Showing 13487 items
1 January, 2001
We investigated foraging behavior of Wandering Albatrosses (Diomedea exulans) breeding at South Georgia to assess how sex and season-specific foraging patterns relate to provisioning performance. We estimated Wandering Albatross chicks…1 January, 2001 by Peter Convey, William Block
Body-water content of field-fresh samples of the springtail, Cryptopygus antarcticus Willem (Collembola, Isotomidae) was measured at monthly intervals over 11 years (1984–1995) at Signy Island, in the maritime Antarctic. A…1 January, 2001 by Roger Worland, William Block
Ice nucleation was studied in field-fresh and acclimated (4°C without food for 11–20 days) samples of the springtail Cryptopygus antarcticus Willem (Collembola, Isotomidae) at Rothera Research Station, Adelaide Island on…1 January, 2001 by Iain Staniland
The study aimed to test the utility of instruments deployed on marine mammals for measuring physical oceanographic variation and, using this method, to examine temperature variation in the coastal waters…Read more on Measurement of ocean temperatures using instruments carried by Antarctic fur seals
1 January, 2001
1 This study examined the changing status of the marine ecosystem at the island of South Georgia (Southern Ocean) using up to 27 variables measured over 22 years from three…Read more on Monitoring a marine ecosystem using responses of upper trophic level predators
1 January, 2001
Multi-frequency acoustic data (18, 38 and 120 kHz) were collected in conjunction with pelagic trawl sampling for gelatinous macrozooplankton during a cruise to the Namibian Benguela in September 1999. Sampling…Read more on Acoustic observations of jellyfish in the Namibian Benguela
1 January, 2001
The Autonomous Underwater Vehicle (AUV) Autosub-1 made observations of the sea surface with an upward-looking echosounder during fish surveys in the vicinity of Shetland and Orkney (North Sea) in July…1 January, 2001 by Andrew Clarke
The seasonal pattern of food intake and tissue energy status was measured over a 2 year period for two populations of the common Antarctic echinoid Sterechinus neumayeri living on contrasting…1 January, 2001
Seasonal changes in feeding activity, metabolic rate and major tissue energy concentrations of the infaunal bivalve Laternula elliptica were monitored over a 12 degrees month period in relation to phytoplankton…1 January, 2001 by Andrew Clarke
Many benthic marine invertebrates exhibit a seasonal cycle in activities such as feeding, growth and reproduction. In temperate regions, this seasonality is typically correlated with coincident cycles in photoperiod, temperature…1 January, 2001 by Lloyd Peck
Oxygen consumption (MO2) and ammonium excretion rates were recorded monthly over 2 yr for the regular Antarctic echinoid Sterechinus neumayeri to investigate metabolic activity in relation to seasonal food limitation…1 January, 2001
Bathymetric and seismic data show that the southernmost segment of the EastScotia Ridge (segment E9) is anomalous in its curved plan form, and in the presence of a large axial…1 January, 2001
The population structure of black-browed (Thalassarche melanophris and T. impavida) and grey-headed (T. chrysostoma) albatrosses was examined using both mitochondrial DNA (mtDNA) and microsatellite analyses. mtDNA sequences from 73 black-browed…1 January, 2001
The discovery of gullies and debris aprons raises the question of the existence of aqueousenvironments on Mars in recent geological times and its astrobiological implications. Three cases of such environments…Read more on Recent aqueous environments in Martian impact craters: an astrobiological perspective
1 January, 2001
A single fossil leaf of Nothofagus from CRP-3 drillhole in the Victoria Land Basin provides further evidence for woody vegetation in the Tertiary of East Antarctica. The plicate vernation of…1 January, 2001
Coniferous foliage from the Albian of AlexanderIsland, Antarctica, is assigned to the Araucariaceae, Podocarpaceae, and Taxodiaceae based on attached or associated fertile remains. Araucarian foliage represented by Araucaria alexandrensis sp.…1 January, 2001
Whistler-mode waves propagating to ground stations along geomagnetic-field-aligned paths provide powerful tools for investigating bulk motions of the magnetospheric plasma and thus the corresponding convection electric fields. Natural whistlers from…1 January, 2001
New data suggest that the eastern margin of the Argentine Precordillera terrane comprises Grenvillian basement and a sedimentary cover derived from it that were together affected by Middle Ordovician deformation…1 January, 2001 by John King
Calculated surface fluxes from seven surface layer parameterizations are verified against 45 months of observations from Halley, Antarctica, with a temporal resolution of 1 h. The surface layer parameterizations are…1 January, 2001
Observations of recent volcanic eruptions in Iceland and detailed studies of sub-glacially erupted deposits and the interaction of lava and pyroclastic flows with snow and ice have provided important new…Read more on Study of volcano/ice interactions gains momentum
1 January, 2001
Recently, the paradigm that the dynamic magnetosphere displays sandpile-type phenomenology has been advanced, in which energy dissipation is by means of avalanches which do not have an intrinsic scale. This…1 January, 2001
The characterization of global energy storage and release in the coupled solar wind-magnetosphere system remains one of the fundamental problems of space physics. Recently, it has been realised that a…Read more on Avalanching and self organised criticality, a paradigm for geomagnetic activity?
1 January, 2001 by Gareth Chisham, Michael Pinnock
In the high-latitude dayside ionosphere, the movement of the HF radar spectral width boundary (SWB) provides a good proxy for the movement of the open-closed field line boundary around magnetic…1 January, 2001 by Andrew Clarke
Marine organisms in Antarctica live in an environment which exhibits variability in physical processes over a wide range of temporal scales, from seconds to millennia. This time scale tends to…1 January, 2001 by Mark Clilverd
During the total solar eclipse observed in Europe on August 11, 1999, measurements were made of the amplitude and phase of four VLF transmitters in the frequency range 16–24 kHz.…Read more on Total solar eclipse effects on VLF signals: observations and modeling
1 January, 2001
Astrobiology has recently been feted as a science for the twenty-first century. Founded as a science in the Soviet Union in 1953, its recent manifestation has been accompanied by a…1 January, 2001
Ultraviolet radiation is an important natural physical influence on organism function and ecosystem interactions. The UVradiation fluxes in extraterrestrial environments are substantially different from those experienced on Earth. On Mars,…1 January, 2001
The Martianpolar ice caps are regions of substantial scientific interest, being the most dynamic regions of Mars. They are volatile sinks and thus closely linked to Martian climatic conditions. Because…Read more on Martian polar expeditions: problems and solutions
1 January, 2001
In the Archean era (3.8–2.5 Ga ago) the Earth probably lacked a protective ozone column. Using data obtained in the Earth’s orbit on the inactivation of Bacillus subtilis spores we…1 January, 2001
The input of nutrients into arctic polar deserts, aided by some physical processes, can result in localized areas of high biological productivity--"micro-oases." We examined the vegetation cover, and microbial and…1 January, 2001
During July 2000 we used an electronic personal dosimeter (X-2000) and a biological dosimeter (Deutsches Zentrum für Luft- und Raumfahrt: Biofilm) to characterize the UV radiation exposure of arctic field…1 January, 2001
In this paper, numerical weather prediction analyses from four major centers are compared—the Australian Bureau of Meteorology (ABM), the European Centre for Medium-Range Weather Forecasts (ECMWF), the U.S. National Centers…1 January, 2001
The recent history of global initiatives to reduce seabird bycatch in longline fisheries is reviewed, highlighting in turn the activities of environmental and industry non-governmental organizations (NGOs), national governments, and…Read more on Off the hook? Initiatives to reduce seabird bycatch in longline fisheries
1 January, 2001 by Adrian Jenkins, David Vaughan
We present newly acquired airborne radar data showing ice thickness and surface elevation for Pine Island Glacier, Antarctica. These data, when combined with earlier measurements, suggest the presence of a…Read more on Investigations of an ‘ice plain’ in the mouth of Pine Island Glacier, Antarctica
30 December, 2000
We have identified first evidence for the presence of submarine hydrothermal activity along the East Scotia Ridge an isolated back-arc spreading centre located at 55–60°S in the Atlantic sector of…1 July, 2000
Copyright © Scientific Committee on Antarctic Research, 2000Read more on Antarctic digital database, version 3.0. Database, manual and bibliography
1 June, 2000 by Nigel Meredith, Richard Horne
The temporal evolution of electron distributions and associated wave activity following substorm injections in the inner magnetosphere are investigated using data from the CRRES satellite. Equatorial electron distributions and concomitant…1 January, 2000
Krill, or euphausiids, a group of immense importance in marine ecosystems, comprises over 80 species, most of which are planktonic. Krill are widespread with species to be found in all…1 January, 2000
A series of experiments was carried out in February 1999 at South Georgia (Subarea 48.3) to examine the effects of different weighting regimes on the incidental mortality of birds caught…1 January, 2000 by Michael Pinnock
The Super Dual Auroral Radar Network (SuperDARN) radars are proving to be a very powerful experimental tool for exploring solar wind-magnetosphere-ionosphere interactions. They measure the autocorrelation function (ACF) of the…1 January, 2000 by Lloyd Peck
Antarctic anemones of the genus Halcampoides inhabit low intertidal and shallow subtidal zones. They readily burrow into soft sediments following disturbance. The process of re-burying was recorded using time-lapse video…Read more on Burrowing in the Antarctic anemone, Halcampoides sp., from Signy Island, Antarctica
1 January, 2000
Large, biomass-dominant Southern Ocean copepod species have been much studied, but small and mesopelagic species also play major rôles in these ecosystems. However, little is known of some basic aspects…1 January, 2000
Excretion by Antarctic krill Euphausia superba (hereafter ‘‘krill’’) is measured typically in small containers of filtered seawater for 12–24 h, which may cause a reduction of swimming, feeding, and metabolism.…Read more on Ammonium excretion by Antarctic krill Euphausia superba at South Georgia
1 January, 2000
The Mana Pools sedimentary basin lies within the Zambezi mobile belt in northern Zimbabwe. New and preexisting magnetotelluric data and the available seismic reflection data are used to constrain the…Read more on A magnetotelluric model of the Mana Pools basin, northern Zimbabwe
1 January, 2000 by Roger Worland, William Block
Hydromedion sparsutum is a locally abundant herbivorous beetle on the sub-Antarctic island of South Georgia, often living in close association with the tussock grass Parodiochloa flabellata. Over a 4-day period…1 January, 2000 by David Vaughan
It has been suggested that as much as 90% of the discharge from the Antarctic Ice Sheet is drained through a small number of fast-moving ice streams and outlet glaciers…Read more on Widespread complex flow in the interior of the Antarctic Ice Sheet
1 January, 2000
Phosphorus is scarce in Beacon Sandstone of the McMurdo Dry Valleys, Antarctica, and any input from precipitation is minimal. In endolithic microbial communities recycling of P by the action of…Read more on Phosphatase activities of endolithic communities in rocks of the Antarctic Dry Valleys
1 January, 2000
The phosphomonoesterase activity of a microbialcommunity dominated by Chroococcidiopsis in arock sample from the Antarctic dry desert was comparedwith that of a non-axenic culture of thecyanobacterium isolated from the same…1 January, 2000
We report low temperature gradients (from 60% to 12% of geothermal), and extrapolated temperatures offset from modern bottom water temperatures, in sediments from the central Scotia Sea. We examine possible…1 January, 2000
Tape recordings of two types of vocalisations were used to assess burrow occupancy by white-chinned petrels (Procellaria aequinoctialis) at South Georgia. Birds responded to the rattle call on 74% of…1 January, 2000
The white-chinned petrel (Procellaria aequinoctialis) is an abundant, widespread petrel breeding in tussock grassland at sub-Antarctic islands. Over the last decade it has been killed in large numbers in temperate…1 January, 2000
The foraging range and principal feeding areas of White-chinned Petrels breeding at South Georgia were determined using satellite telemetry. Foraging trips during incubation lasted 12–15 days and covered 3000–8000 km…1 January, 2000 by William Block
Specimens of six enchytraeid species from a wide range of terrestrial habitats were cooled to –25oC and rewarmed at 1oC min-1 and their cryobiological features measured by DSC. All were…Read more on DSC studies of freezing in terrestrial enchytraeids (Annelida: Oligochaeta)
1 January, 2000
The absolute gut evacuation rate (GER) (g day−1) of Harpagifer antarcticus increased with increasing ration mass, fish mass only influenced the absolute GER at a daily ration level of 0·3%…1 January, 2000
This study tests the hypothesis that an endothermic homeotherm should minimise heat flux in cold polar waters by minimising skin temperature. Temperature variability was measured at the surface of the…Read more on Skin temperatures during free-ranging swimming and diving in Antarctic fur seals
1 January, 2000
1. The study tested the hypothesis that the occurrence of pregnancy in mammals that are capital breeders will be most closely related to state variables that are indices of food…Read more on State-dependent fertility in pinnipeds: contrasting capital and income breeders
1 January, 2000 by Eugene Murphy, Philip Trathan
Ocean physics is a key aspect of the operation of island ecosystems, yet the hydrodynamics is sometimes poorly understood. A high-resolution oceanographic survey to the north of South Georgia identified…1 January, 2000 by Jonathan Watkins
Much of the distribution range of Antarctic krill, Euphausia superba, is covered by permanent or seasonal sea ice. Sea ice extent has been implicated as a major factor affecting reproductive…Read more on Effects of sea ice cover on the swarming behaviour of Antarctic krill,Euphausia superba
1 January, 2000
On Bird Island, South Georgia, albatrosses (n = 140), penguins (n = 100), and fur seals (n = 206) were sampled for Campylobacter jejuni. C. jejuni subsp. jejuni was recovered…1 January, 2000
1 The population density, diversity and productivity of the microbial plankton in an oligotrophic maritime Antarctic lake were studied for a 15-month period between December 1994 and February 1996. 2…Read more on Temporal plankton dynamics in an oligotrophic maritime Antarctic lake
1 January, 2000
Cetricycas antarcticus gen. et sp. nov. occurs in the Late Coniacian to Campanian Lachman Crags Member of the Santa Marta Formation, Marambio Group, James Ross Island, Antarctica. The petrified trunk…Read more on A petrified cycad trunk from the Late Cretaceous of the Larsen Basin, Antarctica
1 January, 2000
A macroflora from John Peaks, Powell Island, contains Sagenopteris nilssoniana, Cladophlebis oblonga, Brachyphyllum sp., Elatocladus confertus, and Sphenopteris sp. The macroflora is best correlated with the Botany Bay Group flora,…1 January, 2000
Publication of the Composite gazetteer of Antarctica by the SCAR Working Group on Geodesy and Geographic Information is a major milestone in the evolution of Antarctic toponymy. It has taken…1 January, 2000 by Gareth Chisham, Michael Pinnock
Poleward‐moving line‐of‐sight velocity “flow bursts” have been observed in the cusp by two southern hemisphere SuperDARN HF radars with overlapping fields‐of‐view. This has allowed the estimation of unambiguous two‐dimensional velocity…1 January, 2000 by Gareth Chisham, Michael Pinnock
We present data from conjugate SuperDARN radars describing the high-latitude ionosphere's response to changes in the direction of IMF By during a period of steady IMF Bz southward and Bx…1 January, 2000 by Andrew Clarke
1. We have examined large-scale geographical patterns in species richness for continental shelf bryozoan assemblages in the North Atlantic. Bryozoans are common and often abundant benthic organisms, but they have…1 January, 2000
As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of ∼106 km2 and total as much as…Read more on The state and future of Mars polar science and exploration
1 January, 2000 by Mark Clilverd
Unusually low whistler mode group delay times are observed by VLF Doppler receivers at both Faraday, Antarctica, and Dunedin, New Zealand, following magnetic storms. These are typically caused by plasmaspheric…1 January, 2000 by Michael Pinnock
The antiparallel merging hypothesis states that reconnection takes place on the dayside magnetopause where the solar and geomagnetic fields are oppositely directed. With this criterion, we have mapped the predicted…Read more on The ionospheric footprint of antiparallel merging regions on the dayside magnetopause
1 January, 2000
We aim to identify the important steps in the evolution of the ecosystem approach to management under the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR). The first…1 January, 2000 by Peter Convey
The South Sandwich Islands are an isolated maritime Antarctic volcanic island arc 550-600km south-east of South Georgia. The terrestrial biology of the islands, with emphasis on the unique habitats associated…Read more on The terrestrial micro-arthropod fauna of the South Sandwich Islands
1 January, 2000 by Dominic Hodgson, Helen Peat, Peter Convey
Aim To carry out as comprehensive a survey as practicable of the flora (higher plants, mosses, liverworts, lichens, basidiomycete fungi and diatoms) of the isolated, volcanically active, South Sandwich Islands…