Found 14053 items
1 February, 1996
The duration of 506 pregnancies in Antarctic fur seals (Arctocephalus gazelld) was measured 1983–1993. On average, pregnancy lasted 359 days, with a range of 340–390 days, representing 20% of the…1 February, 1996
The Diptera are one of the dominant insect consumer groups on sub-Antarctic islands and are thought to contribute significantly to terrestrial ecological processes at many of these islands. The life-cycle…1 February, 1996 by Mark Clilverd, Richard Horne
We report the results of the first multisite campaign using VLF Doppler receivers to detect whistler mode signals in the south Atlantic originating from VLF transmitters in the northern hemisphere.…1 February, 1996 by Roger Worland, William Block
An experiment was conducted to measure the effects of summer warming on the total population densities of soil-dwelling microarthropods in the high Arctic and to compare these results with those…1 February, 1996 by Lloyd Peck
The effect of feeding on metabolism (specific dynamic action; SDA) was assessed in the articulate brachiopod Liothyrella uva (Broderip, 1833) at Signy Island, Antarctica. The response was low and on…1 February, 1996
The diet of lactating female Antarctic fur sealsArctocephalus gazella at South Georgia was investigated during the pup-rearing period (January/March) of 1991–1994. Antarctic krillEuphausia superba was the main prey item, occurring…1 January, 1996 by Paul Rodhouse
The diet of king penguins, Aptenodytes patagonicus, rearing chicks was studied during three consecutive austral winters (1990, 1991 and 1992) at Crozet Islands. The mean stomach content mass of the…1 January, 1996 by Vsevolod Afanasyev
We discuss examples of complex systems composed of many interacting subsystems. We focus on those systems displaying nontrivial long-range correlations. These include the one-dimensional sequence of base pairs in DNA,…1 January, 1996 by Eugene Murphy, Vsevolod Afanasyev
LéVY flights are a special class of random walks whose step lengths are not constant but rather are chosen from a probability distribution with a power-law tail. Realizations of Lévy…Read more on Lévy flight search patterns of wandering albatrosses
1 January, 1996
We examined the accuracy of hydrogen isotope dilution (tritium and deuterium) as a means of determining total body water (TBW), and hence body composition, by comparison with whole-carcass chemical analysis…1 January, 1996
Copepod feeding rates and food selectivity were measured at an oceanic subantarctic site over 5 d in February 1994. A series of gut fluorescence and gut evacuation experiments was carried…1 January, 1996 by John Turner
A case of midtropospheric mesoscale cyclone formation and downward development adjacent to and over the Ross Ice Shelf, Antarctica during May 1988 is presented. This event involved atmospheric phenomena over…Read more on A downward developing mesoscale cyclone over the Ross Ice Shelf during Winter
1 January, 1996 by John King
We examine simulations of the surface mass balance of the sector of the East Antarctic Ice Sheet between 2.4°W and 110.5°E as produced by the United Kingdom Meteorological Office Unified…Read more on A modeling and observational study of East Antarctic surface mass balance
1 January, 1996 by Richard Hindmarsh, Richard Hindmarsh
The mechanical configuration of cavities associated with clasts is discussed, and how this affects the water pressure underneath the clast. The range of permissible water pressure is determined by flow…Read more on Cavities and effective pressure between abrading clasts and the bedrock
1 January, 1996 by Roger Worland, William Block
Larvae and isolated fat body cells of the freeze-tolerant Heleomyza borealis (Diptera, Heleomyzidae) were cooled to sub-zero temperatures between -5 and -40°C at 0.1°C min-1 and then rewarmed at the…Read more on Organism survival and cell integrity in a freeze-tolerant insect
1 January, 1996 by Keith Nicholls
Thermistor cables have been deployed at two sites beneath Ronne Ice Shelf, Antarctica. One site is to the east of a submarine ridge that delineates the eastern boundary of the…Read more on Temperature variability beneath Ronne Ice Shelf, Antarctica, from thermistor cables
1 January, 1996
A comprehensive survey of data on ‘Polar Mesosphere Summer Echoes’, observed by the EISCAT VHF radar during 1988–1993, confirms that (1) these echoes are a summer phenomenon, with a season…Read more on A statistical study of polar mesosphere summer echoes observed by EISCAT
1 January, 1996
In Patagonia a Triassic-Early Jurassic Cordilleran interior magmatic belt preceded the widespread eruption of Middle Jurassic syn-extensional rhyolites. Two plutons (La Calandria and La Leona) represent the easternmost plutonic rocks…Read more on Monzonite suites: the innermost Cordilleran plutonism of Patagonia
1 January, 1996
An experimental study of the fracture mechanics and rheology of ice from the Ronne Ice Shelf, Antarctica, is currently being undertaken. The apparent critical stress-intensity factor (or apparent fracture toughness,…Read more on Experimental fracture and mechanical properties of Antarctic ice: preliminary results
1 January, 1996
Zircon and apatite fission-track data from the LeMay Group accretionary complex and Fossil Bluff Group fore-arc basin sequence on Alexander Island (Antarctica) record a common regional Cretaceous and Cenozoic thermal…1 January, 1996
The stabilized platforms used in marine and airborne gravimeters behave like damped long‐period pendulums. When subjected to horizontal accelerations they tilt, resulting in gravimeter reading errors. The amount of tilt…Read more on Horizontal acceleration corrections in airborne gravimetry
1 January, 1996 by David Vaughan
IN 1978 Mercer1 discussed the probable effects of climate warming on the Antarctic Ice Sheet, predicting that one sign of a warming trend in this region would be the retreat…Read more on Recent atmospheric warming and retreat of ice shelves on the Antarctic Peninsula
1 January, 1996
Epithermal veins in early Triassic turbidites on Hurd Peninsula are isotopically homogeneous over an area of 13 km × 2 km (mean δ34S = +2.2‰, 1σ= 1.7, n = 65)…1 January, 1996 by Eugene Murphy, Philip Trathan
Additional material is available online through the South Georgia GIS project - http://www.sggis.gov.gs/1 January, 1996 by David Barnes
Observations were made on the diet and distribution of eight species of nudibranchs found in Borge Bay, Signy Island, Antarctica. Specimens from seven sites were examined in situ on four…1 January, 1996 by William Block
Water is an essential part of all living organisms and terrestrial arthropods are no exception. They have to balance water loss and water gain to and from their bodies, often…Read more on Cold or drought – the lesser of two evils for terrestrial arthropods?
1 January, 1996
Many endothermic divers regularly exceed the theoretical limit to the duration of aerobic dives, suggesting that assumptions about either the oxygen storage capacity of tissues or the metabolic rate of…1 January, 1996 by Andrew Clarke, Rachel Clarke
Dragonflies and damselflies (Odonata) are important prey for many small falcons, and the recent expansion of the breeding range of the Hobby into eastern England has been associated with an…Read more on The energy content of dragonflies (Odonata) in relation to predation by falcons
1 January, 1996 by Peter Convey
Antarctic terrestrial communities are characterised by their geographical isolation and the survival of extreme environmental stresses. Of particular significance to life history strategies of organisms in continental and maritime. Antarctic…1 January, 1996 by Peter Convey, William Block
In contrast to northern polar areas, the dipteran fauna of Antarctica is depauperate, with only two naturally occurring species of Chironomidae. Surprisingly little is known of the biology of these…Read more on Antarctic diptera: ecology, physiology and distribution
1 January, 1996
The problem of correcting satellite altimeter measurements for errors introduced by topographic surfaces was chosen to test the capabilities of a prototype integrated geographical information system. A system to calculate…1 January, 1996 by Alistair Crame
Although it will probably never be as complete as that known from any of the other continents, the Antarctic fossil record comprises a surprising amount of information. Originally gathered primarily…Read more on Antarctica and the evolution of taxonomic diversity gradients in the marine realm
1 January, 1996
We examine the extent of overlap between South Georgia wandering albatrosses (Diomedea exulans) and local longline fishing for Patagonian toothfish (Dissostichus eleginoides), using satellite-tracking data and precise haul locations, respectively.…1 January, 1996 by Ed King
It has long since been recognised that the Ellsworth-Whitmore mountains (EWM) crustal block possesses an anomalous structural and stratigraphic history relative to its neighbouring West Antarctic crustal blocks, and the…1 January, 1996
The light climate within wet and dry samples of ten mosses from the maritime Antarctic was determined using a computer-controlled optical microprobe system. Irradiances decreased with increasing depth within the…1 January, 1996
Carbon fixation under controlled conditions was measured in three mosses from the maritime Antarctic using an infra-red gas analysis system. Gas exchange parameters were determined during each season in 1993…1 January, 1996 by Jonathan Shanklin
In this paper we briefly describe the processes which lead to the formation of the Antarctic ozone hole, the attributes of the 1994 hole in comparison with previous years and…1 January, 1996
The concept of precautionary measures for krill is discussed. A precautionary catch limit, based on the potential yield model developed by the CCAMLR Scientific Committee's Working Group on Krill (WG-Krill)…Read more on Some thoughts on precautionary measures for the krill fishery
1 January, 1996 by Eugene Murphy
Interannual variability in the Southern Ocean ecosystem has long been noted and physical factors appear to dominate the dynamics. There are, however, few ecological time series available to assess this…Read more on Environment-krill relations in the South Georgia marine ecosystem
1 January, 1996
The nomenclature of the taxon first recorded as Fragilaria (virescens) v. exigua by Grunow in Cleve & Moeller (1878) is examined with regard to the current botanical name, F. exiguiformis…1 January, 1996
The fluorite mineralization from the La Nueva Mine, has a Sm-Nd age of 130 ± 19 Ma, and thus must be related to the Lower Cretaceous late-Gondwanic extensional and magmatic…1 January, 1996 by Richard Hindmarsh, Richard Hindmarsh
The observed ratio of removal of material by (i) scratches gouged by large clasts and (ii) polishing by debris suggests that the latter is the dominant form of bedrock erosion.…1 January, 1996 by Richard Hindmarsh, Richard Hindmarsh
An analysis of the linear stability of marine ice sheets uncoupled from associated ice shelves is presented. The principal feature is a zero eigenvalue associated with infinitesimal shifts along the…Read more on Stability of ice rises and uncoupled marine ice sheets
1 January, 1996 by Richard Hindmarsh, Richard Hindmarsh
Perturbation of divide position is considered by a linearization about the Vialov-Nye solution and also about related solutions with 0(1) relief. Relaxation times of one-sixteenth the fundamental thickness/accumulation-rate time-scale are…1 January, 1996 by Richard Hindmarsh, Richard Hindmarsh
Various spatial discretizations for the ice sheet are compared for accuracy against analytical solutions in one and two dimensions. The computational efficiency of various iterated and non-iterated marching schemes is…Read more on Time-step limits for stable solutions of the ice-sheet equation
1 January, 1996 by Roger Worland, William Block
We tested the hypothesis that habitat temperature is the driving variable determining both the short-term and seasonal patterns of abundance (biomass) of Eying adult non-biting midges (Chironomidae) in the high…Read more on Temperature and the biomass of flying midges (Diptera: Chironomidae) in the high Arctic
1 January, 1996 by Ed King
A new regional aeromagnetic anomaly map covering the southern Weddell Sea and surrounding areas was produced by combining Russian and British magnetic anomaly data acquired between 1973 and 1989. The…1 January, 1996
The Antarctic Peninsula is a Mesozoic–Cenozoic magmatic arc built on Palaeozoic and younger basement. It was formed by processes related to the subduction of Pacific ocean floor at its western…Read more on Arc evolution: a magnetic perspective from the Antarctic Peninsula
1 January, 1996
Diatoms are abundant and diverse in many Antarctic freshwaters, with a general trend of decreasing diversity moving southwards. They form an important component of many benthic algal communities in streams…Read more on The diversity, distribution and ecology of diatoms from Antarctic inland waters
1 January, 1996 by Ed King
We present the first images of sub-seabed structure to be obtained from beneath the Ronne Ice Shelf. Single-fold profiles totalling 158 km were recorded using a new form drag cable…Read more on New seismic data from the Ronne Ice Shelf, Antarctica
1 January, 1996 by Ed King
The Weddell Sea, part of the circumpolar Southern Ocean, is probably the most remote, least known and least accessible sea in the world. Difficult ice conditions have limited the acquisition…Read more on Weddell Sea tectonics and Gondwana break-up: an introduction
1 January, 1996 by Ed King
A re-evaluation of Weddell Sea magnetic anomaly data, in the light of satellite gravity maps, provides important constraints on plate kinematics prior to chron C34 (83 Ma). Although M-series anomalies…Read more on Mesozoic seafloor spreading in the southern Weddell Sea
1 January, 1996
The bedrock geology of the peninsula is described briefly as Upper Jurassic to Lower Cretaceous marine sedimentary, volcanic and volcaniclastic rocks, intruded by igneous bodies. The geomorphological map includes 63…Read more on Geomorphological map of Byers Peninsula, Livingston Island
1 January, 1996
The extant Acari occurring on the inland mountain ranges and nunataks of Continental Antarctica comprise only pre-Pleistocene endemic Prostigmata and Cryptostigmata of which the Prostigmata are the probable earlier colonists.…1 January, 1996
Data from the acoustic surveys of MV SA “Agulhas” and FRV “Walther Herwig”, and the 1981 RRS “John Biscoe” South Georgia acoustic survey were analysed by geostatistical methods. Estimates of…1 January, 1996
Stegonia latifolia (Schwaegr. in Schult.) Vent. ex Broth. is recorded from the Antarctic on the basis of the specimens collected from Signy Island, South Orkney Island and King George Island,…Read more on Antipodal mosses: VI. Stegonia latifolia (Musci, Pottiaceae) in the Antarctic
1 January, 1996
A U-Pb zircon age 0f 285.7+/-1.5 Ma is presented for granodiorite from the Chanchoquin pluton of the Guanta Unit, Elqui Superunit of the Elqui-Limari Batholith. This is the first U-Pb…1 January, 1996 by Lloyd Peck
Nacella concinna (Strebel, 1908) held in seawater enriched with Sr, partially replaced Ca in their shells with Sr The bands laid down were clearly visible In back-scattered, scanning electron microscope…1 January, 1996 by Robert Mulvaney
Evidence from ice cores, borehole temperatures, early expeditions and glacier margins is used to identify the major climate trends of the past 500 years in the Antarctic Peninsula region. Apparent…1 January, 1996
The sensillar field on tarsus I of Halarachne (Halarachnidae: Gamasida), a respiratory tract endoparasite of seals (Pinnipedia) is associated with 12 hair- or peg-like receptor sensilla in the larva and…1 January, 1996 by Robert Mulvaney
Geodetic surveying and ground-based radar profiling were used to determine geometry and surface motion of the ice sheet on the Dyer Plateau, Antarctica, in the vicinity of an ice-core site…Read more on Geometry, motion and mass balance of Dyer Plateau, Antarctica
1 January, 1996
Analysis of the diurnal and seasonal variation of polar patches, as identified in two years of HF-radar data from Halley, Antarctica during a period near sunspot maximum, shows that there…Read more on Diurnal and seasonal occurrence of polar patches
1 January, 1996 by Howard Roscoe
UV–visible measurements of stratospheric constituents require the ratio of a pair of spectra to be determined. If their wavelength calibrations differ and if an array detector is used, at least…1 January, 1996
Incoherent-scatter radar and ionospheric sounding are powerful and complementary techniques in the study of the Earth's ionosphere. The work presented here involves the use of the Tromsø Dynasonde as a…Read more on A comparison of EISCAT and Dynasonde measurements of the auroral ionosphere
1 January, 1996
Volcanic sequences in central Livingston Island can be divided into two broad groups. The older group consists of basalt-dacite lavas, clastic rocks and associated hypabyssal intrusions. The lavas are lithologically…1 January, 1996
Arguably the most significant source of particle precipitation into the ionosphere at mid-latitudes (L ∼2–3), at least for electrons in the tens to hundreds of keV energy range, is that…Read more on Aspects of wave-particle interactions at mid-latitudes
1 January, 1996
The development of and compliance with the code of conduct embodied in the Antarctic Treaty to prevent or minimize the introduction of plants into the Antarctic is outlined. A chronological…Read more on Introduced plants in Antarctica: Potential impacts and conservation issues
1 January, 1996
A depth-averaged finite-difference numerical model has been used to make a preliminary study of the tides under the Filchner‐Ronne Ice Shelf. Open boundary conditions were specified using the global ocean…Read more on Ocean tides under the Filchner-Ronne Ice Shelf, Antarctica
1 January, 1996 by William Block
A total of 21 species of oribatid mites (Acari: Oribatida) are recorded from heat-extracted samples of soil and plant material collected in the Falkland Is., South Atlantic. Previous records of…