Showing 11332 items
1 January, 2004
Impact-shocked gneiss shocked to greater than 10 GPa in the Haughton impact structure in the Canadian High Arctic has an approximately 25-times greater pore surface area than unshocked rocks. These…1 January, 2004
The increasing robotic exploration of Mars and eventual human exploration and settlement of that planet threatens to have a significant environmental impact on scientifically important sites and sites of natural…1 January, 2004
Over the last forty years, the circle of organisms thought worthy of inclusion within an ethical framework has expanded markedly, in large part in response to Aldo Leopold's 'land ethic'.…1 January, 2004
In this paper I explore potential relationships between humans and Martian polar ices. Martian ices contain within them multimillion year histories of atmospheric, geological and maybe even biological processes. Polar…1 January, 2004
During the spring, when ozone depletion at the polar regions is at its maximum and consequently the environmental UV exposure is potentially high, many terrestrial communities are covered in snow…1 January, 2004
Ultraviolet radiation is more damaging on the surface of Mars than on Earth because of the lack of an ozone shield. We investigated micro-habitats in which UV radiation could be…Read more on Zones of photosynthetic potential on Mars and the early Earth
1 January, 2004
High-latitude polar deserts are among the most extreme environments on Earth. Here we describe a large and previously unappreciated habitat for photosynthetic life under opaque rocks in the Arctic and…1 January, 2004 by Martin Collins
A new species and genus of cirrate octopod, Cryptoteuthis brevibracchiata, is described from a single specimen captured at 2274-2300 m in the Porcupine Seabight, northeastern Atlantic. The species possesses characteristics…1 January, 2004
The standard way in which the sea-ice dynamics equation is used in models assumes that the wind stress and ocean drag do not depend on the sea-ice concentration. It is…Read more on On the consistent scaling of terms in the sea-ice dynamics equation
1 January, 2004 by Alistair Crame
Application of a strontium isotope stratigaphy to the Late Cretaceous sedimentary succession of Antarctica has provided the impetus for a comprehensive strati-graphical revision of the terminal Maastrichtian Stage. Both the…1 January, 2004
The marine resources of the Antarctic region are of global significance. In managing Southern Ocean marine resources, especially fisheries, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR)…Read more on Management of Southern Ocean fisheries: global forces and future sustainability
1 January, 2004
High-resolution surface fluxes over the global ocean are needed to evaluate coupled atmosphere–ocean models and weather forecasting models, provide surface forcing for ocean models, understand the regional and temporal variations…1 January, 2004
During end-Neoproterozoic to early Paleozoic time, the southern margin of Gondwana was affected by widespread subduction-related orogenesis. In East Antarctica this event is known as the Ross orogeny, whose manifestation…1 January, 2004 by Geraint Tarling
Adaptive strategies of two fjord populations of Northern krill (Meganyctiphanes norvegica Sars) were studied and compared with other populations from different climatic and oceanic conditions. The Gullmarsfjord (West Sweden) and…1 January, 2004
It is unknown how pelagic marine protists undergo diversification and speciation. Superficially, the open ocean appears homogeneous, with few clear barriers to gene flow, allowing extensive, even global, dispersal. Yet,…1 January, 2004 by David Barnes
The link between movement and migration of organisms to patterns of biodiversity may be an important mechanism of biodiversity maintenance at local scales. but is regularly underestimated in marine studies.…1 January, 2004 by David Barnes
Small-scale patterns of low-, mid- and high-shore intertidal species density, richness and abundance were systematically examined to assess the potential influence of 'mobility' on spatial community dynamics and diversity. Mobile…Read more on Quantifying spatial patterns of intertidal biodiversity: is movement important?
1 January, 2004 by Simon Morley
The diet of the seven star flying squid, Martiala hyadesi, from the South Georgia sector of the Scotia Sea was described front stomach contents collected in winter (June) 2001. Diet…1 January, 2004
Continental-slope and shelf-edge morphology off Marguerite Bay, western Antarctic Peninsula, is investigated using swath-bathymetric data and parametric sub-bottom profiler records, together with sediment cores. Marguerite Bay has a well-defined cross-shelf…1 January, 2004
Fast-flowing ice streams and outlet glaciers currently account for as much as 90% of the discharge from the Antarctic and Greenland Ice Sheets. Although the deformation of subglacial material has…Read more on Thickness and extent of the subglacial till layer beneath an Antarctic paleo-ice stream
1 January, 2004
An unprecedented major stratospheric warming occurred in the Antarctic winter of 2002. We present measurements of winds in the mesosphere-lower thermosphere (MLT) made with MF radars located at Davis (69degreesS,…1 January, 2004 by Robert Larter
An animated reconstruction shows South Pacific plate kinematics between 90 and 45 Ma, using the satellite-derived gravity anomaly field, interpolated isochrons and plate rotation parameters from both published and new…1 January, 2004 by Robert Larter
The onset of independent Bellingshausen plate movement in the South Pacific is estimated at just after chron C33o. This event closely follows a change in the offset sense on the…1 January, 2004
The role of Antarctic epilithic lichens in the primary colonization of rocks and in the formation of soils is receiving attention because of the production of the stress-protective biochemicals needed…1 January, 2004
FT-Raman spectra were obtained for two Antarctic extremophiles, the epilithic lichens Xanthoria elegans and Caloplaca sublobulata from the maritime ecological long-term research site on Leonie Island. Twelve specimens from cloches…1 January, 2004
Detailed FT-Raman spectra of Antarctic cryptoendolithic colonies in Beacon sandstone have revealed some novel information about the biogeological modification process involving iron(III) mobilization by the organism. The previously unreported but…Read more on Biological modification of haematite in Antarctic cryptoendolithic communities
1 January, 2004
The FT-Raman spectra are described of green and red snow algae, Chlamydomona, involved in the colonization of exposed surfaces of the McLeod Glacier, Jane Col, Signy Island, situated at the…1 January, 2004
The Cassini RADAR instrument is a multimode 13.8 GHz multiple-beam sensor that can operate as a synthetic-aperture radar (SAR) imager, altimeter, scatterometer, and radiometer. The principal objective of the RADAR…1 January, 2004
We describe how the exploration of the Martian environment would be considerably enhanced through the use of Raman spectroscopy. Furthermore, Raman spectroscopy is particularly suited for both mineralogical analysis of…Read more on The role of Raman spectroscopy as an astrobiological tool in the exploration of Mars
1 January, 2004
We have analyzed ELF-VLF receiver and search coil magnetometer data from five Antarctic stations from 1998 and 1999 to study quasiperiodic emissions (QPs) and periodic emissions (PEs), which occur as…1 January, 2004
Airglow imager and dynasonde/imaging Doppler interferometer (IDI) radar wind measurements at Halley Station, Antarctica (75.6degreesS, 26.6degreesW) have been used to estimate the seasonal variation of the vertical fluxes of horizontal…1 January, 2004
Airglow imager and dynasonde/IDI radar wind measurements at Halley Station, Antarctica (76degreesS, 27degreesW) have been used to estimate the diurnal variation of the vertical fluxes of horizontal momentum carried by…Read more on Tidal modulation of the gravity-wave momentum flux in the Antarctic mesosphere
1 January, 2004 by Jaume Forcada
Line-transect estimators were developed to assess abundance of coastal dolphins Tursiops truncatus and Stenella coeruleoalba encountered in low densities during aerial sighting surveys. The analysis improved on conventional approaches by…1 January, 2004 by Andrew Clarke, Lloyd Peck
Seasonal changes in protein and nitrogen metabolism have not previously been reported in any Antarctic suspension-feeding species that ceases feeding for extended periods in winter. To provide comparison with data…1 January, 2004 by Gareth Chisham, Mervyn Freeman
The Doppler spectral width of backscatter from the SuperDARN HF radars has been routinely used to identify the ionospheric cusp. The probability distribution of spectral width values has been described…1 January, 2004 by Mervyn Freeman, Simon Morley
A minimal model for the evolution of the global dynamical state of the magnetotail during the substorm has been developed, involving only three simple rules and one free parameter D-the…1 January, 2004 by Claus-Dieter Hillenbrand
Two sediment cores from the deep-sea Murray Canyons area, south of Kangaroo Island, Australia were investigated for quantity and composition of terrigenous material. Spanning the last 175 ka, terrigenous matter…1 January, 2004
In most seabird species incubation shifts shorten when hatching approaches, a behavioural response allowing the chick to be fed soon after hatching. Three mechanisms have been proposed to explain these…1 January, 2004
Northern giant petrels (Macronectes halli) are among the largest and most sexually size dimorphic species of seabirds, with females being only 80% the mass of males. Both sexes scavenge on…Read more on Sexual size dimorphism in northern giant petrels: ecological correlates and scaling
1 January, 2004 by Lloyd Peck
Spermatogenesis, oogenesis and fecundity are described and the gonad index calculated for 10 individuals from each month using histological and image analysis techniques for the Antarctic brittle star Ophionotus victoriae…1 January, 2004
The metabolic rate of moulting macaroni penguins Eudyptes chrysolophus was investigated using three techniques in order to test two hypotheses concerning the energetic cost of the moult fast in penguins.…Read more on Energetics of the moult fast in female macaroni penguins Eudyptes chrysolophus
1 January, 2004
We tested the hypothesis that implanted data loggers have no effect on the survival, breeding success and behaviour of macaroni penguins Eudyptes chrysolophus . Seventy penguins were implanted with heart…Read more on Effects of long-term implanted data loggers on macaroni penguins Eudyptes chrysolophus
1 January, 2004
Shortening of telomeres, specific nucleotide repeats that cap eukaryotic chromosomes, is thought to play an important role in cellular and organismal senescence. We examined telomere dynamics in two long-lived seabirds,…Read more on Telomere loss in relation to age and early environment in long-lived birds
1 January, 2004 by Alistair Crame
Fragments of large, bilamellar aspidostomatid bryozoan colonies occur in Early Miocene glaciomarine sedimentary sequences of the Cape Melville Formation, King George Island, South Shetland Islands, West Antarctica. Investigation of the…1 January, 2004
15 years of weekly Antarctic ice extent and 10 m winds from numerical meteorological reanalyses have been used to test the hypothesis that the Antarctic final winter ice extent (FWE)…1 January, 2004
During some El Nino events Rossby wave trains (RWT) are observed to strongly modulate the seasonal atmospheric circulation of the South Pacific extratropics in the austral winter and spring. Here…1 January, 2004 by Roger Worland, Peter Convey
Population densities of the Collembola Cryptopygus antarcticus and Friesea grisea were compared in two maritime Antarctic habitats with different moisture availability. C. antarcticus was absent from the drier rock platform…1 January, 2004
The relative role of the atmosphere, oceans and cryosphere in contributing towards middle Pliocene warmth (ca 3 Ma BP) is investigated using the HadCM3 coupled ocean-atmosphere general circulation model. The…Read more on Modelling Pliocene warmth: contribution of atmosphere, oceans and cryosphere
1 January, 2004
This paper describes the results from a new palaeoclimate modelling exercise for the Early Cretaceous (Barremian) focussed on the Weald (SE England), using a Limited Area Numerical Climate Model (LAM).…Read more on Cretaceous (Wealden) climates: a modelling perspective
1 January, 2004 by Robert Larter
The analysis of the morphology and stratigraphy of the Antarctic Peninsula Pacific margin offshore from Adelaide Island shows 3 main evolutionary intervals, from the Late Miocene to the recent which…1 January, 2004 by Robert Larter
A Fossil Mounded Sedimentary Body (MB) has been identified in the Miocene sedimentary record on the central continental rise west of Adelaide Island, Antarctic Peninsula, using multichannel seismic reflection profiles.…1 January, 2004 by Jonathan Watkins, Philip Trathan
Following an assessment of Antarctic krill (Euphausia superba) in the Scotia Sea, CCAMLR established a precautionary catch limit of 4 million tonnes and further adopted 15 small-scale management units (SSMUs).…1 January, 2004 by Jonathan Watkins, Philip Trathan
In January and February 2000, a collaborative survey designed to assess the biomass of Antarctic krill across the Scotia Sea was conducted aboard research vessels from Japan, Russia, the UK…1 January, 2004 by Richard Hindmarsh, Richard Hindmarsh
A computational analysis of the accuracy of different approximations to the Stokes equations for momentum balance used in ice sheet modeling is performed by solving a particular tractable form of…1 January, 2004 by Richard Hindmarsh, Richard Hindmarsh
The shallow-ice approximation is used to analyse the normal-mode stability of long-wavelength, thermally coupled, free-surface flows of glaciers and ice sheets along infinite flow sections. The viscosity of the ice…1 January, 2004 by Dominic Hodgson
To compile reference data for palaeolimnological studies using fossil pigments, we examined the extent to which environmental variables, gross morphology and species composition influence the modern pigment content of in…1 January, 2004
Recent genetic studies of natural populations have shown that heterozygosity and other genetic estimates of parental relatedness correlate with a wide variety of fitness traits, from juvenile survival and parasite…1 January, 2004 by Eugene Murphy
Advective processes are recognized as being important in structuring and maintaining marine ecosystems. In the Southern Ocean advective effects are perhaps most clearly observed because the Antarctic Circumpolar Current (ACC)…Read more on Advection, krill, and Antarctic marine ecosystems
1 January, 2004 by Robert Mulvaney
This paper presents an overview of firn accumulation in Dronning Maud Land (DML), Antarctica, over the past 1000 years. It is based on a chronology established with dated volcanogenic horizons…1 January, 2004
Chlorophyll-a (Chl-a) concentrations in surface waters were measured at 137 hydrographic stations occupied by four research vessels participating in the CCAMLR 2000 Survey and the values were compared to estimates…1 January, 2004
During January and February 2000 four research vessels, from Russia, the UK, Japan, and the United States, conducted an oceanographic survey with 137 hydrographic stations within the Scotia Sea and…1 January, 2004
Zoroaster fulgens is a slope-dwelling seastar species that is distributed throughout the Atlantic Ocean. Studies into the population structure and systematics of marine animals have increasingly found that species with…1 January, 2004
Fatty acid biomarkers were used to examine the diet of deep-sea holothurians. We collected 3 species from the Porcupine Seabight and Porcupine Abyssal Plain, NE Atlantic, between 800 and 4850…1 January, 2004 by David Pearce, Kevin Hughes, Thomas Lachlan-Cope
This study used PCR-based molecular biological identification techniques to examine the biodiversity of air sampled over Rothera Point (Antarctic Peninsula). 16S rDNA fragments of 132 clones were sequenced and identified…Read more on A preliminary study of airborne microbial biodiversity over peninsular Antarctica
1 January, 2004 by Kevin Hughes
Despite Antarctica being the largest pristine wilderness on Earth, many coastal Antarctic research stations release untreated sewage waste into the marine environment, which may have negative effects on local wildlife.…1 January, 2004 by Kevin Hughes
Human faecal waste has been discarded at inland Antarctic sites for over 100 years, but little is known about the long-term survival of faecal microorganisms in the Antarctic terrestrial environment…Read more on Long-term survival of human faecal microorganisms on the Antarctic Peninsula
1 January, 2004 by Kevin Hughes
This study describes the distribution of sewage pollution markers (faecal coliforms, Clostridium perfringens and faecal sterols) in seawater and marine sediments around Rothera Research Station, Antarctic Peninsula. Untreated sewage waste…1 January, 2004 by Simon Morley
We estimated fusion frequency with respect to coancestry in the bryozoan Celleporella hyalina, whose briefly planktonic sexually produced larvae settle on algal substrata and proceed to form encrusting colonies by…Read more on Kin or self-recognition? Colonial fusibility of the bryozoan Celleporella hyalina
1 January, 2004 by Teal Riley
Rhyolitic volcanism along the proto-Pacific margin of Gondwana occurred at intervals throughout the Jurassic. Silicic melt generation has been interpreted as a result of interaction between mantle plumes and subduction…1 January, 2004 by Adrian Jenkins
Introduction The continental shelf environment of the Amundsen and Bellingshausen seas differs markedly from that of the other circumpolar seas, where water temperatures are close to the surface freezing point…Read more on Oceanographic observations at the Amundsen shelf break
1 January, 2004 by Adrian Jenkins, Keith Nicholls
[1] The ocean cavity beneath Filchner-Ronne Ice Shelf is observed to respond to the seasonal cycle of water mass production on the continental shelf of the southern Weddell Sea. Here…1 January, 2004 by Eugene Murphy, Jaume Forcada, Philip Trathan
The dynamics of leopard seat Hydrurga leptonyx abundance and residency were investigated both within and between years at Bird Island, South Georgia, using observations of tagged and untagged individuals. Seals…1 January, 2004 by Kevin Newsham
Amino acids constitute one of the largest inputs of organic nitrogen (N) to most polar soils and have been hypothesized to be important in regulating vegetational succession and productivity in…Read more on Rapid amino acid cycling in arctic and antarctic soils
1 January, 2004 by Mark Clilverd
There have been reports in the literature that spaced-antenna MF radars may provide a source of data on Polar Mesospheric Summer Echoes (PMSE). Even though the expected scatter from PMSE…Read more on An alternative explanation of PMSE-like scatter in MF radar data
1 January, 2004 by Roger Worland
Antioxidant enzymes, total glutathione (GSH), and ascorbic acid (ASA) were determined in whole body homogenates of nondiapausing larvae, diapausing larvae during the diapausing period (October, December, and February), and in…1 January, 2004 by Howard Roscoe
Frost flowers grow on newly-formed sea ice from a saturated water vapour layer. They provide a large effective surface area and a reservoir of sea salt ions in the liquid…1 January, 2004
A multi-ship, multi-national survey to assess the acoustic biomass of Antarctic krill across the Scotia Sea was undertaken in January and February 2000. In addition, a total of 135 Rectangular…1 January, 2004
The age of firn air in Antarctica at pore close-off depth is only known for a few specific sites where firn air has been sampled for analyses. We present a…Read more on Model calculations of the age of firn air across the Antarctic continent
1 January, 2004 by Jonathan Watkins
Salp abundance and length frequency were measured during the large-scale CCAMLR 2000 Survey conducted in the Atlantic Sector of the Southern Ocean in the 1999/2000 season. Results from regional surveys…Read more on Salp distribution and size composition in the Atlantic sector of the Southern Ocean
1 January, 2004 by Andy Smith, Ed King
Seismic data from Rutford Ice Stream, West Antarctica show high amplitude, reversed-polarity reflections from parts of the bed. Only interfaces between ice and water, or between water and sediment have…1 January, 2004 by David Vaughan, John King
Redistribution of snow by the wind can drive spatial and temporal variations in snow accumulation that may affect the reconstruction of paleoclimate records from ice cores. In this paper we…Read more on Wind-borne redistribution of snow across an Antarctic ice rise
1 January, 2004 by Mark Belchier
Notothenia rossii was the first target species in Southern Ocean fisheries. The species was already heavily fished at the beginning of the 1970s. The closure of the fishery for this…1 January, 2004
During the austral summer of 2002, a large and persistent phytoplankton bloom was detected with SeaWiFS imagery in the Georgia Basin to the north-west of South Georgia, while waters to…1 January, 2004 by Peter Ward
SeaWiFS was used to examine the spatial and temporal distribution of chlorophyll-a (chl-a) concentrations around the island of South Georgia during four summers between October 1997 and March 2001. A…1 January, 2004 by Mai Mai Lam
[1] Traveling convection vortices (TCVs) are a powerful tool for probing the nature of the coupling between the solar wind, the magnetosphere, and the ionosphere. There is no reliable model…Read more on A test of the magnetospheric source of travelling convection vortices
1 January, 2004 by Robert Larter
Marine geoscientists from the British Antarctic Survey BAS) have carried out a wide range of seismic and sonar investigations over the past eighteen years in the sector of the Southern…1 January, 2004 by Peter Convey
We describe the application of molecular biological techniques to estimate eukaryotic diversity (primarily fungi, algae, and protists) in Antarctic soils across a latitudinal and environmental gradient between approximately 60 and…Read more on Molecular analysis of geographic patterns of eukaryotic diversity in Antarctic soils
1 January, 2004
1. Bacterioplankton production was measured in the water columns of two ultra-oligotrophic, freshwater Antarctic lakes (Crooked Lake and Lake Druzhby) during an annual cycle. In both lakes bacterial production, measured…Read more on Bacterioplankton production in freshwater Antarctic lakes
1 January, 2004
The azooxanthellate scleractinian coral Lophelia pertusa has a near-cosmopolitan distribution, with a main depth distribution between 200 and 1000 m. In the northeast Atlantic it is the main framework-building species,…1 January, 2004
Lopheliapertusa and Madrepora oculata are azooxanthellate corals with nearly cosmopolitan distributions. They form cold-water reefs in the upper bathyal zone on continental margins and offshore banks [A.D. Rogers, Int. Rev.…Read more on A deep-sea slant on the molecular phylogeny of the Scleractinia
1 January, 2004 by Philip Leat, Robert Larter
The intra-oceanic South Sandwich subduction system is distinctive in having a narrow slab with slab edges at its northern and southern ends. We present new geochemical data to investigate magma…1 January, 2004 by Hilmar Gudmundsson
The reaction of alpine glaciers to shifts in the equilibrium line altitude (ELA) is calculated by using a two-dimensional numerical model to solve the full equations for the velocity and…Read more on On estimating length fluctuations of glaciers caused by changes in climatic forcing
1 January, 2004 by Katrin Linse
Agassiz trawl, epibenthic sledge and large box core samples were made in the Scotia and northern Weddell Seas during the 2002 ANDEEP expeditions with R.V. Polarstern at 21 locations (774-6348…1 January, 2004
A ubiquitous feature of the high latitude ocean is the occurrence of convective clouds that are organized into two-dimensional structures known as roll clouds or cloud streets. In this paper,…Read more on A high-resolution simulation of convective roll clouds during a cold-air outbreak