Showing 11205 items
1 January, 1993
A series of observations, using a dual-frequency calibrated echosounder operating at 38 and 120 kHz, of a patch of Euphausia superba close to South Georgia in 1986 is described. Sea…1 January, 1993
Seventeen species of decapod crustaceans have been described from Campanian through Paleocene rocks in the Santa Marta, López de Bertodano, and Sobral Formations of the James Ross Basin, Antarctica. Of…1 January, 1993
Satellite radar interferometry (SRI) provides a sensitive means of monitoring the flow velocities and grounding-line positions of ice streams, which are indicators of response of the ice sheets to climatic…1 January, 1993
Rock moisture content was determined for rock samples on different aspects of rock outcrops on Livingston Island during a summer season. As a result of the dominant rainbearing northerly winds…1 January, 1993
A stock of biotite-muscovite-garnet leucogranite crops out in the lower course of Río Cisnes as an unusual minor lithology within the predominantly dioritic to tonalitic North Patagonian Batholith. Foliated and…Read more on Granite generation and rapid unroofing related to strike-slip faulting, Aysén, Chile
1 January, 1993 by Richard Hindmarsh, Richard Hindmarsh
Although the mechanics and qualitative dynamics of grounded ice sheets and ice shelves are fairly well understood, this is not true for the transition between the two. In consequence, the…1 January, 1993
Because the northern elephant seal (Mirounga angustirostrus) was heavily exploited during the 19th century, it experienced an extreme population bottleneck. Since then, under legislative protection in the United States and…1 January, 1993
Miocene-Recent continental alkalic basalts were erupted along the Antarctic Peninsula as a result of decompressional melting of the asthenosphere caused by the formation of slab-windows beneath the continental margin following…1 January, 1993 by Robert Larter
On the basis of multichannel seismic reflection, magnetics and bathymetry data, a Pleistocene-Holocene (1 January, 1993 by Richard Horne
The propagation, growth and absorption of electromagnetic ion cyclotron waves in the Pc 1 frequency range is investigated using the HOTRAY ray tracing program for a realistic distribution of thermal…1 January, 1993
The Antarctic Peninsula region has exprienced a long-term warming trend over the twentieth century, with the 1971-90 mean at Faraday being 1.9°C warmer than the mean over 1903-41 based on…1 January, 1993 by Robert Larter
The outer shelf on the Antarctic Peninsula Pacific margin south of 63°30′S is underlain by Pliocene-Pleistocene prograding sequences which have been produced mainly by the action of ice sheets grounded…1 January, 1993
The question is posed: "what limits the presence, distribution, and abundance of life in Antarctica?" Traditionally, continental isolation has been considered to restrict the arrival of new species and extreme…1 January, 1993 by Ed King
An alternative seismic source was investigated in an experiment conducted near Rothera Station, Antarctic Peninsula. The source was an airgun fired above the snow surface. Comparison shots using explosive and…Read more on Seismic characteristics of an airgun fired over snow
1 January, 1993 by John King
Simple models are used to assess the factors controlling near-surface winds over an Antarctic ice shelf. Observations from Halley Station and an automatic weather station situated close to the coastal…Read more on Control of near-surface winds over an Antarctic ice shelf
1 January, 1993
We analyze ionospheric convection patterns over the polar regions during the passage of an interplanetary magnetic cloud on January 14, 1988, when the interplanetary magnetic field (IMF) rotated slowly in…1 January, 1993
The effect of maternal age and condition on the date of parturition and the duration of the perinatal period of Antarctic fur seals at Bird Island, South Georgia, were investigated…1 January, 1993
Geosat radar altimetry defines a pattern of closely spaced curvilinear gravity anomalies in the northern Weddell Sea and adjacent parts of the southwest Atlantic. These anomalies are caused by a…Read more on Seafloor spreading in the Weddell Sea and southwest Atlantic since the Late Cretaceous
1 January, 1993
Larval fish assemblages are considered within the context of the unique ichthyofauna which evolved in Antarctic waters as a result of environmental cooling, glaciation, and isolation by the Antarctic polar…1 January, 1993
We studied the influence of sex of pup, maternal age, birth date of pup, number of foraging trips, and the mean duration of foraging trips at sea and nursing visits…1 January, 1993 by Eugene Murphy
A visual classification was carried out of echo trace characteristics derived from 113 integration intervals of 1 n mi (nautical mile) each taken from the Southern Ocean in the area…1 January, 1993
The distributional features and physical characteristics of 4830 krill (Euphausia superba Dana) aggregations detected acoustically in the Southwest Atlantic between 26 January and 21 February 1981 are described. Results are…1 January, 1993 by Peter Ward
The ability to acoustically separate zooplankton species is an important requirement for ecological studies and to improve biomass estimates. In order to distinguish between Euphausia superba and other swarm-forming macroplankters…1 January, 1993
A new method for high-resolution (3 mm) dielectric profiling of ice cores is described. The method measures the capacitance and conductance of the ice at a single frequency (chosen to…Read more on High-resolution dielectric profiling of ice cores
1 January, 1993
Annual survival of breeding female Sparrowhawks Accipiter nisus was estimated by a capture-recapture procedure in three different areas, Eskdale and Annandale in southern Scotland and Rockingham Forest in east-central England.…Read more on Annual survival of Sparrowhawks Accipiter nisus breeding in three areas of Britain
1 January, 1993 by Keith Nicholls
Two vertical ice temperature profiles from locations in the Antarctic Peninsula unaffected by meltwater are presented. A simple time-dependent heat diffusion-advection model is used to infer broad surface temperature variations…Read more on Extending the Antarctic meteorological record using ice-sheet temperature profiles
1 January, 1993 by Andrew Clarke
The growth rate of the infaunal nuculanid bivalve Yoldia eightsi at Factory Cove, Signy Island, South Orkney Islands (maritime Antarctica), was estimated from internal shell increments and 45Ca incorporation of…1 January, 1993
Thelidium austroatlanticum sp. nov. is described from Signy island; it is characterized by an epilithic thallus, more or less appressed involucrellum, and 1-septate spores 30–40 μm long. Thelidium incavatum is…1 January, 1993 by Peter Ward
The natural diets of adult female Euchaeta antarctica, E. farrani, E. rasa and E. biloba, as well as male and female copepod stage V E. antarctica, were compared through gut…Read more on Summer and winter diet of four carnivorous copepod species around South Georgia
1 January, 1993 by Lloyd Peck
The punctate brachiopods Liothyrella neozelanica and Neothyris lenticularis were compared with the impunctate Notosaria nigricans and the bivalve molluscs Mytilus edulis and Lima colorata in terms of the force needed…Read more on The tissues of articulate brachiopods and their value to predators
1 January, 1993
The simple technique of point counting is very quick and is suitable for shipboard use, or in any study where high accuracy is not necessary. Point-counting smear slides yields results…1 January, 1993
The records, taxonomy and geographical distribution of 528 species of Acari collected from the Antarctic, sub-Antarctic islands and the Southern Ocean are collated. Included are free-living and phoretic mites, parasites…1 January, 1993
Nine species of marine littoral Halacaridae were collected from Husvik Harbour, South Georgia, all of which are new to the fauna of the island. These include Isobactrus microdens Newell, Rhombognathus…1 January, 1993
Terrestrial sedimentary rocks at Hope Bay, northern Graham Land are well known for their diverse but poorly-preserved fossil flora, previously assigned ages ranging from Early Jurassic-Early Cretaceous. The beds form…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 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