Showing 11923 items
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)…1 January, 1990
References Citations Metrics Reprints & Permissions PDF Abstract Five species of dimitobelid belemnites are described from the Cretaceous of James Ross Island, Antarctic Peninsula. Dimitobelus (Dimitobelus) stimulus…1 January, 1990 by Jonathan Watkins
Encaged aggregations of live krill in good to pristine condition have been ensonified at 38 and 120 kHz. Concurrent underwater television observations of behavior resemble those made by underwater divers…Read more on Target strengths of Antarctic krill (Euphausia superba) at 38 and 120 kHz
1 January, 1990
The UCL-Sheffield coupled thermosphere/ionosphere model has been used to assess the consequences of a heat source from ring current ion precipitation during a geomagnetic storm. Such a source might in…1 January, 1990
By means of re‐evaluating a number of properties of rock tablets left in the field for varying time periods, an estimation of rock breakdown rates is attained. From data obtained…Read more on Mechanical weathering rates on Signy Island, maritime Antarctic
1 January, 1990 by Paul Rodhouse
A bottom-trawl survey of the Falklands Interim Conservation Zone was carried out during July and August 1988. Samples of Loligo gahi were collected from depths of 50–400 m and analysed…1 January, 1990
Using a variety of techniques, the susceptibility of a species of Zygnerna (Chlorophyta) from the Antarctic to freezing was investigated with freshly collected and cultured material. There was no evidence…1 January, 1990
The effects of temperature and radiation flux on the partitioning of photosynthetically fixed carbon into four intracellulai metabolic pools was investigated for natural phytoplankton assemblages from an Antarctic freshwater lake.…1 January, 1990
1 Earlier work with albatrosses led to the hypothesis that a critical element influencing ovarian development each year is whether the ovary responds to rising gonadotrophin secretion by secreting progesterone…1 January, 1990
Initial results are presented from two methods whereby burst precipitation events in the lower ionosphere, almost certainly induced by VLF wave‐particle interactions in the magnetosphere, have been detected using a…Read more on Wave-induced burst precipitation events detected with a digital ionosonde
1 January, 1990 by John King
Profiles of wind speed, temperature and turbulent fluxes of heat and momentum in the lowest 32 m have been measured at a station on an antarctic ice shelf. During the…Read more on Some measurements of turbulence over an antarctic ice shelf
1 January, 1990
Voyagers 1 and 2 discovered radio emissions at Jupiter, Saturn and Uranus which were similar to those already studied in the Earth's magnetosphere. Terrestrial myriametric radiation, TMR, emanates from electrostatic…Read more on Remote sensing of planetary plasma by means of natural radio emissions
1 January, 1990 by Robert Mulvaney
The dielectric stratigraphy of a 130 m ice core from Dolleman Island, Antarctic Peninsula, shows large variations in the dielectric relaxation process and in conductivity. A comparison with the chemical…Read more on Chemical evidence in polar ice cores from dielectric profiling
1 January, 1990
The continuum theory of mixtures is used as the mathematical framework for a four-constituent model of a natural snowpack. The general conservation equations in point form are derived from appropriate…1 January, 1990
Recent mathematical models treat a natural snow-pack as a mixture body consisting of solid ice grains, liquid water, and a gas made up of air and water vapour. Such a…1 January, 1990
The first observations are presented from Halley, Antarctica, of quasi-periodic (QP)_VLF intensity variations modulated at the frequency of concurrent Pc3 magnetic pulsations. Seen on broadband frequency-time plots, the QP emissions…Read more on Quasi-periodic VLF emissions and concurrent magnetic pulsations seen at L = 4
1 January, 1990
The three-dimensional microstructure of Tolypothrix mats from the bottom of a maritime antarctic lake of Signy Island, South Orkneys, was examined. Samples from mats at two depths, 4 and 6 m,…Read more on The fine structure of an algal mat from a freshwater maritime antarctic lake
1 January, 1990
Six of the eight species of beetles at South Georgia, the southernmost beetles of the world, were investigated in outdoor arenas with pitfall traps for their diel patterns of locomotory…1 January, 1990
The physiological adaptations required to survive exposure to low temperatures must be of great importance in allowing nematodes to colonize extreme terrestrial environments, such as Antarctic fellfields. Seasonal variation in…1 January, 1990
A joint IAS/Geological Society of London meeting, organized by the British Sedimentological Research Group, was held in London at the Geological Society on 9-11 May 1989, to address the problem…Read more on Sea level changes at active plate margins: processes and products
1 January, 1990
Oxygen-isotope analysis of well-preserved macrofossils from the Santonian-Campanian of James Ross Island and the Maastrichtian of Vega Island, Antarctica, indicates that cool high-paleolatitude temperatures prevailed during the Late Cretaceous and…1 January, 1990 by Jonathan Watkins
Gut fullness of 3264 Antarctic krill in 38 swarms was estimated using fluorometric determination of chlorophyll a . There was a very wide range of gut fullness (maximum value 3277…1 January, 1990 by Roger Worland, William Block
The body water content and resistance to desiccation were studied in two perimylopid beetles, Perimylops antarcticus and Hydromedion sparsutum, a chironomid midge, Eretmoptera murphyi, and two spiders, Notiomaso australis and…1 January, 1990
Fabry-Perot interferometer measurements of the Doppler shift of the 5577Å O1S emission are used to derive neutral wind velocities at E-region altitudes over Halley, Antarctica (Λ=61°). These measurements, recorded during…Read more on Lower thermospheric wind measurements near 60° Λ from 5577Å Doppler interferometry
1 December, 1989
The number of Antarctic fur seals (Arctocephalus gazella) in the area of the Scotia Sea has been increasing. Observation of their distribution on the breeding grounds are important to help…1 December, 1989 by Jonathan Watkins
A technique for moult staging Antarctic krill (Euphausia superba Dana) was used in the analysis of field samples to predict intermoult periods and hence assess growth and the effects of…1 December, 1989
Hydrocarbons in the environment occur as complex mixtures. The detection of low-level anthropogenic contamination can be difficult as many of the compounds can also be found in biogenic materials. Results…1 December, 1989
The records obtained from a monostatic acoustic sounder run at Halley, Antarctica, have been analysed with the use of data from instruments on a 32 m mast and from radiosonde…Read more on Acoustic sounding of the atmospheric boundary layer at Halley, Antarctica
1 December, 1989
The Dobson ozone spectrometer has been used for studies of the ozone layer for about 60 years. It remains indispensable for assessing the accuracy of satellite-borne instruments. The steps which…Read more on Measurements of total ozone using Dobson spectrometers: Some comments on their history