal of this review is to…12 February, 2014 by Iain Staniland, Jaume Forcada, Peter Fretwell
We describe a method of identifying and counting whales using very high resolution satellite imagery through the example of southern right whales breeding in part of the Golfo Nuevo, Península…Read more on Whales from space: counting southern right whales by satellite
12 February, 2014 by Fausto Ferraccioli, Hugh Corr, Tom Jordan
We present a detailed analysis of bed roughness beneath Institute and Möller Ice Streams, west Antarctica, using radio-echo sounding data (RES) acquired in the austral summer of 2010/11. We assess…11 February, 2014 by Vsevolod Afanasyev
Recent years have seen a growing consensus that events during one part of an animal's annual cycle can detrimentally affect its future fitness. Notably, migratory species have been shown to…10 February, 2014 by Andrew Wood, Jaume Forcada, Richard Phillips
Species in comparative demography studies often have a common phylogenetic or evolutionary ancestry and hence, they cannot fully be treated as independent samples in the statistical analysis. Although the serious…9 February, 2014 by Richard Phillips
Summary 1.Interspecific competitive interactions typically result in niche differentiation to alleviate competition through mechanisms including character displacement. However, competition is not the sole constraint on resource partitioning, and its effects…5 February, 2014 by Sandra McInnes, Sandra McInnes
Dividing the world into nine regions, this first paper describes literature records of the limno-terrestrial tardigrades (Tardigrada) reported from Central America. Updating previously published species lists we have revised the…Read more on Annotated zoogeography of non-marine Tardigrada. Part I: Central America
5 February, 2014 by Catharine Horswill, Hugh Venables, Iain Staniland, Norman Ratcliffe, Philip Trathan, Stacey Adlard
Competition for food among populations of closely related species and conspecifics that occur in both sympatry and parapatry can be reduced by interspecific and intraspecific spatial segregation. According to predictions…1 February, 2014 by Claus-Dieter Hillenbrand, Michael Meredith
The Antarctic Circumpolar Current is key to the mixing and ventilation of the world’s oceans. This current flows from west to east between about 45° and 70°S connecting the Atlantic,…1 February, 2014 by Hilmar Gudmundsson
Over the past 40 years Pine Island Glacier in West Antarctica has thinned at an accelerating rate, so that at present it is the largest single contributor to sea-level rise…Read more on Retreat of Pine Island Glacier controlled by marine ice-sheet instability
1 February, 2014 by Paul Holland
Sinking dense plumes are important in many oceanographic settings, notably the polar formation of deep and bottom waters. The dense water sources feeding such plumes are commonly affected by tidal…1 February, 2014 by Claus-Dieter Hillenbrand
Using a one-dimensional numerical model of ice-stream flow with robust grounding-line dynamics, we explore controls on paleo-ice-stream retreat in Marguerite Bay, Antarctica, during the last deglaciation. Landforms on the continental…1 February, 2014 by Adrian Jenkins, Paul Holland, Satoshi Kimura
Ocean freezing within ice-shelf basal crevasses could potentially act as a stabilizing influence on ice shelves; however, ice-ocean interaction and ocean dynamics within these crevasses are as yet poorly understood.…Read more on Modelling ice-ocean interaction in ice shelf crevasses
1 February, 2014 by Rosie Williams
The ability of unicellular green algal species such as Chlamydomonas reinhardtii to produce hydrogen gas via iron-hydrogenase is well known. However, the oxygen-sensitive hydrogenase is closely linked to the photosynthetic…30 January, 2014 by Nigel Meredith, Richard Horne
Whistler mode chorus is an important magnetospheric emission, playing a dual role in the acceleration and loss of relativistic electrons in the Earth's outer radiation belt. Chorus is typically generated…29 January, 2014 by Mark Clilverd
Using Microwave Limb Sounder (MLS/Aura) and Medium Energy Proton and Electron Detector (MEPED/POES) observations between 2005–2009, we study the longitudinal response of nighttime mesospheric OH to radiation belt electron precipitation.…27 January, 2014 by Richard Phillips
For more than 60 yr, electronic tags (including acoustic transmitters, archival loggers, and satellite tags) have been applied to free-ranging marine vertebrates to track their behaviour and characterize their spatial…23 January, 2014 by John King
A combination of observational data and modelling reveals the potential significance of the north and tropical Atlantic Ocean in driving change in Antarctic winds and sea ice on decadal timescales…Read more on Climate science: A resolution of the Antarctic paradox
23 January, 2014 by Deborah Pardo
Allocation decisions depend on an organism's condition which can change with age. Two opposite changes in life-history traits are predicted in the presence of senescence: either an increase in breeding…21 January, 2014 by Rachel Cavanagh
The rapid expansion of human activities threatens ocean-wide biodiversity. Numerous marine animal populations have declined, yet it remains unclear whether these trends are symptomatic of a chronic accumulation of global…Read more on Extinction risk and conservation of the world’s sharks and rays
21 January, 2014 by Stephen Roberts
Lake sediments contain valuable information about past volcanic and seismic events that have affected the lake catchment, and they provide unique records of the recurrence interval and magnitude of such…16 January, 2014 by Michael Meredith
The fate of a deep boundary current that originates in the Southeast Pacific and flows southward along the continental slope of South America is elucidated. The current transports poorly ventilated…Read more on Deep boundary current disintegration in Drake Passage
15 January, 2014 by Richard Phillips
Animal populations are frequently limited by the availability of food or of habitat. In central-place foragers, the cost of accessing these resources is distance-dependent rather than uniform in space. However,…15 January, 2014 by Eugene Murphy, Emma Young, Sally Thorpe
The waters around South Georgia are among the most productive in the Southern Ocean, with zooplankton populations close to the island, in particular Antarctic krill, supporting vast colonies of higher…10 January, 2014 by Adrian Jenkins, Povl Abrahamsen, Jan De Rydt, Paul Holland, Pierre Dutrieux
Pine Island Glacier has thinned and accelerated over recent decades, significantly contributing to global sea-level rise. Increased oceanic melting of its ice shelf is thought to have triggered those changes.…Read more on Strong sensitivity of Pine Island ice-shelf melting to climactic variability
9 January, 2014 by Richard Phillips
Tracking technology has revolutionized knowledge of seabird movements; yet, few studies have examined sex differences in distribution and behavior of small to medium-sized, sexually-monomorphic seabirds. Application of bird-borne geolocation-immersion loggers…8 January, 2014 by Philip Trathan, Peter Fretwell
We describe a new breeding behaviour discovered in emperor penguins; utilizing satellite and aerial-survey observations four emperor penguin breeding colonies have been recorded as existing on ice-shelves. Emperors have previously…7 January, 2014 by Sebastian Rosier
Tides play an important role in ice sheet dynamics by modulating ice stream velocity, fracturing, and moving ice shelves and mixing water beneath them. Any changes in ice shelf extent…Read more on Modeling Antarctic tides in response to ice shelf thinning and retreat
3 January, 2014 by Fausto Ferraccioli, Hugh Corr, Tom Jordan
Repeat-pass ICESat altimetry has revealed 124 discrete surface height changes across the Antarctic Ice Sheet, interpreted to be caused by subglacial lake discharges (surface lowering) and inputs (surface uplift). Few…1 January, 2014 by Alex Brisbourne, Andy Smith, Ed King, Keith Makinson, Keith Nicholls, Paul Holland
Seismic reflection soundings of ice thickness and seabed depth were acquired on the Larsen C Ice Shelf in order to test a sub-shelf bathymetry model derived from the inversion of…Read more on Seabed topography beneath Larsen C Ice Shelf from seismic soundings
1 January, 2014 by Alexander Tate, Claus-Dieter Hillenbrand, Philip Leat, Robert Larter
New multibeam bathymetric data from the southeastern Weddell Sea show significant differences in surface morphology of the outer continental shelf and slope between two adjacent cross-shelf troughs. These are the…1 January, 2014 by Melody Clark
Increasing temperatures and glacier melting at the Western Antarctic Peninsula (WAP) are causing rapid changes in shallow coastal and shelf systems. Climate change-related rising water temperatures, enhanced ice scouring, as…