Found 14046 items
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