Found 14089 items
1 January, 1990
The three-dimensional microstructure of Tolypothrix mats from the bottom of a maritime antarctic lake of Signy Island, South Orkneys, was examined. Samples from mats at two depths, 4 and 6 m,…Read more on The fine structure of an algal mat from a freshwater maritime antarctic lake
1 January, 1990
Six of the eight species of beetles at South Georgia, the southernmost beetles of the world, were investigated in outdoor arenas with pitfall traps for their diel patterns of locomotory…1 January, 1990
The evolution of magmatic activity along the Pacific margin of southern South America and West Antarctica is considered in terms of the alignment, timing and petrogenesis of calc-alkaline granitoid emplacement.…Read more on The Paleozoic and Andean magmatic arcs of West Antarctica and southern South America
1 January, 1990
The physiological adaptations required to survive exposure to low temperatures must be of great importance in allowing nematodes to colonize extreme terrestrial environments, such as Antarctic fellfields. Seasonal variation in…1 January, 1990
A joint IAS/Geological Society of London meeting, organized by the British Sedimentological Research Group, was held in London at the Geological Society on 9-11 May 1989, to address the problem…Read more on Sea level changes at active plate margins: processes and products
1 January, 1990
Oxygen-isotope analysis of well-preserved macrofossils from the Santonian-Campanian of James Ross Island and the Maastrichtian of Vega Island, Antarctica, indicates that cool high-paleolatitude temperatures prevailed during the Late Cretaceous and…1 January, 1990 by Jonathan Watkins
Gut fullness of 3264 Antarctic krill in 38 swarms was estimated using fluorometric determination of chlorophyll a . There was a very wide range of gut fullness (maximum value 3277…1 January, 1990 by Roger Worland, William Block
The body water content and resistance to desiccation were studied in two perimylopid beetles, Perimylops antarcticus and Hydromedion sparsutum, a chironomid midge, Eretmoptera murphyi, and two spiders, Notiomaso australis and…1 January, 1990
Fabry-Perot interferometer measurements of the Doppler shift of the 5577Å O1S emission are used to derive neutral wind velocities at E-region altitudes over Halley, Antarctica (Λ=61°). These measurements, recorded during…Read more on Lower thermospheric wind measurements near 60° Λ from 5577Å Doppler interferometry
1 December, 1989
The number of Antarctic fur seals (Arctocephalus gazella) in the area of the Scotia Sea has been increasing. Observation of their distribution on the breeding grounds are important to help…1 December, 1989 by Jonathan Watkins
A technique for moult staging Antarctic krill (Euphausia superba Dana) was used in the analysis of field samples to predict intermoult periods and hence assess growth and the effects of…1 December, 1989
Hydrocarbons in the environment occur as complex mixtures. The detection of low-level anthropogenic contamination can be difficult as many of the compounds can also be found in biogenic materials. Results…1 December, 1989
The records obtained from a monostatic acoustic sounder run at Halley, Antarctica, have been analysed with the use of data from instruments on a 32 m mast and from radiosonde…Read more on Acoustic sounding of the atmospheric boundary layer at Halley, Antarctica
1 December, 1989
The Dobson ozone spectrometer has been used for studies of the ozone layer for about 60 years. It remains indispensable for assessing the accuracy of satellite-borne instruments. The steps which…Read more on Measurements of total ozone using Dobson spectrometers: Some comments on their history
1 December, 1989 by Lloyd Peck
Scaling patterns of shell thickness, shell volume, total animal volume, internal tissue volume and mantle cavity volume in the brachiopod Liothyrella uva (Broderip, 1833) were investigated in relation to shell…Read more on Scaling patterns in the Antarctic brachiopod Liothyrella uva (Broderip, 1833)
1 December, 1989
Chick feeding in common diving petrels (Pelecanoides urinatrix exsul) and South Georgia diving petrels (P. georgicus) was studied on Bird Island, South Georgia. Complete chick meals removed from the proventriculus…Read more on Chick feeding in the diving petrels Pelecanoides georgicus and P. urinatrix exsul
1 November, 1989
A net sampling survey was conducted around the island of South Georgia during July/August 1983. This study compares the age structure and vertical and horizontal distributions of the dominant copepods…Read more on Distribution of six major copepod species around South Georgia during an austral winter
1 November, 1989
The physical explanation of the changes of the maximum electron concentration of the F2 layer, NmF2. as a result of geomagnetic disturbances has proved elusive even after several decades of…Read more on Geomagnetic storms in the Antarctic F-region. II. Physical interpretation
1 November, 1989 by Roger Worland, William Block
The consumption of fresh plant materials by adults and larvae of Hydromedion sparsutum and Perimylops antarcticus (Col., Perimylopidae) was estimated from the production of faecal pellets and amount of excreted…1 November, 1989 by Roger Worland, William Block
Metabolic rates were studied in adults and larvae of the two phytophagous beetles Hydromedion sparsutum and Perimylops antarcticus (Col., Perimylopidae) indigenous to the Sub-Antarctic island of South Georgia. From the…1 October, 1989
The effects of low temperatures, freezing and desiccation on a cyanobacterium (Phormidium) and an alga (Prasiola) from terrestrial Antarctic habitats were investigated. Net photosynthesis per unit dry weight, measured by…1 October, 1989
Three species of calanoid copepods, Boeckella michaelseni, Parabroteas sarsii and Pseudoboeckella poppei were recorded from 6 freshwater localities in the Husvik area, South Georgia. Of the latter species two distinct…1 October, 1989
The Cretaceous of west James Ross Island, Antarctica represents the proximal fill of a late Mesozoic back‐arc basin that was probably initiated by oblique extension during the early development of…1 October, 1989 by Robert Mulvaney
A 133 m deep Antarctic ice core from Dolleman Island, Antarctic Peninsula, has been profiled by dielectric measurements in the AF‐LF (20 Hz ‐ 100 kHz) frequency range. This has…1 October, 1989
Recent GLORIA and SeaMARC II sidescan sonar surveys have imaged virtually the whole of the Easter microplate, and revealed unprecedented detail and complexity in its tectonic fabric and history. There…Read more on Comprehensive sonar imaging of the Easter microplate
1 September, 1989
The hypothesis that sunlight may induce the enzymes involved in the vitamin D pathway has been tested by comparing the ability to synthesize vitamin D3 and its 25 hydroxy metabolite…Read more on Effect of phototherapy on serum 25-hydroxyvitamin D in the Antarctic
1 September, 1989
An Ekman analysis of the surface drainage winds over a sloping ice surface is reported. Ekman pumping by the boundary layer leads to the formation of an upper tropospheric cyclonic…1 September, 1989
A terrestrial sequence on Livingston Island, South Shetland Islands, known as the Williams Point Beds contains a well-preserved, diverse fossil flora previously assigned a Triassic age. Because of their supposed…1 September, 1989
Upper Jurassic–Lower Cretaceous anoxic mudstones and air-fall ashes of the Nordenskjöld Formation are exposed on the eastern coast of Graham Land. Deformation of the strata has a long history spanning…22 August, 1989 by Michael Pinnock
Study of the near-Earth plasma environment and its interactions with the solar wind has reached a stage where major progress will come only from taking a global view of the…1 August, 1989
The southern elephant seal is among the most sexually dimorphic and polygynous of all mammals: males may be more than 10 times the weight of reproducing females and only the…Read more on Parental investment in southern elephant seals, Mirounga leonina
1 August, 1989 by Jonathan Shanklin
New interferometric observations of the Wolf-Rayet star AS431 using the MERLIN network are presented. These observations had a sensitivity sufficient to map the stellar-thermal continuum radio emission with a beam…Read more on MERLIN observations of the Wolf–Rayet star AS431 (WR147)-a double radio source
1 August, 1989
The development of the thymus was examined in different stages of Harpagifer sp. from Signy Island (South Orkney Islands; 60°43′S, 45°38′W). The thymus was typical, both in position and structural…1 August, 1989
The epiphytic diatoms of filamentous matforming algae in Sombre Lake, Signy Island, South Orkneys, Antarctica were examined in a field study from January to March 1987. Results reveal 1) a…Read more on Depth-related changes in benthic diatom assemblages of a maritime Antarctic lake
1 July, 1989
Schistidium antarctici is the commonest of five bryophytes known in the Windmill Islands area of Wilkes Land, Greater Antarctica. In moist habitats it forms closed carpets, but in dry sites…1 June, 1989
Maternal investment, in terms of pup birth mass, in gestation by Antarctic fur seals (Arctocephalus gazella) was related to the date of birth in two consecutive years. There were significant…Read more on Pre-natal investment in reproduction by female Antarctic fur seals
1 June, 1989
This research examines the energy budget of breeding female Antarctic fur seals, both when food was plentiful and when it is scarce. The energy expenditure and change in body mass…Read more on Foraging energetics of Antartic fur seals in relation to changes in prey availability
1 June, 1989
The structure and function of swimming muscles in Antarctic fish is reviewed, the emphasis being on the highly endemic sub-order Notothenioidei. Adult stages of the vast majority of species swim…Read more on Antarctic fish muscles — structure, function and physiology