Found 14065 items
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
1 January, 2001 by Alistair Crame
There is evidence from the fossil record to suggest that latitudinal gradients in taxonomic diversity may be time-invariant features, although almost certainly not on the same scale as that seen…Read more on Taxonomic diversity gradients through geological time
1 January, 2001
Early Paleozoic orogenesis has been recognized along the southern African (Saldanian orogeny) and East Antarctic (Ross orogeny) sectors of the Gondwana paleo- Pacific margin. However, the absence of a contemporaneous…1 January, 2001
Since the early 1990s, the Cape Roberts Project has been working to document, through sediment drilling, the proximal record of Antarctic ice sheet history and climate for the southwestern part…1 January, 2001
A total of eighteen species of marine ostracods, in at least twelve genera, have been recovered from Early and Late Oligocene glacio-marine sediments from boreholes CRP-3 and CRP-2/2A in the…1 January, 2001 by Adrian Jenkins, Andy Smith, David Vaughan, Hugh Corr, Keith Makinson, Keith Nicholls
Rutford Ice Stream is in many ways a typical Antarctic outlet glacier. Constrained by a subglacial-bed trough to the east of the Ellsworth Mountains, it drains an area of 49,000…1 January, 2001 by Mark Clilverd
There are two distinctly different causes of phase and amplitude perturbations of subionospheric VLF transmissions (termed “Trimpis”): (1) ionization enhancement in the ionospheric D region due to whistler-induced electron precipitation…1 January, 2001
Mackerel icefish (Cllanzpsocephal[~gsz rnnnvi) are widespread on the South Georgia shelf, Antarctica, and have been fished commercially since the early 1970s. They are known to feed predominantly on krill. An…Read more on Variations in condition indices of mackerel icefish at South Georgia from 1972 to 1997
1 January, 2001
Historical information on the distribution of spawning and larval mackerel icefish (Champsocephalus gunnari) within CCAMLR Subarea 48.3 (South Georgia and Shag Rocks) is assessed. This is considered alongside new data…Read more on Spawning locations of mackerel icefish at South Georgia
1 January, 2001
Silicified gymnosperm trunks usually more than 30 cm in diameter and several metres in length occur abundantly in the lower part of the mid-AptianCerroNegroFormation, which crops out on ByersPeninsula, LivingstonIsland,…1 January, 2001
The leaf longevity and seasonal timing of leaf abscission within a plant community is closely related to climate, a phenomenon referred to as leaf phenology. In this paper the leaf…Read more on Leaf phenology of some mid-Cretaceous polar forests, Alexander Island, Antarctica
1 January, 2001
The biodiversity and terrestrial ecology of the Late Albian Triton Point Formation (Fossil Bluff Group), Alexander Island, Antarctica is analysed to improve our understanding of polar biomes during the mid-Cretaceous…1 January, 2001
The botanical identity and facies distribution of fossil charcoal is described from Middle to Late Cenomanian (90–94 Ma) fluvial to estuarine units at Pecínov quarry, near Prague, Czech Republic. Braided…1 January, 2001 by Adrian Fox
Automatic digital elevation model (DEM) generation has become an established technique within mapping agencies. This paper assesses the effectiveness of automatic DEM generation using area-based matching for glaciated terrain in…1 January, 2001
It has been suggested previously that the presence and abundance of indigenous species have a marked influence on the likelihood of invasion of a community. It has also been suggested…1 January, 2001 by Lloyd Peck
The metabolism of a coastal mysid population ŽPraunus flexuosus. from the West Solent South England. has been studied in different seasons winter, spring and summer.. Metabolic responses to copper 0,…Read more on Effects of copper exposure on the metabolism of the mysid Praunus flexuosus
1 January, 2001 by Lloyd Peck
The reproductive biology, in response to temperature, season and copper, of a coastal population of opossum shrimps (Crustacea: Mysidacea) was measured. The reproductive pattern for Praunus flexuosus at Keyhaven (west…Read more on Reproduction, seasonality, and copper toxicity in the coastal mysid Praunus flexuosus
1 January, 2001
Microsatellites were used to conduct an analysis of paternity of Antarctic fur seals (Arctocephalus gazella) from Bird Island, South Georgia. At most, only 28% of pups at our study site…1 January, 2001
To assess the biological implications of ozone depletion over the Antarctic Peninsula, the ultraviolet (UV) regime of two Antarctic cyanobacterial communities (composed of Leptolyngbya sp. and Phormidium sp.) was manipulated…Read more on Tolerance of Antarctic cyanobacterial mats to enhanced UV radiation
1 January, 2001 by Paul Rodhouse
Acoustic survey methods are now widely used for stock assessments of finfish, both those with and without swimbladders, but their application to squid stocks has been limited in the past,…Read more on Investigations of squid stocks using acoustic survey methods
1 January, 2001
Twenty-four macaroni penguins (Eudyptes chrysolophus) from three groups, breeding males (N=9), breeding females (N=9) and moulting females (N=6), were exercised on a variable-speed treadmill. Heart rate (fH) and mass-specific rate…Read more on Heart rate and rate of oxygen consumption of exercising macaroni penguins
1 January, 2001
XRD analysis of weathering rinds on ocean-deposited ice rafted clasts provide a snapshot of palaeo-terrestrial conditions prevailing at the time of rind formation. Investigation of weathering rinds found on some…1 January, 2001 by Richard Phillips
Seabirds may be able to increase their foraging efficiency by learning the whereabouts of predictable sources of prey and returning repeatedly to these locations. The occurrence of such foraging area…1 January, 2001
Magnetic properties of bulk sediment samples taken from three cores from the Scotia Sea, Antarctica were determined using a fully-automated variable field translation balance. Fine-grained detrital magnetite is identified as…Read more on Magnetic properties of Upper Quaternary sediments from the Scotia Sea, Antarctica
1 January, 2001
Although Sims Island (73°17′S/78°33′W), a bedrock peak in Carroll Inlet on the English Coast of eastern Ellsworth Land (Fig. 1), had previously been observed and photographed from the air (e.g.…1 January, 2001
Lower Cretaceous conglomeratic strata exposed on southern Sobral Peninsula were deposited on a deep-marine apron in the back-arc Larsen Basin close to its faulted boundary with the Antarctic Peninsula magmatic…1 January, 2001
The Pedersen Formation includes conglomerate-dominated successions exposed on Pedersen Nunatak (142 m thick) and southern Sobral Peninsula (750–1000 m thick). As re-defined here, it also includes mudstone and sandstone in…1 January, 2001 by Roger Worland, Peter Convey
The hygropreference of adult Cryptopygusantarcticus and Alaskozetesantarcticus was investigated over 2 h at 5, 10 and 20°C, along humidity gradients (9–98% RH) established by means of different salt solutions. Two…1 January, 2001 by Richard Hindmarsh, Richard Hindmarsh
Marine ice sheets with mechanics described by the shallow-ice approximation by definition do not couple mechanically with the shelf. Such ice sheets are known to have neutral equilibria. We consider…Read more on Dynamical processes involved in the retreat of marine ice sheets
1 January, 2001 by Dominic Hodgson
The Rauer Islands contain more than fifty shallow lakes and small ephemeral ponds. Despite their proximity to the Vestfold fills - one of the most diverse and intensively studied lake…Read more on Limnology and biology of saline lakes in the Rauer Islands, eastern Antarctica
1 January, 2001 by Dominic Hodgson
Lake sediments in the Larsemann Hills contain a great diversity ofbiological and physical markers from which past environments can be inferred. In order to determine the timing of environmental changes…Read more on Were the Larsemann Hills ice-free through the Last Glacial Maximum?
1 January, 2001 by Adrian Jenkins
Much of the Antarctic coastline comprises large, floating ice shelves, beneath which waters from the open ocean circulate. The interaction of the seawater with the base of these ice shelves…1 January, 2001 by Mervyn Freeman, Richard Horne
We present anewsimulationcode for electrostatic waves in one dimension which uses the Vlasovequation to integrate the distribution function and Ampère'sequation to integrate the electric field forward in time. Previous Vlasovcodes…1 January, 2001
Reproductive pentoxylalean material from the Albian Triton Point Formation, Fossil Bluff Group of Alexander Island, Antarctica is the youngest record of this group globally. Leaves are referred to Taeniopteris daintreei…Read more on Palaeoecology and taxonomy of Pentoxylales from the Albian of Antarctica
1 January, 2001
A psychrophilic, aerobic bacterium designated A2iT was isolated from marine sediment recovered from shallow waters surrounding Adelaide Island, Antarctica (67S 34H S, 68S 07H W). The organism exhibited xylanolytic and…1 January, 2001 by Robert Mulvaney
In 1997 a 121 m ice core was retrieved from Lomonosovfonna, the highest ice field in Spitsbergen, Svalbard (1250 m a.s.l.). Radar measurements indicate an ice depth of 126.5 m,…1 January, 2001
Within the global context, Antarctica has a key role to play in understanding long-term change in the upper atmosphere, both because of its isolation from the rest of the world…Read more on Antarctica’s role in understanding long-term change in the upper atmosphere
1 January, 2001
In the mesosphere and lower thermosphere the contrasts between the Antarctic and Arctic regarding both the energy inputs and the consequent dynamics, energetics and chemistry mean that comparative polar observations…Read more on Antarctic-Arctic contrasts – key pointers to mesospheric dynamics and energetics
1 January, 2001
The mesosphere and lower thermosphere have long suffered from their inaccessibility to research balloons and satellites alike. As a result, basic knowledge about this central region of the atmosphere is…1 January, 2001 by Adrian Jenkins
Upper boundary conditions for numerical models of the ocean are conventionally formulated under the premise that the boundary is a material surface. In the presence of an ice cover, such…1 January, 2001
Analysis of the Batoka Basalts exposed in the Zambezi Gorge some 40 km east of Victoria Falls characterizes them as high Fe, moderately high Ti, and low K, P, and…1 January, 2001
The first Carboniferous and ?Permian marine macrofaunas from the Antarctic continent are described from three sites near Mount King, Alexander Island, Antarctic Peninsula. They include bivalves, brachiopods, bryozoans, crinoids, gastropods,…1 January, 2001 by John King
We have used micrometeorological data collected at Halley Research Station, Antarctica, to estimate monthly totals of snow sublimation. Direct sublimation from the snow surface is calculated using bulk-transfer formulae, while…Read more on The seasonal cycle of sublimation at Halley, Antarctica
1 January, 2001 by John King
The Hadley Centre climate model version HadAM2 is used to study the sensitivity of modelled Antarctic climate to the parametrization of surface and boundary-layer heat fluxes under stable conditions. Specifically,…1 January, 2001 by Thomas Lachlan-Cope
Monitoring of the remote SouthSandwichIslands volcanic arc, using advanced very high resolution radiometer (AVHRR) data, has identified a radiant pixel on channels 3 (3.55–3.93 μm) and (rarely) 4 (10.3–11.3 μm).…1 January, 2001 by John Turner, Thomas Lachlan-Cope
Surface-based observations were taken of cloud and precipitation particles on the Avery Plateau (66°50.34′S 65°29.58′W), Antarctic Peninsula from 25 November to 13 December 1995. This paper considers cloud parameters on…1 January, 2001 by John Turner, Thomas Lachlan-Cope
The pattern of inter‐annual variability in the atmospheric circulation around Antarctica has a maximum over the Amundsen‐Bellinghausen Sea (ABS), which is particularly strong during the winter (June, July and August).…1 January, 2001
Palaeomagnetic poles for a stable continental block are typically defined from a combination of declination and inclination information from several temporally constrained studies. Poles from regions that have undergone vertical-axis…1 January, 2001 by Robert Larter
Global earthquake catalogues do not record any earthquakes south of Bransfield Strait beneath the Antarctic Peninsula or its flanking continental shelves. Such low seismicity is consistent with neotectonic interpretations which…1 January, 2001
Strontium isotope stratigraphy was used to date 5 discrete horizons within the CRP-3 drillhole. A single in situ modiolid bivalve fragment at 10.88 mbsf gives an age of 30.9 (±0.8)…Read more on Strontium isotope stratigraphy for CRP-3, Victoria Land Basin, Antarctica
1 January, 2001
Stable isotope analyses of marine bivalve growth increment samples have been used to estimate early Oligocene (29.4 - 31.2) Ma and early Miocene (24.0 Ma) seafloor palaeotemperatures from the southwestern…1 January, 2001
Planetary wave signatures, with periods of approximately 16, 10 and 5 days have been observed at altitudes ranging from 30 km to 220 km over Halley (76°S, 26°W), Antarctica. A…1 January, 2001
1. Beaver Lake, a large epishelf lake in eastern Antarctica was sampled on two occasions during the austral summer of 2000. Two sites, one 1 km offshore and another 6…1 January, 2001
The lithosphere responds to loading by elastic flexure which is followed by viscous relaxation, the amount of which depends on the stress duration. This study compares results of an Earth…Read more on Effects of a viscoelastic lithosphere on the isostatic bedrock response
1 January, 2001 by Richard Hindmarsh, Richard Hindmarsh
We use a self-gravitating viscoelastic model of the Earth and a dynamically consistent marine ice-sheet model to study the relationships between marine ice-sheet dynamics, relative sea level, basal topography and…1 January, 2001
This paper deals with present-day gravity changes in response to the evolving Greenland ice sheet. We present a detailed computation from a 3-D thermomechanical ice sheet model that is interactively…1 January, 2001 by Lloyd Peck
A series of 10 samples from sediment in and adjacent to a shallow coastal iceberg scour at Signy Island, Antarctica, were taken by hand coring from 17 December 1993 until…1 January, 2001 by Lloyd Peck
The concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured in several soft-tissue types of the Antarctic soft-shelled clam, Laternula elliptica, which had been collected from…1 January, 2001
Air samples were taken on board the RRS Bransfield (typically for 24−72 h), during an Atlantic cruise from the U.K. to Antarctica in October−December 1998, to investigate the global scale…1 January, 2001
The circadian rhythms of many night-shift workers are maladapted to their imposed behavioural schedule, and this factor may be implicated in the increased occurrence of cardiovascular disease (CVD) reported in…Read more on Postprandial hormone and metabolic responses amongst shift workers in Antarctica
1 January, 2001
The sub-antarctic mite genus Neohyadesia (Acari: Astigmata) is known from two described taxa: N. signyi from Signy Island (South Orkney Islands, South Atlantic Province), and a subspecies, N. s. punctulata…1 January, 2001 by Gareth Marshall
Meteorological surface observations from the Antarctic Peninsula began in the mid-1940s. The most reliable long-term (~50 years) temperature record from this region has been obtained from Faraday station on the…1 January, 2001
Retinal visual fields were determined using an ophthalmoscopic reflex technique in two seabird species of the family Procellariidae: white-chinned petrel Procellaria aequinoctialis and antarctic prion Pachyptila desolata. The binocular fields…1 January, 2001 by Sandra McInnes, Sandra McInnes
How true is the statement: “The camera never lies”? Trick photography has a long and varied history, and good fakes are extremely difficult to refute. Now computer software makes it…