Found 14049 items
1 January, 1990
The wandering albatross breeding population at Bird Island, South Georgia has declined since 1961 at a rate of 1.0% per annum. Similar declines have occurred elsewhere in the Subantarctic. (2)…1 January, 1990
References Citations Metrics Reprints & Permissions PDF Abstract Five species of dimitobelid belemnites are described from the Cretaceous of James Ross Island, Antarctic Peninsula. Dimitobelus (Dimitobelus) stimulus…1 January, 1990 by Jonathan Watkins
Encaged aggregations of live krill in good to pristine condition have been ensonified at 38 and 120 kHz. Concurrent underwater television observations of behavior resemble those made by underwater divers…Read more on Target strengths of Antarctic krill (Euphausia superba) at 38 and 120 kHz
1 January, 1990
The UCL-Sheffield coupled thermosphere/ionosphere model has been used to assess the consequences of a heat source from ring current ion precipitation during a geomagnetic storm. Such a source might in…1 January, 1990
By means of re‐evaluating a number of properties of rock tablets left in the field for varying time periods, an estimation of rock breakdown rates is attained. From data obtained…Read more on Mechanical weathering rates on Signy Island, maritime Antarctic
1 January, 1990 by Paul Rodhouse
A bottom-trawl survey of the Falklands Interim Conservation Zone was carried out during July and August 1988. Samples of Loligo gahi were collected from depths of 50–400 m and analysed…1 January, 1990
Using a variety of techniques, the susceptibility of a species of Zygnerna (Chlorophyta) from the Antarctic to freezing was investigated with freshly collected and cultured material. There was no evidence…1 January, 1990
The effects of temperature and radiation flux on the partitioning of photosynthetically fixed carbon into four intracellulai metabolic pools was investigated for natural phytoplankton assemblages from an Antarctic freshwater lake.…1 January, 1990
1 Earlier work with albatrosses led to the hypothesis that a critical element influencing ovarian development each year is whether the ovary responds to rising gonadotrophin secretion by secreting progesterone…1 January, 1990
Initial results are presented from two methods whereby burst precipitation events in the lower ionosphere, almost certainly induced by VLF wave‐particle interactions in the magnetosphere, have been detected using a…Read more on Wave-induced burst precipitation events detected with a digital ionosonde
1 January, 1990 by John King
Profiles of wind speed, temperature and turbulent fluxes of heat and momentum in the lowest 32 m have been measured at a station on an antarctic ice shelf. During the…Read more on Some measurements of turbulence over an antarctic ice shelf
1 January, 1990 by Richard Horne
The HOTRAY ray tracing code is used to study the refraction of electrostatic waves into Z mode radiation, and to calculate the path integrated growth rate. A plasma density model…1 January, 1990 by Richard Horne
The HOTRAY ray tracing code is used to study the refraction of electrostatic waves into Z mode radiation, and to calculate the path integrated growth rate. A plasma density model…1 January, 1990 by Richard Horne
While observed frequency bandwidths of auroral Z mode radiation cannot be directly accounted for in terms of direct cyclotron maser instability generation, ray tracing in a hot plasma indicates that…Read more on Ray tracing of auroral Z mode radiation, AKR and auroral hiss
1 January, 1990
Voyagers 1 and 2 discovered radio emissions at Jupiter, Saturn and Uranus which were similar to those already studied in the Earth's magnetosphere. Terrestrial myriametric radiation, TMR, emanates from electrostatic…Read more on Remote sensing of planetary plasma by means of natural radio emissions
1 January, 1990
This volume attempts to present both a comprehensive overview of the south polar and subpolar volcanic provinces, and summary data on the status of knowledge of each volcano or volcano…Read more on Volcanoes of the Antarctic Plate and Southern Ocean
1 January, 1990 by Robert Mulvaney
The dielectric stratigraphy of a 130 m ice core from Dolleman Island, Antarctic Peninsula, shows large variations in the dielectric relaxation process and in conductivity. A comparison with the chemical…Read more on Chemical evidence in polar ice cores from dielectric profiling
1 January, 1990
The continuum theory of mixtures is used as the mathematical framework for a four-constituent model of a natural snowpack. The general conservation equations in point form are derived from appropriate…1 January, 1990
Recent mathematical models treat a natural snow-pack as a mixture body consisting of solid ice grains, liquid water, and a gas made up of air and water vapour. Such a…1 January, 1990
The first observations are presented from Halley, Antarctica, of quasi-periodic (QP)_VLF intensity variations modulated at the frequency of concurrent Pc3 magnetic pulsations. Seen on broadband frequency-time plots, the QP emissions…Read more on Quasi-periodic VLF emissions and concurrent magnetic pulsations seen at L = 4
1 January, 1990
Alexander Island contains several belts of melange in a wide accretionary complex. One melange belt in the northwest of the island incorporates both oceanic and trench-fill material. It evolved by…Read more on Deformation in an accretionary melange, Alexander Island, Antarctica
1 January, 1990 by Peter Ward
The vertical distribution of five species of fish larvae and their prey species was studied in late winter and summer at Cumberland East Bay, South Georgia. Prey type varied between…1 January, 1990
Eleven of the 17 freshwater lakes from Signy Island, South Orkney Islands, Antarctica were sampled by snorkel divers. A list of diatom taxa identified from benthic samples is presented. Most…Read more on A preliminary study of benthic diatoms in contrasting lake environments
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