Showing 11923 items
1 January, 1999
Recent disintegration of ice shelves on the Antarctic Peninsula has highlighted the need for a better understanding of ice shelf fracture processes generally. In this paper we present a fracture…1 January, 1999
The rates of plankton community production and respiration were determined from in vitro changes in dissolved inorganic carbon and dissolved oxygen and the incorporation of (NaHCO3)-C-14 at a coastal site…1 January, 1999
Polar patch was the name given originally to a spatially limited enhancement of the 630-nm emission observed in the dark polar cap. More recently, the term has been applied to…Read more on Riometer and HF radar signatures of polar patches
1 January, 1999
In the last decade there has been a great deal of interest in the detection and understanding of phenomena occurring above active thunderstorms. The discovery of the optical phenomena now…Read more on Red sprites, upward lightning, and VLF perturbations
1 January, 1999 by Mark Clilverd
It has been reported that propagation of very low frequency (VLF) waves in the Earthionosphere waveguide might provide an indication of imminent earthquakes [Hayakawa et al., 1996; Molchanov et al.,…Read more on Modeling of subionospheric VLF signal perturbations associated with earthquakes
1 January, 1999 by Mark Clilverd
Magnetospheric line Radiation (MLR) events are relatively narrowband VLF signals that sometimes drift in frequency, and have been observed in both ground based and satellite data sets. Line radiation has…Read more on Magnetospheric line radiation observations at Halley, Antarctica
1 January, 1999
Red sprites were discovered by chance in 1989 when a low-light TV system was pointed above an active thunderstorm. Red sprites are associated with columns of ionization in the Earth-ionosphere…Read more on VLF scattering from red sprites: Application of numerical modeling
1 January, 1999
Red sprites were discovered by chance in 1989 when a low-light TV system was pointed above an active thunderstorm. Optically, they are observed as clusters of short-lived (∼50 ms) pinkish-red…1 January, 1999 by Howard Roscoe
In June 1996, 16 UV-visible sensors from 11 institutes measured spectra of the zenith sky for more than 10 days. Spectra were analysed in real-time to determine slant column amounts…1 January, 1999 by Howard Roscoe, Thomas Lachlan-Cope
Photographs of clouds taken with a camera with a large aperture ratio must have a short depth of focus to resolve small droplets. Hence the sampling volume is small, which…1 January, 1999 by Roger Worland
Abstract.The alpine tree weta Hemidiena maori Pictet et Saussure (Orthoptera: Stenopelmatidae) is a large, flightless insect found above the treeline on many of the mountain ranges of the South Island…1 January, 1999
Miocene–Recent alkaline volcanic rocks form numerous outcrops scattered widely throughout the Antarctic Peninsula and eastern Ellsworth Land. They occur mainly as short-lived (typically 1–2 million years) monogenetic volcanic fields but…1 January, 1999
Tephrochronology studies in the south polar region are reviewed and evaluated. There have been numerous investigations of tephra layers in ice cores, reflecting the continuing importance of ice cores as…Read more on The upper Cenozoic tephra record in the south polar region: a review
1 January, 1999 by Mervyn Freeman
We firmly establish a certain class of post-midnight ELF/VLF wave events as a signature of the substorm expansion phase. These substorm chorus events (SCEs) have been observed near L =…1 January, 1999
Bryum argenteum, B. pseudotriquetrum and Ceratodon purpureus are the predominant mosses in Victoria Land, continental Antarctica. All have cosmopolitan distributions and are widespread throughout Antarctica with wide ecological amplitudes resulting…1 January, 1999 by Andrew Clarke, Lloyd Peck
A survey of pelagic larvae was undertaken between November 1992 and February 1995 at Signy Island, Antarctica (60° 43′ S, 45° 36′ W). A diver–towed net and hand–held plankton pump…1 January, 1999
The Falkland Islands are one segment of the Permo-Triassic Gondwanian Fold Belt that was displaced during the fragmentation of Gondwana. Palæomagnetic, structural and palæocurrent data, reviewed in this paper, provide…Read more on Reconstruction and break-out model for the Falkland Islands within Gondwana
1 January, 1999 by Philip Leat
Ocean floor magnetic anomalies show that New Zealand was the last continental fragment to separate from Antarctica during Gondwana break-up, drifting from Marie Byrd Land, West Antarctica, about 84 Ma…1 January, 1999
In this paper Beck (1998)reviews the database of palaeomagnetically observed rotations in the Andean margin of South America, in particular with respect to the well known change in sense of…Read more on On the mechanism of crustal block rotations in the Central Andes — Comment
1 January, 1999 by Philip Trathan
Acoustic data from the Polish FIBEX survey in the West Atlantic were analysed using recent acoustic target strength estimates of krill (SC-CAMLR, 1991a). This analysis indicated that the acoustic densities…Read more on Status of the Polish FIBEX acoustic data from the West Atlantic
1 January, 1999
This paper reports the first attempts at geo-location of albatrosses using miniature data loggers attached to seabirds for extended periods of time. The paper highlights the potential of data loggers…1 January, 1999 by David Vaughan, Gareth Marshall, John Turner
Forecasts from the ECMWF re-analysis project (ERA) covering the period 1979–1993 are used to examine the spatial and temporal distribution of net snow accumulation (precipitation minus evaporation) over the Antarctic…1 January, 1999
The Auriga Nunataks shear zone places new tectonic and temporal constraints on the Mesozoic evolution of West Antarctica. The shear zone is a long-lived, arc-orthogonal, ductile transfer fault that preserves…1 January, 1999 by David Vaughan
Recent in situ measurements of surface mass balance and improved calculation techniques are used to produce an updated assessment of net surface mass balance over Antarctica. A new elevation model…Read more on Reassessment of net surface mass balance in Antarctica
1 January, 1999 by Paul Rodhouse
Mastigophora brevipinnis Owen, 1856, is a ‘fossil teuthid’ presently considered to be a member of the coleoid cephalopod Suborder Loligosepiina Jeletzky, which in turn has been placed by various authors…1 January, 1999 by Claire Waluda, Paul Rodhouse, Philip Trathan
The fishery for Illex argentinus in the Southwest Atlantic is subject to large inter-annual variability in recruitment strength. In this paper we attempt to build a predictive model using sea…1 January, 1999
Consistent diel patterns in foraging depths have been recorded in several avian predators which feed on pelagic prey, but nothing is known about such effects in bottom feeding seabirds. In…1 January, 1999
Mesozooplankton (predominantly 200–2000 μm) were sampled at a shelf and an oceanic station close to South Georgia, South Atlantic, during austral spring (October/November) 1997. Onshelf zooplankton biomass was extremely high at…1 January, 1999 by Jonathan Watkins
There is considerable spatial structure within the South Georgia krill-based ecosystem in terms of predator demand, commercial fishery pressure and krill abundance. Here we investigate the hypothesis that there is…Read more on Variation in the distribution of Antarctic krill Euphausia superba around South Georgia
1 January, 1999 by Jonathan Watkins
A composite recruitment index based on density data derived from acoustic surveys and on length-frequency data obtained from either target or station net hauls is described. This composite index is…1 January, 1999
The hypothesis of self-organised criticality (SOC) predicts that certain open dissipative systems evolve to a critical state where all energy release statistics display power law distributions for event occurrence, size…1 January, 1999
Differences in morphometry between five populations of black-browed albatrosses (Diomedea melanophrys) and four populations of grey-headed albatrosses (D. chrysostoma) are examined. Two clear groups of black-browed albatrosses are evident, with…1 January, 1999
The marine habitat exploited by black-browed Diomedea melanophrys and grey-headed albatrosses D. chrysostoma breeding at Campbell Island, New Zealand, was studied using satellite telemetry. Data were analysed in relation to…1 January, 1999
In the Southern Ocean white-chinned petrels Procellaria aequinoctialis form the majority of the bird bycatch in longline fisheries. Satellite tracking of breeding birds from the Crozet islands and from South…1 January, 1999
There is an apparent mismatch between the high carbon demand of seals and seabirds breeding on the subantarctic island of South Georgia and the overall low primary production measured in…1 January, 1999
Eight groups of mafic dikes and related high-level stocks cut Triassic accretionary complex and Mesozoic magmatic arc formations on Livingston Island. Some are affected by silicic/sericitic alteration, related to Cretaceous…1 January, 1999 by Eric Wolff
As part of the European Project for Ice Coring in Antarctica, a new deep ice core is being drilled at Dome C. Two electrical methods have been used on the…Read more on Comparison of Holocene electrical records from Dome C and Vostok, Antarctica
1 January, 1999 by Eric Wolff
A snowpit in Coats Land, Antarctica, has been sampled in order to obtain a record of Cd, Cu and Zn covering the period 1923–1986. The snowpit record gives an indication…Read more on Antarctic snow record of cadmium, copper, and zinc content during the twentieth century
1 January, 1999 by Roger Worland, William Block
The site of ice nucleation in the freeze-tolerant, sub-Antarctic beetleHydromedion sparsutumhas been investigated. Ice+bacteria, active at above −2.0°C, were isolated from the guts of beetles and identified as a fluorescentPseudomonasspecies.…1 January, 1999
For activity and survival in extreme terrestrial Antarctic habitats, lithobiontic cyanobacteria depend on key biomolecules for protection against environmental stress and for optimization of growth conditions. Their ability to synthesize…1 January, 1999
HF radar data during equinoctial, small IMF By conditions have enabled the substorm growth phase to be studied in both hemispheres. This has revealed highly conjugate behavior during the substorm…20 May, 1998 by Eric Wolff, John Hall, Robert Mulvaney
Aerosol and fresh snow concentrations have been determined at three coastal Antarctic stations, Dumont d'Urville, Halley, and Neumayer. Model estimates suggest that dry deposition, including that caused by wind pumping,…20 May, 1998 by Eric Wolff
Aerosol black carbon concentrations have been measured between 1992 and 1995 at Halley station using an aethalometer. The complete record is dominated by a number of events of high concentration…20 May, 1998 by Eric Wolff
Aerosol samples have been collected at three stations on the coast of Antarctica. At Dumont d'Urville Station, samples have been collected for 4 years, at Halley Station for 2 years,…Read more on Coastal Antarctic aerosol and snowfall chemistry
1 January, 1998
Management of the mackerel icefish (Champsocephalus gunnari) at South Georgia is complicated by the likelihood of substantial periodic variations in natural mortality rates. These may be associated with increased consumption…1 January, 1998 by Peter Convey, Rod Arnold
Two populations of the world's most southerly diving beetle (Lancetes angusticollis) were studied on sub-Antarctic South Georgia between November 1995 and April 1996. Parallel observations were made on laboratory cultures…1 January, 1998
Longlining operations for Dissostichus eleginoides off South Georgia were assessed for interactions with seabirds and the effectiveness of measures employed by CCAMLR to mitigate seabird mortality. Following an agreement between…1 January, 1998
Twelve epipelagic copepod species were reviewed to compare their adaptations to the short primary production season and low temperatures which characterise the Southern Ocean. The species show a spectrum of…Read more on Life cycle strategies of epipelagic copepods in the Southern Ocean
1 January, 1998
Band-limited Pc-3 pulsations were observed on one day with pulsation magnetometers, photometers and in VLF activity at South Pole and simultaneously, electric field pulsations were observed in the ionospheric cusp…Read more on The coherence scale length of band-limited Pc3 pulsations in the ionosphere
1 January, 1998
A new numerical model of the high latitude ionosphere is used in conjunction with data from the EISCAT radar facility to study the formation and structure of polar patches. Inputs…Read more on Modelling studies of the effects of cusp inputs on the polar ionosphere
1 January, 1998
The Antarctic Ice Sheet is today an important part of the global climate engine, and probably has been so for most of its long existence. However, the details of its…Read more on Ice sheet history from Antarctic continental margin Sediments: the ANTOSTRAT approach
1 January, 1998
The Antarctic Ice Sheet is a key feature of the global climate engine today, and has been so for most of its 35 Myr or longer history. It influences global…1 January, 1998
The Antarctic cryosphere has had a major effect on Cenozoic global climates, sea levels, oceanography, and Southern Hemisphere biota. Yet the climatic history of Antarctica and its contribution to global…Read more on Coordinated effort in progress to decipher cenozoic ice sheet evolution
1 January, 1998 by Andrew Clarke, David Barnes
The seasonality of polypide cycling has been investigated for three species of erect bryozoans from Antarctica: Isoseculiflustra rubefacta (Kluge, 1914), Nematoflustra flagellata (Waters, 1904) and Himantozoum antarcticum (Calvet, 1905). Approximately…1 January, 1998 by Andrew Clarke, David Barnes
The cheilostome bryozoan Fenestrulina rugula is a major component of the encrusting fauna of physically disturbed shallow water habitats in Antarctica. On rocks collected from Rothera Point, Adelaide Island, F.…Read more on The ecology of an assemblage dominant: the encrusting bryozoan Fenestrulina rugula
1 January, 1998 by Ed King
New multifold seismic‐reflection and wide‐angle reflection/refraction data across George VI Sound, Antarctic Peninsula, show the presence of graben and horst structures indicating an extensional origin. The data suggest that rocks…Read more on New seismic data support Cenozoic rifting in George VI Sound, Antarctic Peninsula
1 January, 1998 by William Block
Ecophysiological features, including survival and recovery from freezing and determination of the freezable water content, are reported for a cold-adapted cockroach Celatoblatta quinquemaculata Johns 1966 (Dictyoptera, Blattidae) inhabiting alpine communities…1 January, 1998 by Roger Worland, William Block
The effects of chilling (to temperatures above the supercooling point, SCP) and freezing on respiration of adults and larvae of two coleopterans living on sub-Antarctic South Georgia (54°S, 37°W),Hydromedion sparsutumandPerimylops…Read more on Respiratory responses to chilling and freezing in two sub-Antarctic insects
1 January, 1998 by Paul Rodhouse
The oegopsid squid family Onychoteuthidae presently comprises six genera (Moroteuthis, Onychoteuthis, Ancistroteuthis, Kondakovia, Onykia and Chaunoteuthis) but the status of some of these is still uncertain. An interdisciplinary study was…Read more on A phylogenetic study of the squid family Onychoteuthidae (Cephalopoda: Oegopsida)
1 January, 1998
Previous reviews have recognized patterns of lactation in pinnipeds divided along phylogenetic lines. This study extended previous models of lactation in pinnipeds by explicitly taking into account all the energetic…Read more on Time and energy constraints in pinniped lactation
1 January, 1998
Based on interviews with 93 fishermen in northern Haiti and Jamaica during 1997 an assessment was made of the likelihood that monk seals survive in this region of the West…Read more on Circumstantial evidence for the presence of monk seals in the West Indies
1 January, 1998
This study examined the foraging locations of adult male and female Antarctic fur seals (Arctocephalus gazella) in the Scotia Sea during the postbreeding period. Satellite transmitters were used to track…Read more on Dispersal of male and female Antarctic fur seals (Arctocephalus gazella)
1 January, 1998 by Jonathan Watkins
Accurate estimation of krill biomass by acoustic techniques is dependent on a number of factors of which one of the most fundamental is accurate echosounder calibration. The Simrad EK500 scientific…1 January, 1998 by Jonathan Watkins, Peter Ward
Acoustic surveys in the vicinity of the sub-Antarctic island of South Georgia during a period of exceptionally calm weather revealed the existence of a number of horizontally extensive yet vertically…Read more on Acoustic discrimination of Southern Ocean zooplankton
1 January, 1998 by Jonathan Watkins
Acoustic Dopplerd current profilers (ADCPs) are being used increasingly to derive estimates of zooplankton and micronekton abundance. The absence of a practical means for users to perform ADCP calibration, however,…1 January, 1998 by Paul Rodhouse
Cephalopod fisheries are among the few still with some local potential for expansion; in fact, as groundfish landings have declined globally, cephalopod landings have increased. We propose the hypothesis that,…Read more on Cephalopod and groundfish landings: evidence for ecological change in global fisheries?
1 January, 1998
Fertile fern foliage described as Lophosoria cupulatus sp. nov. contains the distinctive spore Cyatheacidites annulatus. The fossil foliage is morphologically similar to the Early Cretaceous form-genera Gleichenites and Microphyllopteris, whose…Read more on Early Cretaceous fern foliage from President Head, Snow Island, Antarctica
1 January, 1998
The power law dependence of the power spectrum of auroral indices, and in-situ magnetic field observations in the earth's geotail, may be evidence that the coupled solar wind-magnetospheric system exhibits…Read more on A simple avalanche model as an analogue for magnetospheric activity
1 January, 1998 by Mark Clilverd
The aa index provides the longest continuous data set which can be used in the analysis of magnetospheric and ionospheric phenomenology. All phases of the solar cycle show increases in…Read more on Increased magnetic storm activity from 1868 to 1995
1 January, 1998
The mean number of primaries molted by Gray-headed Albatrosses (Diomedea chrysostoma) varied with year and previous breeding experience independently, but was not related to individual reproductive success over a longer…Read more on factors affecting primary molt in the gray-headed albatross
1 January, 1998
We compare observed temperature variations in Antarctica with climate-model runs over the last century. The models used are three coupled global climate models (GCMs) — the UKMO, the CSIRO and…1 January, 1998 by Peter Convey
The oribatid mite Alaskozetes antarcticus is found over a wide range of southern latitudes, between the cool temperate Falkland Islands (51–52°S) and Alexander Island (71–72°S). It is one of the…1 January, 1998
Deception Island is a large volcanic centre in Bransfield Strait, a very young marginal basin between the South Shetland Islands and Antarctic Peninsula. It has a historical record of volcanic…1 January, 1998
The effect of varying diet and environmental conditions at the Marginal Ice Zone (MIZ) on the fatty acid and hydrocarbon compositions of five species of copepod and krill, Euphausia superba,…1 January, 1998 by Andrew Clarke
Particulate material recovered over an 18-month period from sediment traps deployed at a shallow-water nearshore Antarctic site was analysed for photosynthetic pigments, aliphatic hydrocarbons and fatty acids. All components showed…1 January, 1998
The North Scotia Ridge is a series of islands and submarine ridges extending 2000 km from Tierra del Fuego to South Georgia in the western South Atlantic. The ridge forms…1 January, 1998
The Falkland Islands lie on a displaced crustal block presently forming part of the South American plate. The islands possess two roughly orthogonal structural grains, the relative chronology of which…1 January, 1998
Colonization of artificial substrata was monitored on sheltered rocky shores at Husvik, South Georgia (54° 11′S; 36° 40′W) and Cumbrae, Scotland (55° 46′N; 4° 55′W) from mid summer to early…1 January, 1998
Stauromedusae are cnidarians that have attracted relatively little ecological study, especially in the southern hemisphere. They are Scyphozoa that develop directly from the scyphistoma, and each consists of a calyx…1 January, 1998
The Holocene Murta basalts represent a small volume monogenetic centre located in the northern Patagonian Andes at the latitude of the Chile Triple Junction. These basalts show morphological evidence of…