Found 14046 items
1 January, 1979
Using expressions for ice-shelf creep derived by Weertman (1957) and Thomas (1973[b]) a general method is developed for calculating equilibrium thickness profiles, velocities, and strain-rates for any ice shelf. This…1 January, 1979
Vertical shear stress in ice shelves cannot be precisely zero, since the upper and lower surfaces are generally not parallel. By performing stress balance on a vertical column in an…1 January, 1979
Monthly samples (August 1974 to February 1976) and cultured material have been used to describe ovotestis maturation, spawning, and larval development of the Antarctic opisthobranch Philine gibba Strebel. Ovotestis maturation…Read more on Reproductive biology of the antarctic opisthobranch Philine gibba Strebel
1 January, 1979
A system to facilitate the analysis of wide-band VLF data from goniometer receivers has been designed and built and is now in use. Whistlers and other types of VLF phenomena…1 January, 1979
A new design of tiltmeter has been used to measure the tidal bending of the Ronne Ice Shelf, Antarctica. By this means the point at which the ice sheet leaves…Read more on Tidal flexure of ice shelves measured by tiltmeter
1 January, 1979
19 new K–Ar mineral ages of 78-201 Ma and 3 Rb–Sr whole rock isochron ages of 81 ± 10, 127±4 and 181±30 Ma are presented from units of continental crust,…1 January, 1979
Climatic warming could cause increased melting from Antarctic ice shelves. Continued weakening of the ice shelves in this way would result in the ultimate collapse of most of the West…Read more on Effect of climatic warming on the West Antarctic ice sheet
1 January, 1979
1. During the course of a nutritional survey on an Antarctic base, leucocyte ascorbic acid estimations (Denson & Bowers, 1961) were found to be significantly affected (P < 0.0001) by…Read more on Leucocyte ascorbic acid and the leucocyte count
1 January, 1979
Resection can be used to measure the velocity of a glacier even where the co-ordinates of rock stations are unknown. The method is an adaptation of conventional semi-graphic resection and…1 January, 1979
Bransfield Strait is a narrow basin separating the South Shetland Islands from the Antarctic Peninsula and is attributed to recent back-arc extension behind the South Shetland volcanic arc. The volcanic…1 January, 1979
Polar ice is now thought to be marginally birefringent at radio echo-sounding frequencies. An experiment on the polarization behaviour of 60 MHz radio echoes from the bed of both ice…Read more on Depolarization of radio waves can distinguish between floating and grounded ice sheets
1 January, 1979
Measurements of metabolic rate in the terrestrial miteAlaskozetes antarcticus showed that the ability for metabolic temperature compensation is lacking in adults of this species. Animals cultured at 0 and 10°C…Read more on Effect of temperature change on the metabolic rate of an antarctic mite
1 January, 1979
Measurements of oxygen consumption in all post-embryonic life stages of U.K. cultured Alaskozetes antarcticus (Acari: Cryptostigmata) showed that log10 respiration rate was linearly related to log10 live weight, while loge…Read more on Respiratory metabolism of Alaskozetes antarcticus
1 January, 1979
Apparently igneous zircons from the Glen Dessary syenite complex give concordant U-Pb ages averaging 456 ± 5 Ma which is taken to date crystallization. The complex was deformed and metamorphosed…1 September, 1978
During recent years there has been a steady increase in the total world fish catch (including shellfish) to a plateau, reached in the early 1970's, of around 70 million tonnes.…1 January, 1978
The flow rate and ionic composition of bile during spontaneous secretion were measured in anaesthetized penguins in which the enterohepatic circulation had been interrupted and with i.v. injection of saline…1 January, 1978
Major and trace element analyses and strontium isotope ratios are presented for twenty-four samples of lavas and plugs from the early Tertiary lava pile in Mull. The samples were selected…1 January, 1978
This expedition to Iceland was concerned with ice depth soundings of the largest ice cap in Europe and involved both the development of impulse radar systems and the use of…Read more on Cambridge University Vatnajökull Expedition, 1977
1 January, 1978 by William Block
Determinations of oxygen uptake of size classes I, II, III and IV of the collembolan Cryptopygus antarcticus Willem at +5°, +10° and +20°C were made at South Georgia, sub-Antarctic. The…Read more on Oxygen Uptake by Cryptopygus antarcticus (Collembola) at South Georgia
1 January, 1978 by William Block
1. 1. Comparative analyses of standard metabolism, as measured by weight specific oxygen consumption, for Antarctic and temperate terrestrial Acari show that polar forms of the Cryptostigmata and Mesostigmata exhibit…Read more on Metabolic adaptations of antarctic terrestrial micro-arthropods
1 January, 1978
The major direct effects of man on seal populations are caused by hunting. Subsistence hunting using traditional methods has a long history and generally resulted in a balance between the…1 January, 1978
It is widely accepted that return currents from the auroral electrojet are responsible for the magnetic bays in the D component. The different directions of the return currents, at either…1 January, 1978
To understand the recent dielectric measurements made on HF-doped ice single crystals requires a full knowledge of the concentration of electrical defects present in ice and their subsequent interactions. Previous…Read more on Theoretical models for interpreting the dielectric behaviour of HF-doped ice
1 January, 1978
FLEXING of ice shelves may dissipate enough tidal energy to have a significant effect on the Moon's retreat from the Earth. It is generally agreed that tidal friction slows the…Read more on Dissipation of tidal energy by Antarctic ice shelves
1 January, 1978
Dates of climatic episodes recorded in deep-sea cores are compared with the dates of palaeomagnetic polarity transitions during the Upper Pliocene period. The chance that the number of observed coincident…Read more on Climatic change and geomagnetic field reversals: A statistical correlation
1 January, 1978
An empirical model of the variation of electron concentration with height is described which overcomes some limitations found in practice with a previous widely used model (Bradley and Dudeney, 1973).…1 January, 1978
Five main British Antarctic Survey stations were occupied throughout the year. These were Faraday and Halley (the two geophysical observatories), Signy (the main biological station), Grytviken (a multi-disciplinary sub-Antarctic station)…1 January, 1978
In the calculation of atmospheric total ozone from ultraviolet spectrometry, the particulate scattering term is usually regarded as a linear function of wavelength. A method due to R. E. Basher,…1 January, 1978
A major rockfall occurred near the summit of Paulsen Peak (1877 m) and initiated a slide of rock, firn, and ice debris 4 km down the Lyell Glacier, South Georgia,…Read more on A major rockfall and debris slide on the Lyell Glacier, South Georgia
1 January, 1978
The concentrations and distributions of alkanes have been determined in samples of sediment, fish, benthos and a land plant mixture from King Edward Cove, South Georgia. The fish muscle and…1 January, 1978
Temperatures from 10 m bore holes have been analysed to determine the spatial variation of mean annual surface temperature over the Antarctic Peninsula. In general there is a decrease in…Read more on The Spatial Distribution of 10 m Temperatures in the Antarctic Peninsula
1 January, 1978 by Andrew Clarke
Following growth under sub-optimal concentrations of nutrients, cells ofChlorella emersonii accumulated lipid and became more resistant to the damage caused by freezing and thawing. These results suggest that the factor…1 January, 1978
Remnants of Early Archaean rocks (>FX3000 m.y. old) are reported from most continents. A critical review of the radiometric data shows that few of these are well authenticated and most…Read more on Early Archaean rocks and geochemical evolution of the earth’s crust
1 January, 1978
Full chemical analyses, including some trace elements and both oxygen and strontium isotope abundance data are presented for samples collected from a traverse across the outcrop of the early Tertiary…1 January, 1978
The population of Antarctic Fur seals Arctocephalus gazella at South Georgia is increasing rapidly and is therefore of great interest. Investigations of the population depend on two main techniques. (1)…Read more on Population size and age determination in the Antarctic fur seal Arctocephalus gazella
1 January, 1978
Quantative population data for shallow Antarctic soft-bottom communities in King Edward Cove, South Georgia indicate that although once grossly polluted by organic effluent and fuel oil from a whaling station,…1 January, 1978
Two species of aquatic moss (Calliergon sarmentosum and Drepanocladus sp.) occur in deep water in Moss Lake, Signy Island (60° 43′S, 45° 38′W). Their elongate stems support a structurally complex…Read more on The biology of an Antarctic aquatic moss community
1 January, 1978
Stresses occur in the uppermost 10 m of a glacier as a result of temperature fluctuations at the surface. A model is set up of a typical year's surface temperature…1 January, 1978
Philine gibba is redescribed using large samples collected from the original type locality (South Georgia, South Atlantic). The specimens examined are compatible with all but one previous description which differs…1 January, 1978
(1) The source and availability of nutrients to the predominantly non-vascular cryptogam vegetation of Signy Island. South Orkney Islands, in the maritime Antarctic, are briefly discussed. (2) The concentrations of…1 January, 1977
Geological field work in Antarctica and the off-lying islands during the past two decades has contributed materially to the establishment of the stratigraphical succession in both East and West Antarctica.…1 January, 1977
In the absence of identified magnetic anomalies in the southernmost Atlantic and Indian Oceans, palaeomagnetic data provide the most precise test of the initial relative positions of East and West…Read more on Towards a more certain reconstruction of Gondwanaland
1 January, 1977
The occurence of propagating wave-like disturbances in the atmosphere at ionospheric heights is well documented, but their causes and role in the energy balance of the atmosphere is poorly understood.…Read more on Radio wave doppler studies of the Antarctic ionosphere
1 January, 1977
For several years marine biologists of British Antarctic Survey have been studying the nearshore communities at Signy Island and South Georgia. Most of these studies have been continued throughout the…Read more on Antarctic marine secondary production and the phenomenon of cold adaptation
1 January, 1977
Ozone measurements have been made regularly at Argentine Islands and Halley Bay since 1957. A recent critical review of the data revealed inconsistencies in the extraterrestrial constants adopted for the…Read more on Ozone measurements at British Antarctic Survey stations
1 January, 1977
A review is presented of studies, including recent work by members of the British Antarctic Survey, on the primary productivity of plankton, ice-flora and benthos in both marine and freshwater…1 January, 1977
The ice-free area around Ablation Point (70° 49' S, 68° 25' W) is of particular limnological interest. Numerous ponds and pools lie on coastal moraines and large, permanently ice-covered lakes…Read more on A limnological survey of the Ablation Point area, Alexander Island, Antarctica
1 January, 1977
The composition of the terrestrial Antarctic flora and fauna and the distribution patterns of a number of species and of the principal vegetation types is now reasonably well established, at…1 January, 1977
Observations of natural electromagnetic phenomena, embracing frequencies ranging from millihertz to tens of kilohertz, have made a major contribution to our knowledge of the terrestrial environment extending out to many…Read more on Very low frequency electromagnetic phenomena: ‘whistlers’ and micropulsations
1 January, 1977
There are fewer species of marine mammals in the Antarctic than in the Arctic, probably because of the wide deep ocean with no geographical barriers to promote speciation. The stocks…1 January, 1977
The Antarctic fur seal Arctocephalus gazella is a polygynous Otarid in which a single pup is produced annually by cows over the age of 2 years. Following exploitation to the…1 January, 1977
A prime objective of atmospheric science research in Antarctica is to use the special conditions found there to throw new light on global problems and, in particular, to test theories…Read more on The importance of the Antarctic in atmospheric sciences
1 January, 1977
The Antarctic Peninsula is a good place for studies that take advantage of its wide range of latitude. Other worthwhile investigations are those that set in context the glacier/climate relationships…Read more on Glaciological research in the Antarctic Peninsula
1 January, 1977
The stratigraphical limits on the age of the Freetown intrusion, Sierra Leone, are very wide, yet the intrusion has not previously been accurately dated by isotopic methods, despite a number…