Showing 13487 items
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
1 January, 2004
The opening of Southern Ocean gateways was critical to the formation of the Antarctic Circumpolar Current and may have led to Cenozoic global cooling and Antarctic glaciation. Drake Passage was…Read more on Shackleton Fracture Zone: no barrier to early circumpolar ocean circulation
1 January, 2004
The diet and reproductive performance of two sympatric penguin species were studied at Signy Island, South Orkney Islands between 1997 and 2001. Each year, Adelie (Pygoscelis adeliae) and chinstrap (P.…1 January, 2004
A series of 26 meteorological rockets ("falling spheres,'' FS) were launched in January and February 1998 from the Antarctic research station Rothera (68degreesS, 68degreesW). These flights gave densities and temperatures…Read more on Temperatures and horizontal winds in the Antarctic summer mesosphere
1 January, 2004 by Peter Convey
Ameronothroid mites, including Ameronothridae, Fortuyniidae and Selenoribatidae, are unique among the Oribatida through having a global distribution from the tropics to the poles, and occupying a diversity of habitats including…Read more on Latitudinal variation in habitat specificity of ameronothrid mites (Oribatida)
1 January, 2004 by Gareth Marshall, John King, John Turner, Thomas Lachlan-Cope
We demonstrate that recent observed trends in the annual and austral summer Southern Hemisphere Annular Mode (SAM) are unlikely to be due to internal climate variability, since they exceed any…Read more on Causes of exceptional atmospheric circulation changes in the Southern Hemisphere
1 January, 2004
The distribution and density of the Amazon's two contrasting endemic dolphins-boto, or Amazon river dolphin, Inia geoffrensis, and tucuxi, Sotalia fluviatilis-were examined on two adjoining large rivers in western Brazil.…1 January, 2004
The size and structure of a community of Amazon river dolphins or botos, Inia geoffrensis (de Blainville, 1817), was investigated using boat surveys and long-term observations of recognisable animals. Year-round,…1 January, 2004
Habitat use by the boto, or Amazon river dolphin Inia geoffrensis, was investigated in and around the Mamiraua Reserve, Brazil. Largely forested with numerous channels and lakes, Mamiraua comprises a…1 January, 2004 by John Turner, Thomas Lachlan-Cope
Intermittent atmospheric blocking-high activity in the South Tasman Sea is shown to play a key role in delivering substantial snowfall as far south as at least 75degreesS on the central…1 January, 2004 by Simeon Hill
In stock assessments of short-lived species, De Lury depletion models are commonly applied in which commercial catches and changing catch rates are used to estimate resource abundance. These methods are…1 January, 2004
An extensive variety of instruments, including Geotail, DMSP F11, SuperDARN, and IMP-8, were monitoring the dayside magnetosphere and ionosphere between 14:00 and 18:00 UT on 18 January 1999. The location…1 January, 2004 by Mark Clilverd
This paper discusses the use of ground magnetometer data to derive plasma mass density profiles of the dayside plasmapause region with spatial and temporal resolution in the range 0.15-0.4 R-E…Read more on Monitoring the plasmapause using geomagnetic field line resonances
1 January, 2004 by Andrew Clarke, John King, Michael Meredith
[ 1] A year-round sequence of hydrographic casts is used to trace the evolution of the upper ocean waters in Marguerite Bay, western Antarctic Peninsula (wAP), between 1998 and 2002.…1 January, 2004 by Richard Horne
We analyze wave and particle data from the CRRES satellite to determine the variability of plasmaspheric hiss (0.1 < f < 2 kHz) with respect to substorm activity as measured…1 January, 2004
The Himalia Ridge Formation (Fossil Bluff Group), Alexander Island is a 2.2-km-thick sequence of Upper Jurassic-Lower Cretaceous conglomerates, sandstones and mudstones, derived from an andesitic volcanic arc and deposited in…1 January, 2004 by Roger Worland
Antarctica has long been recognised as a putative analogue for Mars' past (1) and any life there is surviving in extreme conditions. Raman spectroscopy has been proved as a suitable…Read more on Raman spectroscopic studies of Antarctic endoliths and epiliths
1 January, 2004
Macaroni Eudyptes chrysolophus and gentoo Pygoscelis papua penguins occur sympatrically at Bird Island (54degrees00'S, 38degrees02'W), South Georgia, and have a similar diet. Macaroni penguins forage at shallower depths and further…1 January, 2004
This study investigated the degree to which the behavior of a predator in the marine environment can be used to indicate the availability of prey. It examined this in Antarctic…1 January, 2004 by Mark Belchier, Simon Morley
The biology of the bigeye grenadier Macrourus holotrachys caught as by-catch in the Patagonian toothfish Dissostichus eleginoides longline fishery conducted around South Georgia was investigated to improve data available for…Read more on The biology of the bigeye grenadier at South Georgia
1 January, 2004 by Robert Mulvaney
Over the period 1972-98 the height of the snow surface at eight Antarctic sites in Palmer Land and on Alexander Island has been measured with respect to fixed points on…Read more on Recent variations in surface mass balance of the Antarctic Peninsula ice sheet
1 January, 2004 by Eugene Murphy, Jonathan Watkins, Sally Thorpe
A coupled physical-biological model analysis was undertaken to examine the seasonal development of the distribution of antarctic krill (Euphausia superba Dana) in the Scotia Sea. The origin and fate of…1 January, 2004 by Eugene Murphy, Michael Meredith, Philip Trathan, Peter Ward, Sally Thorpe
During December 2000 and January 2001 we conducted a high-resolution hydrographic and bioacoustic transect (RRS James Clark Ross cruise 57) that extended across the South Georgia shelf from close to…1 January, 2004
Within the past 7 years, the northern Larsen Ice Shelf has broken up so it is now possible to sample the sea floor that formerly lay beneath it. Box cores…1 January, 2004 by Philip Trathan
Procellariiform seabirds (petrels, albatrosses and shearwaters) forage over thousands of square kilometres for patchily distributed prey resources. While these birds are known for their large olfactory bulbs and excellent sense…Read more on Testing olfactory foraging strategies in an Antarctic seabird assemblage
1 January, 2004 by David Pearce, Kevin Newsham
We tested the preferences of three nematode taxa, Geomonhystera villosa, Plectus spp. and Teratocephalus spp., extracted from moss at Signy Island in the Maritime Antarctic, for two microalgae, three microfungi…Read more on Differing preferences of Antarctic soil nematodes for microbial prey
1 January, 2004 by Keith Nicholls
We report on oceanographic observations made at the northern end of Larsen C Ice Shelf in the western Weddell Sea. It appears that the Larsen C continental shelf is flushed…Read more on Summertime water masses off the northern Larsen C Ice Shelf, Antarctica
1 January, 2004 by Keith Nicholls
[1] Multiyear time series of ocean current and temperatures from beneath Filchner-Ronne Ice Shelf, Antarctica, demonstrate both seasonal and interannual variability. The seasonal signal is visible at all measurement sites,…1 January, 2004 by Keith Makinson, Keith Nicholls
We present oceanographic data from beneath the northern Ronne Ice Shelf. The data were collected during the austral summer of 2002–2003 from four sites located near the ice front in…Read more on Circulation and water masses beneath the northern Ronne Ice Shelf, Antarctica
1 January, 2004 by Mark Clilverd
PMSE or Polar Mesosphere Summer Echoes are a well-known phenomenon in the summer northern polar regions, in which anomalous VHF/UHF radar echoes are returned from heights similar to85 km. Noctilucent…Read more on The impact of PMSE and NLC particles on VLF propagation
1 January, 2004
During the late Neogene, the Lambert Glacier–Amery Ice Shelf drainage system flowed across Prydz Bay in an ice stream that reached the shelf edge and built a trough mouth fan…Read more on Prydz Bay fan and the history of extreme ice advances in Prydz Bay
1 January, 2004 by Andrew Orr, Gareth Marshall
[1] We demonstrate a mechanism whereby the impact of stronger circumpolar westerly winds on the mountains of the Antarctic Peninsula contributes significantly to the enhanced warming trend observed over its…1 January, 2004
As the German contribution to the Southern Ocean Global Ocean Ecosystems Dynamics Study (SO GLOBEC), RV Polarstern visited the Eastern Bellingshausen Sea between 18 April and 1 May 2001. This…1 January, 2004 by Gareth Chisham, Michael Pinnock
Super Dual Auroral Radar Network (DARN) radars often detect a distinct transition in line-of-sight Doppler velocity spread, or spectral width, from 200 m s(-1) at higher latitude. They also detect…1 January, 2004
December 25th 2003 will see the Beagle 2 lander arrive at the surface of Mars in the Isidis region, allowing for the first time in situ measurements of ultraviolet (UV)…1 January, 2004 by Lloyd Peck
1. The anostracan fairy shrimp Branchinecta gaini inhabits one of the most hostile environments on earth, living in pools and lakes in Antarctica. Between January 2002 and January 2003 temperatures…1 January, 2004 by Lloyd Peck
Burrowing was investigated in two Antarctic infaunal bivalve molluscs, Laternula elliptica and Yoldia eightsi, representing amongst the least and most active members of the class Bivalvia in the Southern Ocean.…1 January, 2004 by David Barnes, Lloyd Peck
Oxygen consumption (MO2) and activity were evaluated in Antarctic Bryozoa. Three species representing two different morphologies, flat sheet, laminar forms, Isoseculiflustra tenuis and Kymella polaris, and the bush form Camptoplites…Read more on Metabolic flexibility: the key to long-term evolutionary success in Bryozoa?
1 January, 2004 by Lloyd Peck
1. Biological capacities to respond to changing environments dictate success or failure of populations and species over time. The major environmental feature in this context is often temperature, and organisms…Read more on Extreme sensitivity of biological function to temperature in Antarctic marine species
1 January, 2004 by Richard Phillips
Although albatrosses typically show strong natal philopatry, a small proportion of birds emigrate to distant colonies, occasionally establishing new breeding sites and potentially initiating speciation events. Patterns of albatross distribution…1 January, 2004 by Richard Phillips
Breeding ecology of brown skuas (Catharacta antarctica lonnbergi) was studied at Bird Island, South Georgia in the austral summers of 2000/2001-2003/2004. A complete census recorded 467 breeding pairs in 3.55…1 January, 2004 by Janet Silk, Richard Phillips, Vsevolod Afanasyev
Geolocation (Global Location Sensing or GLS logging) using archival light-recording tags offers considerable potential for tracking animal movements, yet few studies of flying seabirds have exploited this technology. Our study…Read more on Accuracy of geolocation estimates for flying seabirds
1 January, 2004 by Janet Silk, Richard Phillips
Sexual segregation by micro- or macrohabitat is common in birds, and usually attributed to size-mediated dominance and exclusion of females by larger males, trophic niche divergence or reproductive role specialization.…1 January, 2004 by Eric Wolff
An analytical method for the direct determination of mercury (Hg) in polar snow and ice cores and surface snow based on inductively coupled plasma sector field mass spectrometry (ICP-SFMS) has…1 January, 2004 by Robert Larter
1 January, 2004 by Andrew Clarke
The mega-epibenthos of two different geographic areas, the Antarctic Peninsula and the high Antarctic (eastern Weddell Sea), were investigated using underwater video. The distribution of the marine fauna at shallow…1 January, 2004
The Ellsworth-Whitmore Mountains (EWM) are one of five terranes that form West Antarctica. Constraining the positions of these terranes in pre-break up Gondwana is crucial to understanding the history of…1 January, 2004 by Eric Wolff, Robert Mulvaney
It has recently been shown that much sea-salt aerosol around the coast of Antarctica is generated not from open water, but from the surface of newly formed sea ice. Previous…Read more on A reinterpretation of sea-salt records in Greenland and Antarctic ice cores?
1 January, 2004 by David Barnes
Patterns of zooplankton vertical movement are often difficult to interpret because of multiple, complex and confounding environmental factors. Behavioural adaptations to these environmental variables are compared within and between the…1 January, 2004
Hope Bay and Botany Bay, Graham Land, Antarctica have yielded two of the most diverse floras known from the Jurassic. Because of its high diversity, as well as its early…Read more on Lower Jurassic floras from Hope Bay and Botany Bay, Antarctica
1 January, 2004
Resolving the spatial variability in the population structure of Antarctic krill (Euphausia superba) requires a synoptic sample, as in the design of the CCAMLR 2000 Survey. However, this approach is…1 January, 2004
The measurement of spatial overlap between predators and fisheries exploiting a common prey source is dependent upon the measurement scale used; inappropriate scales may produce misleading results. Previous assessments of…1 January, 2004 by Jonathan Watkins
Baleen whales are an important group of predators on Antarctic krill in the Southern Ocean. During the CCAMLR 2000 Survey to estimate the biomass and distribution of Antarctic krill, International…1 January, 2004
A non-hydrostatic numerical weather prediction model has been employed to Simulate idealized katabatic flows over a moderate slope and adjoining ice shelf. The topography of Coats Land and the adjoining…Read more on The dynamics of idealized katabatic flow over a moderate slope and ice shelf
1 January, 2004 by Philip Leat, Teal Riley
U-Pb SHRIMP ages are reported for three rhyolite flows from the Lebombo rift region of the Karoo volcanic province. Two flows are interbedded with the Sabie River Basalt Formation and…1 January, 2004 by Mark Clilverd
It has been suggested that whistler-induced electron precipitation (WEP) may be the most significant inner radiation belt loss process for some electron energy ranges. One area of uncertainty lies in…Read more on Investigating radiation belt losses though numerical modelling of precipitating fluxes