Showing 11862 items
1 January, 2006
Dating Jurassic terrestrial floras in the Antarctic Peninsula has proved problematic and controversial. Here U–Pb series dating on detrital zircons from a conglomerate interbedded with fossil plant material provide a…1 January, 2006
Recent detailed mapping, section logging and an improved understanding of the geological evolution of the Antarctic Peninsula provide a robust framework for an improved lithostratigraphic subdivision of the Latady Basin,…1 January, 2006 by Teal Riley
The Jurassic Mount Poster Formation of eastern Ellsworth Land, southern Antarctic Peninsula, comprises silicic ignimbrites related to intracontinental rifting of Gondwana. The identification of less voluminous basaltic and sedimentary facies…1 January, 2006 by Nigel Meredith, Richard Horne
We present an analysis of the electron phase space density in the Earth's outer radiation belt during three magnetically disturbed periods to determine the likely roles of inward radial diffusion…Read more on Phase space density analysis of the outer radiation belt energetic electron dynamics
1 January, 2006
Geomagnetic data from five northern hemisphere observatories at latitudes ranging from 22 degrees N to 67 degrees N have been used to investigate long-term trends in planetary wave activity in…1 January, 2006 by Adrian Jenkins, Hugh Corr, Keith Nicholls
Basal melting of Antarctica’s floating ice shelves accounts for between 15 and 35% of the total mass loss from the ice sheet and helps to precondition the shelf waters for…1 January, 2006 by Adrian Jenkins, Hugh Corr, Keith Nicholls
Precise measurements of basal melting have been made at a series of 14 sites lying within a few kilometres of the grounding line of the Ronne Ice Shelf, Antarctica, where…1 January, 2006 by Adrian Jenkins, Keith Nicholls
Within the cavity beneath Filchner-Ronne Ice Shelf (FRIS), High Salinity Shelf Water (HSSW) is transformed into Ice Shelf Water (ISW) by a combination of melting and freezing at the ice…1 January, 2006 by Anna Jones, Eric Wolff, John Turner, Steve Colwell
Since March 2003, measurements of surface ozone have been made at the British Antarctic Survey Clean Air Sector Laboratory (CASLab) at Halley station in coastal Antarctica. Detailed measurements of boundary…1 January, 2006 by Martin Collins
We deployed 2 porpoise (Phocoena phocoena) carcasses at bathyal depth (2555 to 2710 m) in the Porcupine Seabight, NE Atlantic for periods of 1 wk and 6 mo respectively. Consumption…Read more on Consumption of large bathyal food fall, a six month study in the NE Atlantic
1 January, 2006 by John King
The Antarctic research stations of Dome C and Halley lie at similar latitudes (∼75°S) and are thus subject to similar diurnal variation of solar radiation at the top of the…1 January, 2006 by David Barnes
In order to study taxon richness, biodiversity and abundance patterns in the North Atlantic from temperate latitudes through Arctic to high Arctic latitudes, we recorded the faunas (at ELWS level)…1 January, 2006 by Thomas Lachlan-Cope
Tropical Pacific–high southern latitude teleconnections are shown to be caused by Rossby wave dynamics and are sensitive to the exact pattern of sea surface temperature (SST) anomalies forcing anomalous ascent.…1 January, 2006 by Mai Mai Lam, Michael Pinnock
The temporal and spatial variability of nightside magnetic reconnection is described using two-dimensional ionospheric measurements during the growth phase and early expansion phase of a single substorm. Two techniques (A…1 January, 2006 by Philip Trathan
Sea surface temperature (SST) time-series from the southwest Atlantic and the El Niño 4 region in the western Pacific were compared to an index of annual calving success of the…Read more on Global climate drives southern right whale (Eubalaena australis) population dynamics
1 January, 2006 by Katrin Linse
Bouvet Island is one of the most isolated islands in the Southern Ocean and its marine benthic fauna has rarely been investigated and so is poorly known. This study adds…1 January, 2006 by David Barnes, Katrin Linse, Peter Enderlein
Much has been made of body-size variability with latitude, and extreme body sizes in polar waters, but body size has never been investigated along a latitudinal gradient within polar waters.…Read more on Body size and growth of benthic invertebrates along an Antarctic latitudinal gradient
1 January, 2006 by Andrew Clarke, David Barnes, Huw Griffiths, Katrin Linse
For many decades molluscan data have been critical to the establishment of the concept of a global-scale increase in species richness from the poles to the equator. Low polar diversity…Read more on Biodiversity and biogeography of Antarctic and sub-Antarctic mollusca
1 January, 2006 by Eric Wolff
We determine the physicochemical habitat for microorganisms in subsurface terrestrial ice by quantitatively constraining the partitioning of bacteria and fluorescent beads (1–10 m) between the solid ice crystals and the…1 January, 2006 by Eric Wolff
Sea-salt aerosols represent a significant fraction of the aerosol optical depth over the oceans, and thus their response to changes in climate represents an important potential feedback on climate. Model…1 January, 2006 by Keith Makinson
The ice front region of Ronne Ice Shelf lies near the critical latitude of the semidiurnal M2 tide, the principal tidal constituent in the southern Weddell Sea. Here the Coriolis…1 January, 2006 by Keith Makinson
Ice streams are major drainage routes, through which much of the ice in Antarctica flows from the continent. They flow at speeds of up to two orders of magnitude greater…Read more on Future hot water drilling on Rutford Ice Stream 2004/05
1 January, 2006 by Keith Makinson
High Salinity Shelf Water (HSSW) flowing into the cavity beneath Filchner-Ronne Ice Shelf (FRIS) occupies the lower portion of the water column. Tidal mixing is likely to be a primary…Read more on Tidal vertical mixing beneath Filchner-Ronne Ice Shelf
1 January, 2006 by Gareth Marshall
We examine the impact that changes in the winter Southern Hemisphere (SH) meridional sea surface temperature (SST) gradient have on the sign and strength of the SH Annular Mode (SAM).…1 January, 2006 by Gareth Marshall, John King
Since the mid-1960s, rapid regional summer warming has occurred on the east coast of the northern Antarctic Peninsula, with near-surface temperatures increasing by more than 2°C. This warming has contributed…1 January, 2006 by Richard Hindmarsh, Richard Hindmarsh
Radar-detected internal layering contained in some ice divides shows upwarped arches termed Raymond bumps. The distribution of their amplitude with height can date the onset of divide flow, reflecting changes…1 January, 2006 by Peter Convey, Rolf Maslen
Nematode worms are one of the most important soil faunal groups in Antarctica. However, relatively little is known about their wider distribution, biogeography and history in the region, and taxonomic…1 January, 2006
A rapid increase in the variety, quality, and quantity of observations in polar regions is leading to a significant improvement in the understanding of sea ice dynamic and thermodynamic processes…1 January, 2006 by Mark Clilverd, Michael Rose
Plasmaspheric ducts may execute Doppler oscillations driven by propagating ultra-low frequency (ULF) waves. We examined about 100 such events recorded over 1 year under magnetically quiet conditions at L =…1 January, 2006 by Mark Clilverd, Nigel Meredith, Richard Horne
Plasmaspheric hiss is an electromagnetic wave emission responsible for electron loss from the radiation belts, particularly in the slot region (2 < L < 3). There are two leading theories…1 January, 2006 by Nigel Meredith, Richard Horne, Sarah Glauert
Following enhanced magnetic activity the fluxes of energetic electrons in the Earth's outer radiation belt gradually decay to quiet-time levels. We use CRRES observations to estimate the energetic electron loss…Read more on Energetic outer zone electron loss timescales during low geomagnetic activity
1 January, 2006
We explore methods of dating a 101 m ice core from a bare ice ablation area in the Yamato Mountains, Dronning Maud Land, East Antarctica. There are two unknowns, the…1 January, 2006 by Mark Belchier, Simon Morley
We present the first fecundity and egg size data for three species of lithodid crab from Antarctic waters south of the Polar Front, caught in the fisheries operating around the…Read more on Reproductive strategies of sub-Antarctic lithodid crabs vary with habitat depth
1 January, 2006
A function that approximates atmospheric tidal behavior in the polar regions is described. This function is fitted to multistation radar measurements of wind in the mesosphere and lower thermosphere with…Read more on A climatology of tides in the Antarctic mesosphere and lower thermosphere
1 January, 2006 by Kevin Newsham, Rolf Maslen, Sandra McInnes, Sandra McInnes
A sample of the liverwort Cephaloziella varians was collected on 1 January 1999 at Rothera Point on the Wright Peninsula, Adelaide Island, western Antarctic Peninsula and was partially dried and…Read more on Survival of antarctic soil metazoans at −80°C for six years
1 January, 2006 by Keith Nicholls
As a result of their importance in the production of Antarctic Bottom Water, processes over the Antarctic continental shelf have a strong impact on the global ocean. Some of the…Read more on Interannual variability beneath Filchner-Ronne Ice Shelf, Antarctica
1 January, 2006
All-sky CCD observations of short-period mesospheric gravity waves have been made from Halley Station, Antarctica (76°S, 27°W). On 27 May, 2001, an unusual wave event exhibiting several features characteristic of…Read more on An unusual mesospheric bore event observed at high latitudes over Antarctica
1 January, 2006 by Michael Pinnock
Auroral westward flow channels (AWFCs) are intense, narrow channels of westward drift overlapping the equatorward edge of the auroral oval in the pre-magnetic midnight sector. They are a close relative…Read more on On the occurrence of auroral westward flow channels and substorm phase
1 January, 2006 by Richard Hindmarsh, Richard Hindmarsh
The effect of spatial variations in ice thickness, accumulation rate and lateral flow divergence on radar-detected isochrone geometry in ice sheets is computed using an analytical method, under assumptions of…1 January, 2006 by Andrew Clarke, Lloyd Peck
The Antarctic gastropods Marseniopsis mollis (Smith, 1902) and Torellia mirabilis (Smith, 1907) lay eggs in the late austral summer and autumn; these hatch the following late winter and early summer.…1 January, 2006 by David Barnes, Lloyd Peck, Peter Convey
Knowledge of Antarctic biotas and environments has increased dramatically in recent years. There has also been a rapid increase in the use of novel technologies. Despite this, some fundamental aspects…1 January, 2006 by Andy Smith
Laterally continuous subglacial sediments are a necessary component for ice streaming in the modern onset regions of the ice streams draining the Siple Coast of West Antarctica on the basis…1 January, 2006 by Mervyn Freeman, Richard Horne
Collisionless magnetic reconnection requires the violation of ideal MHD by various kinetic-scale effects whose relative importance is uncertain. Recent research has highlighted the potential importance of wave-particle interactions by showing…Read more on Anomalous resistivity and the non-linear evolution of the ion-acoustic instability
1 January, 2006 by Mervyn Freeman
We present an analysis of the electric and magnetic wave spectra on kinetic scales during several crossings of a reconnecting current sheet. The spectra were measured from 1 Hz or…1 January, 2006 by Richard Phillips, Vsevolod Afanasyev
The white-chinned petrel Procellaria aequinoctialis is a medium-sized procellariiform with a circumpolar subAntarctic breeding distribution. Feeding during both day and night, and often competing aggressively for bait, offal and discards,…1 January, 2006 by Richard Phillips
Although a variety of techniques (including water-offloading, and spontaneous and induced regurgitation) are used routinely to obtain fresh stomach samples from seabirds, there have been few studies of their efficacy…Read more on Efficacy and effects of diet sampling of albatross chicks
1 January, 2006 by Philip Trathan, Richard Phillips
Long-term studies at Bird Island, South Georgia, show that numbers of wandering, black-browed and grey-headed albatrosses have been decreasing since the late 1970s. To determine the status of the total…1 January, 2006
Naturally occurring microbial communities are complex, with autotrophs and heterotrophs often similarly sized and impossible to separate by conventional size fractionation approaches. However, if it was possible to identify specific…1 January, 2006 by Andrew Clarke
Through functional analyses, integrative physiology is able to link molecular biology with ecology as well as evolutionary biology and is thereby expected to provide access to the evolution of molecular,…Read more on Trade-offs in thermal adaptation: the need for a molecular to ecological integration
1 January, 2006 by Martin Collins
The oceanic abyss (depths greater than 3000 m), one of the largest environments on the planet, is characterized by absence of solar light, high pressures and remoteness from surface food…Read more on The absence of sharks from abyssal regions of the world’s oceans
1 January, 2006
A detailed record of late Pleistocene deglaciation followed by mid-Holocene ice shelf breakup and late Holocene re-growth is contained in continental shelf sediments in the northern Larsen area, northeast Antarctic…1 January, 2006 by Peter Convey
The molecular weight distributions and hydrolysable neutral sugar composition of dissolved organic carbon (DOC) was investigated in four maritime Antarctic lakes on Signy Island of different trophic status; Heywood Lake…1 January, 2006
British Antarctic Survey director Chris Rapley (above) first conceived the idea of an International Polar Year back in early 2003. It has now grown into the world’s largest coordinated science…1 January, 2006 by Iain Staniland
The spatial and temporal variability in the fish component of the diet of Antarctic fur seals (Arctocephalus gazella (Peters, 1875)) in the Atlantic sector of the Southern Ocean was examined…1 January, 2006
Observations from a novel autonomous Doppler sodar wind profiling system are described and analysed. These include the first continuous wintertime soundings of katabatic winds over Antarctica - a continent with…Read more on Profiles of katabatic flows in summer and winter over Coats Land, Antarctica
1 January, 2006 by Philip Leat, Teal Riley
A suite of mafic dykes from the Underberg region of southern KwaZulu-Natal (South Africa) were intruded at 178 Ma, coincident in age with the major Okavango Dyke Swarm of Botswana,…Read more on Overlap of Karoo and Ferrar magma types in KwaZulu-Natal, South Africa
1 January, 2006 by David Vaughan, Hugh Corr
The East Antarctic Ice Sheet (EAIS) is the largest reservoir of ice on the planet by an order of magnitude. Compared with the West Antarctic Ice Sheet (WAIS), it is…Read more on Switch-off of a major enhanced ice flow unit in East Antarctica
1 January, 2006 by David Vaughan, Hugh Corr
Radio-echo sounding data are used to investigate bed roughness beneath the three enhanced-flow tributaries of Slessor Glacier, East Antarctica. Slow-moving inter-tributary areas are found to have rough beds, while the…Read more on Basal conditions beneath enhanced-flow tributaries of Slessor Glacier, East Antarctica
1 January, 2006 by Mark Clilverd
Solar proton events (SPE) are major, though infrequent, space weather phenomena that can produce hazardous effects in the near-Earth space environment. A detailed understanding of their effects depends upon knowledge…Read more on Dynamic geomagnetic rigidity cutoff variations during a solar proton event
1 January, 2006 by Elaine Fitzcharles, Mark Belchier, Simon Morley
The genetic structure of Patagonian toothfish populations in the Atlantic and western Indian Ocean Sectors of the Southern Ocean (SO) were analysed using partial sequences of the mitochondrial 12S rRNA…1 January, 2006 by Gareth Marshall, Howard Roscoe, John King
Stratospheric change associated with the Antarctic ozone hole is clearly implicated in changing surface climate near 65°S in late summer, in both measurements and models, via downward propagation of height…1 January, 2006 by Howard Roscoe
The Brewer–Dobson circulation brings tropospheric air, accompanied by CFCs and greenhouse gases, into the stratosphere. Many models predict an increased circulation associated with an increase in greenhouse gases, such as…Read more on The Brewer–Dobson circulation in the stratosphere and mesosphere – Is there a trend?
1 January, 2006 by Howard Roscoe
The Royal Society expedition to Antarctica established a base at Halley Bay, in support of the International Geophysical Year of 1957–1958. Surface ozone was measured during 1958 only, using a…1 January, 2006 by Gareth Marshall
Precipitation delivery mechanisms for Dolleman Island (DI), located off the east coast of the Antarctic Peninsula, are investigated using reanalysis and back trajectory data. The Southern Annular Mode (SAM) and…1 January, 2006 by Robert Larter
Seismic reflection profiles, bathymetric and magnetic data collected along and across the continental margin of the Bellingshausen Sea provide new constraints and interpretations of the oceanic basement structure and Cenozoic…1 January, 2006
The bivalve Adamussium colbecki is an endemic Antarctic pectinid that can be locally abundant in nearshore habitats, sometimes as the dominant species. However, its distribution around the Antarctic continent is…1 January, 2006
Approaches to describe gene regulation networks can be categorized by increasing detail, as network parts lists, network topology models, network control logic models or dynamic models. We discuss the current…1 January, 2006
We studied the diet of Antarctic krill, Euphausia superba, at five stations across the southwest Atlantic sector in summer 2003 by analyzing stomach content, fatty acids, and stable isotopes on…1 January, 2006 by Katrin Linse
Records of extant Monoplacophora are still scarce, often limited to single specimens or empty shells. Little is known about monoplacophoran diversity, distribution and biology. This study summarizes the present distributional…1 January, 2006
Satellite radar altimeters and scatterometers deployed over ice sheets experience backscatter from the surface and from within the snowpack, termed surface and volume backscatter respectively. In order to assess the…1 January, 2006 by Michael Meredith
This paper synthesizes our understanding of the Arctic's large-scale freshwater cycle. It combines terrestrial and oceanic observations with insights gained from the ERA-40 reanalysis and land surface and ice-ocean models.…1 January, 2006 by Fausto Ferraccioli
During the austral summer of 2001/02 five thousand line kilometres of airborne radio echo sounding and aeromagnetic data were collected in the region of three tributaries of Slessor Glacier, East…1 January, 2006 by Richard Horne, Sarah Glauert
Observations of the relativistic electron flux increases during the first days of November, 2003 are compared to model simulations of two leading mechanisms for electron acceleration. It is demonstrated that…1 January, 2006 by Richard Horne
Whistler mode chorus emissions in the Earth's magnetosphere extend from the plasmapause to the boundary of trapping. Knowledge of the pitch angle and energy scattering rates is essential for accurate…Read more on Bounce-averaged diffusion coefficients for field-aligned chorus waves
1 January, 2006 by Keith Nicholls
In the period 1979–2003 the mass of “giant” icebergs (icebergs larger than 18.5 km in length) calving from Antarctica averaged 1089 ± 300 Gt yr−1 of ice, under half the…Read more on Contribution of giant icebergs to the Southern Ocean freshwater flux
1 January, 2006 by Adrian Jenkins
Model simulations of circulation and melting beneath Fimbulisen, Antarctica, obtained using an isopycnic coordinate ocean model, are presented. Model results compare well with available observations of currents and hydrography in…Read more on Modeling ocean processes below Fimbulisen, Antarctica
1 January, 2006
The hydraulic behaviour of meltwater during subglacial basaltic eruptions in temperate ice is of paramount importance in understanding the eruptive processes, lithofacies and architecture of the edifices formed. Hydraulics also…1 January, 2006
Terrestrial volcanism occurred extensively on Brabant Island, northern Antarctic Peninsula, during the Late Quaternary (< 200 ka; probably entirely Late Pleistocene). Two compositionally distinct volcanic sequences formed three large shield…1 January, 2006 by Peter Fretwell
Cape Purvis is a conspicuous promontory on southern Dundee Island. It forms a prominent mesa that contrasts with the smooth, shield-like (snow-covered) topography of the remainder of the island. The…1 January, 2006
New outcrops of Late Neogene sedimentary deposits discovered on James Ross and Vega islands, northern Antarctic Peninsula, are fossiliferous and contain mainly fragmented pectinids amongst other as yet unstudied biota.…1 January, 2006
Back in the mid-nineteenth century British explorer James Clark Ross took his ships, HMS Terror and HMS Erebus, farther south than anyone else had been. He now lends his name…1 January, 2006 by Peter Fretwell
A new approach to modelling patterns of glacio-isostatic land uplift during the Holocene in mainland Scotland, UK, is described. The approach is based upon altitude measurements at the inner margin…1 January, 2006 by Dominic Hodgson, James Smith, Stephen Roberts
George VI Ice Shelf is the largest ice shelf on the western side of the Antarctic Peninsula and its northern margin marks the southern most latitudinal limit of recent ice…1 January, 2006
Soil samples from the summit of Coulman Island in northern Victoria Land, continental Antarctica (lat. 73o28'S, 169o45'E) were cultured and after nine weeks they have yeilded sterile shoots of a…1 January, 2006
Eruptions of Öræfajökull have produced mafic and silicic magmas, and have taken place in both glacial and interglacial periods. The geology of the volcano records the differing response of magmas…Read more on Subglacial and ice-contact volcanism at the Oraefajokull stratovolcano, Iceland
1 January, 2006
As part of a collaborative research program between British Antarctic Survey, U.K. and Utah State University, USA, all sky airglow images were recorded at Halley Station Antarctica (75.5 S, 26.7…Read more on A novel joint space-wavenumber analysis of an unusual Antarctic gravity wave event
1 January, 2006
This is the first study to use both molecular and fossil data to date the divergence of taxa within the coleoid cephalopods (octopus, squid, cuttlefish). A dataset including sequences from…Read more on Divergence time estimates for major cephalopod groups: evidence from multiple genes
1 January, 2006 by Howard Roscoe
A solar occultation sensor, the Improved Limb Atmospheric Spectrometer (ILAS)-II, measured 5890 vertical profiles of ozone concentrations in the stratosphere and lower mesosphere and of other species from January to…1 January, 2006
Fatty acid biomarker analyses of Cassidulina crassa, a dominant calcareous foraminieran at 55-m water depth in Arthur Harbor, Anvers Island (64°46′S, 64°04′W), Antarctica, revealed that this species responds rapidly to…1 January, 2006
Experimental trials were conducted onboard a stern trawler to identify the relative efficacy of three emerging mitigation measures (tori lines, warp scarer and Brady baffler) designed to reduce seabird mortality…1 January, 2006
A new Greenland Ice Core Chronology (GICC05) based on multi-parameter counting of annual layers has been obtained for the last 42 ka. Here we compare the glacial part of the…Read more on The Greenland Ice Core Chronology 2005, 15–42 ka. Part 2: comparison to other records
1 January, 2006 by Eugene Murphy, Geraint Tarling, Jonathan Watkins
The growth rates of postlarval krill (Euphausia superba) were measured across a wide range of environments in the Scotia Sea and around South Georgia using the Instantaneous Growth Rate (IGR)…