Found 14112 items
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 Claus-Dieter Hillenbrand, James Smith, Robert Larter
Summary Understanding the past glacial history of regions undergoing potential rapid deglaciation is essential in order to estimate the possible threat of sea level rise. Recently acquired data have given…1 January, 2007
Polar biology is on the threshold of a revolution based on new technologies (e.g. genomics, proteomics), which will greatly enhance our knowledge of polar ecosystems and their biodiversity. The broad…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 Fausto Ferraccioli, Philip Leat, Tom Jordan
The polar regions play an important role in Earth's geodynamic and climatic systems. Modern airborne geophysical surveys combine radio-echo sounding, aeromagnetic and aerogravity methods to explore the geology of these…1 January, 2007 by Carl Robinson, Fausto Ferraccioli, Hugh Corr, Tom Jordan
As we enter the IPY geological boundary conditions for the stability of the East Antarctic Ice Sheet (EAIS) remain largely unknown. During the 2005/06 field season a major new aerogeophysical…1 January, 2007 by David Vaughan, Fausto Ferraccioli, Hugh Corr, Tom Jordan
The West Antarctic Ice Sheet is currently undergoing rapid change in particular over the Amundsen Sea Embayment (ASE). Previous aerogeophysical investigations over the Ross Sea Embayment reveal that the underlying…1 January, 2007 by Dave Ingham
The British Antarctic Survey(BAS) is implementing a phased approach to completely redevelop Rothera Research Station, with the first phase currently work in progress. BAS operates five major research stations 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 by Teal Riley
Five of six Rb-Sr muscovite mineral isochron ages from the Scotia Metamorphic Complex of the South Orkney Islands, West Antarctica, average 190 ± 4 Ma. The muscovite ages are interpreted…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 by Robert Larter
The Amundsen Sea embayment of West Antarctica is in a prominent location for a series of tectonic and magmatic events from Paleozoic to Cenozoic times. Seismic, magnetic and gravity data…1 January, 2007 by Fausto Ferraccioli
More than 500,000 line-km of new airborne and shipborne data, recently acquired by the international community over East Antarctica and surrounding regions, significantly upgrade the Antarctic Digital Magnetic Anomaly Project…Read more on New magnetic anomaly map of East Antarctica and surrounding regions
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 Claus-Dieter Hillenbrand, James Smith, Joanne Johnson, Robert Larter
The threat, in terms of sea level rise, posed by the potential rapid deglaciation of West Antarctica means there is an urgent need to know more about the speed and…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
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 Richard Hindmarsh, Richard Hindmarsh
The Pliocene (c. 5.3 - 1.8 Myr BP) was the last epoch of geological time in which global temperatures were generally higher than modern. It is important if we are…Read more on Characterizing ice sheets during the Pliocene: evidence from data and models
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 by Claus-Dieter Hillenbrand, Robert Larter
A major glacial trough ("Belgica Trough") on the continental shelf in the southern Bellingshausen Sea acted as an important outlet for ice draining the West Antarctic Ice Sheet during the…1 January, 2007 by Richard Hindmarsh, Richard Hindmarsh
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 Fausto Ferraccioli, Hugh Corr, Tom Jordan
James Ross Island (JRI) exposes a Miocene-Recent alkaline basaltic volcanic complex that developed in a back-arc, east of the northern Antarctic Peninsula. JRI has been the focus of several geological…Read more on High-resolution airborne gravity imaging over James Ross Island (West Antarctica)
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…