Showing 11923 items
1 January, 1998
Strontium isotope stratigraphy provides a chronology for Cenozoic cryogenic strata in the northern Antarctic Peninsula and allows an assessment of diachronism in onset of glacial conditions between East and West…1 January, 1998
Aptian to Pliocene time-series of X-ray fluorescence data from the Antarctic Peninsula are used to assess the degree of chemical weathering and maturity of sediments deposited prior, and subsequent to…1 January, 1998
Clay mineral, sedimentological and geochemical data show that the northern Antarctic Peninsula (Seymour Island, La Meseta Formation) experienced a climatic deterioration from very warm, non-seasonally wet conditions at the end…1 January, 1998
The breakup of ice shelves has been widely regarded as an indicator of climate change1, with observations around the Antarctic Peninsula having shown a pattern of gradual retreat, associated with…Read more on Breakup and conditions for stability of the northern Larsen Ice Shelf, Antarctica
1 January, 1998
The Mesozoic Fossil Bluff Group of Alexander Island contains trench-slope and forearc basin deposits that formed during the eastward subduction of oceanic crust beneath the Antarctic Peninsula region. The oldest…1 January, 1998 by Mervyn Freeman
A sharp latitudinal gradient in the Doppler spectral width is often observed in the nightside data from the SuperDARN HF radars. We use an excellent conjunction between the Halley HF…Read more on The nightside ionospheric response to IMF by changes
1 January, 1998
The specification, development and deployment of an automated observatory designed to operate unattended for a year in the extreme climatic conditions of the polar regions is presented. Solar- and wind-powered…Read more on Automated observatories for geospace research in polar regions
1 January, 1998
Lichens have a primary role in the biodeterioration of rock substrata and in soil formation. In extreme Antarctic rock-face habitats, their exposed epilithic growth form makes them vulnerable to environmental…1 January, 1998
Information on natural mortality rates of the mackerel icefish (Champsocephalus gunnari) from the period prior to known large-scale commercial harvesting is discussed. After careful consideration of the data and available…1 January, 1998 by Mervyn Freeman
We compare the large-scale goemagnetic response to the three magnetic clouds observed by Wind in October 1995 (OCT95), May 1996 (MAY96), and January 1997 (JAN97), studying specifically storm and substorm…Read more on Geoeffectiveness of three Wind magnetic clouds: A comparative study
1 January, 1998
The Dufek intrusion, in the northern part of the Pensacola Mountains, Antarctica, is part of an extensive, Middle Jurassic igneous province that was related to, and emplaced just prior to…1 January, 1998
Vertical facies associations within the CRP- 1 drillcorc reveal a strong cyclicity and facilitate the development of a sequence stratigraphic framework. The sedimentary record appears to be punctuated by a…1 January, 1998 by Adrian Fox
Aerial photography has been used as a mapping tool in the Antarctic Peninsula region since the late 1920s. Following pioneering work by Wilkins in 1928, Ellsworth in 1934 and the…Read more on Climate-change indicators from Archival aerial photography of the Antarctic Peninsula
1 January, 1998 by Mervyn Freeman
The buffetting of the magnetosphere by the solar wind is the cause of many phenomena in the magnetosphere and the ionosphere, and affects the way in which we observe many…Read more on Magnetopause motions in a Newton-Busemann approach
1 January, 1998
We describe the calibration and interpretation of interferograms generated from ERS-I synthetic aperture radar Single Look Complex (SAR. SLC) images of the Rutford Ice Stream area. Ground surveys provide over…1 January, 1998
The ability of the Utah energy-balance and snowmelt model (UEB) to simulate decline in snow water equivalent (SWE) at an extreme location was assessed. Field data were collected at Paternoster…Read more on Snowmelt modelling on Signy Island, South Orkney Islands
1 January, 1998
Cores and 3.5 kHz, sub-bottom profiles collected from the continental slope and rise near 64°S, 52°W, off the tip of the Antarctic Peninsula, reveal transport and depositional processes in a…Read more on A sediment record of cyclic bottom-current variability from the northwest Weddell Sea
1 January, 1998 by Paul Rodhouse
A scientific research fishing expedition targeting the oceanic/slope ommastrephid squid Martialia hyadesi was undertaken by a Korean-registered squid jigger in CCAMLR area 48.3, near South Georgia, in June 1996, providing…1 January, 1998 by Jonathan Watkins, Paul Rodhouse
During a research cruise of the British Antarctic Survey ship RRS James Clark Ross in February 1996, more than 2 000 individuals of the ommastrephid squid, Martialia hyadesi, were caught…Read more on Attribtuion of acoustic echoes to squid in the south Atlantic
1 January, 1998
The Mesozoic-Cenozoic volcanic arc of the Antarctic Peninsula is represented on Adelaide Island by a sedimentary and volcanic succession intruded by plutons. 40Ar-39 Ar step-heating age spectra have been obtained…Read more on The stratigraphy and geochronology of Adelaide Island
1 January, 1998 by Eric Wolff
Two years worth of daily aerosol data has been collected from Halley station, Antarctica, between February 1991 and February 1993. The seasonal cycle of sea-salt aerosol was found to peak…1 January, 1998
Rock temperature data collected at one-minute intervals from both the horizontal surface and the four cardinal directions of a rock outcrop show the influence of record interval and aspect on…1 January, 1998
US Joint Ice Center (JIC) Antarctic sea ice extent data, the longest continuous series of its kind for this part of the world, are compared with direct passive microwave-based estimates…1 January, 1998
The Byers Group, exposed in the western South Shetland Islands, is a thick (at least 2.7 km) succession recording Late Jurassic–Early Cretaceous sedimentation and volcanism on the Pacific flank of…1 January, 1998
The northern, James Ross Island region of the Larsen Basin, on the eastern, back-arc margin of the Antarctic Peninsula magmatic arc, includes one of the thickest and most complete Upper…1 January, 1998 by Richard Hindmarsh, Richard Hindmarsh
The time-dependent physics of ice sublimation through thin layers of till is considered, to determine whether sublimation could be sufficiently slow to permit the preservation of ice for 8 Ma…Read more on Sublimation of ice through sediment in Beacon Valley, Antarctica
1 January, 1998 by Dominic Hodgson, Nadine Johnston
A recent rapid increase in the number of Antarctic fur seals on Signy Island has caused extensive changes to terrestrial and freshwater ecosystems. A palaeolimnological study was carried out to…1 January, 1998 by Dominic Hodgson
Lake sediment cores from Midge Lake, Livingston Island, South Shetland Islands and Sombre Lake, Signy Island, South Orkney Islands were analysed for volcanic tephra using light microscopy and magnetic susceptibility.…1 January, 1998 by William Block
Extensive studies on invertebrates from Ny-Ålesund, Spitsbergen, Svalbard and more limited data on aphids from Abisko, Sweden, produced the following main conclusions: (1) The population response to raised summer temperatures…1 January, 1998 by Eugene Murphy
Historical observations of the large-scale flow and frontal structure of the Antarctic Circumpolar Current in the Scotia Sea region were combined with the wind-induced surface Ekman transport to produce a…1 January, 1998 by Richard Horne
The possibility of electron stochastic energization to relativisitic energies (≥ 1 MeV) via resonant wave-particle interactions during a magnetic storm is explored. The minimum electron energy Emin for cyclotron resonant…1 January, 1998 by John King
Atmospheric wave-trains of climate anomalies are investigated as a candidate for linking low and high latitude atmospheric signals during Pacific Ocean warm (ENSO) and cold (La Niña) events. Study results,…1 January, 1998
An area of mudwave development has been identified from the northwestern Powell Basin, northern Weddell Sea, Antarctica. The wave-field is located near the base of the continental slope in water…1 January, 1998
F region peak heights, derived from ionospheric scaled parameters through 38-year data series from both Argentine Islands (65°S, 64°W) and Port Stanley (52°S, 58°W) have been analyzed for signatures of…1 January, 1998
The implementation of a technique to derive mesospheric winds from HF radar observations of meteor echoes at Halley (76°S, 27°W), Antarctica, is described. The meteor echoes are observed at near…1 January, 1998 by Anna Jones, John Turner
A regular occurrence during the 1990s has been the excursion of the edge of the springtime Antarctic ozone hole over the southernmost region of the South American continent. Given the…1 January, 1998
Observations of satellite passes monitored at Halley and Terra Nova Bay have been combined to produce for the first time measurements of ionospheric electron content spanning the Antarctic continent. Results…Read more on Ionospheric electron content across the Antarctic continent
1 January, 1998
The dynasonde at Halley, Antarctica, is operated throughout the year making ionogram soundings every five minutes. The extensive database of observations from 1993 and 1994 has been processed to investigate…1 January, 1998
New constraints on the age of the Cockburn Island Formation, northern Antarctic Peninsula, resulting from whole rock laser-stepped heated 40Ar–39Ar dating of associated basalt and palaeomagnetic re-calibration of the ranges…1 January, 1998
The longest-known pectinid-bearing deposit in the Antarctic, the "Pecten-conglomerate" of Cockburn Island in the James Ross Island group, northern Antarctic Peninsula, is herein formally named the Cockburn Island Formation. A…1 January, 1998
Antarctic late Cenozoic pectinid-bearing sedimentary strata are chiefly confined to localities in the northern part of the Antarctic Peninsula, in the McMurdo Sound area, and Marine Plain, East Antarctica. Ages…Read more on Stratigraphy of Antarctic late Cenozoic pectinid-bearing deposits
1 January, 1998
Macrofossil content from the Miocene part of CRP-1 core, Cape Roberts (Victoria Land Basin) is scant and mostly limited to a few pectinid bivalves and serpulid polychaetes. Selective diagenesis has…1 January, 1998
Levels of persistent organic pollutants (POPs), such as polychlorinated biphenyls and pesticides have been determined in ambient air at Signy Island, Antarctica, over a period of 17 weeks. Mean concentrations…1 January, 1998 by John King, Thomas Lachlan-Cope
We use snow surface temperatures obtained from thermal infrared (TIR) satellite imagery, together with radiosonde profiles of free-air temperature and high-resolution topographic data to study the thermal structure of the…1 January, 1998 by John King
Temperature records from stations on the west coast of the Antarctic Peninsula show a very high level of interannual variability and, over the last 50 years, larger warming trends than…1 January, 1998 by John King
Long term air and snowfall chemistry measurements have been performed at the three coastal Antarctic stations Dumont d'Urville (66°40′S, 140°1′E), Neumayer (70°39′S, 8°15′W), and Halley (75°35′S, 26°19′W). The results have…1 January, 1998 by Ed King, Philip Leat, Robert Larter
The simple tectonic history of the South Sandwich island arc, a classic intra-oceanic arc lying in the South Atlantic Ocean, provided excellent opportunities for the Sandwich Lithospheric and Crustal Experiment…Read more on South Sandwich slices reveal much about arc structure, geodynamics, and composition
1 January, 1998
Strontium isotope stratigraphy was used to date five discrete horizons within CRP- 1. Early and late Quaternary (0 87- 1 3 Ma and 0-0 67 Ma respectively) age sediments overlie…Read more on Strontium-isotope stratigraphy of the CRP-1 drillhole, Ross Sea, Antarctica
1 January, 1998 by Robert Mulvaney
Year-round aerosol samples collected in the boundary layer at coastal Antarctic sites (Dumont D'Urville, Neumayer, and Halley) indicate a seasonal cycle of ammonium concentrations with a minimum in winter (April–September).…1 January, 1998
Multiple-year time series of the weight ratio R of methane sulfonic acid (MSA) to non-sea-salt sulfate (nss SO4) in aerosols collected at three coastal Antarctic stations Neumayer (70°39′S, 8°15′W), Halley…1 January, 1998 by Michael Pinnock
The Finnish radar of CUTLASS has been operational since February 1995. Between 0620 and 0800 UT on August 25 1995, a region of ionospheric scatter, which was limited to only…Read more on CUTLASS observations of convection in the cusp region
1 January, 1998 by Mervyn Freeman
We use the Goose Bay HF radar to investigate the behavior of the electric field within the substorm current wedge for a small substorm (< 200 nT) which occurred on…Read more on The behavior of the electric field within the substorm current wedge
1 January, 1998
An extended interval of strong northward interplanetary magnetic field (IMF) was observed by the Wind spacecraft located at an upstream distance of ∼193 RE from February 8–10, 1995, with a…Read more on Multipoint study of a substorm on February 9, 1995
1 January, 1998 by Philip Leat
The isotopic difference between modern Indian Ocean and Pacific or North Atlantic Ocean ridge mantle (e.g. variably lower 206Pb/204Pb for a given εNd and 208Pb/204Pb) could reflect processes that occurred…1 January, 1998 by Gareth Marshall, John King
The Southern Hemisphere reveals markedly different circulation patterns associated with extreme warm and cold Antarctic Peninsula (AP) winter temperatures. Warm winters are associated with negative 500 hPa height anomalies in…1 January, 1998 by Gareth Marshall, John Turner
In this study we correlate temporal features within the electrical conductivity (acidity) traces of four shallow firn cores obtained from the southern Antarctic Peninsula to synoptic-scale variations in the regional…1 January, 1998
Aerobiological sampling was conducted year-round at three sites on Signy Island, maritime Antarctic, between December 1992 and January 1994, and during the summer at a fourth coastal site. The concentrations…1 January, 1998
Anterior eye structure and retinal visual fields were determined in grey–headed and black–browed albatrosses, Diomedea melanophris and D. chrysostoma (Procellariiformes, Diomedeidae), using keratometry and an ophthalmoscopic reflex technique. Results for…Read more on Eye structure and amphibious foraging in albatrosses
1 January, 1998
The diving behaviour of Antarctic fur seal (Arctocephalus gazella) pups on Bird Island, South Georgia (54°S, 38°W), was examined during February-April 1996 using capillary-tube depth gauges (CDGs) and time-depth recorders…Read more on Diving behaviour of Antarctic fur seal (Arctocephalus gazella) pups
1 January, 1998
This study examined the relative contribution of environmental variation and the seasonal demands of pup rearing on the foraging behaviour of female Antarctic fur seals Arctocephalus gazella at Bird Island,…Read more on Foraging responses of Antarctic fur seals to changes in the marine environment
1 January, 1998
Alexander Island, situated off the west coast of the Antarctic Peninsula, contains a suite of Late Cretaceous to Early Tertiary subduction-related magmatic rocks. The rocks occupy a fore-arc position 100–200…1 January, 1998 by Robert Larter
Quantitative estimates of the rates and azimuths of Phoenix plate convergence with the Antarctic Peninsula have been derived from plate rotation calculations for two periods in the Late Cretaceous and…Read more on Late Cretaceous to early Tertiary subduction history of the Antarctic Peninsula
1 January, 1998 by Sandra McInnes, Sandra McInnes
The Tardigrada is a cosmopolitan phylum of pre-Pangaean origin, yet tardigrade families and genera show distinct biogeographic components isolated by two major geological events. Separate Laurasian and Gondwanan familial clusters…1 January, 1998 by Thomas Lachlan-Cope
The British Antarctic Survey operates both aircraft and ships in the Antarctic. High quality weather forecasts can have a large impact on safe operations at high southern latitudes. This paper…1 January, 1998 by Lloyd Peck
The reproductive cycle of the Antarctic articulate brachiopod Liothyrella uva (Broderip, 1833) is described from monthly samples collected between September 1985 and July 1987 from a population at Signy Island,…Read more on Reproductive patterns in the Antarctic brachiopod Liothyrella uva
1 January, 1998 by Eric Wolff
The concentrations of sulfur-containing species (sulfate and methanesulfonate (MSA)) of aerosols collected at three coastal Antarctic sites (Neumayer, Dumont d'Urville, and Halley) have been studied in order to investigate the…1 January, 1998
We report recent mapping of Spiess Ridge with the Hawaii-MR1 sidescan sonar. Spiess Ridge is an unusual elongate 90 by 50 km volcanic feature on the slow spreading Southwest Indian…Read more on Spiess Ridge: An axial high on the slow spreading Southwest Indian Ridge
1 January, 1998
New Hawaii-MR1 sonar data show that the southernmost Mid-Atlantic Ridge joins the South American–Antarctic Ridge by an obliquely opening rift and overlaps Spiess Ridge, the westernmost segment of the Southwest…Read more on The present configuration of the Bouvet triple junction
1 January, 1998
The existence of seasonal changes in concentrations of water-soluble carbohydrates in arthropods (both freezing-tolerant and intolerant species) from Signy Island was demonstrated. Seasonal patterns of variation, imposed by seasonality of…1 January, 1998
Quaternary deposits in six sediment cores from the Scotia Sea, Antarctica, were examined for the presence of volcanic ash layers. The cores were recovered from water depths of 3369-4025 m.…1 January, 1998 by Eric Wolff, Robert Mulvaney
Postdepositional loss of nitrate in near-surface snowfall is well known, with mean levels of nitrate in ice cores of around 20 to 80 ng g−1, while nitrate in surface snow…1 January, 1998 by Eugene Murphy
Most analyses of marine microbial systems in the seasonally ice covered areas of the Southern Ocean have been based on data from the major embayment areas of the Ross and…1 January, 1998 by Eugene Murphy, Jonathan Watkins, Philip Trathan
Interannual variability is a characteristic feature of the Southern Ocean ecosystem, yet the relative roles of biological and physical processes in generating these fluctuations are unknown. There is now extensive…1 January, 1998 by Richard Hindmarsh, Richard Hindmarsh
A linearized perturbation about a two-dimensional Vialov-Nye icesheet profile is used to investigate the sensitivity of the divide position at Siple Dome, West Antarctica, to small changes in the accumulation…Read more on Sensitivity of the divide position at Siple Dome, West Antarctica to boundary forcing
1 January, 1998 by Philip Trathan
Gobionotothen gibberifrons1 January, 1998
This paper investigates the climate change in two atmosphere-ice-ocean coupled climate models - the UKMO and the CSIRO - in the Antarctic region over the next century. The objectives were…1 January, 1998
There are five species in the genus Ditrichum Hampe in the Antarctic: D. heteromallum (Hedw.) Britt., D. conicum (Mont.) Mitt., D. austrogeorgicum (Card.) Seppelt, D. lewis-smithii Ochyra and D. gemmiferum…1 January, 1998 by Michael Pinnock
We report a case study of decameter-scale electron density irregularities associated with polar cap patches and auroral (boundary) blobs in the southern high-latitude F region ionosphere. The observations were carried…1 January, 1998
Beak shapes in nine species of Southern Ocean octopodids were measured using seven size-standardized ratios. The results were analysed using principal component analysis and discriminant function analysis and show that…1 January, 1998
In long-lived and monogamous species, with partners separated between breeding seasons, the previous mate usually returns and waiting is therefore rewarded, thus contributing to mate retention as an adaptive strategy.…Read more on Divorce in king penguins: asynchrony, expensive fat storing and ideal free mate choice
1 January, 1998
Marie Byrd Land, Antarctica, is a major part of the proto-Pacific supercontinental margin. On the basis of new geochronological and geochemical data relating to its pre-Jurassic evolution, Marie Byrd Land…1 January, 1998 by Philip Leat, Teal Riley
The field occurrence, age, classification and geochemistry of the Mesozoic volcanic rocks of Patagonia and West Antarctica are reviewed, using published and new information. Dominated by rhyolitic ignimbrites, which form…1 January, 1998
Field and earthquake data are presented which show that small faults can be important during block rotation. `Small' here means those faults which are at least an order of magnitude…Read more on Evidence for the importance of `small’ faults on block rotation
1 January, 1998 by Helen Peat
The British Antarctic Survey's Antarctic Plant Database holds over 50,000 herbarium records for Antarctic and sub-Antarctic flowering plants and cryptogams held in herbaria world-wide. In addition, it holds information on…Read more on The Antarctic Plant Database: a specimen and literature based information system