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…1 January, 1991
Halozetes belgicae is distributed widely in the Subantarctic and maritime Antarctic, with subspecies described from Macquarie Island and the South Sandwich Islands. A morphometrical study, based largely on the development…Read more on The cryptostigmatid mite Halozetes belgicae (Michael) in the maritime Antarctic
1 January, 1991
The dielectric profiling (DEP) technique is described and some of the differences between it and standard electrical tools used in ice core analysis are discussed. The results of DEP analysis…Read more on Application of the dielectric profiling technique to ice core studies
1 January, 1991
The sedimentary fill of the Cretaceous-Tertiary Larsen Basin, located at the northern tip of the Antarctic Peninsula, records the evolution of the Antarctic Peninsula source terrain. Uplift, and the possible…1 January, 1991
A 5–6 km thick, Cretaceous–Tertiary, marginal basin succession is exposed in the James Ross Island area (northern Antarctic Peninsula). Deep‐marine fan facies and slope‐apron facies (c. 2.5 km) are succeeded…1 January, 1991
Early diagenetic (precompactional) concretions are abundant throughout the Cretaceous-Tertiary Marambio Group Larsen Basin, Antarctica. Four distinct concretion types are recognised: (1) spherical-subspherical concretions: (2) sheet concretions; (3) fossil-nucleated concretions; and…1 January, 1991
The polar regions are unique laboratories for carrying out research on both the atmosphere and the near-Earth space environment. The relatively undisturbed conditions help us explore phenomena like the greenhouse…Read more on Atmospheric and space research from polar regions
1 January, 1991
Whistler activity at L ≃ 4 is known to be a function of longitude, peaking in the Weddell Sea sector of Antarctica; a combination of source and propagation factors, the…1 January, 1991
Eight isolates of bacteria from the soils of maritime Antarctica and Antarctic peninsula have been identified as members of the genus Janthinobacterium. Based on their morphology, physiological characteristics, biochemical characteristics…1 January, 1991 by Andy Smith
New tiltmeter data are presented from Doake Ice Rumples on Ronne Ice Shelf, Antarctica. Five sites which showed a tidal ice-shelf flexure have been analysed using an elastic beam model…Read more on The use of tiltmeters to study the dynamics of Antarctic ice-shelf grounding lines
1 January, 1991
Six species of Stereocaulon and one unnamed taxon (close to S. glabrum) are reported from South Georgia, the maritime Antarctic islands and Antarctic Peninsula. S. caespitosum is new to the…Read more on The lichen genus Stereocaulon in Antarctica and South Georgia
1 January, 1991
The Advanced Ionospheric Sounder at Halley (75° 31′S, 26° 59′W) in Antarctica has been used to observe the F-region disturbance caused by an atmospheric gravity wave. Observations at 4.5 MHz…Read more on Compression and rarefaction of F-region plasma caused by an atmospheric gravity wave
1 January, 1991
The world's largest colony of the black-browed albatross Diomedea melanophrys on Steeple Jason Island, Falkland Islands was systematically censused for the first time in December 1987. Colony area was estimated…1 January, 1991
Results from a detailed profile in a 5.54 m multi-year sea-ice core from the rift area in the southern part of George VI Ice Shelf are presented. Stratigraphy, stable isotopes…1 January, 1991
A precise Rb‐Sr isochron age of 97.0 ± 0.5 Ma is presented for whole‐rock and mineral samples from the Mandamus Igneous Complex, North Canterbury. A low 87Sr/ 86Sr initial ratio…1 January, 1991
The reliability of various criteria (throat feather length and the characteristics of rectrices and upper tail‐coverts) previously suggested for ageing Starlings was assessed using a sample of known‐aged birds. Total…Read more on Ageing criteria in the Starling Sturnus vulgaris
1 December, 1990 by Andrew Clarke
Several recent studies have shown the potential value of chloroform-soluble fluorescent age pigments (FAPs) in determining the age of marine invertebrates with no permanent hard parts. The primary assumption in…Read more on The accumulation of fluorescent age pigments in the trochid gastropod Monodonta lineata
1 December, 1990 by Alistair Crame, John Turner
The International Conference on the Role of the Polar Regions in Global Change was hosted by the Geophysical Institute and Center for Global Change and Arctic System Research of the…Read more on Role of the polar regions in global change. Fairbanks, Alaska, 11–15 June 1990
1 December, 1990
The structural relationship between West Antarctic crustal blocks has remained uncertain due to a lack of information concerning sub‐ice crustal structure. A regional aeromagnetic reconnaissance of Ellsworth Land between 72…1 December, 1990 by Richard Horne
The range of applicability of an improved quasilongitudinal approximation for whistler-mode waves in the equatorial magnetosphere (4 ≲ L ≲ 6.6) is specified based on the direct comparison between numerical…Read more on Quasilongitudinal approximation for whistler-mode waves in the magnetospheric plasma
1 December, 1990
Marie Byrd Land is amongst the most inaccessible and least visited regions of Antarctica. It contains a large alkaline volcanic province, with 18 large central volcanoes and numerous small satellitic…1 December, 1990
Population growth rates of Antarctic and temperate isolates of the microflagellate Heteromita globosa Stein and of the ciliate Colpoda cucullus Müller were determined during incubation both under constant 3.5° and…1 December, 1990
The diversity of bacterial communities isolated from Antarctic lake sediment in chemostats under constant low temperature (8°C) or diurnally fluctuating temperature (1°C to 16°C) was examined. The median optimum temperature…Read more on The selection of microbial communities by constant or fluctuating temperatures
1 December, 1990
(1) Radio-telemetry was used to study the activity patterns of gentoo penguins, Pygoscelis papua, at Bird Island, South Georgia, throughout the breeding season, to assess variation in foraging effort (foraging…1 December, 1990
In crested penguins, Eudyptes spp., the first-laid (A) egg is smaller than the second-laid (B) egg and although viable rarely survives to hatching. I studied survival and growth to fledging…1 November, 1990 by Richard Horne
The ray paths of unstable electromagnetic waves generated inside the plasmapause during magnetic storm conditions are followed using the HOTRAY code. Unducted waves which are preferentially generated in the field…Read more on Ion cyclotron absorption at the second harmonic of the oxygen gyrofrequency
1 November, 1990
Digital ionosondes such as the Dynasonde disclose that the ionosphere is seldom horizontal even when it is plane stratified to a good approximation. The local magnetic dip does not then…1 October, 1990 by Michael Pinnock
The Geospace Environment Modeling (GEM) Program is directed toward modeling the coupled solar wind/magnetosphere/ionosphere system. The inter‐calibration of ground‐based observations of the ionosphere and satellite observations has been identified as…Read more on Simultaneous HF-radar and DMSP observations of the cusp
1 October, 1990 by Paul Rodhouse
Cephalopod remains were collected, at regular intervals throughout the fledging period, from the stomach contents of chicks of the grey-headed albatrossDiomedea chrysostoma at Bird Island, South Georgia, in 1984 and…Read more on Cephalopod prey of the grey-headed albatross Diomedea chrysostoma
1 October, 1990
Earlier views regarding the relative insignificance of Antarctic science have been rudely shattered by recent developments. The International Geophysical Year (IGY) of 1957–1958 represented a major turning point for research…Read more on Science, environment and resources in Antarctica
1 October, 1990 by Jonathan Watkins
An effect of the very patchy distribution of Antarctic krill (Euphausia superba Dana) in various forms of aggregation is that a single swarm may not provide an unbiased estimate of…Read more on Sampling biological characteristics of krill: Effect of heterogeneous nature of swarms
1 October, 1990
The breeding biology of the gentoo penguin, Pygoscelis papua, was studied over a three‐year period (1986–1988) at Bird Island, South Georgia, with particular reference to birds of known age or…1 September, 1990
The arrival of Antarctic fur seals at a breeding beach on Bird Island, South Georgia, was studied over five consecutive breeding seasons, 1983 to 1987. Experienced bulls arrived first and…1 September, 1990 by William Block
Nematodes of the families Heterorhabditidae and Steinernematidae are obligate parasites of a wide range of insects (Poinar 1979). The third stage juvenile of these nematodes is a non-feeding infective form…Read more on Tests of Antarctic soils for insect parasitic nematodes
1 September, 1990 by Paul Rodhouse
Post-recruit Illex argentinus were collected from the fishery on the Patagonian Shelf between 1986 and 1988. Age was determined by analysis of daily growth increments in ground sections of the…