Found 14053 items
1 November, 1996 by Mervyn Freeman
Clouds of energetic electrons, injected sporadically into the nightside magnetosphere during substorm expansion phase onsets, can generate VLF whistler mode noise through the gyroresonance instability, which may then be observed…Read more on Post midnight VLF chorus events, a substorm signature observed at the ground nearL= 4
1 November, 1996
Heterotrophic protozoa have a global distribution in terrestrial habitats. The functional groups significantly represented are zooflagellates, cillates, gymnamoebae and testate amoebae. Their range extends into the Antarctic zone, but the…1 November, 1996
In this study we consider the phase relationships between the oscillations of various ionospheric signatures associated with Pcl geomagnetic pulsations. Investigations using a simple analytical method and a numerical model,…Read more on The phase relationships of the ionospheric signatures of Pc1 geomagnetic pulsations
1 November, 1996
Microorganisms are fundamental to the functioning of Antarctic ecosystems. Although microbial biomass can be immense in Southern Ocean blooms and freshwater cyanobacterial mats, species richness is generally more restricted than…Read more on Antarctic microbial diversity: the basis of polar ecosystem processes
1 October, 1996 by Adrian Fox
Unique place-names are essential for scientific fieldwork in Antarctica. This shorter contribution describes how duplication of place-names in British Antarctic Territory has been avoided by the systematic naming of geographically…Read more on Pioneers of photogrammetry commemorated in Antarctic place-names
1 October, 1996
Bacterial production and heterotrophic nanoflagellate (HNAN) bacterivory were determined concurrently with measurements of abundance and biomass at weekly intervals between 30 December 1993 and 11 February 1994 at a shallow,…1 October, 1996 by Paul Rodhouse
The species composition, abundance, vertical distribution, biovolume and carbon content of gelatinous nekton in the Antarctic Polar Frontal Zone are described from a series of RMT25 hauls collected from a…1 October, 1996 by Andy Smith
Analysis of seismic data provides a new technique to measure basal melting of an ice shelf close to the grounding line. Internal reflections have been observed within the ice on…Read more on Ice shelf basal melting at the grounding line, measured from seismic observations
1 September, 1996
The energy expenditure of ten (five male, five female) wandering albatrosses (Diomedea exulans Linnaeus 1758) brooding chicks on Bird Island, South Georgia, was measured using doubly-labelled water. At-sea foraging behaviour…Read more on The foraging behaviour and energetics of wandering albatrosses brooding chicks
1 September, 1996
Approximately 54% of the world population of southern elephant seals (Mirounga leonina) breeds at South Georgia. A partial survey in 1951 and a complete survey in 1985, together with counts…Read more on Status of southern elephant seals at South Georgia
1 September, 1996
For the first time, photosynthesis of Myriogramme mangini (Gain) Skottsberg, one of the dominant red macroalgae in the sublittoral of Signy Island (South Orkney Islands), was studied in situ under…1 September, 1996
Sediment traps were deployed in an oligotrophic, seasonally anoxic maritime Antarctic lake for 15 months. Immediately after the onset of the inflow in spring many iron oxyhydroxide aggregates were collected…1 September, 1996 by Andrew Clarke, Raymond Leakey
Seawater chlorophyll a concentration (size-fractionated at 20, 2, and 0.2 µm) and temperature have been measured weekly from December 1988 to August 1994 at a nearshore shallow-water station at Signy…1 September, 1996 by Alistair Crame
Praeaucellina umbonoradiata gen. et sp. nov. is a small pteriomorph bivalve from the Upper Jurassic-Lower Cretaceous of Antarctica which can be referred to the family Oxytomidae, within the superfamily Monotoidea.…Read more on A new oxytomid bivalve from the Upper Jurassic – Lower Cretaceous of Antarctica
1 September, 1996
Total electron content (TEC) measurements obtained at two Antarctic stations over nine months beginning early in 1994 have been analysed as a first step to performing ionospheric tomography. Two receiving…1 September, 1996 by Jonathan Watkins, Philip Trathan
Using stomach lavage samples from macaroni penguins Eudyptes chrysolophus Brandt breeding at Bird Island, South Georgia and concurrent net samples caught within the penguin foraging range, we examined the potential…1 September, 1996
A continuous 37-year record of the geomagnetic field from Argentine Islands Geomagnetic Observatory at Faraday research station (65°S, 64°W), Antarctica, has been analysed to reveal a 27-month periodicity in the…1 September, 1996 by Philip Trathan
Samples of Antarctic krill collected from 6 seabird species and Antarctic fur seal during February 1986 at South Georgia were compared to krill from scientific nets fished in the area…Read more on Krill caught by predators and nets: differences between species and techniques
1 September, 1996
The Permo-Triassic Trinity Peninsula Group is a widespread, regionally metamorphosed metasedimentary sequence in northern Graham Land, Antarctica, which forms the local ‘basement’ to the mainly Jurassic–Cretaceous Antarctic Peninsula magmatic arc.…1 September, 1996 by John Turner
An account is given of the Antarctic First Regional Observing Study of the Troposphere (FROST) project, which has been organized by the Physics and Chemistry of the Atmosphere Group of…Read more on The Antarctic First Regional Observing Study of the Troposphere (FROST) Project
1 September, 1996 by Philip Trathan, Peter Ward
Two dominant Antarctic copepod species, Rhincalanus gigas and Calanus simillimus, were sampled at stations along a 420 km transect running from Maurice Ewing Bank (50°S, 42°W) towards South Georgia (54°S,…1 September, 1996
During winter research cruises to South Georgia (1983 and 1993) fish eggs were abundant in the neuston. Examination of the external sculpturing and the micropyle morphology of the eggs collected…1 September, 1996 by Philip Trathan
Substantial open-ocean phytoplankton blooms in the Antarctic Zone to the northwest of South Georgia, South Atlantic are described. Chlorophyll a, nutrient and physical oceanography data, collected between 2 and 5…1 September, 1996 by Mark Clilverd
Whistler mode signals from the NAA transmitter (24 kHz) received at Faraday, Antarctica are processed to obtain the Doppler shift at a much higher time resolution than has previously been…Read more on Doppler shift pulsations on whistler mode signals from a VLF transmitter
1 September, 1996
An examination of notothenioid fish of three species, including 23 immature Notothenia coriiceps Richardson, revealed seven acanthocephalan species, including two Echinorhynchida occurring in the intestine and five Polymorphida in the…Read more on Acanthocephalan infection of inshore fishes at the South Orkney Islands
1 August, 1996
Heterotrophic dinoflagellates and their herbivory were quantified at a coastal site in East Antarctica in the vicinity of the Australian Antarctic station of Davis (68° 35' S, 77° 58' E).…1 August, 1996
By using time-depth recorders to measure diving activity and the doubly-labelled water method to determine energy expenditure, the relationship between foraging behaviour and energy expenditure was investigated in nine Antarctic…1 August, 1996 by Eugene Murphy, Peter Ward
A zooplankton community in the Polar Frontal Zone north of South Georgia was sampled for 5 days in February 1994. Feeding of various copepodite stages of six copepod species was…1 August, 1996 by Alistair Crame
New correlations of marine clastic sedimentary rocks exposed within the James Ross Basin, Antarctica have shown that the mid-to late Cretaceous succession is in excess of 5 km thick. Plotting…Read more on Late Cretaceous extinction patterns in Antarctica
1 August, 1996
We review quantitative studies of the cephalopod diet of seabirds, with details of all species forming more than 5% by numbers or mass of seabird diets. Although squid are widespread…1 August, 1996 by John King
We present measurements of the components of the energy and mass balance of the snow surface at Halley Research Station, Antarctica. During the winter months, when insolation is small or…Read more on The surface energy and mass balance at Halley, Antarctica during winter
1 August, 1996
The fish component of the diet of black browed and grey-headed albatrosses at South Georgia was investigated by intercepting 155 meals from adults arriving to feed chicks during February 1986…1 August, 1996 by Paul Rodhouse
Cephalopods are voracious, versatile predators. They generally have a short life span and a single spawning event followed by death. Populations are subject to dramatic fluctuations and their impact on…1 August, 1996
Tipula montana, an upland tipulid of northern Britain and generally considered a montane species, was collected from the northern heath habitat of Waskerley Common, County Durham. The growth rate of…1 August, 1996 by Andrew Clarke
Cephalopods, like all other animals, have to decide how to allocate resources; maintenance processes, growth of somatic and reproductive tissues, and locomotor activity all have costs. We should like to…Read more on Energetics: The Costs of Living and Reproducing for an Individual Cephalopod
1 July, 1996 by William Block
Eleven species of oribatid mites are reported from 26 maritime Antarctic islands. The oribatid faunas of Fredriksen, Atriceps (South Orkney Is.), Cockburn, Seymour, Vega, Brabant, Adelaide, Lagoon, Léonie, Horseshoe, Alexander…Read more on Oribatid mites (Acari: Oribatida) of the maritime Antarctic and Antarctic Peninsula
1 July, 1996 by Jonathan Watkins
Dual frequency (38 and 120 kHz) acoustic surveys of shelf-break regions in the vicinity of the Willis Islands, South Georgia, and Coronation Island, South Orkneys, both in the Atlantic sector…1 July, 1996
Pregnant female southern elephant seals vary in size by more than a factor of three when they come ashore to give birth and nurse their pups. Pups are fed exclusively…1 July, 1996
This paper explores the biological consequences of climate change by integrating the results of a tripartite investigation involving fumarole, field manipulation and laboratory incubation experiments. The geographical region for this…1 July, 1996 by Ed King
A new type of drag cable has been developed, which was successfully used to collect seismic reflection data on an Antarctic ice shelf. Standard geophone elements were encapsulated in polyurethane…Read more on A towed geophone system for use in snow-covered terrain
1 July, 1996 by Mark Clilverd
The very low frequency (VLF) NPM signal from Hawaii was recorded at two closely spaced (∼50 km) receivers (located at Palmer and Faraday stations) on the Antarctic Peninsula. Measurements of…1 July, 1996
The flavonoid composition of Bryum algens from Antarctica is presented. It is shown that there exist two extreme patterns, with a range of intermediate forms. The patterns range from a…30 June, 1996
A novel approach is described which can help to determine, from ground-based data, which of the possible production mechanisms for the mid-latitude F-region ionospheric trough is dominant during a particular…Read more on Variations in the altitude of the F2 peak associated with trough-formation processes
1 June, 1996
The biota and environment of fumarolic ground recently discovered near Mount Rittmann are described. Three patches (about 1 m2 each) of the moss Pohlia nutans were found in a minor…1 June, 1996 by Mark Clilverd
Whistler-mode signals from a single VLF transmitter that have propagated in the same duct, have been observed simultaneously at Faraday, Antarctica (65°S, 64°W) and Dunedin, New Zealand (46°S, 171°E). The…Read more on Ducted whistler-mode signals received at two widely spaced locations
1 June, 1996 by Peter Convey
Reproductive allocation (reproductive biomass relative to vegetative biomass) and seed production were measured for samples of the two native phanerogams occurring in Antarctica. Material collected on South Georgia (subantarctic), Signy…1 June, 1996
Fractal dimensions (D) of image perimeters of 4 macroalgae (Macrocystis pyrifera, Desmarestia menziesii, Schizoseris condensata, Palmaria georgica) collected at South Georgia, Southern Ocean were established over a wide scale range.…1 June, 1996
The dependence of shoot growth and growth form on water availability was studied experimentally in six species of maritime Antarctic moss. Under all conditions the largest growth increments were observed…1 June, 1996
The British Antarctic Survey (BAS) provides medical care for the scientists and support staff working on British scientific bases and research vessels in the Antarctic. The BAS directs significant resources…Read more on Establishing a postgraduate qualification in remote health
1 June, 1996
Data on size structure and maturity of the commercially exploited Loligo gahi population in Falkland Island waters were collected by the Fisheries Department of the Falkland Islands Government for the…1 June, 1996 by William Block
1. Tolerance of high summer temperatures was investigated in seven common species of oribatid mite (Acarina) and springtail (Collembola) found in soils associated with dominant vegetation types in West Spitsbergen,…Read more on Can high Arctic soil microarthropods survive eleveated summer temperatures?
1 June, 1996
In a study on size and reproductive behaviour in the southern elephant seal,Mirounga leonina, on South Georgia from 1991 to 1993, large size, measured as nose to hind flipper length,…1 June, 1996
Biomass allocation and growth by the clonal plant Acaena magellanica were characterized for three populations grazed by introduced reindeer on the subantarctic island of South Georgia. Annual growth markers (internode…1 June, 1996
The occurrence of fish in the diet of the Antarctic fur seal (Arctocephalus gazella) at Bird Island, South Georgia was investigated by analysis of fish otoliths in scats (faeces) collected…1 June, 1996 by Robert Larter
Multichannel seismic reflection profiles from the continental rise west of the Antarctic Peninsula between 63° and 69°S show the growth of eight very large mound-shaped sedimentary bodies. MCS profiles and…Read more on Giant sediment drifts on the continental rise west of the Antarctic Peninsula
1 June, 1996 by Eugene Murphy, Jonathan Watkins, Paul Rodhouse, Philip Trathan
Predator data and exploratory fishing in the Scotia Sea have revealed the presence of cephalopod stocks in the Antarctic Polar Frontal Zone (PFZ). This is a vast, remote region where…1 June, 1996 by Philip Leat
At Mount Charity, north-eastern Palmer Land, Rb–Sr whole-rock dating has identified three successive phases of granitoid emplacement in Triassic (232 ± 4 Ma), Jurassic (168 ± 1 Ma), and Cretaceous…1 May, 1996
The coastal sea ice in the vicinity of Davis Station, Antarctica (68* 35' S, 77* 58' E), supported a diverse microbial community which varied in composition and biomass in response…1 May, 1996
A previously reported porphyry Cu + Mo deposit in an Eocene pluton within the South Shetland Island magmatic arc has been re-interpreted as three distinct hydrothermal assemblages. The oldest assemblage…1 May, 1996 by David Barnes, Lloyd Peck
Prevalence (proportion of host organisms covered) and cover of encrusting epibiota were investigated for four Antarctic and two New Zealand species of deep-sea brachiopods. All epibiota was identified to the…1 May, 1996
Sediment profiles from several lakes/ponds in the northern, ice-free area of James Ross Island, Antarctica, were the subject of a multi-disciplinary palaeoenvironmental investigation. The results, obtained from lithological, geomagnetic, geochemical…1 May, 1996 by Andrew Clarke
There are few instances where a knowledge of the thermal physiology, habitats and lifestyles of a group of closely related species can be mapped onto a well-supported phylogeny and a…Read more on Evolution and adaptive radiation of antarctic fishes
1 May, 1996
The North Scotia Ridge controls the eastward and northward flow of the Antarctic Circumpolar Current (ACC) emerging from Drake Passage. Existing physical oceanographic data in this region are sparse and…1 May, 1996 by Eric Wolff, Robert Mulvaney
Dimethyl sulfide, methane sulfonate, non-sea-salt sulfate and sulfur dioxide concentrations in air were obtained during a cruise between the U.K. and the Antarctic during the period October 1992–January 1993. In…1 May, 1996 by Adrian Jenkins
The first oceanographic measurements across a deep channel beneath the calving front of Pine Island Glacier reveal a sub-ice circulation driven by basal melting of 10–12 m yr−1. A salt…Read more on Antarctic ice sheet melting in the southeast Pacific
1 May, 1996 by Eugene Murphy, Philip Trathan
To investigate the role of sea ice cover on penguin populations we used principal component analysis to compare population variables of Adélie (Pygoscelis adeliae) and chinstrap (Pygoscelis antarctica) penguins breeding…1 May, 1996
Southern elephant seals spend two periods on land each year, during breeding and moult, exposed to intensive UV radiation. The time between periods on land are spent at sea, with…1 April, 1996
Within the Albian Fossil Bluff Group of Alexander Island, Antarctica, sheet flood deposits have preserved palaeosols within situfernsAlamatus bifariusDouglas andAculea acicularissp. nov. Reconstructed as upright ferns, with fronds arising from…1 April, 1996
Seven species of angiospermous leaves from the mid to Late Albian of Alexander Island, Antarctica provide further evidence of angiosperm radiation into high southern palaeolatitudes. The leaves have both palmate…1 April, 1996 by Peter Convey, William Block
As an addendum to a recent publication on the terrestrial arthropod fauna of the Byers Peninsula Site of Special Scientific Interest (SSSI), which included preliminary identification of four Collembola, we…1 April, 1996
When fish are patchily distributed, unstratified trawl surveys give highly variable abundance estimates. If the patches are small and mobile, it is impractical to use pre-stratified or multi-stage adaptive designs…Read more on A combined acoustic and trawl survey for efficiently estimating fish abundance
1 April, 1996
Waveforms computed using the new whistler model derived from Maxwell's equations were analysed. In the calculations, realistic model values for magnetospheric parameters were used. The results accurately described whistler-mode propagation…Read more on Whistler-mode propagation: results of model calculations for an inhomogeneous plasma
1 April, 1996
Wild-caught female harbor seals (Phoca vitulina) were classified as sexually mature or immature on the basis of standard body length (< 125 cm immature, > 125 cm mature) and plasma…1 April, 1996
The dynamics of bacterioplankton and protozooplankton in two maritime Antarctic lakes (Heywood Lake and Sombre Lake, Signy Island, South Orkneys) were studied during the phase of ice break-out (December and…Read more on Microbial dynamics during the summer ice-loss phase in maritime Antarctic lakes
1 April, 1996
We have studied a hydromagnetic wave event in the early noon sector of the cusp region, using HF radar data collected in the southern hemisphere and ground-based magnetic data from…Read more on Conjugate cusp-region ULF pulsation responses to the solar wind event of May 23, 1989
1 April, 1996
The application of a two-frequency algorithm to the in situ estimation of large zooplankton is explored in an effort to use information from more than one acoustic frequency. To accomplish…1 April, 1996
The moss Drepanocladus uncinatus (Hedw.) Warnst., from coastal freshwater habitats on the sub-Antarctic island of South Georgia harbours two species of hemi-edaphic oribatid mite namely Edwardzetes elongatus Wallwork (Ceratozetidae) and…1 April, 1996 by Jonathan Watkins
A commercial data-visualization package, AVS, and database are used as the basis for a powerful and highly flexible acoustic data analysis system. The system is easy to use and can…Read more on A visualization-based post-processing system for analysis of acoustic data
1 April, 1996
Data collected between 1926 and 1990, during the Discovery Investigations and fourteen subsequent cruises, have allowed the description of spatial and temporal variability of temperature, salinity, phosphate, silicate, nitrate and…1 March, 1996 by David Barnes
Over 4000 bryozoan-bryozoan interactions were recorded from a total of 985 rocks from six locations at Signy Island in the maritime Antarctic. The majority of these interactions were interspecific ings.…1 March, 1996 by Andrew Clarke, David Barnes
A total of 985 rocks with a wide range of surface areas were examined from six locations at Signy Island in the maritime Antarctic. The shallowest site was intertidal and…1 March, 1996
The pattern of prey distribution can profoundly affect the foraging behavior and success of a predator. In pelagic marine ecosystems, where prey is often patchily distributed, predators must be able…Read more on Temporal scales of foraging in a marine predator
1 March, 1996
The Byers Group, exposed on Byers Peninsula, Livingston Island and Snow Island, Antarctica, is a mudstone-dominated sequence deposited in a fore-arc setting. Palynological studies on parts of the Byers Group…1 March, 1996 by John King
The seasonal and spatial variation of downward longwave radiation (L↓) at the surface of the Antarctic ice sheet is studied using data from four stations. L↓ is found to depend…1 March, 1996
The activity and behaviour of a free-living Antarctic fish,Notothenia coriiceps Richardson (formerlyN. neglecta), was investigated using a high-sensitivity, underwater TV camera at Signy Island, South Orkney Islands. Detailed observations of…Read more on Locomotory activity and behaviour of the Antarctic teleostNotothenia coriiceps
1 March, 1996
In 1991 Chamsocephalus gunnari1 March, 1996 by Richard Horne
Using the HOTRAY code, we demonstrate that lightning-generated whistlers which enter the magnetosphere over a broad range of latitudes (Δλ ≈ 5°) just inside the plasmapause are strongly focused by…Read more on Whistler absorption and electron heating near the plasmapause
1 March, 1996
There is increasing evidence of climate change in Antarctica, especially elevated temperature and ultraviolet B (UVB) flux within the ozone “hole.” Its origins are debatable, but the effects on ice…Read more on Response of pioneer soil microalgal colonists to environmental change in Antarctica
1 February, 1996
The body composition, milk consumption, and growth efficiency of Antarctic fur seal (Arctocephalus gazella) pups were measured over three consecutive lactation periods (1990–1992) at Bird Island, South Georgia. The body…