Showing 11154 items
1 January, 2007 by Lloyd Peck
Polar conditions (low and stable seawater temperature coupled with highly seasonal primary productivity) constrain reproduction in benthic invertebrates. The reproductive cycle of the common Antarctic sea urchin Sterechinus neumayeri was…1 January, 2007 by Lloyd Peck
The fish species Notothenia angustata inhabits temperate waters (10 °C), yet retains physiological traits that show it once existed at sub-zero temperatures. We determined the free-ranging activity, heart rate and…1 January, 2007
The growth rate of atmospheric carbon dioxide (CO2), the largest human contributor to human-induced climate change, is increasing rapidly. Three processes contribute to this rapid increase. Two of these processes…1 January, 2007 by Melody Clark
Background: Duplicated genes are common in vertebrate genomes. Their persistence is assumed to be either a consequence of gain of novel function (neofunctionalisation) or partitioning of the function of the…Read more on Persistence of duplicated PAC1 receptors in the teleost, Sparus auratus
1 January, 2007
An interpretative modeling analysis is conducted to simulate the diurnal variations in OH and HO2 + RO2 observed at Summit, Greenland in 2003. The main goal is to assess the…1 January, 2007 by Geraint Tarling
Backscattering strength was estimated from 127 shipboard surveys with an acoustic Doppler current profiler (ADCP) made during Drake Passage transits from 1999 to 2004. The backscattering strength is used to…1 January, 2007 by Gareth Chisham, Mervyn Freeman, Michael Pinnock
The Super Dual Auroral Radar Network (SuperDARN) has been operating as an international co-operative organisation for over 10 years. The network has now grown so that the fields of view…1 January, 2007 by Peter Convey
Antarctica and its surrounding islands lie at one extreme of global variation in diversity. Typically, these regions are characterized as being species poor and having simple food webs. Here, we…Read more on Spatial and temporal variability across life’s hierarchies in the terrestrial Antarctic
1 January, 2007
Geomagnetic pulsation in the Pc3–4 bands have been studied at high Antarctic latitudes during the local summer. The statistical relation between the occurrence probability of Pc3 and Pc4 pulsations and…1 January, 2007 by Lloyd Peck, Melody Clark
We describe the levels of natural arm damage in the Antarctic brittle star Ophionotus victoriae and the rate of arm regeneration over the period of 1 yr, as measured in…Read more on Delayed arm regeneration in the Antarctic brittlestar Ophionotus victoriae
1 January, 2007 by Michael Thorne, Roger Worland, Melody Clark
Background Ice, snow and temperatures of -14°C are conditions which most animals would find difficult, if not impossible, to survive in. However this exactly describes the Arctic winter, and the…1 January, 2007 by Andrew Clarke, David Barnes, Huw Griffiths, Alistair Crame, Katrin Linse
The aim of this study was to use data for gastropod and bivalve molluscs to determine whether the fauna of the Southern Ocean is sufficiently well known to establish robust…1 January, 2007 by Andrew Clarke, Eugene Murphy, Nadine Johnston
Antarctica offers a unique natural laboratory for undertaking fundamental research on the relationship between climate, evolutionary processes and molecular adaptation. The fragmentation of Gondwana and the development of wide-scale glaciation…1 January, 2007 by Andrew Clarke, David Barnes, Eugene Murphy, John King, Lloyd Peck, Michael Meredith
The Antarctic Peninsula is experiencing one of the fastest rates of regional climate change on Earth, resulting in the collapse of ice shelves, the retreat of glaciers and the exposure…Read more on Climate change and the marine ecosystem of the western Antarctic Peninsula
1 January, 2007 by Mark Clilverd, Nigel Meredith, Richard Horne, Sarah Glauert
The tilt and offset of the Earth's magnetic field can significantly affect the longitudinal and seasonal distribution of electron density in the plasmasphere. Here we show that for the solar…1 January, 2007 by Mark Clilverd
Precipitation of relativistic electrons into the atmosphere has been suggested as the primary loss mechanism for radiation belt electrons during large geomagnetic storms. Here we investigate the geographical spread of…1 January, 2007 by David Pearce
We launched a cryptoendolithic habitat, made of a gneissic impactite inoculated with Chroococcidiopsis sp., into Earth orbit. After orbiting the Earth for 16 days, the rock entered the Earth's atmosphere…1 January, 2007
We report on a case of left main bronchus occlusion by an inhaled foreign body at a remote Antarctic scientific base during the austral winter. We present the dilemmas of…1 January, 2007 by Martin Collins, Mark Belchier
The distribution and diet of juvenile (1 January, 2007 by Thomas Bracegirdle
We assess 19 coupled models from the IPCC fourth assessment report archive from the simulation of the 20th century, based on the calculation of " skill scores.'' The models show…Read more on An Antarctic assessment of IPCC AR4 coupled models
1 January, 2007
We measured egg hatching tunes and stage specific naupliar development tinges of the key calanoid copepods Calanus helgolandicus and C. finmarchicus in response to temperature, food quantity and food type.…1 January, 2007 by Geraint Tarling
Antarctic krill Euphausia superba are key to most Antarctic ecosystems, particularly at South Georgia, where penguins and seals rely on them for their breeding success each summer. Changes in krill…Read more on Behaviour affects local-scale distributions of Antarctic krill around South Georgia
1 January, 2007 by Geraint Tarling, Philip Trathan
Question: How does the female macaroni penguin balance her own needs with those of her chick during breeding? Features of the model: We model the behaviour of female macaroni penguins…1 January, 2007
Glacial and post-glacial shelf sedimentation near the Larsen C and former Larsen B ice shelves is compared to records from ice shelves farther north, which underwent mid-Holocene retreat. A core…1 January, 2007
The growing world population increases the demand for water, energy, and land. This demand for natural resources impacts the transport of material and the supply of nutrients in the coastal…Read more on Potential impact of changes in river nutrient supply on global ocean biogeochemistry.
1 January, 2007 by Sandra McInnes, Sandra McInnes
Low Lake, a freshwater pool at Cape Denison, Commonwealth Bay, Antarctica (67 degrees 20'40"S; 142 degrees 40'45 '' E) was sampled for protists and invertebrates. Forty species of protists were…Read more on Low life in Low Lake, a freshwater pool at Commonwealth Bay, Antarctica
1 January, 2007 by Vsevolod Afanasyev
In most long-lived animal species, juveniles survive less well than adults. A potential mechanism is inferior foraging skills but longitudinal studies that follow the development of juvenile foraging are needed…1 January, 2007
We present a detailed statistical analysis of acoustic emission time series from laboratory rock fracture obtained from different experiments on different materials including acoustic emission controlled triaxial fracture and punch-through…1 January, 2007 by Eugene Murphy, Mervyn Freeman, Richard Phillips, Vsevolod Afanasyev
The study of animal foraging behaviour is of practical ecological importance1, and exemplifies the wider scientific problem of optimizing search strategies2. Lévy flights are random walks, the step lengths of…Read more on Revisiting Lévy flight search patterns of wandering albatrosses, bumblebees and deer
1 January, 2007 by Katrin Linse
We examined deep-sea benthic data on polychaetes, isopods and bivalves from the Atlantic sector of the Southern Ocean. Samples were taken during the expeditions EASIZ II (1998), ANDEEP I and…1 January, 2007
The hydroxyl (OH) rotational temperature and band emission rate have been derived using year-round, ground-based measurements of the infrared OH nightglow from Sweden from 1991 to 2002. Recent work has…Read more on Seasonal variation in the correlation of airglow temperature and emission rate
1 January, 2007 by Geraint Tarling
A series of eight replicated acoustic surveys, four by day and four by night, was undertaken in Gullmarsfjord on the Swedish west coast during two 24-h periods on 8 and…1 January, 2007 by Peter Ward, Sophie Fielding
Net sampling within the vicinity of the Crozet archipelago, in the Indian Ocean sector of the Southern Ocean, was conducted during late spring/summer (November 2004-January 2005) to describe the composition,…1 January, 2007 by Eric Wolff, Robert Mulvaney
Continuous sea salt and mineral dust aerosol records have been studied on the two EPICA (European Project for Ice Coring in Antarctica) deep ice cores. The joint use of these…1 January, 2007
[1] During the Northern Hemisphere summer, absorbed solar radiation melts snow and the upper surface of Arctic sea ice to generate meltwater that accumulates in ponds. The melt ponds reduce…Read more on A continuum model of melt pond evolution on Arctic sea ice
1 January, 2007
U-Pb detrital zircon geochronology from the upper Cambrian to Devonian part of the Ellsworth Mountains succession, Antarctica, yields dominant late Mesoproterozoic and late Neoproterozoic–Cambrian age populations that are onsistent with…1 January, 2007 by Elaina Ford
Recent advances in the performance of CCD detectors have enabled a high time resolution study of the high latitude upper thermosphere with Fabry-Perot Interferometers(FPIs) to be performed. 10-s integration times…1 January, 2007
The Neogene Meyer Desert Formation, Sirius Group, at Oliver Bluffs in the Transantarctic Mountains, contains a sequence of glacial deposits formed under a wet-based glacial regime. Within this sequence fluvial…1 January, 2007 by Andrew Clarke, Lloyd Peck
Growth rates in Antarctic ectotherms are generally considered to be low in comparison to temperate and tropical species. Food consumption plays a major role in determining animal growth rates, but…1 January, 2007
Growth is a fundamental process within all marine organisms. In soft tissues, growth is primarily achieved by the synthesis and retention of proteins as protein growth. The protein pool (all…Read more on Protein metabolism in marine animals: the underlying mechanism of growth
1 January, 2007 by Sandra McInnes, Sandra McInnes
The preservation of tardigrade eggs and exuviae in Antarctic lake sediments provided an opportunity to assess post-glacial colonisation and Holocene tardigrade dynamics on the southern continent. Tardigrade eggs were recovered…1 January, 2007 by Martin Collins
Natural bioluminescence (that not mechanically stimulated by human intervention) produced by organisms on the seafloor of the northeast Atlantic ocean between 970 and 4,800 m depth was examined using an…1 January, 2007
During the Late Miocene the Mediterranean experienced a period of extreme salinity fluctuations known as the Messinian Salinity Crisis (MSC). The causes of these high amplitude changes in salinity are…Read more on The Mediterranean hydrologic budget from a Late Miocene global climate simulation
1 January, 2007
Despite increasing interest in long-distance migration, the wintering areas, migration corridors, and population mix in winter quarters of most pelagic marine predators are unknown. Here, we present the first study…Read more on Trans-equatorial migration and mixing in the wintering areas of a pelagic seabird
1 January, 2007 by Lloyd Peck
This study reports the first multi-year observations on the reproductive patterns for an Antarctic predator/scavenger, Odontaster validus (Koehler 1912). Seastars were collected monthly from a shallow site (15–20 m depth)…1 January, 2007 by Anna Jones, Eric Wolff, Markus Frey
It has been shown that sunlit snow and ice plays an important role in processing atmospheric species. Photochemical production of a variety of chemicals has recently been reported to occur…Read more on An overview of snow photochemistry: evidence, mechanisms and impacts
1 January, 2007
INTRODUCTION: The potential advantage of including a psychological test battery in the selection process for service in the Antarctic was examined in 348 applicants for employment in Antarctica with the…Read more on Psychological selection of Antarctic personnel: the “SOAP” instrument
1 January, 2007
Foraging behaviour and energy expenditure were measured continuously throughout the chick-rearing period of free-ranging macaroni penguins Eudyptes chrysolophus. These data were integrated with values obtained from the literature on body…Read more on Feeding, fasting and foraging success during chick rearing in macaroni penguins
1 January, 2007 by Mark Clilverd
The equatorial plasma density and composition at L = 2.5 were studied during an extended disturbed interval using field line resonance measurements (yielding plasma mass density), naturally and artificially stimulated…1 January, 2007 by Hilmar Gudmundsson
[1] Surface speeds of Rutford Ice Stream, West Antarctica, are known to vary by around 10–20% (depending on location) with a fortnightly periodicity corresponding to a springneap tidal cycle. The…Read more on Tides and the flow of Rutford Ice Stream, West Antarctica
1 January, 2007 by Richard Phillips
Many seabirds nesting in areas bordering the North Sea have recently experienced large annual variation in breeding success, including reproductive failures in some cases. In contrast, the breeding success of…1 January, 2007 by Roger Worland, Peter Convey
The plasticity of an organism's phenotype may vary spatially and temporally, and across levels of physiological organisation. Given the adaptive value of plasticity in heterogeneous environments, it might be expected…1 January, 2007 by Roger Worland, Peter Convey
The effect of moulting on the cold hardiness of the oribatid mite Alaskozetes antarcticus (Michael) is investigated. Non moulting animals show clear seasonal patterns of cold hardiness with high supercooling…1 January, 2007 by Roger Worland, Peter Convey
Darwin was an early exponent of the importance of ‘occasional means of dispersal’ in accounting for the present-day distribution of plants and animals. This study examined the implications of capture…1 January, 2007 by Roger Worland, Peter Convey
Aerial dispersal has been frequently proposed as a potential mechanism by which polar terrestrial arthropods are transported to, and settle the ice free habitats of Antarctica, but to date there…1 January, 2007 by Adrian Jenkins
In March 2003 several autonomous underwater vehicle (AUV) missions were carried out under sea ice in the western Bellingshausen Sea. Data from the upward-looking acoustic Doppler current profiler (ADCP) on…1 January, 2007 by Victoria Peck
The Pliocene may have been characterized by permanent El Niño–like conditions. Initial modeling studies suggest that this may have contributed to Pliocene warmth. The termination of this state may have…Read more on A permanent El Niño–like state during the Pliocene?
1 January, 2007 by Anna Jones
Surface ozone records from ten polar research stations were investigated for the dependencies of ozone on radiative processes, snow-photochemisty, and synoptic and stratospheric transport. A total of 146 annual data…1 January, 2007
A Rayleigh-scatter lidar has been operated at the Atmospheric Lidar Observatory (ALO) on the Utah State University (USU) campus (41.7°N, 111.8°W) since August 1993. During the morning of 22 June…Read more on Observations of a noctilucent cloud above Logan, Utah (41.7oN, 111.8oW) in 1995
1 January, 2007
A cumulative total of over 5 years of data from an MF radar situated at Rothera (67°S, 68°W) on the Antarctic Peninsula have been used to derive climatologies of periodic…1 January, 2007 by Sally Thorpe, Simeon Hill
Expansion of the krill fishery in the Scotia Sea – Antarctic Peninsula region beyond the current precautionary catch limit requires the development and assessment of methods for subdividing the regional…1 January, 2007
The stage-specific abundance and egg production rates of Calanus helgolandicus were determined on a near-weekly basis over 2 yr at a 50 m deep station in the SW English Channel…1 January, 2007
The solar wind exhibits scaling typical of intermittent turbulence in the statistics of in situ fluctuations in both the magnetic and velocity fields. Intriguingly, quantities not directly accessed by theories…Read more on On the fractal nature of the magnetic field energy density in the solar wind
1 January, 2007 by Jaume Forcada, Philip Trathan
Much debate surrounds the exact rules that influence mating behaviour, and in particular the selective forces that explain the evolution of female preferences. A key example is the lek paradox,…Read more on Female fur seals show active choice for males that are heterozygous and unrelated
1 January, 2007 by Adrian Jenkins, Paul Holland
In winter, brine rejection from sea ice formation and export in the Weddell Sea, offshore of Filchner-Ronne Ice Shelf (FRIS), leads to the formation of High Salinity Shelf Water (HSSW).…Read more on Validity of the Ice Shelf Water plume concept under Filchner-Ronne Ice Shelf
1 January, 2007 by Paul Holland
The growth (melt) rate of frazil ice is governed by heat transfer away from (towards) the ice crystal, which can be represented by the Nusselt number. We discuss choices for…1 January, 2007 by Adrian Jenkins, Paul Holland
A two-dimensional plume model is used to study the interaction between Filchner-Ronne Ice Shelf, Antarctica and its underlying ocean cavity. Ice Shelf Water (ISW) plumes are initiated by the freshwater…Read more on Ice Shelf Water plume flow beneath Filchner-Ronne Ice Shelf, Antarctica
1 January, 2007 by Kevin Hughes, Melody Clark
Little is known about the effects of hydrocarbons and fuel oil on Antarctic filamentous fungi in the terrestrial Antarctic environment. Growth of fungi and bacteria from soils around Rothera Research…Read more on Tolerance of Antarctic soil fungi to hydrocarbons
1 January, 2007 by Hamish Pritchard
Ice shelves play an important role in determining regional ocean properties and in modulating ice flux from land to sea. Their dynamics are complex, however, and localised rifts and zones…1 January, 2007
Annually resolved ice core records from different regions over the Greenland ice sheet (GrIS) are used to investigate the spatial and temporal vari- ability of calcium (Ca2+, mainly from mineral…1 January, 2007
During high-speed solar wind streams, substorms occur repetitively and relativistic electron fluxes enhance significantly. It has recently been proposed that enhanced dawnside chorus waves lead to the energization of the…1 January, 2007
A two day workshop on Southern Ocean cephalopods was held in Hobart, Tasmania, Australia prior to the triennial 2006 Cephalopod International Advisory Council (CIAC) symposium. The workshop provided a second…1 January, 2007 by Adrian Jenkins
[1] Contrary to popular belief, the melting of floating ice (in the form of ice shelves, icebergs and sea ice) may have a non-zero impact on sea level. This is…1 January, 2007 by Adrian Jenkins
Introduction George VI Ice Shelf, sandwiched between the western coast of Palmer Land and the eastern coast of Alexander Island, is the largest and most studied of the west Antarctic…Read more on Circulation and melting beneath George VI Ice Shelf, Antarctica
1 January, 2007 by Joanne Johnson
We report chemical compositions of authigenic alteration minerals in subglacially erupted hyaloclastite breccias from James Ross Island, Antarctica, which provide a geochemical proxy for paleoenvironment. Analyses of zeolites (phillipsite and…Read more on Zeolite compositions as proxies for eruptive paleoenvironment
1 January, 2007 by Anna Jones
Chemical processes in the troposphere are driven by a combination of factors. Emissions from the Earth’s surface, either natural or anthropogenic, are the primary source of trace gases in the…1 January, 2007 by Eric Wolff
A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage…Read more on Orbital and millennial Antarctic climate variability over the past 800,000 years
1 January, 2007 by Roger Worland
Antioxidant enzymes (CAT, catalase; GPx, selenium nondependent glutathione peroxidase; GST, glutathione-S-transferase; GR, glutathione reductase; DHAR, dehydroascorbate reductase) were determined in the mitochondria of diapausing and non-diapausing larvae and pupae of…1 January, 2007 by David Barnes
How animals are distributed in the world's largest surface environment, the deep sea, is poorly understood. The ANDEEP (ANtarctic benthic DEEP-sea biodiversity, colonisation history and recent community patterns) III cruise…1 January, 2007
We developed new perspectives to identify important questions and to propose approaches for future research on marine food web lipids. They were related to (i) structure and function of lipids,…1 January, 2007
The Milankovitch theory of climate change proposes that glacial–interglacial cycles are driven by changes in summer insolation at high northern latitudes. The timing of climate change in the Southern Hemisphere…1 January, 2007 by Alistair Crame
The Cenomanian-Santonian biostratigraphy of the James Ross Basin, north-eastern Antarctic Peninsula is in need of comprehensive revision. This is being achieved by the systematic re-investigation of a series of key…Read more on Coniacian ammonites from James Ross Island, Antarctica
1 January, 2007 by Fausto Ferraccioli
The Antarctic magnetic anomaly map compiled marine and airborne surveys collected south of 60 degrees S through 1999 and used Magsat data to help fill in the regional gaps between…1 January, 2007
The 2 most common experimental methods used to estimate rates of juvenile growth in marine copepods are the molt rate (MR) method, and the artificial cohort (AC) method. Recently, we…1 January, 2007 by Ed King
We conducted a seismic experiment on polar firn on Adelaide Island, Antarctica. We measured the speed of compressional and shear waves at different depths in the firn by sampling waves…Read more on Use of shear waves to measure Poisson’s ratio in polar firn
1 January, 2007 by Andy Smith, Ed King
We present seismic and radar data from the onset region of Rutford Ice Stream, West Antarctica, which show the form and internal structure of a variety of bed forms beneath…1 January, 2007 by Richard Hindmarsh, Richard Hindmarsh
The largest channels on Mars are the Northwestern Slope Valleys (NSVs) of Tharsis, which have previously been interpreted as the probable erosional trace of catastrophic flooding. It is argued here…Read more on Did ice streams shape the largest channels on Mars?