Found 13319 items
1 January, 1981
The Earth's plasmapause is a source of natural radio emission in the myriametric wavelength range (λvac∼10 km) and several mechanisms have been proposed for its generation. One such theory advocates…Read more on First remote sensing of the plasmapause by terrestrial myriametric radiation
1 January, 1981
Heavy metal variations in polar ice cores may reflect changes in global airborne pollution1. Reported profiles from Antarctica1–3 and Greenland4, where sampling resolution was normally larger than a year, have…Read more on Short-term fluctuations in heavy metal concentrations in Antarctic snow
1 January, 1981
(1) In 1911 and 1925 reindeer, Rangifer tarandus L., were introduced to the subantarctic island of South Georgia, where there is a species-poor vascular flora and no interspecific competition. (2)…1 January, 1981
SUMMARY. The ecology of the phytoplankton of Heywood Lake, Signy Island, South Orkney Islands, Antarctica was investigated during 1969–72. The lake, which is ice‐covered for 8–10 months per year, is…1 January, 1981
Spectrograms of broad-band ELF/VLF goniometer data obtained from ground based measurements made at Halley, Antarctica (L = 4.3, conjugate near St. Anthony, Newfoundland) have shown the presence of discrete line…Read more on Magnetospheric VLF line radiation observed at Halley, Antarctica
1 January, 1981
The agonistic and sexual activity of individual male Southern elephant seals (Mirounga leonina) was studied during the breeding season at South Georgia. Harem bulls were older and larger than non‐harem…Read more on Aggression and sexual activity of male Southern elephant seals, Mirounga leonina
1 January, 1981
The Black-browed Albatross Diomedea melanophris and Grey-headed Albatross D. chrysostoma are similar in size and weight and breed at the same time, but have substantial dietary differences. To study the…1 January, 1981
The weight loss of incubating Black-browed Albatrosses (Diomedea melanophris) and Grey-headed Albatrosses (D. chrysostoma) was measured at Bird Island, South Georgia. The rate of weight loss did not differ significantly…1 January, 1981
George VI Ice Shelf is about 450 km long, 20–70 km wide, and averages 250 m in thickness. It is bordered by Alexander Island to the west and by the…1 January, 1981
The growth of 29 Black-browed and 46 Grey-headed Albatross chicks was studied for 95 d after hatching at Bird Island, South Georgia. A family of sigmoid curves was explored to…1 January, 1981
For locations normally equatorward of the auroral oval, it is established that there is a strong inverse association between the variations in the maximum plasma frequency of the ionosphere and…1 January, 1981
Detailed analyses of ionograms from South Georgia (54°S, 37°W; L = 1.9) show that a nocturnal intermediate layer is frequently seen between the E- and F-regions in the height range…Read more on The nocturnal intermediate layer over South Georgia
1 January, 1981
ELF and VLF radio signals were recorded in the afternoon to early morning (local time) between 24 March and 4 April 1979, in Northern Scandinavia. Apart from signals of natural…1 January, 1981
Prior to Late Triassic–Early Jurassic times, the geological history of the Antarctic Peninsula region was dominated almost entirely by Gondwana sequences that together comprised a major arc-trench system. Subduction complex,…1 January, 1981
Simultaneous broadband whistler recordings made during the International Magnetospheric Study (IMS) at the two Antarctic stations Halley and Siple have been used to study longitudinal variations in the radius of…1 January, 1981
A launch, suspension and recovery technique for oceanic, in situ, 14C productivity measurements is described. Ship's time for deployment of 125 ml incubation bottles at several depths down to 100…Read more on A deployment method for in situ oceanic primary production measurement
1 January, 1981
Four methods of investigating the thermal plasma density near the plasmapause have been intercompared for the period 1 to 15 July 1972. These methods are whistlers, the double floating probe…1 January, 1981
Power Line Harmonic Radiation and associated emissions observed at Siple [1, 2] are compared with line radiation activity observed at Halley, Antarctica [3]. We discuss the evidence for a Sunday…Read more on VLF line radiation observed at Halley and Siple
1 November, 1980
The social organization and behaviour of 35 individually recognizable territorial male Antarctic Fur seals (Arctocephalus guzellu), were studied during the breeding season at South Georgia. Adults of both sexes remain…1 September, 1980
Field mapping and structural studies in northern Sierra Leone by an I.G.S. team have established a stratigraphic sequence in this part of the Archaean of the West African Craton. An…1 August, 1980
A tradition of biological research in the Antarctic was established by Cook 200 years ago. This tradition has been built on by other British expeditions, notably the ‘Discovery’ Investigations. The…1 August, 1980 by Andrew Clarke
The concept of ‘metabolic cold adaptation’, namely that polar marine ectotherms are adapted in having an elevated basal metabolic rate, has been examined in the light of recent biochemical, physiological…Read more on A reappraisal of the concept of metabolic cold adaptation in polar marine invertebrates
1 August, 1980
The population structure and social organization of the Southern Elephant Seal, Mirounga leonina, were studied at South Georgia principally by extensive field census work and determination of age and reproductive…1 August, 1980
The majority of Antarctic benthic invertebrates so far studied do not produce pelagic larvae, but develop non-pelagically by means of egg capsules, brooding or viviparity. The predominance of protected development…Read more on Reproductive adaptations of Antarctic benthic invertebrates
1 August, 1980
Antarctic lakes present a wide variety of physical, chemical and biological conditions, and are not always the simplified systems imagined by earlier workers. The volume of data on lakes of…1 May, 1980
Body weight and body fat changes (calculated from skinfold thickness) that occurred in a male population spending a year on an Antarctic base are described. There was a marked individual…Read more on A longitudinal study of body weight and body fat changes in Antarctica
1 May, 1980
An energy balance survey was conducted on an Antarctic base on 12 individuals for periods varying between 6 and 12 months. Energy expenditure was estimated using two activity/dairy card techniques…Read more on The measurement of daily energy expenditure—an evaluation of some techniques
1 May, 1980
A dietary survey was carried out on an Antarctic base over a period of 6 to 12 months on twelve individuals. Three methods of determining individual food and energy intake…Read more on The measurement of food and energy intake in man—an evaluation of some techniques
1 May, 1980 by Andrew Clarke
The lipid content and composition of cultured Penaeus merguiensis were examined by lipid extraction, thin-layer chromatography and capillary gas chromatography. The lipid content, 1.99% fresh weight, was higher than in…Read more on Lipid content and composition of cultured Penaeus merguiensis fed with animal food
1 January, 1980 by William Block
Three components of the survival strategy of a terrestrial Antarctic mite, Alaskozetes antarcticus (Acari: Cryptostigmata) are considered: overwintering survival, energetics and life history. Supercooling is an important feature of its…Read more on Survival strategies in polar terrestrial arthropods
1 January, 1980 by William Block
1 Individual supercooling points ranged from ‐2 to ‐44°C for six species of springtails, five species from the Swiss Alps and one from lowland Britain. Individuals of Isotomurus alticola (Carl)…1 January, 1980
Satellite images of Ronne and Filchner ice shelves show a variety of surface features many of which are believed to indicate flow lines in the ice. Sufficient imagery is now…1 January, 1980 by Andrew Clarke
Krill, Euphausia superba Dana, sampled from waters around South Georgia in 1978 contained 10–11% protein, 2–6% lipid, 0.3–0.6% carbohydrate, 2% chitin, and 3–4% mineral ash (all mean values, % fresh…Read more on The biochemical composition of krill, Euphausia superba Dana, from South Georgia
1 January, 1980
At the sub-Antarctic island of South Georgia 25 of the 29 breeding species are seabirds. Fifteen of these have recently been studied in some detail. By examining the timing of…Read more on Food, feeding ecology and ecological segregation of seabirds at South Georgia
1 January, 1980
Oxygen uptake by the peat of two Antarctic bryophyte communities (a moss turf and a moss carpet) is converted to organic matter loss and used to derive the rate of…Read more on Peat respiration and decomposition in Antarctic terrestrial moss communities
1 January, 1980 by Peter Ward
Information on small scale distributions of three species of Antarctic zooplankton is reviewed. Aggregations of the euphausiid Euphausia superba, the tunicate Salpa thompsoni, and the amphipod Parathemisto gaudichaudii are compared,…1 January, 1980
(1) Three Antarctic moss banks were studied in detail: two dominated by Polytrichum alpestre Hoppe and one by Chorisodontium aciphyllum (Hook. f. et Wils.) Broth. (2) The rate of upward…Read more on The rate of peat accumulation in Antarctic moss banks