Found 14046 items
1 January, 1991
Results from a detailed profile in a 5.54 m multi-year sea-ice core from the rift area in the southern part of George VI Ice Shelf are presented. Stratigraphy, stable isotopes…1 January, 1991
A precise Rb‐Sr isochron age of 97.0 ± 0.5 Ma is presented for whole‐rock and mineral samples from the Mandamus Igneous Complex, North Canterbury. A low 87Sr/ 86Sr initial ratio…1 January, 1991
The reliability of various criteria (throat feather length and the characteristics of rectrices and upper tail‐coverts) previously suggested for ageing Starlings was assessed using a sample of known‐aged birds. Total…Read more on Ageing criteria in the Starling Sturnus vulgaris
1 December, 1990 by Andrew Clarke
Several recent studies have shown the potential value of chloroform-soluble fluorescent age pigments (FAPs) in determining the age of marine invertebrates with no permanent hard parts. The primary assumption in…Read more on The accumulation of fluorescent age pigments in the trochid gastropod Monodonta lineata
1 December, 1990 by Alistair Crame, John Turner
The International Conference on the Role of the Polar Regions in Global Change was hosted by the Geophysical Institute and Center for Global Change and Arctic System Research of the…Read more on Role of the polar regions in global change. Fairbanks, Alaska, 11–15 June 1990
1 December, 1990
The structural relationship between West Antarctic crustal blocks has remained uncertain due to a lack of information concerning sub‐ice crustal structure. A regional aeromagnetic reconnaissance of Ellsworth Land between 72…1 December, 1990 by Richard Horne
The range of applicability of an improved quasilongitudinal approximation for whistler-mode waves in the equatorial magnetosphere (4 ≲ L ≲ 6.6) is specified based on the direct comparison between numerical…Read more on Quasilongitudinal approximation for whistler-mode waves in the magnetospheric plasma
1 December, 1990
Marie Byrd Land is amongst the most inaccessible and least visited regions of Antarctica. It contains a large alkaline volcanic province, with 18 large central volcanoes and numerous small satellitic…1 December, 1990
Population growth rates of Antarctic and temperate isolates of the microflagellate Heteromita globosa Stein and of the ciliate Colpoda cucullus Müller were determined during incubation both under constant 3.5° and…1 December, 1990
The diversity of bacterial communities isolated from Antarctic lake sediment in chemostats under constant low temperature (8°C) or diurnally fluctuating temperature (1°C to 16°C) was examined. The median optimum temperature…Read more on The selection of microbial communities by constant or fluctuating temperatures
1 December, 1990
(1) Radio-telemetry was used to study the activity patterns of gentoo penguins, Pygoscelis papua, at Bird Island, South Georgia, throughout the breeding season, to assess variation in foraging effort (foraging…1 December, 1990
In crested penguins, Eudyptes spp., the first-laid (A) egg is smaller than the second-laid (B) egg and although viable rarely survives to hatching. I studied survival and growth to fledging…1 November, 1990 by Richard Horne
The ray paths of unstable electromagnetic waves generated inside the plasmapause during magnetic storm conditions are followed using the HOTRAY code. Unducted waves which are preferentially generated in the field…Read more on Ion cyclotron absorption at the second harmonic of the oxygen gyrofrequency
1 November, 1990
Digital ionosondes such as the Dynasonde disclose that the ionosphere is seldom horizontal even when it is plane stratified to a good approximation. The local magnetic dip does not then…1 October, 1990 by Michael Pinnock
The Geospace Environment Modeling (GEM) Program is directed toward modeling the coupled solar wind/magnetosphere/ionosphere system. The inter‐calibration of ground‐based observations of the ionosphere and satellite observations has been identified as…Read more on Simultaneous HF-radar and DMSP observations of the cusp
1 October, 1990 by Paul Rodhouse
Cephalopod remains were collected, at regular intervals throughout the fledging period, from the stomach contents of chicks of the grey-headed albatrossDiomedea chrysostoma at Bird Island, South Georgia, in 1984 and…Read more on Cephalopod prey of the grey-headed albatross Diomedea chrysostoma
1 October, 1990
Earlier views regarding the relative insignificance of Antarctic science have been rudely shattered by recent developments. The International Geophysical Year (IGY) of 1957–1958 represented a major turning point for research…Read more on Science, environment and resources in Antarctica
1 October, 1990 by Jonathan Watkins
An effect of the very patchy distribution of Antarctic krill (Euphausia superba Dana) in various forms of aggregation is that a single swarm may not provide an unbiased estimate of…Read more on Sampling biological characteristics of krill: Effect of heterogeneous nature of swarms
1 October, 1990
The breeding biology of the gentoo penguin, Pygoscelis papua, was studied over a three‐year period (1986–1988) at Bird Island, South Georgia, with particular reference to birds of known age or…1 September, 1990
The arrival of Antarctic fur seals at a breeding beach on Bird Island, South Georgia, was studied over five consecutive breeding seasons, 1983 to 1987. Experienced bulls arrived first and…1 September, 1990 by William Block
Nematodes of the families Heterorhabditidae and Steinernematidae are obligate parasites of a wide range of insects (Poinar 1979). The third stage juvenile of these nematodes is a non-feeding infective form…Read more on Tests of Antarctic soils for insect parasitic nematodes
1 September, 1990 by Paul Rodhouse
Post-recruit Illex argentinus were collected from the fishery on the Patagonian Shelf between 1986 and 1988. Age was determined by analysis of daily growth increments in ground sections of the…1 September, 1990
Our understanding of polar vegetation and climate through time has expanded enormously in the past five years as a consequence of improved logistics, detailed studies of plant fossils in their…Read more on Climate change and the evolution of high-latitude terrestrial vegetation and floras
1 September, 1990
The Shackleton Range occupies a key geological position in Antarctica (Fig. 1). Its location, at the edge of the continental craton between the mobile belts of the Transantarctic Mountains (TAM)…Read more on European geological initiative for the Shackleton Range
1 September, 1990 by Eric Wolff
In their upper layers, the polar ice sheets contain a detailed record of changes in the atmosphere over the industrial period. Measurements from air bubbles in ice have shown that…Read more on Signals of atmospheric pollution in polar snow and ice
1 August, 1990 by Peter Ward
A net sampling survey was conducted around the island of South Georgia in the austral summer 1981/1982 and again in winter 1983. This paper uses Principal Components Analysis to elucidate…Read more on Mesoscale distribution of zooplankton around South Georgia
1 August, 1990 by Lloyd Peck
Modified micro-Winkler and couloximetric methods are described for the measurement of oxygen in small volumes of water. The former uses a sample size of 1 cm3, while the latter is…Read more on Two methods for the assessment of the oxygen content of small volumes of seawater
1 July, 1990
Subduction of young, hot oceanic lithosphere and a major episode of lithospheric extension have been considered as key tectonomagmatic factors in the genesis of ‘Setouchi-type’ continental magnesian andesites. We present…1 July, 1990
A model has been set up to investigate the wet and dry aerosol removal processes which occur in clean air over the Antarctic Peninsula. Input for the model was obtained…1 June, 1990 by Michael Pinnock
Two conjugate HF radars are currently operating at Goose Bay, Labrador, and Halley Station, Antarctica, and are providing continuous, high temporal resolution measurements of plasma convection over large areas of…1 June, 1990
Three species of free-living Antarctic fellfield nematodes, Eudorylaimus coniceps, E. spaulli and E. pseudocarteri exhibited differing degrees of both strategies of cold-hardiness; freeze-tolerance and freeze-avoidance. Bimodal distributions of supercooling points…Read more on Strategies of cold-hardiness in three species of Antarctic dorylaimid nematodes
1 May, 1990
The relationship between quasi-periodic VLF emissions and micropulsations is briefly reviewed, and then discussed with reference to an event recorded at Halley, Antarctica, on day 257 in 1986. VLF emissions…Read more on Quasi-periodic particle precipitation and Trimpi activity at Halley, Antarctica
1 May, 1990
Two‐dimensional models are presented for the crustal structure of the Antarctic Peninsula, a Mesozoic‐Cenozoic magmatic arc on the southeast Pacific margin. The models are constrained by measured rock properties. The…1 May, 1990 by Paul Rodhouse
Growth increments have been reported to occur in the squid beak, radula, gladius and statolith. Of these, the statolith, which is part of the organ responsible for detection of linear…Read more on Age determination in squid using statolith growth increments
1 May, 1990
LEP (lightning electron precipitation) bursts can be detected on the ground because they cause transient perturbations (known as ‘Trimpi events’) in the received amplitude and phase of subionospherically propagating radio…Read more on The trimpi effect in antarctica: observations and models
1 April, 1990 by Richard Horne
The narrow-band structure of terrestrial myriametric radiation (TMR) is investigated by ray tracing electrostatic waves in a hot plasma which contains a loss cone distribution. Path-integrated growth of electrostatic waves…Read more on Narrow-band structure and amplitude of terrestrial myriametric radiation
1 April, 1990
Distribution, size composition and behaviour of Euphausia superba were investigated in the northwestern Weddell Sea (59–63°S, 45–52°W) in October-November 1988 using RMT trawling, SCUBA diving and visual examination of the…1 April, 1990 by Roger Worland, William Block
1. Freezing was lethal in the eggs, larvae, pupae and adults of the blowflies Calliphora vicina R‐D. and Calliphora vomitoria (L.), but varying degrees of supercooling were found. 2. Cold…Read more on Cold resistance in all life stages of two blowfly species (Diptera, Calliphoridae)
1 April, 1990
Adult Antarctic fur seals (Arctocephalus gazella) were immobilized with Zoletil® (n= 172), ketamine (n= 30), ketamine mixed with diazepam (n= 23) and with ketamine mixed with xylazine (n= 45). Response…1 April, 1990
Cortaderia pilosa is the dominant pasture species in the Falkland Islands. Extensive sheep ranching for wool production is the primary land use, but present range management grossly under-utilizes the annual…1 April, 1990
Under conditions of moderately-energetic particle precipitation typical of the equatorward side of the auroral oval, plasma densities obtained from routine analysis of EISCAT Common Program data are often a factor…1 March, 1990
We studied the distribution and abundance of marine birds in Bransfield Strait and southern Drake Passage during January and February 1985. We identified clusters of bird species, “communities” with similar…1 March, 1990
The regional geology and lithostratigraphy of the Late Cretaceous strata of north-east James Ross Island have been described by a number of authors (e.g. Olivero et al. 1986, Pirrie 1989).…1 March, 1990
In recent years, Man has become increasingly aware of the damage that he is doing to the Earth's atmospheric environment. There are two separate-but interrelated-effects, namely the greenhouse effect due…Read more on The Antarctic atmosphere: A hot topic in a cold cauldron
1 March, 1990
Antarctic cryptogamic communities are often remarkable for their uniformity in vegetation structure and floristic composition. Many typically exist as closely related units of vegetation in a continuum of variation which…Read more on Plant community dynamics in Wilkes Land, Antarctica
1 March, 1990 by Peter Ward
Euphausiid life histories and distribution in the vicinity of South Georgia were studied from a series of samples taken in April 1980, November–December 1981, and July–August 1983. Size frequency data…Read more on Euphausiid life cycles and distribution around South Georgia
1 March, 1990
The process of colonization of Antarctic fellfield soils by micro- organisms has two phases: Firstly, the immigration, survival and establishment of microbial propagules thenlselves, and secondly the stabilization of the…Read more on Microbial colonization processes in Antarctic fellfield soil – an experimental overview
1 February, 1990
Regression functions of total length on carapace length and total length on removed carapace length were calculated for Antarctic krill Euphausia superba Dana for those classes of sex and maturity…1 February, 1990
Following more than 200 Ma of subduction of Pacific oceanic crust beneath the west coast of the Antarctic Peninsula, subduction ceased by a series of ridge crest-trench collisions. However, magmatism…1 February, 1990 by Richard Horne
Three model electron distribution functions representative of the region between the plasmapause and the geostationary orbit are constructed. These models are used to compare numerical solutions of the hot electromagnetic…1 February, 1990
Coomansus gerlachei shows a strong seasonal variation in its supercooling ability, with most individuals freezing between -5° and -7°C, in a discrete high group, or between -15° and -26°C in…1 February, 1990 by Paul Rodhouse
In a recent paper (Goulletquer & Wolowicz, 1989), data are presented which show that determination of the organic content of mollusc shells by weight loss on ignition may over-estimate this…1 January, 1990
The history of the British Antarctic Survey, and of its predecessors, Operation Tabarin and Falkland Islands Dependencies Survey, is outlined. The objectives, stock, and organization of the Survey's library and…Read more on The library of the British Antarctic Survey, Cambridge
1 January, 1990
Neck collars of man-made marine debris were seen on 208 Antarctic fur seals (and removed from 170) during the 142 days of the 1988–1989 pup-rearing season at Bird Island, South…Read more on Entanglement in man-made debris of Antarctic fur seals at Bird Island, South Georgia
1 January, 1990 by Roger Worland, William Block
This paper provides an introduction to the literature on the drying of porous solids and the relevance of these drying theories to the drying of Collembola in general, and hygrophilic…1 January, 1990
New field mapping and an integrated trace element and Nd isotopic study have been undertaken on the Jurassic-Cretaceous Larsen Harbour Complex on the island of South Georgia, recognized as a…1 January, 1990
A mixture of tiletamine and zolazepam at a combined dose of 1 mg/kg was a reliable and safe agent for immobilising wild grey seals (Halichoerus grypus) and southern elephant seals…1 January, 1990 by William Block
Arthropods, as poikilotherms, adapt to cold environments in a variety of ways that include extension of locomotory activity to low temperatures, enhancement of metabolic rate and maintenance of a positive…Read more on Cold Tolerance of Insects and Other Arthropods [and Discussion]
1 January, 1990 by William Block
Dehydration experiments were conducted on individual Collembola at 0% relative humidity with the temperature ramped from 5 to 34°C at the rate of 0.5°C min−1. Continuous records of weight loss…1 January, 1990
The age distribution of breeding female Antarctic fur seals at Bird Island, South Georgia, in 1988 was compared with the age distribution of a sample obtained in 1971–1973. The mean…1 January, 1990 by Andrew Clarke
Faecal egestion and ammonia excretion were measured in the Antarctic limpet Nacella concinna (Strebel, 1908) at Signy Island during the austral summer of 1986/87. Limpets were sampled from nearby shallow…1 January, 1990 by Andrew Clarke
1. 1. The proximate (water, protein, lipid, mineral ash) and elemental (carbon, nitrogen, phosphorus) composition of eggs of the freshwater prawn Macrobrachium rosenbergii (de Man, 1879) (Crustacea, Decapoda) were determined…1 January, 1990
The aliphatic and aromatic hydrocarbon content of seawater and a selection of marine pelagic organisms from the Bransfield Strait, Antarctica were evaluated. The patterns of the hydrocarbons found indicated that…Read more on Hydrocarbons in the seawater and pelagic organisms of the Southern Ocean
1 January, 1990
Only a few years ago most interested people thought (and many said in print) that accidental killing of Antarctic animals as a consequence of commercial fishing operations was minimal to…Read more on Impact of incidental mortality on Antarctic marine vertebrates [Guest editorial]
1 January, 1990
Ringing of 20,000 Wandering Albatrosses over 30 years at Bird Island, South Georgia has produced only 81 recoveries (i.e. excluding controls), fairly evenly distributed between birds ringed as adults and…Read more on Recoveries of wandering albatrosses diomedea exulans ringed at South Georgia 1958–1986
1 January, 1990
The wandering albatross breeding population at Bird Island, South Georgia has declined since 1961 at a rate of 1.0% per annum. Similar declines have occurred elsewhere in the Subantarctic. (2)…