Found 14049 items
1 January, 2007
We present a new conceptual model where supercontinents, by focusing subduction on narrow areas of the 670 km mantle discontinuity, trigger superplume events and initiate their own fragmentation. This supercontinent-triggered…1 January, 2007 by David Vaughan
A recent report from Working Group I of the Intergovernmental Panel on Climate Change [IPCC, 2007] highlighted the increasingly precise observations of sea level rise that are obtainable from satellite…1 January, 2007 by David Vaughan, Robert Arthern
Ice sheet retreat, hypotheses of instability could be missing important processes that limit the rate or extent of retreat, or conversely, Ice sheet behavior is strongly influenced by processes at…Read more on Why is it hard to predict the future of ice sheets?
1 January, 2007 by David Vaughan, Hugh Corr
Subglacial Lake Ellsworth (SLE) was identified using reconnaissance data collected in the 1970s, here we present more detailed surveys. SLE lies beneath 3.2 km of ice in a subglacial valley…Read more on Topographic and hydrological controls on Subglacial Lake Ellsworth, West Antarctica
1 January, 2007 by Mark Clilverd
We utilise hydroxyl observations from the MLS/Aura satellite instrument to study the latitudinal extent of particle forcing in the northern polar region during the January 2005 solar proton event. MLS…1 January, 2007 by Dominic Hodgson
There is a long-standing belief that microbial organisms have unlimited dispersal capabilities, are therefore ubiquitous, and show weak or absent latitudinal diversity gradients. In contrast, using a global freshwater diatom…Read more on Historical processes constrain patterns in global diatom diversity
1 January, 2007 by Adrian Jenkins
Glaciers which drain the West Antarctic Ice Sheet (WAIS) into the Amundsen Sea are accelerating and thinning rapidly. These observations have been attributed to the regional oceanography whereby heat contained…Read more on Oceanic heat transport onto the Amundsen Sea shelf through a submarine glacial trough
1 January, 2007 by Emma Young, Peter Ward, Sally Thorpe
During late December 2004 and early January 2005 the plankton community to the south and west of South Georgia was investigated. Satellite imagery had shown the surface expression of a…1 January, 2007 by Peter Ward
In this study we report the abundance, fecundity and an index of mortality of Oithona similis across a large latitudinal and temperature range within the Southern Ocean. The abundance of…1 January, 2007
The first underwater digital photographs obtained by cameras carried by Shags PhaJacrocorax aristoteJis showed the birds diving in areas dominated by soft coral Alcyonium digitatum and feeding on butterfish PhoJis…1 January, 2007 by Paul Holland
A drag law accounting for Ekman rotation adjacent to a flat, horizontal boundary is proposed for use in a plume model that is written in terms of the depth-mean velocity.…Read more on The effect of a new drag law parameterization on Ice Shelf Water plume dynamics.
1 January, 2007 by Claus-Dieter Hillenbrand
This paper explores the effects of preservation and taphonomy on the ultrastructure of recent and fossil (Quaternary and Neogene) Globigerinoides using scanning electron microscopy and thin section petrography. We show…1 January, 2007 by Tom Jordan
Magnetic anomaly data are presented from a new helicopter-borne high-resolution aeromagnetic survey in southern McMurdo Sound. Anomaly data have been acquired at a common 305 m elevation above the McMurdo…1 January, 2007 by Eric Wolff
Polar ice cores contain, in trapped air bubbles, an archive of the concentrations of stable atmospheric gases. Of the major non-CO2 greenhouse gases, methane is measured quite routinely, while nitrous…Read more on Methane and nitrous oxide in the ice core record
1 January, 2007 by Eric Wolff
Predicting the future of our Earth and its climate requires models that contain good representations of the key processes that might take place. Our only way to determine what these…Read more on Frozen in time: the chemistry of polar ice cores
1 January, 2007 by Eric Wolff
Ice cores have been a cornerstone of global change research in recent decades. Europe has been at the forefront of this science, particularly through the GRIP and EPICA projects funded…1 January, 2007 by Eric Wolff
Recent recommendations for the expression of time units in Quaternary Science Reviews appear still to leave room for confusion. Here, I propose that the entire palaeoclimate community should agree on…1 January, 2007 by Anna Jones, Eric Wolff
Ice cores provide the most direct evidence available about the past atmosphere. For long-lived trace gases, ice cores have provided clear evidence that in the last two centuries, concentrations of…Read more on Past atmospheric composition and chemistry from ice cores – progress and prospects
1 January, 2007
We show that correlated dynamics and long time memory persist in self-organized criticality (SOC) systems even when forced away from the defined critical point that exists at vanishing drive strength.…1 January, 2007 by Roger Worland
The Antarctic collembolan, Cryptopygus antarcticus (Willem), can switch its supercooling point (SCP) between 'winter' and 'summer' modes of cold hardiness over a matter of hours. High resolution temporal scaling of…1 January, 2007 by Robert Mulvaney
The atmospheric histories of two potent greenhouse gases, tetrafluoromethane (CF4) and hexafluoroethane (C2F6), have been reconstructed for the 20th century based on firn air measurements from both hemispheres. The reconstructed…Read more on Atmospheric trends and radiative forcings of CF4 and C2F6 inferred from firn air
1 January, 2007
The relationship between predator sizes and prey sizes is well documented for terrestrial but rarely for marine ecosystems. We show that wandering albatrosses, the biggest albatross species, feed on larger…Read more on Predator–prey interactions: why do larger albatrosses eat bigger squid?
1 January, 2007 by Andrew Wood, Paul Rodhouse
Assessing the consumption of prey by predators in the marine environment is key to fisheries assessment and management. Although environmental and ecological variations can affect the consumption of certain prey…1 January, 2007
The unusually harsh environmental conditions of terrestrial Antarctic habitats result in ecosystems with simplified trophic structures, where microbial processes are especially dominant as drivers of soil-borne nutrient cycling. We examined…1 January, 2007
Soil-borne microbial communities were examined via a functional gene microarray approach across a southern polar latitudinal gradient to gain insight into the environmental factors steering soil Nand C-cycling in terrestrial…1 January, 2007 by David Pearce, Kevin Newsham
Although soil-borne bacteria represent the world's greatest source of biological diversity, it is not well understood whether extreme environmental conditions, such as those found in Antarctic habitats, result in reduced…Read more on Patterns of bacterial diversity across a range of Antarctic terrestrial habitats
1 January, 2007 by Zhaomin Wang
The MPM-2, an Earth system model of intermediate complexity, is employed to study the climate system response to natural forcings during the pre-industrial era (1000-1800 AD), with a special focus…Read more on Simulation of the climatic effects of natural forcings during the pre-industrial era
1 January, 2007
We examine the geomagnetic field and space plasma disturbances developing simultaneously in the solar wind, in the inner and outer magnetosphere, and on the ground from 0730 to 2030 UT…1 January, 2007 by Peter Convey
The diversification of Antarctic springtails and mites is likely to have occurred as a result of the glaciation and isolation of the Antarctic continent completed by ~10 million years ago,…1 January, 2007
Pi1 observations, because of their higher frequency, hold the promise of providing better temporal resolution for accurate timing of substorm onsets, thus continuing to be a matter of considerable importance…Read more on An attempt to locate substorm onsets using Pi1 signatures
1 January, 2007 by Fausto Ferraccioli, Tom Jordan
Subglacial sediments are an important control on fast flowing ice in West Antarctica but their spatial distribution over catchment-wide areas is still largely unknown. Previously, airborne gravity anomalies could not…Read more on Locating subglacial sediments across West Antarctica with isostatic gravity anomalies
1 January, 2007 by John Turner, Thomas Bracegirdle
Sea ice plays a key role for climate and is important as habitat and for human activities and economies. Observations show and models indicate that climate and sea-ice regimes are…1 December, 2006
Radar altimeters are one of the main tools for measuring elevation changes across the Antarctic and Greenland ice sheets and larger ice caps. A ground-based radar was deployed in autumn…1 December, 2006 by Andy Smith
Ten passive seismic recording stations were deployed in a 9 km by 6 km array on Rutford Ice Stream, West Antarctica, to detect microearthquakes from the ice stream bed. The…1 December, 2006
Physical, chemical and biological variables were quantified in 19 subantarctic lakes (South Georgia) as a prelude to comparing these pristine systems with temperate lakes and to improve the knowledge of…23 October, 2006
We present results of an implementation of the Elastic Viscous Plastic (EVP) sea ice dynamics scheme into the Hadley Centre coupled ocean-atmosphere climate model HadCM3. Although the large-scale simulation of…1 October, 2006 by Mark Clilverd
During the northern hemisphere winter of 2003–2004 significant levels of stratospheric odd nitrogen (NOX) were observed descending from the mesosphere. Here we study subionospheric radio wave propagation data from Ny…Read more on Ionospheric evidence of thermosphere-to-stratosphere descent of polar NOx
9 August, 2006 by Mark Clilverd
High altitude nuclear explosions (HANEs) and geomagnetic storms can produce large scale injections of relativistic particles into the inner radiation belts. It is recognised that these large increases in >1…Read more on The atmospheric implications of radiation belt remediation
1 August, 2006 by Michael Meredith
Analysis of satellite altimeter data reveals anomalously high Eddy Kinetic Energy (EKE) in the Antarctic Circumpolar Current (ACC) during the period 2000–2002. Around 2–3 years earlier (1998), the circumpolar eastward…12 July, 2006 by Robert Mulvaney
Four trihalomethane (THM; CHCl3, CHBrCl2, CHBr2Cl and CHBr3) and two dihalomethane (DHM; CH2BrCl and CH2Br2) trace gases have been measured in air extracted from polar firn collected at the North…1 July, 2006
The Soufrière Hills volcano, Montserrat, West Indies, has undergone a series of dome growth and collapse events since the eruption began in 1995. Over 90% of the pyroclastic material produced…1 May, 2006 by Gabriele Stowasser, Martin Collins
Fatty acid and stable isotope analyses have previously been used to investigate foraging patterns of fish, birds, marine mammals and most recently cephalopod species. To evaluate the application of these…1 April, 2006 by Povl Abrahamsen, Keith Nicholls
The cavities beneath Antarctic ice shelves are among the least studied regions of the World Ocean, yet they are sites of globally important water mass transformations. Here we report results…Read more on Measurements beneath an Antarctic ice shelf using an autonomous underwater vehicle
1 April, 2006 by Mark Clilverd
Ozone observations from the GOMOS instrument together with a coupled ion and neutral chemistry model are used to study the effects of the January 2005 solar storms on the polar…Read more on Destruction of the tertiary ozone maximum during a solar proton event
7 March, 2006
Images of mesospheric airglow and radar-wind measurements have been combined to estimate the difference in the vertical flux of horizontal momentum carried by high-frequency gravity waves over two dissimilar Antarctic…Read more on Regional variations of mesospheric gravity-wave momentum flux over Antarctica
1 March, 2006 by Eugene Murphy, Geraint Tarling, Jonathan Watkins
We used the instantaneous growth rate method to determine the effects of food, temperature, krill length, sex, and maturity stage on in situ summer growth of krill across the southwest…1 March, 2006 by David Barnes
In July 2003 Kirsty Brown, a marine biologist at Rothera Research Station (West Antarctic Peninsula), was attacked and drowned by a leopard seal (Hydrurga leptonyx). As a direct consequence, a…1 February, 2006
Rosemary Bank is a broadly domed and elongate seamount with a diameter of 70 km, occurring in water depths of between 300 and 2300 m, 120 km west of the…1 February, 2006 by Martin Collins
A long-synonymized species Benthoctopus normani (Massy 1907) (Cephalopoda: Octopodidae) is redescribed from material collected over 30 years by the National Oceanography Centre, Southampton and the National Museums of Scotland. It…1 February, 2006
Simulation modeling was used to reconstruct Black-browed Albatross (Diomedea melanophris) population trends. Close approximations to observed data were accomplished by annually varying survival rates, reproductive success, and probabilities of returning…13 January, 2006 by Lloyd Peck
Understanding thermal limits and the ability of species to cope with changing temperatures is crucial for a cause and effect understanding of climate effects on organisms and ecosystems. Data available…1 January, 2006 by Alistair Crame
The James Ross Basin, at the northern tip of the Antarctic Peninsula, provides the thickest and best-exposed onshore Cretaceous and Early Tertiary sedimentary succession in Antarctica. When compared with other…1 January, 2006 by Gareth Chisham, Mervyn Freeman
We present a spatial structure function analysis of ionospheric velocity, measured by the Halley Super Dual Auroral Radar Network (SuperDARN) radar over five years. We show evidence for scale-free velocity…1 January, 2006 by Mervyn Freeman
Over recent years, substorm chorus events (SCEs) have been proposed as a useful indicator of substorm onset. The events are regularly seen in the data from the VELOX (VLF/ELF Logger…Read more on Association of substorm chorus events with drift echoes
1 January, 2006 by Povl Abrahamsen
From 1993 to 1996, three oceanographic moorings were deployed in the north-western Barents Sea, each with a current meter and an upward-looking sonar for measuring ice drafts. These yielded three…Read more on Ice draft and current measurements from the north-western Barents Sea, 1993-96
1 January, 2006
Understanding the relationship between soil biodiversity and ecosystem functioning is critical to predicting and monitoring the effects of ecosystem changes on important soil processes. However, most of Earth's soils are…Read more on Diversity and distribution of Victoria Land biota
1 January, 2006 by Peter Convey
The chironomid midges Belgica antarctica, Eretmoptera murphyi (subfamily Orthocladiinae) and Parochlus steinenii (subfamily Podonominae), are the only Diptera species currently found in Antarctica. The relationships between these species and a…1 January, 2006
The Greenland Ice Core Chronology 2005, GICC05, is extended back to 42 ka b2k (before 2000 AD), i.e. to the end of Greenland Stadial 11. The chronology is based on…Read more on The Greenland Ice Core Chronology 2005, 15–42ka. Part 1: constructing the time scale
1 January, 2006
Numerous factors influence the increased health risks of seamen. This study investigated sleep (by actigraphy) and the adaptation of the internal clock in watch-keeping crew compared to day workers, as…1 January, 2006 by Fausto Ferraccioli
Airborne geophysical surveys play a pivotal role in imaging subglacial geology and characterizing broad areas of the Antarctic liothsphere. Ground-based geophysics, coupled with airborne geophysics and geology, is essential to…Read more on Recent aeromagnetic and deep electromagnetic exploration projects in East Antarctica
1 January, 2006 by David Barnes, Katrin Linse
Bouvet (Bouvetøya) is a geologically young and very remote island just south of the Polar Front. Here we report samples taken during the RV “Polarstern" cruise ANTXXI/2 on 3 days…1 January, 2006 by Robert Arthern, Richard Hindmarsh, Richard Hindmarsh
The problem of forecasting the future behaviour of the Antarctic ice sheet is considered. We describe a method for optimizing this forecast by combining a model of ice sheet flow…1 January, 2006 by David Vaughan, Robert Arthern
Different parts of Antarctica receive different amounts of snowfall each year. In this paper we map the variations of the mean annual snow accumulation across the ice sheet. We also…1 January, 2006 by David Vaughan, Fausto Ferraccioli
Marine and rift sediments exert a fundamental control on ice stream flow in the West Antarctic Ice Sheet, and hence on its mass balance and stability. In contrast, most ice…Read more on East Antarctic ice stream tributary underlain by major sedimentary basin
1 January, 2006 by Eric Wolff, Robert Mulvaney
Precise knowledge of the phase relationship between climate changes in the two hemispheres is a key for understanding the Earth's climate dynamics. For the last glacial period, ice core studies1,…Read more on One-to-one coupling of glacial climate variability in Greenland and Antarctica
1 January, 2006 by Andrew Clarke, Claire Allen, Dominic Hodgson, David Barnes, Peter Convey
Aim To investigate the major paradigms of intense isolation and little anthropogenic influence around Antarctica and to examine the timings and scales of the modification of the southern polar biota.…Read more on Incursion and excursion of Antarctic biota: past, present and future
1 January, 2006 by David Barnes
Demonstrable examples of marine interference-competition on ecological, and particularly evolutionary, time-scales have been highly confined in space. However, studies of such competition across large-scale space are conversely mere ‘snapshots’ in…Read more on Temporal-spatial stability of competition in marine boulder fields
1 January, 2006 by David Barnes
Bouvet Island is, uniquely, thousands of km from the next nearest land, even other islands. Its Southern Ocean location, isolation and the exposure of its surrounding cliffs have resulted in…Read more on A most isolated benthos: coastal bryozoans of Bouvet Island
1 January, 2006 by David Barnes, Katrin Linse, Peter Enderlein, Simon Morley
Benthic communities in several fjords and sheltered bays of the north coast of South Georgia Island were examined using SCUBA and shore sampling in November 2004. It is one of…Read more on Shallow benthic communities of South Georgia Island
1 January, 2006
Some organisms are particularly appropriate models for investigation of variability in time and space for given environments. The erect bryozoan Cellarinella nutti, an endemic Antarctic species, is one such organism:…1 January, 2006 by Eric Wolff, Robert Mulvaney
Two 788 m conductivity records from ice cores drilled at Dome C, Antarctica, provide an unprecedented opportunity to examine the past roughness of the Antarctic surface. By measuring the distribution…Read more on A 44 kyr paleoroughness record of the Antarctic surface
1 January, 2006 by Andrew Clarke, David Barnes
The variability of Southern Ocean sea-surface temperatures (SST) are important to understanding coastal biology yet are poorly known amongst biologists. We compare sea temperatures at a constant depth (10–20 m)…Read more on Spatial and temporal variation in shallow seawater temperatures around Antarctica
1 January, 2006 by Eric Wolff
Short communication - no abstract1 January, 2006 by Philip Leat
176Hf/177Hf isotopes provide information about the behaviour of so-called immobile elements in subduction environments. Early studies of Hf isotopes in subduction zones reached different conclusions regarding the mobility of high-field-strength…1 January, 2006
This paper combines four years of radar wind data from Halley and Scott Base in an attempt to resolve the zonal structure of the semi-diurnal tide over Antarctica and to…1 January, 2006 by Richard Phillips
An important aspect of foraging ecology is the extent to which different individuals or genders within a population exploit food resources in a different manner. For diving seabirds, much of…