Found 14089 items
1 April, 1991
Comparison of the size, shape and shell morphology in littoral and sub-littoral morphs of the Antarctic limpet Nacella concinna reveal differences in shell morphology which are enhanced by structural anomalies…1 March, 1991
The first observations of the signatures of Pc1 pulsations in ionosonde echo data are reported. Oscillations are frequently observed in Doppler velocity, echo amplitude, group range and skymap echo-location position,…1 March, 1991
Progesterone in Antarctic fur seals was undectable from 1–2 days before parturition to 4–6 days after parturition. There was a rapid increase in progesterone to 20 ng/ml between 6 and…1 March, 1991 by David Vaughan
THE breaking up of ice shelves around the Antarctic Peninsula has been cited1 as a “sign that a dangerous warming is beginning in Antarctica”. Here we present satellite images showing…Read more on Rapid disintegration of the Wordie Ice Shelf in response to atmospheric warming
1 March, 1991 by Michael Pinnock
Two case studies are presented of the large-scale nightside ionospheric plasma convection observed simultaneously in the two polar regions using HF backscatter radars. The case studies occur during geomagnetically quiet…Read more on Studies of conjugate plasma convection in the vicinity of the Harang discontinuity
1 March, 1991
The bivalve Aulacomyella is described formally from Tithonian deposits of the Antarctic Peninsula region for the first time. Two species are recognized. A. willeyi Kelly sp. nov. was collected in…Read more on The bivalve Aulacomyella from the Early Tithonian (Late Jurassic) of Antarctica
1 March, 1991 by Michael Pinnock
Identifying the causative mechanisms at the magnetopause that produce a variety of transient plasma velocity signatures in the high latitude ionosphere is difficult. Correct identification is of fundamental importance in…1 February, 1991
The life cycles and distribution of three dominant copepods,Calanoides acutus, Calanus simillimus andRhincalanus gigas were studied from the “Discovery” collections in the Scotia Sea earlier this century.C. simillimus is a…1 February, 1991 by Andrew Clarke
Cold adaptation encompasses all those aspects of an organism's physiology that allow it to live in polar regions. With the exception of the special case of the need to avoid…Read more on What is cold adaptation and how should we measure it?
1 February, 1991
Blood chemistry and haematological parameters have been determined in the Antarctic teleosts, Notothenia neglecta Nybelin and Notothenia rossii Richardson at 2° C. Samples were taken using chronically implanted dorsal aortic…1 February, 1991
The apparent polar wander paths (= APWPs) for the northern and southern continents have been redetermined using revised time-scales and data. When plotted on the conventional Pangea, Pangea A, the…1 February, 1991
The breeding biology of the macaroni penguin, Eudyptes chrysolophus, was studied over four years, 1976 and 1986–88, at Bird Island, South Georgia. Birds were migratory, being absent during winter (May…1 January, 1991
Volume 1 contains the introduction and history, as well as place names A-L.; Volume 2 contains names L-Z as well as references and a list of associated place-names.Read more on The history of place-names in the British Antarctic Territory
1 January, 1991
The diving pattems of two male and one female Blue-eyed Cormorants Phalacrocorax atriceps were recorded with continuous-recording time-depth recorders for l0-13 days during the 1990 breeding season. For the female…1 January, 1991
A digital ionosonde has been used at Halley (75°31′S, 26°59′W) to examine the fading on time scales of a few seconds of 4.5 MHz signals reflected from sporadic-E ionization. Fourier…Read more on The rapid fading of radio waves reflected from sporadic-E ionization
1 January, 1991
Energy expenditure of fasting territorial male Antarctic fur seals at South Georgia was measured by mass loss and analysis of carcass composition using tritium dilution in 1987 and 1988. Mean…1 January, 1991
A histochemical and electron microscopy study was carried out on muscle growth in demersal stages of the Antarctic teleost Notothenia neglecta Nybelin. The total number of myotomal muscle fibres was…Read more on Muscle growth in the Antarctic teleost, Notothenia neglecta (Nybelin)
1 January, 1991
The intense magnetic storm of December 19, 1980 occurred during a major rocket and balloon geophysical research campaign at Siple Station, Antarctica. A balloon flight measuring the electric field and…Read more on The intense magnetic storm of December 19, 1980: Observations atL= 4
1 January, 1991
Analyses of a core from the deepest known moss peat bank in Antarctica, on Elephant Island, South Shetlands, show that this Chorisodontium aciphyllum-dominated bank began to grow ca. 5500 14C…1 January, 1991 by John Turner
Analysis of AVHRR data collected during the summer and winter over the Ross Ice Shelf reveals complex patterns of curvilinear stripes. In particular, a large, looping pattern of stripes is…1 January, 1991 by Andrew Clarke
The deep-water prawn Pandalus borealis Kroyer, 1838 was sampled at six locations from Krossfjord, Spitsbergen (79⚬N, close to the known northerly limit of distribution) to Kosterfjord, Sweden (58⚬N, close to…Read more on Egg Size and Reproductive Output in the Deep-Water Prawn Pandalus borealis Kroyer, 1838
1 January, 1991 by Andrew Clarke, Lloyd Peck
The polar marine environment is characterised by low stable temperatures with seasonal variations ranging from ±3°C at lower latitudes to only ±0.2°C at high latitudes. The Arctic basin is dominated…1 January, 1991 by Mark Clilverd
Whistler mode group delays from the VLF Doppler experiment at Faraday, Antarctica (65°S, 64°W) show an annual variation that has a maximum in December and a minimum in June/July. Assuming…1 January, 1991
The pattern and characteristics of diving of two male blue‐eyed shags Phalacrocorax atriceps were studied, using continuous‐recording time‐depth recorders, for a total of 15 consecutive days during which the depth,…Read more on Diving patterns and performance in the Antarctic blue-eyed shag Phalacrocorax atriceps
1 January, 1991
The attachment to artificial substrata (carborundum paper) of cyanobacteria and algae isolated from Antarctic fellfield soils was investigated using a simulated flow apparatus. Generally, the rugosity of the substratum was…1 January, 1991
The survival and growth of four genera of cyanobacteria and microalgae isolated from Antarctic fellfield soils were investigated. Survival of freezing and desiccation were studied by vital staining, and the…Read more on Effects of physical factors on the survival and growth of antarctic terrestrial algae
1 January, 1991
Investigation of the seasonal changes in composition of an immature Antarctic fellfield cyanobacterial/microalgal community has demonstrated a repeated periodicity. The community consisted of only 14 species. Early spring growth of…Read more on The seasonal periodicity of algae on Antarctic fellfield soils
1 January, 1991
This study documents the palaeoenvironments of a Jurassic-Cretaceous boundary black shale-tuff sequence exposed on the east coast of the Antarctic Peninsula. Sedimentological and palaeontological indices show that, during the deposition…1 January, 1991 by John Turner
Seasat's contributions to ice sheet glaciology are explored with emphasis on the experience gained from this mission and on how this has assisted in defining future satellite missions. The sensors…Read more on The contribution of Seasat to ice sheet glaciology
1 January, 1991
1. Plasma metabolites and nutrients of macaroni penguins (Eudyptes chrysolophus) arriving on land in good condition, following intense feeding, for breeding and moulting were investigated. 2. The pre-breeding female birds…1 January, 1991 by Adrian Jenkins
Detailed glaciological studies have been completed at 28 sites lying on an approximate flow line, extending 760 km across Ronne Ice Shelf. Parameters measured at each location include ice velocity,…Read more on Ice-ocean interaction on Ronne Ice Shelf, Antarctica
1 January, 1991 by William Block
Live and dead specimens of the Antarctic collembolan Cryptopygus antarcticus (Willem) dry, under constant external conditions of temperature (25 or 35°C) and r.h. (0%), like most hygric soil arthropods. The…Read more on Drying processes in the Antarctic collembolan Cryptopygus antarcticus (Willem)
1 January, 1991
Samples of Loligo gahi (D'Orbigny) were collected from commercial fishing vessels in the Falkland Islands Interim Conservation and Management Zone (FICZ) between March and October 1987, and from the R/V…Read more on Post-recruit growth of the Patagonian squid Loligo gahi (d’Orbigny)
1 January, 1991
Sundström (1986) erected the genus Proboscia for solenoid diatoms whose valves tapered to a proboscis, but only assigned one species to it, the boreal Rhizosolenia alata Brightwell. We have found…1 January, 1991
Five fossil species of Rhizosolenia are known only from the distal parts of the valve. The resemblance of these tubular structures to the proboscis of the modern genus Proboscia Sundström,…1 January, 1991
During winter 1989 at South Georgia, gentoo penguins showed a very rapid change in diet over a 10-day period. On 11-12 July, food samples were of low masses (150g) and…1 January, 1991 by John King
1 January, 1991 by Robert Larter
The Antarctic Peninsula was a magmatic arc subducting Pacific Ocean floor throughout the Mesozoic. During the Cenozoic, subduction ceased at each of a series of ridge‐crest–trench collisions, which migrated northeast…1 January, 1991
THE tectonic fabric of the sea floor created at spreading ridges generally curves in the direction of ridge offset near transform faults, owing to the influence of shearing stress on…Read more on Unusual sea-floor fabric near the Bullard fracture zone imaged by GLORIA sidescan sonar
1 January, 1991
Different environmental conditions, particularly daylength and intensity of natural light, may influence the ability of shiftworkers to adapt to the abrupt phase-shifts of 24 h time cues imposed by the…