Found 14049 items
1 November, 1992
The main changes in the distribution and abundance of marine top predators in the Antarctic in the last two centuries were caused by hum an over-exploitation. Hypotheses that increases in…Read more on Southern Ocean environmental changes: effects on seabird, seal and whale populations
1 November, 1992
The factors causing the cessation of growth and decline of microalgal communities on Antarctic fell-field soils during late summer were investigated. Physical and chemical amendments were applied within small enclosures…1 November, 1992
Management of Antarctic krill, Euphausia superba, and the mackerel icefish, Champsocephalus gunnari under the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is discussed in relation to changes…Read more on Managing Southern Ocean krill and fish stocks in a changing environment
1 November, 1992
Antarctic continental soils are arid, saline and lacking in organic matter, whereas maritime soils, in a wetter environment, range from structureless lithosols to frozen peat. Two important factors in the…Read more on Rock weathering, soil development and colonization under a changing climate
1 November, 1992
New assemblages of Radiolaria, including some of the few occurrences of high southern latitude Jurassic and Cretaceous radiolarian faunas, show that several localities in the LeMay Group of Alexander Island…1 November, 1992
New evidence, provided by bracketing marine molluscan faunas, suggests a Late Albian age for fossil forests in the upper part of the Fossil Bluff Group of Alexander Island. These in…1 November, 1992 by Lloyd Peck
A new desorber design for use in the couloximetric determination of oxygen in water samples is described. In comparison with previous systems it significantly improves the efficiency of transfer of…Read more on An improved desorber design for use in couloximetry
1 November, 1992
In the Southern Ocean, inorganic macronutrients are very rarely depleted by phytoplankton growth. This has led to speculation on possible additional CO2 drawdown in this region. However, the effects of…1 November, 1992 by Paul Rodhouse
Samples of the squid Martialia hyadesi were collected aboard two Japanese squid-jigging vessels carrying out commercial fishing trials at the Antarctic Polar Frontal Zone, north Scotia Sea, in February 1989.…1 October, 1992 by Peter Convey
A technique for the accurate determination of lipid content of very small quantities of biological tissue was applied to two Antarctic oribatid mites,Alaskozetes antarcticus andHalozetes belgicae, and a collembolan,Cryptopygus antarcticus.…Read more on Seasonal lipid contents of Antarctic microarthropods
1 October, 1992
Lightning-induced ionisation enhancements (LIEs) are usually produced by short (~ 1 s) bursts of energetic electrons precipitated from the radiation belts in the process of amplifying whistlers. During their short…1 October, 1992 by Lloyd Peck
Brachiopods were once dominant in all the oceans of the world. but their distributions are non more restricted. There are few species which are found in shallow warm habitats and…Read more on Body volumes and internal space constraints in articulate brachiopods
1 October, 1992
Methods for estimating tag loss and sightability of tags are presented. Rates of tag loss were estimated for metal and several varieties of plastic cattle ear tags in a long-term…Read more on Effectiveness of various cattle ear tags as markers for Weddell seals
1 October, 1992
A technique for preparing simple, large scale maps of remote and poorly surveyed areas is described, whereby semicontrolled aerial photograph print laydowns are superimposed on enlarged satellite imagery.1 October, 1992 by Michael Pinnock
The majority of current ground‐based radar experiments measuring ionospheric convection flows derive the ionospheric flow vectors from line‐of‐sight (l‐o‐s) velocity measurements made from a single radar site. In order to…1 September, 1992 by Peter Ward
Seventeen Longhurst Hardy Plankton Recorder profiles were taken over a diel cycle in January 1990 to study the feeding of four major copepods over the South Georgia shelf. Ontogenetic changes…1 September, 1992
Twenty two samples collected from the Tertiary La Meseta Formation of Cape Wiman, Seymour Island, Antarctic Peninsula yielded abundant and moderately diverse assemblages of marine palynoflora, dominated by dinoflagellate cysts,…Read more on Eocene microplankton from La Meseta Formation, northern Seymour Island
1 September, 1992
The James Ross Island area is recognized as one of the geological treasures of Antarctica. It exposes a section of 5–6 km of Cretaceous and Tertiary marine sedimentary strata with…Read more on Palynology of the James Ross Island area, Antarctic Peninsula
1 September, 1992
Palynological analyses of the Marambio Group sediments of Humps Island (Santa Marta and López de Bertodano formations) indicates that there is minor displacement across a prominent NW–SE trending normal fault…Read more on Palynology of the Marambio Group (Upper Cretaceous) of northern Humps Island
1 September, 1992
Studies of Quaternary glacial stratigraphy and morphology around the Antarctic Peninsula have shown that James Ross Island in the western Weddell Sea probably has the best occurrences of stratigraphic sections…Read more on Late Pleistocene and Holocene glacial history of James Ross Island, Antarctic Peninsula
1 September, 1992
Palynomorph assemblages from the Lachman Crags Member of the Santa Marta Formation, north-west James Ross Island, Antarctic Peninsula are described. By basis of comparison with other Southern Hemisphere localities, particularly…1 September, 1992
Palynomorph assemblages are reported from the Kotick Point and Whisky Bay formations in west and north-west James Ross Island, Antarctic Peninsula. The microfloras, particularly the dinoflagellate cyst florules, indicate an…1 September, 1992 by Robert Mulvaney
Methane sulphonic acid (MSA) in an ice core from Dolleman Island (70°35′S, 60°56′W) shows significantly high concentrations (typically 1-2 µm, but up to 5 µm) compared to values recorded in…Read more on The ratio of MSA to non-sea-salt sulphate in Antarctic Peninsula ice cores
1 September, 1992
A sedimentary sequence, c. 5–6 km thick, extending from the Kimmeridgian–Upper Eocene crops out in the James Ross Island area, northern Antarctic Peninsula. This succession is the most important onshore…1 September, 1992
Samples from the lower Cape Lamb Member, López de Bertodano Formation, Cape Lamb, Vega Island, Antarctic Peninsula have yielded rich and diverse marine palynofloral assemblages. The overall character of the…1 September, 1992
An allochthonous block of the Nordenskjöld Formation from north-west James Ross Island, Antarctic Peninsula has yielded a diverse marine palynoflora. Dinoflagellate cyst assemblages from the 185 m thick sequence are…1 August, 1992 by Peter Ward
Twelve Longhurst Hardy Plankton Recorder (LHPR) profiles were taken over a 16 h period in January 1990, in order to study feeding of four copepod species at an Antarctic oceanic…Read more on Diel vertical migration and feeding of copepods at an oceanic site near South Georgia
1 August, 1992
The morphology of the respiratory system of the femaleVarroa jacobsoni (Oudemans, 1904) is described. The mobile, appendage-like, emergent peritreme may be ‘raised’ to lie against the ventral integument or ‘lowered’…1 July, 1992
The roles of maternal age and experience, on the one hand, and individual, year and random effects on the other, in influencing avian egg-size and hatching success have been much…1 July, 1992
Upper Quaternary pelagic and hemipelagic sediments from the Scotia Sea and South Scotia Ridge range from diatom ooze to diatom-bearing mud. Diatom content increases northwards, and at most sites diatom-rich…Read more on High-resolution diatom stratigraphy of Quaternary sediments from the Scotia Sea
1 July, 1992 by John Turner, Thomas Lachlan-Cope
Sequences of images from geostationary satellites have been used for some time to track clouds and so produce an estimate of the wind at cloud height (see/1/ and /2/). However,…Read more on The effect of resolution on high latitude cloud track winds produced from AVHRR imagery
1 July, 1992
The accuracy and efficiency with which radio echo parameters may be estimated by a programmable ionosonde of high resolution depend upon software-designed strategies of pulse set design and receiving antenna…Read more on Toward an optimum receiving array and pulse set for the Dynasonde
1 June, 1992
Measurement of pressure fluctuations provides the best means of detecting atmospheric internal gravity waves at the Earth's surface. We have developed an instrument which is sufficiently sensitive to detect the…Read more on A microbarograph for internal gravity wave studies in Antarctica
1 June, 1992
South Georgia is a highly glacierized island with a range of glacier types including corrie, valley and tidewater ice bodies. Glaciologically, it occupies a strategic location between South America and…Read more on Glacier fluctuations on South Georgia during the 1970s and early 1980s
1 June, 1992
Retention of mineral elements in precipitation by mosses and lichens involving ion exchange and chelation mechanisms is a source of nutrients for these biota growing on rocks and nutrient poor…Read more on Retention of precipitation nitrogen by Antarctic mosses, lichens and fellfield soils
1 June, 1992 by Roger Worland, William Block
Diapause larvae of the European corn borer (Ostrinia nubilalis (Hubn.)) and the related Mediterranean noctuid Sesamia cretica Led. possess sufficient supercooling ability to avoid freezing over their normal environmental temperature…Read more on Comparison of the cold hardiness of two larval Lepidoptera (Noctuidae)
1 June, 1992
Newly formed bottom water (θ ≤ −0.7°C) in the northern Weddell Sea flows E or NE at speeds up to 10–15 cm/s, with velocity decreasing towards the centre of the…1 June, 1992
We present data on diving pattern and performance (dive depth, duration, frequency and organization during the foraging trip) in gentoo penguins Pygoscelis papua, obtained using time-depth recorders (n= 9 birds,…1 June, 1992
An examination of 111 fish of eight species, including 92 immature Notothenia rossii Richardson revealed nine acanthocephalan species, including four Echinorhynchida occurring in the alimentary tract and five Polymorphida in…Read more on Acanthocephalan infection of inshore fish in two fjords at South Georgia
1 May, 1992
The bdelloid rotifers Philodina gregaria Murray and Adineta grandis Murray were both cultured through three generations. The results suggested the following models for calculation purposes: (1) that individual Adineta grandis…Read more on The reproductive strategies of two Antarctic rotifers
1 May, 1992 by Paul Rodhouse
Samples of male Illex argentinus were taken from the catch of a Japanese squid jigging vessel on the Patagonian Shelf during March 1986 and an analysis was carried out on…1 May, 1992 by Paul Rodhouse
Samples of male Illex argentinus were taken from the catch of a Japanese squid jigging vessel on the Patagonian Shelf during March 1986 and an analysis was carried out on…Read more on Production of soma and gonad in maturing male Illex argentinus (Mollusca: Cephalopoda)
1 April, 1992
The fine structure of a cyanobacterial mat collected from the fellfield ecosystems of Signy Island, Antarctica, was examined using some novel light and scanning electron microscope techniques. The mat was…Read more on Fine structure of a terrestrial cyanobacterial mat from Antarctica
1 April, 1992 by Andrew Clarke
Data on reproductive biology are presented for five benthic caridean shrimps from the high Antarctic (Chorismus antarcticus, Notocrangon antarcticus, Nematocarcinus lanceopes, Lebbeus antarcticus and Eualus kinzeri). The first three species…Read more on Reproductive biology of caridean decapods from the Weddell Sea
1 April, 1992
The alimentary tracts of 12 species of Antarctic squid were examined visually and serologically for the presence of Euphausia superba. Only four species, Alluroteuthis antarcticus, Galiteuthis glacialis, Martialia hyadesi and…1 April, 1992
The Chiloé-Chonos region seems to preserve the oldest depositional events in the fore-arc accretionary complex of the Southeast Pacific margin. There are isolated occurrences of low-grade metamorphic rocks, including slates…Read more on Magmatism and tectonics in continental Chiloé, Chile (42°–42°30′S)
1 April, 1992
The age of the granites of the La Esperanza region of the Somuncura Batholith, North Patagonian Massif has been revised, based in part on RbSr whole-rock data obtained by reanalyzing…1 April, 1992
Major- and trace-element (XRF and INAA) and Nd-isotope analyses are presented on a Jurassic bimodal association of basic greenstones and silicic metavolcanic rocks from the Black Coast, northeast Palmer Land,…1 April, 1992
Long-term studies of seabirds, some now 30–40 years old, have begun to reveal significant age-related changes in the survival and reproduction o f these long-lived animals. Evidence for density-dependent regulation…1 March, 1992
The mineral nitrogen (NH4-N + NO3-N) in precipitation occurring at continental and maritime Antarctic sites has been determined. Precipitation at sites remote from animal activity contained much less mineral N…Read more on Precipitation nitrogen at maritime Signy Island and continental Cape Bird, Antarctica
1 March, 1992
Recently, fossil land mammals have been recorded in the James Ross Island area, east of the Antarctic Peninsula, from the marine middle-late Eocene strata of Seymour Island. These include two…1 March, 1992
During a three month research cruise near the island of South Georgia, sea surface temperature (SST) increased from c. 2°C to over 4°C. Satellite derived SST show that this corresponded…1 March, 1992 by Richard Horne
We evaluate the convective growth of ion-cyclotron waves in the Io plasma torus using realistic plasma parameters. Significant wave amplification is restricted to two dominant frequency bands. As originally proposed…Read more on Ion-cyclotron waves at Jupiter: Possibility of detection by Ulysses
1 March, 1992
The movements of two wandering albatrosses, one of each sex, breeding at South Georgia, were tracked using satellite telemetry, particularly to assess whether such birds could be at risk from…Read more on Satellite tracking of wandering albatrosses (Diomedea exulans) in the South Atlantic
1 March, 1992 by John Turner
The study of the “polar low episode” over the northern parts of the Norwegian Sea and the Barents Sea from 12 December 1982 to 16 December 1982 is continued. The…Read more on Polar lows and arctic instability lows in the Bear Island region
1 March, 1992 by Eric Wolff
An improved technique for concentrating heavy metals onto the surface of tungsten wires, prior to analysis by electrothermal atomic absorption spectrometry, is reported. Ultraclean methods and materials, described here, have…1 March, 1992 by John Turner, Thomas Lachlan-Cope
The value of satellite temperature sounding data in polar lows research is investigated through a comparison of satellite temperature profiles produced using radiances from the TIROS Operational Vertical Sounder (TOVS)…1 March, 1992
Sulphide-bearing quartz veins were first observed on Hurd Peninsula, Livingston Island, at Henry Bluff in 1958 (Hobbs 1968). Subsequent mapping of the host Miers Bluff Formation (MBF) in western Hurd…1 March, 1992
A sample of 111 fish of eight species caught in two fjords at South Georgia were examined for digenean trematode parasites. The alimentary tracts of all specimens were infected with…Read more on Digenean Trematoda infection of inshore fish at South Georgia
1 February, 1992
In a case study from June 8–9, 1982, data from ground whistler stations Siple and Halley, Antarctica, located at L ∼4.3 and spaced by ∼2 hours in MLT, and from…1 February, 1992 by Andrew Clarke
We have analysed the proximate composition and elemental (C,H,N) composition of eight gelatinous zooplankton from the Southern Ocean (two ctenophores, one anthomedusan, two siphonophorcs, one scyphozoan, one annelid and one…Read more on Proximate and elemental composition of gelatinous zooplankton from the Southern Ocean
1 February, 1992
King Penguins are the second largest of all diving birds and share with their congener, Emperor Penguins, breeding habits strikingly different from other penguins. Our purpose was to determine the…Read more on Diving behavior and energetics during foraging cycles in king penguins
1 February, 1992 by Eric Wolff
Antarctic and Greenland ice core samples were studied using two different stratigraphic electrical techniques. The electrical conductivity measurement (ECM) technique is a dc method, while dielectric profiling (DEP) is an…Read more on The chemical basis for the electrical stratigraphy of ice
1 February, 1992 by Jonathan Watkins
Measurements on krill from distinct swarms and echo-sounder measurements of the same swarms have been analysed using multivariate methods. The analysis has addressed the problems of whether krill swarms in…1 February, 1992
We present the initial results of a quantitative investigation of the volatile geochemistry of Deception Island, an active volcano situated near the spreading axis of a Quaternary ensialic marginal basin…1 February, 1992
Changes in plasma luteinizing hormone (LH), testosterone, oestradiol, and progesterone were measured throughout the breeding and molt cycle in free-living male and female macaroni (Eudyptes chrysolophus) and gentoo (Pygoscelis papua)…1 February, 1992
Plasma levels of LH, testosterone, estradiol, and progesterone were measured, during the breeding season, in adult and immature macaroni (Eudyptes chrysolophus) and gentoo (Pygoscelis papua) penguins, at Bird Island, South…1 January, 1992
This study describes a method for extracting post-canine or incisor teeth from live antarctic fur seals (Arctocephalus gazella) and southern elephant seals (Mirounga leonina) respectively and their use to determine…Read more on Aging live Antarctic fur seals and southern elephant seals
1 January, 1992 by Howard Roscoe
Radiative transfer within an interferometric spectrometer is discussed in relation to measurements of infrared transmittance spectra of gases. It is shown that for certain types of interferometric spectrometers, radiation from…1 January, 1992 by William Block
1 January, 1992
The diving behaviour of 11 lactating female Antarctic fur seals (Arctocephalus gazella) was recorded for a total of 254 animal-days at sea. Median and maximum dive depths for individuals varied…Read more on Diving behaviour of lactating Antarctic fur seals
1 January, 1992
On the basis of geochemical signatures, Mesozoic magmatism in Antarctica is divided into the Ferrar Magmatic Province and the Dronning Maud Land Province. The tholeiitic magmatism of the Ferrar Magmatic…Read more on Coats Land dolerites and the generation of Antarctic continental flood basalts
1 January, 1992
Heart rate (fH) and rate of oxygen uptake (VO2) were measured in six subadult California sea lions Zalophus californianus while they were at rest and while they were swimming for…1 January, 1992 by Andrew Clarke
Although a tendency for high latitude marine invertebrates to avoid pelagic larval stages was first described in the 19th century, the most detailed early study was that of Thorson in…1 January, 1992 by Andrew Clarke
Samples of ovigerous female Ceratoserolis trilobitoides carrying newly spawned (stage A1) eggs in the marsupium were obtained from Borge Bay, Signy Island (South Orkney Islands), the continental shelf near Elephant…Read more on Egg size and composition in Ceratoserolis (Crustacea: Isopoda) from the Weddell Sea
1 January, 1992 by Mark Clilverd
Whistler mode group delays observed at Faraday, Antarctica (65° S, 64° W) and Dunedin, New Zealand (46° S, 171° E) show sudden increases of the order of hundreds of milliseconds…1 January, 1992 by Mark Clilverd
Whistler mode signals from NLK (24.8 kHz) were received at Dunedin, New Zealand during 1989-90. The arrival bearing of the signals shows a bimodal distribution which is consistent with the…1 January, 1992
During 1986, a series of special VLF transmissions at ∼3 kHz and ∼5 kHz were made from the crossed dipole antenna at Siple Station, Antarctica, which simulated transmissions from a…1 January, 1992 by Alistair Crame
With the recent rapid increase in our knowledge of the palaeontological history of both polar regions it has become apparent that they should now be regarded as something more than…1 January, 1992
The Antarctic marine environment contains a range of hydrocarbons at low concentrations, which are generally biogenic in origin. All major classes of hydrocarbons have been found in the Antarctic ecosystem.…Read more on Natural and anthropogenic hydrocarbons in the Antarctic marine environment
1 January, 1992
Low level hydrocarbon contamination is measurable in the vicinity of Antarctic stations, N-alkane and polycyclic aromatic hydrocarbon (PAH) concentrations in seawater and sediment at Signy Station, South Orkney Islands indicated…1 January, 1992
Field studies carried out on the Antarctic brown macroalga Himantothallus grandifolius (A. Gepp et E.S. Gepp) A.D. Zinova (Desmarestiales, Phaeophyta) during two summers and an intervening winter season are described.…1 January, 1992
The prediction of short-term (100 year) changes in the mass balance of ice sheets and longer-term (1000 years) variations in their ice volumes is important for a range of climatic…Read more on The response of large ice sheets to climatic change