Showing 13455 items
1 January, 1987 by Keith Nicholls
A model pulsed wavefield is presented that enables the behaviour of the associated wave dislocations to be computed exactly. It consists of three intersecting beams of plane-wave pulses. Because the…Read more on Three-beam model for studying dislocations in wave pulses
1 January, 1987
We report a distribution—free approach to the detection of density—dependence in the variation of population abundance, measured by a series of annual censuses. The method uses the correlation coefficient between…Read more on The detection of density-dependence from a series of annual censuses
1 January, 1987
This paper discusses the present understanding of ionospheric storms, in particular storm effects in the F-layer and their relationship to changes of thermospheric composition. After summarizing the main effects of…1 January, 1987
Over the past 50 years, ideas relating to the physical features and dynamics of ice sheets have evolved materially, primarily due to modern technological advances in the acquisition of basic…Read more on Fifty years of progress in understanding ice sheets
1 January, 1987
Average north polar currents for the winter season have been derived from geomagnetic hourly means at six levels of geomagnetic activity. The twin-vortex pattern, normally associated with more disturbed conditions,…Read more on The effect of geomagnetic activity on north polar currents in winter
1 January, 1987
The poleward edge of the main ionospheric trough can often be regarded as the ionospheric signature of the equatorward boundary of the plasma sheet. We use Advanced Ionospheric Sounder observations…Read more on Is the poleward edge of the trough a sensitive indicator of geospace interactions?
1 January, 1987 by Paul Rodhouse
Cephalopod beaks from the stomach contents of “wandering albatross” (Diomedea exulans L.) chicks from Bird Island, South Georgia, were sampled between May and September in 1983 and 1984. Lower beaks…Read more on Cephalopod prey of the wandering albatross Diomedea exulans
1 January, 1987
Optical methods of studying the atmosphere are one valuable means of investigating atmospheric behaviour at heights ranging from less than 1 km to several hundred km. Some examples are given…Read more on Antarctica — A unique laboratory for atmospheric studies by optical methods
1 January, 1987
Declination, or the difference between true and magnetic north, is one of the earliest parameters to have been measured systematically over the earth's surface. Values are available for South Georgia…Read more on Measurement of declination at South Georgia 1700–1984
1 January, 1987
A model has been constructed which grafts IRI topside profiles to field-aligned diffusive equilibrium profiles at a “reference level” near 650 km altitude. For different values of geographic latitude, longitude,…Read more on A suggested model for the IRI plasmapheric distribution
1 January, 1987
The impacts of pollution resulting from large explosive volcanic eruptions on the atmospheric heat budget and planetary albedo are not in doubt1,2. However, the effects of volcanic aerosols on the…Read more on Global surface-temperature responses to major volcanic eruptions
1 January, 1987
Sandstone detrital modes for a representative sample of the Trinity Peninsula Group in northern Graham Land are described and assessed. Whereas the volumetrically dominant quartz and feldspar were derived principally…1 January, 1987
The plasmapause and the mid-latitude ionospheric trough have been observed simultaneously from two Antarctic stations, Halley and Faraday, during five winter nights covering a range of geomagnetic disturbance conditions. The…1 January, 1987
The Ellsworth Mountains‐Thiel Mountains ridge and adjoining areas are divided into three tectonic provinces: (1) Haag Nunataks, (2) Thiel Mountains, and (3) Ellsworth‐Whitmore Mountains crustal block. Haag Nunataks are part…1 January, 1987
The relevance of the term “Gondwanian orogeny” to deformation within upper Paleozoic to Mesozoic rocks of the Antarctic Peninsula is reviewed, and the tectogenesis of deformation within this time frame…Read more on The Gondwanian orogeny within the Antarctic Peninsula: a discussion
1 January, 1987
The soluble carbohydrate and polyhydric alcohol (polyol) content of fruticose lichens, cushion mosses and early vegetative colonizers of maritime Antarctic fellfield soils were examined by gas-liquid chromatography during 18 months.…1 January, 1987
Gas liquid chromatography and a commercially available strip of 20 conventional biochemical tests were used for the rapid sorting of strains of environmental bacterial isolates into similar ecophysiological groups. This…1 January, 1987
Gabbroic stocks and/or diabasic sills crop out in the southern Heritage Range of the Ellsworth Moutains, in the Hart Hills 400 km southwest of the Ellsworth Mountains, and in the…1 January, 1987
Ellsworth‐Whitmore Mountains crustal block (EWM) is a belt of small mountain ranges, hills, and nunataks which trend northward 500 km from the Thiel Mountains of the Transantarctic range to the…1 January, 1987 by Peter Ward
The reproductive biology of the predatory calanoid copepod Euchaeta antarctica Giesbrecht was investigated in two interconnected fjord systems at South Georgia. Counts of the number of spermatophores attached to adult…1 January, 1987
New analysis procedures are used to show that the main phase mid-latitude storm effects conform to consistent patterns in local time when suitable selection rules are applied, with averaging over…15 November, 1986
A year‐long tidal record has been obtained from beneath the George VI Ice Shelf, Antarctica. An unusual feature of the record is a significant response in tidal species 3 to…Read more on The tidal spectrum underneath Antarctic ice shelves
1 November, 1986
We have examined the variations of electron precipitation at L ≈ 4 as inferred from riometer measurements of cosmic radio noise absorption made during 1975 at Siple Station and Halley…1 September, 1986
Nonthermal continuum is observed at 1.2 kHz on Voyagers 1 and 2 within the Jovian magnetosphere. It is seen in the magnetospheric cavity on both the dayside and nightside, being…1 July, 1986
A series of 50 male and 42 female mites of the prostigmatid family Tydeidae from the maritime Antarctic were each scored for 67 morphological characters. Ordination of each data set…1 June, 1986
Blood samples were collected from free-living incubating Diomedea albatross during single incubation shifts, both daily (wandering albatross D. exulans and every 2 days (grey-headed albatross D. chrysostoma and black-browed albatross…Read more on Corticosterone secretion through long incubation shifts in Diomedea albatrosses
1 June, 1986 by Alistair Crame
As a result of recent field work, a new lithostratigraphic group is defined on the west coast of James Ross Island, Antarctica. Characterised by comparatively coarse-grained sediments, the Gustav Group…Read more on Lithostratigraphy of the Cretaceous strata of west James Ross Island, Antarctica
1 February, 1986
Gonadal size and the circulating concentrations of two pituitary hormones (luteinizing hormone and prolactin) and three gonadal steroids (testosterone, progesterone and oestradiol‐17β) were measured in two closely related Diomedea albatrosses…1 February, 1986
(1) A sampling programme has been designed to detect whether multiple scales of pattern (or aggregation) occur in arthropod distributions. A secondary aim was to relate arthropod pattern with environmental…1 January, 1986
Se describen areniscas del Cretacico Superior, expuestas en las cercanias de Punta Arenas, sur de Chile, las que exhiben laminacion convoluta y estratificacion cruzada, tipo "hummocky". Estas capas se formaron…1 January, 1986
1. Single fast and small bundles of slow fibres were isolated from the muscles of an elasmobranch (dogfish, Scyliorhinus canicula) and an Antarctic teleost (Notothenia neglecta). A third fibre type…1 January, 1986
1. Force and ATPase activity were measured in skinned, fast muscle fibres isolated from the myotomes of Antarctic, temperate and tropical fish. 2. Maximum isometric tension was inversely related to…1 January, 1986
A multidisciplinary project was carried out in an attempt to improve understanding of the evolution and inter-relationship of magmatism and metalliferous mineralization in the central and southern Andes. This has…1 January, 1986
Samples of adult Alaskozetes antarcticus, an Antarctic cryptostigmatid mite, were collected in winter and summer. In 4 separate experiments, mites were maintained under relative humidities in the range: 0, 26,…Read more on Effects of contrasting relative humidities on the cold tolerance of an Antarctic mite
1 January, 1986
Samples of a cryptostigmatid mite, Alaskozetes antarcticus, were collected during summer and winter on Signy Island, South Orkney Islands, in the maritime Antarctic. In four experiments, adult mites were maintained…Read more on Effects of ingestion of liquids on the cold tolerance of an Antarctic mite
1 January, 1986
On occasion the third hop of an echoing magnetospheric whistler exceeds the first hop in intensity over some low range of frequencies. Case studies show that this anomalous behavior can…Read more on The third hop whistler anomaly: possible evidence of df/dt-dependent wave amplification