Found 14112 items
1 January, 1993
The Caytoniales are represented in the Early Jurassic floras from Hope Bay and Botany Bay, Antarctica, as completeleaves and detached leaflets (Sagenopteris) together with microsporophylls (Caytonanthus). Systematic sampling at Botany…Read more on Caytoniales in Early Jurassic floras from Antarctica
1 January, 1993
Antarctic plankton community respiration rates were determined from in vitro changes in dissolved oxygen. Oxygen consumption rates, measured at in situ temperatures between 0 and 6°C, were found to lie…Read more on Temperature and Antarctic plankton community respiration
1 January, 1993
The paper by Giletti et al. 1961 is seen as a major landmark in the evolution of dating techniques in polymetamorphic terrains. We consider certain critical issues from each of…Read more on Unravelling dates through the ages: geochronology of the Scottish metamorphic complexes
1 January, 1993
Collections of preserved terrestrial and freshwater plants and animals, made since the earliest expeditions to the Antarctic and sub-Antarctic, have been the basis of our understanding of the biological composition…Read more on New significance for Antarctic biological collections and taxonomic research
1 January, 1993
Electron temperatures in the vicinity of the magnetospheric equator were estimated from dispersion measurements on 24 whistlers observed and digitally recorded at Halley, Antarctica (76 deg S, 27 deg W;…Read more on Magnetospheric electron temperatures inferred from whistler dispersion measurements
1 January, 1993
Isolated, Late Miocene volcanogenic sequences in northern Alexander Island, Antarctic Peninsula, form an unusual, cogenetic association of volcaniclastic, sandy-gravelly lithofacies (including tillites) and volcanic (lava/hyalocalstite) lithofacies. Using simple lithofacies analysis…1 January, 1993
The SWEAT hypothesis, linking the Southwest US and East Antarctica as conjugate rift margins of a Neoproterozoic continent has lead to major revisions of late Precambrian and early Cambrian reconstructions.…Read more on The changing face of late Precambrian and early Palaeozoic reconstructions
1 January, 1993 by William Block
1 The year-round biology of a high arctic aphid is described for the first time. 2 The life-cycle is shown to be genetically determined, and thus markedly different to temperate…Read more on Extreme adaptive life-cycle in a high arctic aphid, Acyrthosiphon svalbardicum
1 January, 1993 by William Block
Identification of three previously unknown morphs of Acyrthosiphon svalbardicum Heikinheimo (Hemiptera: Aphididae) on Spitsbergen.1 January, 1993 by David Vaughan
The presence of crevasses on the surface of ice masses indicates that a fracture criterion has been met. Understanding how crevasses form will provide information about the stress and strain-rate…Read more on Relating the occurrence of crevasses to surface strain rates
1 January, 1993 by David Vaughan
Wilkins Ice Shelf has an area of 16000 km2 and lies off the west coast of the Antarctic Peninsula bounded by Alexander, Latady, Charcot and Rothschild islands. Several ice shelves,…Read more on A synthesis of remote sensing data on Wilkins Ice Shelf, Antarctica
1 January, 1993 by William Block
Supercooling points and the presence of antifreeze compounds were measured for both nymphs and adults of Steganacarus magnus (Nicolet) collected from a coniferous forest soil in southern England in March,…Read more on Aspects of cold hardiness in Steganacarus magnus (Acari: Cryptostigmata)
1 January, 1993
Four campaigns of the Worldwide Atmospheric Gravity-wave Study (WAGS) have taken place in the European sector. On many occasions the onset of auroral activity in the evening and midnight sector,…Read more on Worldwide atmospheric gravity-wave study in the European sector 1985–1990
1 December, 1992 by Alistair Crame
The Cretaceous period is often regarded as one of "greenhouse" warmth, with perhaps its acme occurring in the late Albian stage (100 Ma ago). However, it is now apparent that,…Read more on Late Cretaceous palaeoenvironments and biotas: an Antarctic perspective
1 December, 1992 by William Block
Temperatures within soil and plant habitats on Signy Island in the maritime Antarctic were measured during 1987. Four sites were monitored using minithermistors attached to a data logging system. Three…1 December, 1992
Icefish (Champsocephalus) were taken as bycatch during krill fishing operations from a research vessel. The data indicate that the bycatch of fish in the commercial krill fishery may be significant…Read more on Bycatch of fish in the South Atlantic krill fishery
1 December, 1992
Trilobites devonicos de Buill, Chile (42°S). Se describe un trilobites calmoniido (Calmoniidae gen. nov. aff. Bainella Rennie, 1930) un trilobites lacopoide indeterminado y un coral zafrentido, recolectados en rodados de…1 December, 1992 by Ed King
Details are presented of seismic velocities at a site near Rothera Point, Adelaide Island, Antarctic Peninsula. The snow/firn velocity structure was obtained using a 24-channel Bison 9000 seismograph, recording the…Read more on Short-offset seismic refraction results near Rothera Station, Antarctic Peninsula
1 December, 1992
A 45 m length of ice core from Dolleman Island, Antarctic Peninsula has been dielectrically analysed at 5 cm resolution using the dielectric profiling (DEP) technique. The core has also…Read more on Sea salt dependent electrical conduction in polar ice
1 December, 1992
The diurnal vertical distribution and abundance of fish larvae was studied by net samples in the 265 m deep fjord of Cumberland East Bay, South Georgia. In early spring the…1 December, 1992
Maximum dive depths have been recorded for a number of sea-bird species using simple lightweight capillary gauges (Burger & Wilson 1988). So far these studies have been confined to penguins…1 December, 1992
When ducted narrow-band VLF pulses pass through the Earth's magnetosphere, small frequency shifts of ∼1 Hz may be observed at the receiving site on the ground. Such shifts may be…1 December, 1992
Sedimentological and structural studies in the Pensacola Mountains, Antarctica, suggest that upper Precambrian clastic sedimentary rocks of the Patuxent Formation and associated bimodal volcanic rocks formed in an intracontinental rift…1 December, 1992
The first fossils from Antarctica were collected from Seymour Island in December 1892, during the voyage of the Jason under Captain C.A. Larsen. The Swedish South Polar Expedition of 1901–1903,…Read more on Sedimentary basins on the east flank of the Antarctic Peninsula: proposed nomenclature
1 December, 1992
The spiny plunder-fish, Harpagifer antarcticus, is a common shallow-water demersal species distributed along the southern limb of the Scotia Arc. A year round study was made of its reproductive biology…1 November, 1992
Circum-Antarctic marine sediments contain a record of past climate and Southern Ocean circulation that both complements and considerably extends the record in the continental ice. Variations in primary biological production,…Read more on The sedimentary record of Antarctic climate change
1 November, 1992
Terrestrial palynofloras from two localities on Williams Point, Livingston, Island, contain angiosperm monocolpates and tricolpates and can be dated as Cenomanian-early Campanian. This fixes the age for a collection of…1 November, 1992 by Andrew Clarke, Alistair Crame
Environmental change is the norm and it is likely that, particularly on the geological timescale, the temperature regime experienced by marine organisms has never been stable. These temperature changes vary…1 November, 1992 by Peter Convey
The biology of a population of the subantarctic chironomid midge Eretmoptera murphyi Schaeffer, introduced to Signy Island in the maritime Antarctic more than 20 years ago, is described. Investment in…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