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Sample records for george island antarctic

  1. A fossil wood flora from King George Island: ecological implications for an Antarctic eocene vegetation

    NARCIS (Netherlands)

    Poole, I.J.; Hunt, Richard J.; Cantrill, David J.

    2001-01-01

    Early Tertiary sediments of the Antarctic Peninsula region continue to yield a rich assemblage of well-preserved fossil dicotyledonous angiosperm wood. The wood flora under consideration is from the Collins Glacier region on Fildes Peninsula, King George Island and is derived from tuffaceous

  2. A fossil wood flora from King George Island: ecological implications for an Antarctic eocene vegetation

    NARCIS (Netherlands)

    Poole, I.J.; Hunt, Richard J.; Cantrill, David J.

    2001-01-01

    Early Tertiary sediments of the Antarctic Peninsula region continue to yield a rich assemblage of well-preserved fossil dicotyledonous angiosperm wood. The wood flora under consideration is from the Collins Glacier region on Fildes Peninsula, King George Island and is derived from tuffaceous sedimen

  3. Aerosols in King George Island (Antarctic peninsula) using PIXE and alpha spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dias da Cunha, K.; Medeiros, G., E-mail: kenya@ird.gov.b, E-mail: kenya@vdg.fis.puc-rio.b [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Leal, M.A.; Lima, C. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Dalia, K.C. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Ciencias da Saude; Barros Leite, C.V. [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), Rio de Janeiro, RJ (Brazil)

    2009-07-01

    The aim of this study was to characterize the airborne particles and particles deposited in the recent snow samples collected at King George Island (Admiralty Bay) in order to evaluate the possible local sources of airborne particles and the aerosol transport from South America to Antarctic at sea level. Airborne particles samples were collected using a cascade impactor and cyclones at several sampling points at Admiralty Bay. Airborne particles were also collected during the ship travel from Rio de Janeiro to Antarctica. The recent snow samples and aerosols collected at several sampling points at Admiralty Bay were analyzed by PIXE for the determination of the elemental mass concentration. Snow samples were analyzed by alpha spectrometry to determine the 232Th, 228Th, 238U and 234U concentrations in snow. The Mass Median Aerodynamic Diameter of airborne particles was determined. The results suggest that there is a correlation between the aerosol samples and the particles deposited in the snow, but the elemental mass distributions are not equal. The snow elemental concentration can be used as an indicator of the elements present in the aerosols. The local aerosol sources (natural and anthropogenic) have been considered to characterize the aerosol transport to Antarctic, mainly King George Island. The main aerosol sources are the marine spray, weathering of local rocks and anthropogenic sources, as the diesel burning in the island. Besides the local aerosol sources the transport of airborne particles from south Atlantic to Antarctic is an important source of airborne particles at King George Island. (author)

  4. The occurrence and development of peat mounds on King George Island (Maritime Antarctic

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    Jerzy Fabiszewski

    2014-02-01

    Full Text Available On King George Island, South Shetlands Islands, a type of peat formation has been discovered which has not previously been reported from the Antarctic. These formations are in shape of mounds up to 7x 15 m in area, with a peat layer of about I m thick. About twenty five cm below the surface there is a layer of permanently frozen peat. The mounds are covered by living mosses (Polytrichum alpinum and Drepanocladus uncinatus, Antarctic hair grass (Deschampsia antarctica and lichens. Erosion fissures occurring on the surface are evidence of contemporary drying and cessation of the mound's growth. The initial phase of the development of the mounds began with a community dominated by Calliergidium austro-stramineum and Deschampsia antarctica, and their further development has been due to peat accumulation formed almost entirely by Calliergidium. The location of the mounds is near a penguin rookery, which clearly conditioned the minerotrophic character of these formations, as compared with the "moss peat banks" formed by Chorisodontium aciphyllum and Polytrichum al-pestre. Moreover, the peat mounds differ from the latter in several ways, e.g. rate of growth and floristic composition. Radiocarbon dating of peat from the base of one mound gave an age of 4090±60 years B.P. This suggests that the age of the tundra on King George Island is about 5000-4000 years.

  5. Development of Antarctic herb tundra vegetation near Arctowski station, King George Island

    Science.gov (United States)

    Kozeretska, I. A.; Parnikoza, I. Yu.; Mustafa, O.; Tyschenko, O. V.; Korsun, S. G.; Convey, P.

    2010-01-01

    We studied the development of the Antarctic herb tundra vegetation formation in relation to the history of deglaciation across a range of habitats near H. Arctowski Research Station (King George Island, South Shetland Islands). Across the three identified environmental zones (coastal, intermediate, periglacial), we quantified the total vegetation cover, cover of the two indigenous flowering plants and bryophytes, age structure and reproductive features of the two flowering plants, and species diversity of mosses and liverworts. Analysis of these data supported the recognition of the three environmental zones; however, there were few indications of systematic differences in biological features of the two higher plants across the three zones, generally supporting the view that these, and the grass Deschampsia antarctica in particular, are effective primary colonists of recently deglaciated ground in this region.

  6. Seasonal variation of algal growth conditions in sheltered Antarctic bays: the example of Potter Cove (King George Island, South Shetlands)

    NARCIS (Netherlands)

    Klöser, H.; Ferreyra, G.; Schloss, I.; Mercuri, G.; Laturnus, F.; Curtosi, A.

    1993-01-01

    Wind, air temperature, surface irradiance, light penetration into the water, salinity and water temperature have been recorded from mid November to mid February in Potter Cove, King George Island. Results are compared with published data on requirements for growth of Antarctic microalgae. The invest

  7. Seasonal variation of algal growth conditions in sheltered Antarctic bays: the example of Potter Cove (King George Island, South Shetlands)

    NARCIS (Netherlands)

    Klöser, H.; Ferreyra, G.; Schloss, I.; Mercuri, G.; Laturnus, F.; Curtosi, A.

    1993-01-01

    Wind, air temperature, surface irradiance, light penetration into the water, salinity and water temperature have been recorded from mid November to mid February in Potter Cove, King George Island. Results are compared with published data on requirements for growth of Antarctic microalgae. The

  8. Characterising terrestrial influences on Antarctic air masses using radon-222 measurements at King George Island

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    S. D. Chambers

    2014-05-01

    Full Text Available We report on one year of high precision direct hourly radon observations at King Sejong Station (King George Island beginning in February 2013. Findings are compared with historic and ongoing radon measurements from other Antarctic sites. Monthly median concentrations reduced from 72 mBq m−3 in late summer to 44 mBq m−3 in late-winter and early-spring. Monthly 10th percentiles, ranging from 29 to 49 mBq m−3, were typical of oceanic baseline values. Diurnal cycles were rarely evident and local influences were minor, consistent with regional radon flux estimates one tenth of the global average for ice-free land. The predominant fetch region for terrestrially influenced air masses was South America (47–53° S, with minor influences also attributed to aged Australian air masses and local sources. Plume dilution factors of 2.8–4.0 were estimated for the most terrestrially influenced (South American air masses, and a seasonal cycle in terrestrial influence on tropospheric air descending at the pole was identified and characterised.

  9. Seasonal variation of algal growth conditions in sheltered Antarctic bays: the example of Potter Cove (King George Island, South Shetlands)

    Science.gov (United States)

    Klöser, Heinz; Ferreyra, Gustavo; Schloss, Irene; Mercuri, Guillermo; Laturnus, Frank; Curtosi, Antonio

    1993-10-01

    Wind, air temperature, surface irradiance, light penetration into the water, salinity and water temperature have been recorded from mid November to mid February in Potter Cove, King George Island. Results are compared with published data on requirements for growth of Antarctic microalgae. The investigated season showed two distinct periods: Early summer lasted until end of December with comparatively cold temperatures, unstable water column and deep penetration of light; late summer started in early January and was characterized by reduced salinity due to meltwater discharge and high turbidity due to suspended sediments. Meltwater influence did not sufficiently change salinity to be responsible for the frequently noted paucity of macroalgal communities in sheltered bays. Shading by suspended sediments was equally considered to be of minor importance, as macroalgae have their optimal growth phase from September to December. During this period, light penetration and depth distribution of macroalgae coincide perfectly. From these results, a general review on depth limitation of macroalgae by light conditions is derived.

  10. Five-year bio-monitoring of aquatic ecosystems near Artigas Antarctic Scientific Base, King George Island

    Institute of Scientific and Technical Information of China (English)

    Mara A Morel; Victoria Braa; Cecilia Martnez-Rosales; Clica Cagide; Susana Castro-Sowinski

    2015-01-01

    Fildes Peninsula, in King George Island, Antarctica, has a great concentration of international facilities, and it has clearly been affected by human activities. The objective of this 5-year study was to assess the impact of anthropogenic activities on the bacterial abundance in water bodies close to Artigas Antarctic Scientific Base (BCAA, in Spanish Base Científica Antártica Artigas). Water samples from areas under different human influence (Uruguay Lake, nearby ponds, and meltwater from Collins Glacier) were aseptically collected and refrigerated until processed. The number of heterotrophic bacteria and Pseudomonas spp. was analyzed using a culture-dependent approach. Physico-chemical properties of the water samples (temperature, pH, and conductivity) were also determined. Results showed that water from the highly affected area, Uruguay Lake, where the pump that provides water to the BCAA is located, did not suffer significant fluctuations in heterotrophic bacterial abundance (104–105 CFU∙mL−1); however, Pseudomonas abundance increased until becoming the predominant population. In other water samples, the number of heterotrophic bacteria and Pseudomonas gradually increased during this 5-year study, by 2014 reaching similar values to those observed for Uruguay Lake. The implications of human activities on Antarctic bacterial abundance are discussed.

  11. Changes in bird communities of Admiralty Bay, King George Island (West Antarctic: insights from monitoring data (1977–1996

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    Sierakowski Kazimierz

    2017-06-01

    Full Text Available The paper summarizes results of twenty years of seabird observations carried out between 1977 and 1996 on the western shore of Admiralty Bay (King George Island, South Shetlands, Antarctic. Changes in population size, distribution and phenology of the breeding species as well as the appearance of non-breeding species are reported. A total of 34 species of birds were observed, including 13 breeding species. Among the non-breeding species, four were observed to visit the site regularly, six rarely, and the remaining 11 were observed only occasionally. Among breeding populations, three Pygoscelis penguin species, the main krill consumers, were most numerous. The Adélie Penguin (P. adeliae dominated among the penguins nesting in the investigated areas, reaching 23,661 breeding pairs in 1978. Two other penguin species were less abundant with population sizes of approximately 7,200 breeding pairs for the Chinstrap Penguin (P. antarcticus and 3,100 breeding pairs for the Gentoo Penguin (P. papua in the same year. During the following two decades, breeding populations of pygoscelid species experienced a declining trend and their numbers were reduced by 68.0% for Chinstrap, 67.1% for Gentoo, and 33.9% for Adélie Penguins. The data reported here represent a unique reference basis and provide valuable information about indicator species, suitable for comparison with contemporary observations of bird populations in the Antarctic Peninsula region, a place of rapidly occurring climate changes and intensive harvesting of marine living resources.

  12. Molecular variation of antarctic grass Deschampsia antarctica Desv. from King George Island (Antarctica

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    Katarzyna J. Chwedorzewska

    2011-01-01

    Full Text Available Deschampsia antarctica Desv. plants collected on King George Islands (Antarctica at two localities that differ in topographic and nutrition conditions exhibited morphological variation that differentiated plants of both locations. The molecular variation characteristic to individuals of both sites was tested using AFLP approach in order to verify whether morphological variation characteristic to the plants resulted from environmental factors or possibly from differences at the DNA level. Four primer pair combinations were used to generate 339 AFLP fragments, 132 of which were polymorphic and allowed evaluation of genetic relationships among D. antarctica individuals. Chi-square test revealed that only 12 signals were discriminative for the plants from both locations. Cluster analysis conducted on these AFLP fragments demonstrated that plants from the location rich in biogenes were more polymorphic than those from poor one. Our data suggest that the phenotypic variation specific to plants of both locations seem to be the result of adaptation to the environmental conditions like soil and moisture rather than reflect genetic differences.

  13. Postglacial relative sea level change at Fildes Peninsula, King George Island (West Antarctic

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    K. V. Polishchuk

    2016-01-01

    Full Text Available Analysis and integration of data obtained in our field and laboratory investigations of 2008–2012 together with results of previous paleogeographic studies were conducted to reveal parameters and factors of the post-glacial changes in the relative sea-level on the Fildes Peninsula and the King George Island. Results of dating of organic material taken from cross-sections of Quaternary deposits, data on morphology of marine landforms as well as on bottom sediments in lakes were used to construct a curve of changes in the relative sea-level.Our research has shown that the rapid rise of relative sea level in the area (since the beginning of the Holocene decelerated about 8000 years BP, achieving its maximum about 7000 years BP. This was followed by the fall of relative sea-level (the land elevation by 18–20  m in total, and it was characterized by relatively high rate of fall during periods of 6000– 5000 years BP, 4000–2500 years BP, and during the last 1500 years; the rate decreased in 5000–4000 years BP and 2500– 1600 years BP. The changes in relative sea level in this region were determined by the following factors: the eustatic component of the global changes in sea-level and, possibly, oscillations in the global sea level of another nature; local parameters of the Last glacial maximum; a course of the Peninsula deglaciation; regional physical characteristics of the Earth's crust and the mantle substances; local tectonic processes, including the isostatic rebound. Since the beginning of the Holocene up to about 7000 years BP, the main contribution to changes of the relative sea-level in this area was made by the global eustatic factor. The subsequent fall of the relative sea-level (elevation of the Peninsula surface proceeded under condition of reduced role of the eustatic factor and predominance of other factors.

  14. Expressed sequence tag analysis of Antarctic hairgrass Deschampsia antarctica from King George Island, Antarctica.

    Science.gov (United States)

    Lee, Hyoungseok; Cho, Hyun Hee; Kim, Il-Chan; Yim, Joung Han; Lee, Hong Kum; Lee, Yoo Kyung

    2008-04-30

    Deschampsia antarctica is the only monocot that thrives in the tough conditions of the Antarctic region. It is an invaluable resource for the identification of genes associated with tolerance to various environmental pressures. In order to identify genes that are differentially regulated between greenhouse-grown and Antarctic field-grown plants, we initiated a detailed gene expression analysis. Antarctic plants were collected and greenhouse plants served as controls. Two different cDNA libraries were constructed with these plants. A total of 2,112 cDNA clones was sequenced and grouped into 1,199 unigene clusters consisting of 243 consensus and 956 singleton sequences. Using similarity searches against several public databases, we constructed a functional classification of the ESTs into categories such as genes related to responses to stimuli, as well as photosynthesis and metabolism. Real-time PCR analysis of various stress responsive genes revealed different patterns of regulation in the different environments, suggesting that these genes are involved in responses to specific environmental factors.

  15. Diversity and extracellular enzymatic activities of yeasts isolated from King George Island, the sub-Antarctic region

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    Carrasco Mario

    2012-11-01

    Full Text Available Abstract Background Antarctica has been successfully colonized by microorganisms despite presenting adverse conditions for life such as low temperatures, high solar radiation, low nutrient availability and dryness. Although these “cold-loving” microorganisms are recognized as primarily responsible for nutrient and organic matter recycling/mineralization, the yeasts, in particular, remain poorly characterized and understood. The aim of this work was to study the yeast microbiota in soil and water samples collected on King George Island. Results A high number of yeast isolates was obtained from 34 soil and 14 water samples. Molecular analyses based on rDNA sequences revealed 22 yeast species belonging to 12 genera, with Mrakia and Cryptococcus genera containing the highest species diversity. The species Sporidiobolus salmonicolor was by far the most ubiquitous, being identified in 24 isolates from 13 different samples. Most of the yeasts were psychrotolerant and ranged widely in their ability to assimilate carbon sources (consuming from 1 to 27 of the 29 carbon sources tested. All species displayed at least 1 of the 8 extracellular enzyme activities tested. Lipase, amylase and esterase activity dominated, while chitinase and xylanase were less common. Two yeasts identified as Leuconeurospora sp. and Dioszegia fristingensis displayed 6 enzyme activities. Conclusions A high diversity of yeasts was isolated in this work including undescribed species and species not previously isolated from the Antarctic region, including Wickerhamomyces anomalus, which has not been isolated from cold regions in general. The diversity of extracellular enzyme activities, and hence the variety of compounds that the yeasts may degrade or transform, suggests an important nutrient recycling role of microorganisms in this region. These yeasts are of potential use in industrial applications requiring high enzyme activities at low temperatures.

  16. A GIS-BASED GLACIER INVENTORY FOR THE ANTARCTIC PENINSULA AND THE SOUTH SHETLAND ISLANDS ——A FIRST CASE STUDY ON KING GEORGE ISLAND

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The aim of the international project “Global Land Ice Measurements from Space (GLIMS)" headed by the US Geological Survey is to establish a world wide glacier inventory based on satellite imagery.This data set will form a first digital baseline study for future glacier monitoring.The presented GIS_based glacier inventory for King George Island is a case study for the area of the Antarctic Peninsula.In the database of the glacier inventory topographic information,specific glaciological parameters as well as metadata will be included.The topographic data consists of drainage basin limits,basin areas,altitudinal ranges,perimeters and mean lengths.Glaciological data sets should comprise information on glacier retreat in different periods,glacier velocities,ice thickness and bedrock topography as well as derived parameters.Modelled and measured mass balance parameters could be included as additional data layers.In particular,these metadata records must comprise background information on data accuracy and data sources and should be compatible with a future data model for the King George Island GIS (KGIS).Three examples illustrate that the GLIMS database will not only contain information valuable for glaciological applications,but also other environmental studies on the island will benefit from this standardised remote sensing data sets.Therefore,a very close link between the data models of KGIS and GLIMS has to be established to enable these synergisms.Finally,better access to historic aerial photography would enable a continuous record of glacier retreat from the beginning of the 1950's onward.

  17. First Measurements of the Earth's Electric Field at the Arctowski Antarctic Station, King George Island, by the New Polish Atmospheric Electricity Observation Network

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    Kubicki, Marek; Odzimek, Anna; Neska, Mariusz; Berliński, Jerzy; Michnowski, Stanisław

    2016-12-01

    Atmospheric electricity measurements are performed all over the globe for getting a better understanding of the processes and phenomena operating in the Earth's electric atmosphere, ionosphere and magnetosphere. Over recent years, we have established coordinated observations of atmospheric electricity, mainly of the vertical component of the Earth's atmospheric electric field, from Polish observation stations: Stanisław Kalinowski Geophysical Observatory in Świder, Poland, Stanisław Siedlecki Polar Station in Hornsund, Svalbard, Norway, and, for the first time, the Henryk Arctowski Antarctic Station in King George Island. The organisation of this network is presented here as well as a preliminary summary of geophysical conditions at Arctowski, important from the point of view of atmospheric electricity observations. In particular, we refer to the geomagnetic observations made at Arctowski station in 1978-1995. We also present the average fair-weather diurnal variation of the atmospheric electric field based on observations made so far between 2013 and 2015.

  18. A 50-years record of dichloro-diphenyl-trichloroethanes and hexachloro-cyclohexanes in lake sediments and penguin droppings on King George Island,Maritime Antarctic

    Institute of Scientific and Technical Information of China (English)

    SUN Li-guang; YIN Xue-bin; PAN Can-ping; WANG Yu-hong

    2005-01-01

    Since the ban on the use of organochlorine pesticides (OCPs) such as dichloro-diphenyl-trichloroethane (DDT) and hexachlorocyclohexane(HCH) in agriculture, their levels have generally dropped. In a number of cases, however, the levels of these OCPs were found to be unchanging or even increasing after the ban. With the aim to unveil the possible causes of these exceptions, we collected two lake cores from King George Island, West Antarctica, and determined their accumulation flux profiles and temporal trends of these OCPs. In the lake core sediments with glacier meltwater input, the accumulation flux of DDT shows an abnormal peak around 1980s in addition to the expected one in 1960s. In the lake core sediments without glacier meltwater input, the accumulation flux of DDT shows a gradual decline trend after the peak in 1960s. This striking difference in the DDT flux profiles between the two lake cores is most likely caused by the regional climate warming and the resulted discharge of the DDT stored in the Antarctic ice cap into the lakes in the Antarctic glacier frontier. Furthermore, to investigate the change of OCPs loadings in the Antarctic coastal ecosystem, we reconstructed the HCH and DDT concentration profiles in penguin droppings and observed a gradual increase for the former and a continuous decrease for the latter during the past 50 years. The increase of HCH seems to be due to the regional warming from the early 1970s and the resulted HCH discharge to the coastal ecosystem by glaciers, meltwater and the illegal use of HCH in the Southern Hemisphere in the recent decade.The different temporal trends of HCH and DDT accumulation rate in the lake core with glacier meltwater input and the aged penguin droppings can be explained by their different water-soluble property.

  19. Sensitivity of glacier mass balance and equilibrium line altitude to climatic change on King George Island, Antarctic Peninsula.

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    Falk, Ulrike; Lopez, Damian; Silva-Busso, Adrian

    2017-04-01

    The South Shetland Islands are located at the northern tip of the Antarctic Peninsula which is among the fastest warming regions on Earth. Surface air temperature increases (ca. 3 K in 50 years) are concurrent with retreating glacier fronts, an increase in melt areas, ice surface lowering and rapid break-up and disintegration of ice shelves. Observed surface air temperature lapse rates show a high variability during winter months (standard deviations up to ±1.0 K/100 m), and a distinct spatial heterogeneity reflecting the impact of synoptic weather patterns especially during winter glacial mass accumulation periods. The increased mesocyclonic activity during the winter time in the study area results in intensified advection of warm, moist air with high temperatures and rain, and leads to melt conditions on the ice cap, fixating surface air temperatures to the melting point. The impact on winter accumulation results in even more negative mass balance estimates. Six years of glaciological measurements on mass balance stake transects are used with a glacier melt model to assess changes in melt water input to the coastal waters, glacier surface mass balance and the equilibrium line altitude. The average equilibrium line altitude (ELA) calculated from own glaciological observations for KGI over the time period 2010 - 2015 amounts to ELA=330±100 m. Published studies suggest rather stable condition slightly negative glacier mass balance until the mid 80's with an ELA of approx. 150 m. The calculated accumulation area ratio suggests rather dramatic changes in extension of the inland ice cap for the South Shetland Islands until an equilibrium with concurrent climate conditions is reached.

  20. A GIS FOR THE ANTARCTIC SPECIALLY MANAGED AREA OF ADMIRALTY BAY,KING GEORGE ISLAND,ANTARCTICA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    ABSTRACT A GIS is proposed as a tool for the managing plan for the Antarctic specially managed area (ASMA) in Admiralty Bay.The ASMA comprises the area considered to be within the glacial drainage basin of the bay.Furthermore,it includes part of SSSI No.8 adjacent to the area but outside of the glacial drainage basin.Three stations and six refuges are located in the area.Using a SPOT satellite image map,the limits of the ASMA are marked and its area is re_calculated.It consists of 362 km2,including 186 km2 island ice field and small cirque glaciers and 32 km2 ice_free field.The rest comprises water of the bay and a small adjacent area (8 km2) of the Bransfield Strait. The ASMA_GIS will consists of 12 data layers ranging from the physiographic settings to the biological and administrative features.All data will be implemented into Arc/Info GIS according to the cartographic guidelines of the SCAR WG_GGI.First,five plans of information will be realised using a topographic database compiled from various sources and data from the revised bathymetric chart published by the Brazilian Navy Hydrographic Survey and also including: 1) Limits of the ASMA and protected areas;2) Glaciological features (e.g.drainage basin limits) and 3) Human presence (e.g.stations and historical sites).These basic GIS layers will be operational in early 2001.Then,additional data on the remaining layers (e.g.hydrology,geology and geomorphology) will be included from published sources. The ASMA_GIS will form an important database for environmental monitoring and studies surveying temporal changes of features such as glacier front positions or bird breading sites.

  1. First Measurements of the Earth’s Electric Field at the Arctowski Antarctic Station, King George Island, by the New Polish Atmospheric Electricity Observation Network

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    Kubicki Marek

    2016-12-01

    Full Text Available Atmospheric electricity measurements are performed all over the globe for getting a better understanding of the processes and phenomena operating in the Earth’s electric atmosphere, ionosphere and magnetosphere. Over recent years, we have established coordinated observations of atmospheric electricity, mainly of the vertical component of the Earth’s atmospheric electric field, from Polish observation stations: Stanisław Kalinowski Geophysical Observatory in Świder, Poland, Stanisław Siedlecki Polar Station in Hornsund, Svalbard, Norway, and, for the first time, the Henryk Arctowski Antarctic Station in King George Island. The organisation of this network is presented here as well as a preliminary summary of geophysical conditions at Arctowski, important from the point of view of atmospheric electricity observations. In particular, we refer to the geomagnetic observations made at Arctowski station in 1978-1995. We also present the average fair-weather diurnal variation of the atmospheric electric field based on observations made so far between 2013 and 2015.

  2. GENOTOXICITY OF SHALLOW WATERS NEAR THE BRAZILIAN ANTARCTIC STATION "COMANDANTE FERRAZ" (EACF, ADMIRALTY BAY, KING GEORGE ISLAND, ANTARCTICA

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    Arthur José da Silva Rocha

    2015-03-01

    Full Text Available Series of biomonitoring surveys were undertaken weekly in February 2012 to investigate the genotoxicity of the shallow waters around the Brazilian Antarctic Station "Comandante Ferraz" (EACF. The comet assay was applied to assess the damage to the DNA of hemocytes of the crustacean amphipods Gondogeneia antarctica collected from shallow waters near the Fuel Tanks (FT and Sewage Treatment Outflow (STO of the research station, and compare it to the DNA damage of animals from Punta Plaza (PPL and Yellow Point (YP, natural sites far from the EACF defined as experimental controls. The damage to the DNA of hemocytes of G. antarctica was not significantly different between sites in the biomonitoring surveys I and II. In survey III, the damage to the DNA of animals captured in shallow waters near the Fuel Tanks (FT and Sewage Treatment Outflow (STO was significantly higher than that of the control site of Punta Plaza (PPL. In biomonitoring survey IV, a significant difference was detected only between the FT and PPL sites. Results demonstrated that the shallow waters in front of the station may be genotoxic and that the comet assay and hemocytes of G. antarctica are useful tools for assessing genotoxicity in biomonitoring studies of Antarctic marine coastal habitats.

  3. A PRIMARY STUDY OF FOSSIL HILL FLORA FROM FILDES PENINSULA OF KING GEORGE ISLAND, ANTARCTICA

    Institute of Scientific and Technical Information of China (English)

    1990-01-01

    The fossil plants studied in this paper were collected by the Chinese Antarctic Expeditions (1986—1987 and 1987—1988) from the locality Fossil Hill on the Fildes Peninsula southwest of the King George Island of the South Shetland Islands.

  4. An englacial image and water pathways of the Fourcade glacier on King George Island, Antarctic Peninsula, inferred from ground-penetrating radar

    Institute of Scientific and Technical Information of China (English)

    LEE; Joohan; KIM; Ki; Young; HONG; Jong; Kuk; JIN; Young; Keun

    2010-01-01

    The distribution of small fractures and water content of the Fourcade glacier on King George Island, Antarctica, was investigated in November 2006 and December 2007 by two ground-based (470-and 490-m-long profiles) and one helicopter-borne (470-m-long profile) ground-penetrating radar (GPR) surveys using 50-, 100-, and 500-MHz antennas. Radar images in the pre-migrated GPR sections are characterized by a smooth ice surface and irregular bed topography, numerous diffraction hyperbolas in the ice and at the glacier bed, strong scattering noise, and near-surface folded layers. Scattering noise above a mound in the center of the profiles is associated with an area of dense fractures extending down from the ice surface that has relatively low reflection strength. Near the northeast ends of the profiles where few englacial fractures occur, scattering noise may result from the presence of warmer ice. A water-filled conduit and an air-filled cavity are interpreted as the source of two distinct hyperbolas in sub-glacial valleys based on the polarity of the reflections. Through migration velocity analysis on 106 hyperbolas, radar velocities were obtained for the 100-MHz ground-based profile. Using the velocities and Paren’s mixture formula, we calculated the water content of the ice to have been in the range of 0.00–0.09. High water content occurs near the glacier margin, in sub-glacial valleys, and in zones of scattering noise.

  5. Paleomagnetism of King George Island, South Shetlands, Antarctica

    Science.gov (United States)

    Slotznick, S. P.; Kirschvink, J. L.; Raub, T. D.; Swanson-Hysell, N.; Edgar, L.

    2011-12-01

    During December of 2009 when the US R/V Lawrence M. Gould was iced out of the Antarctic Peninsula, we collected core and block samples from 17 different flows and dikes at three sampling areas on Weaver Peninsula and Fildes Peninsula, King George Island, South Shetland Islands, Antarctica. Two of the three sampling areas on Weaver Peninsula and Fildes Peninsula were near dikes with Ar-Ar ages of 54.6 ± 3.8 Ma and 57.4 ± 2.1 Ma respectively, close in age to the Paleocene Eocene Thermal Maximum (PETM) (Kraus 2005, Kraus et al. 2007). After removal of significant magnetically soft components by low-temperature cycling and weak AF demagnetization, the basaltic flows from the Weaver Peninsula preserve a dual-polarity characteristic remanence isolated by higher-field AF demagnetization with an in-situ magnetization of D = 166.3, I= 65.4 (n/N = 24/30, α95 = 6.31). This direction, prior to correction for bedding tilt, is indistinct from a plausible Cenozoic reversed polarity magnetization for the site, while correcting for bedding tilt results in anomalously shallow inclinations. This result implies a post-tilting thermochemical remagnetization origin for the characteristic remanence. Analyses of the baked contact, dikes, and conglomerate tests help constrain the age of this event in context of subsequent Cenozoic magmatism on King George Island. Rock magnetic and Kappabridge experiments show that the magnetic mineralogy of the samples is often dominated by magnetite, with titanomagnetite and hematite present in some flows. The results of this multi-site study of Weaver and Fildes Peninsulas add to a growing paleomagnetic database for volcanic rocks from King George Island (Valencio et al. 1979, Kraus et al. 2010, Watts et al. 1984, Nawrocki et al. 2010) and contribute to a better understanding of the complex tectonic and magmatic activity of the South Shetland Islands.

  6. Standardized algal growth potential and/or algal primary production rates of maritime Antarctic stream waters (King George Island, South Shetlands

    Directory of Open Access Journals (Sweden)

    Jana Kvíderová

    2013-10-01

    Full Text Available In addition to the chemical analyses providing total nutrient content, standardized water trophic status bioassays are useful in the determination of available nutrients for primary producers. The aim of the study was to determine the standardized values of algal growth potential (AGP and algal primary productivity rate (APPR of maritime Antarctic stream water using modified AGP/APPR protocols. The standardized values of AGP and the APPR of oligotrophic and mesotrophic water samples from snow-melt streams were measured, and possible nutrient limitation and heavy metal inhibition were evaluated at 5°C and 25°C using polar and temperate strains of Stichococcus bacillaris, respectively. The water samples were enriched for the nutrient limitation tests with 1000 µg l−1 −N, 50 µg l−1 −P, and a mixture of 1000 µg l−1 −N + 50 µg l−1 −P, and for the heavy metal inhibition tests with 1000 µg l−1 Na2-ethylenediaminetetraacetic acid (EDTA. The AGP of oligotrophic samples was significantly lower than that of the mesotrophic ones at both temperatures. In addition, AGP was significantly higher at 5°C than at 25°C. Oligotrophic samples were identified as being nitrogen limited, while no nutrient limitation was observed in the mesotrophic samples. No statistically significant heavy metal inhibition was observed at either temperature. The positive correlation of AGP and water nutrient content indicates that the method used accurately and comprehensively monitors the changes in biological availability of mineral nutrients and can provide a standardized reference point for similar exploration of freshwater ecosystems across both polar regions.

  7. Detection of integron integrase genes on King George Island, Antarctica

    Institute of Scientific and Technical Information of China (English)

    Vernica Antelo; Hctor Romero; Silvia Batista

    2015-01-01

    The presence and diversity of class 1 integrase gene (intI) sequences were evaluated by PCR using previously designed primers. Two clone libraries were constructed from DNA in sediment and microbial mat samples collected on Fildes Peninsula, King George Island, Antarctica.The libraries constructed from samples collected at Halfthree Point (HP) and Norma Cove (NC) contained 62 and 36 partial intI sequences, respectively. These sequences clustered into 10 different groups with <95% amino acid identity. Alignment of the deduced amino acid sequences with those from recognized integron-encoded integrases demonstrated the presence of highly conserved motifs characteristic of intI integrases. The HP library contained 42 nucleotide sequences identical to the class 1 intI gene found in a collection of trimethoprim-resistant (Tmpr) Antarctic Enterobacter sp. isolates, previously collected in the same area. These integrons, located on plasmids, had a genetic organization similar to that of pKOX105 from Klebsiella oxytoca. The 20 remaining HP and NC library sequences were similar to integrase sequences previously determined in a metagenomic analysis of environmental samples. We have demonstrated the presence of integron integrase genes in Antarctic sediment samples. About half these genes were very similar to the class 1 integrons found in human-associated microbiota, suggesting that they originated from human-dominated ecosystems. The remaining integrase genes were probably associated with endemic bacteria.

  8. Speedup and fracturing of George VI Ice Shelf, Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    T. O. Holt

    2013-05-01

    Full Text Available George VI Ice Shelf (GVIIS is located on the Antarctic Peninsula, a region where several ice shelves have undergone rapid breakup in response to atmospheric and oceanic warming. We use a combination of optical (Landsat, radar (ERS 1/2 SAR and laser altimetry (GLAS datasets to examine the response of GVIIS to environmental change and to offer an assessment on its future stability. The spatial and structural changes of GVIIS (ca. 1973 to ca. 2010 are mapped and surface velocities are calculated at different time periods (InSAR and optical feature tracking from 1989 to 2009 to document changes in the ice shelf's flow regime. Surface elevation changes are recorded between 2003 and 2008 using repeat track ICESat acquisitions. We note an increase in fracture extent and distribution at the south ice front, ice-shelf acceleration towards both the north and south ice fronts and spatially varied negative surface elevation change throughout, with greater variations observed towards the central and southern regions of the ice shelf. We propose that whilst GVIIS is in no imminent danger of collapse, it is vulnerable to ongoing atmospheric and oceanic warming and is more susceptible to breakup along its southern margin in ice preconditioned for further retreat.

  9. Fine morphology of four Licmophora (Bacillariophyta, Licmophorales) species from Admiralty Bay and Elephant Island, Antarctic Peninsula

    OpenAIRE

    Fernandes, Luciano F.; Calixto-Feres,Mariana; Tenenbaum,Denise Rivera; Procopiak, Leticia K.; Portinho,Danielle; Hinz, Friedel

    2014-01-01

    In this paper, four Antarctic species of the diatom genus Licmophora namely L. antarctica M. Peragallo, L. belgicae M. Peragallo, L. gracilis (Ehrenberg) Grunow and L. luxuriosa Heiden are described using an electron microscope, based on two collections of samples collected during different expeditions under the Brazilian Antarctic program (Summer of 1994, and 2003 to 2010). Plankton and benthic samplings were carried out at different locations in King George and Elephant Islands, Antarctic P...

  10. Artificial Beach Lighting Survey of St. George Island

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — St. George Island SGI is a significant sea turtle nesting beach for loggerhead and occasionally leatherback sea turtles in the Florida panhandle Lewis et al 1996 ....

  11. Climate Controlled Sedimentation in Maxwell Bay, King George Island, Antarctica

    Science.gov (United States)

    Hass, H.; Kuhn, G.; Wittenberg, N.; Woelfl, A.; Betzler, C.

    2012-12-01

    Climatic change in Antarctica is strongest over the Antarctic Peninsula where in places the annual mean temperatures increased by 0.5 K per decade through the past 60 years. The impact of this warming trend is clearly visible in the form of retreating glaciers and melting ice sheets, loss of sea ice and strong meltwater discharge into the coastal zone. While it is generally accepted that the rapidity of the present climate change bears a significant anthropogenic aspect, it is not clear whether the effects caused by the warming trend are exceptional and unprecedented or whether the reaction of the environment is similar to that of earlier climate phases such as the Medieval Warm Period (MWP) about 1,000 years ago. One of the major goals of the joint international research project IMCOAST is to investigate the strength of the recent warming trend and its impact on the marine environment of the West Antarctic Peninsula (WAP). The study we present here reveals the Upper Holocene climatic history based on high-resolution sediment cores from Maxwell Bay (King George Island, WAP) and information on the actual processes triggered or altered by the recent warming trend based on sedimentologic and hydroacoustic investigations in Potter Cove, a tributary fjord to Maxwell Bay. Long sediment cores from Maxwell Bay reveal grain-size changes that can be linked to cold and warm phases such as the Little Ice Age (LIA) and the MWP. Generally, warm phases are finer grained than cold phases as a result of longer and stronger melting processes during the warm phases. It is suggested that meltwater plumes carry fine-grained sediment out of the surrounding fjords into Maxwell Bay where it settles in suitable areas to produce sediments that have a modal value around 16 μm. This mode is largely absent in sediments deposited during e.g. the LIA. However, post LIA sediments are depleted in the 16 μm-mode sediment suggesting slightly different conditions during the last century. One reason

  12. Study of PCBs and PBDEs in King George Island, Antarctica, using PUF passive air sampling

    Science.gov (United States)

    Li, Yingming; Geng, Dawei; Liu, Fubin; Wang, Thanh; Wang, Pu; Zhang, Qinghua; Jiang, Guibin

    2012-05-01

    Polyurethane foam (PUF)-disk based passive air samplers were deployed in King George Island, Antarctica, during the austral summer of 2009-2010, to investigate levels, distributions and potential sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Antarctic air. The atmospheric levels of ∑ indicator PCBs and ∑14 PBDEs ranged from 1.66 to 6.50 pg m-3 and from 0.67 to 2.98 pg m-3, respectively. PCBs homologue profiles were dominated by di-PCBs, tri-PCBs and tetra-PCBs, whereas BDE-17 and BDE-28 were the predominant congeners of PBDEs, which could be explained by long-range atmospheric transport processes. However, the sampling sites close to the Antarctic research stations showed higher atmospheric concentrations of PCBs and PBDEs than the other sites, reflecting potential local sources from the Antarctic research stations. The non-Aroclor congener PCB-11 was found in all the air samples, with air concentrations of 3.60-31.4 pg m-3 (average 15.2 pg m-3). Comparison between the results derived from PUF-disk passive air sampling and high-volume air sampling validates the feasibility of using the passive air samplers in Antarctic air. To our knowledge, this study is the first employment of PUF-disk based passive air samplers in Antarctic atmosphere.

  13. Occurrence of arbuscular mycorrhizal fungi on King George Island, South Shetland Islands, Antarctica

    Directory of Open Access Journals (Sweden)

    MARISÂNGELA V. BARBOSA

    2017-08-01

    Full Text Available ABSTRACT Arbuscular mycorrhizal fungi make up an important ecological niche in ecosystems, and knowledge of their diversity in extreme environments is still incipient. The objective of this work was to evaluate the density and diversity of arbuscular mycorrhizal fungi in the soil of King George Island in the South Shetland Islands archipelago, Antarctica. For that, soil and roots of Deschampsia antarctica were collected at the brazilian research station in Antarctica. The spore density, species diversity and mycorrhizal colonization in the roots were evaluated. There was a low density of spores (27.4 ± 17.7 and root mycorrhizal colonization (6 ± 5.1%, which did not present statistical difference. Four species of arbuscular mycorrhizal fungi were identified, distributed in two genera: three species of the genus Glomus (Glomus sp1, Glomus sp2 and Glomus sp3 and one of the genus Acaulospora, which was identified at species level (Acaulospora mellea. Greater soil diversity was verified with pH 5.9 and phosphorus concentration of 111 mg dm-3, occurring two species of genus Glomus and A. mellea. Based on literature data, this may be the first record of this species of Acaulospora mellea in Antarctic soils, colonizing D. antarctica plants.

  14. Modern sedimentation patterns in Potter Cove, King George Island, Antarctica

    Science.gov (United States)

    Hass, H. Christian; Kuhn, Gerhard; Wölfl, Anne-Cathrin; Wittenberg, Nina; Betzler, Christian

    2013-04-01

    IMCOAST among a number of other initiatives investigates the modern and the late Holocene environmental development of south King George Island with a strong emphasis on Maxwell Bay and its tributary fjord Potter Cove (maximum water depth: about 200 m). In this part of the project we aim at reconstructing the modern sediment distribution in the inner part of Potter Cove using an acoustic ground discrimination system (RoxAnn) and more than136 ground-truth samples. Over the past 20 years the air temperatures in the immediate working area increased by more than 0.6 K (Schloss et al. 2012) which is less than in other parts of the West Antarctic Peninsula (WAP) but it is still in the range of the recovery of temperatures from the Little Ice Age maximum to the beginning of the 20th century. Potter Cove is a small fjord characterized by a series of moraine ridges produced by a tidewater glacier (Fourcade Glacier). Presumably, the farthest moraine is not much older than about 500 years (LIA maximum), hence the sediment cover is rather thin as evidenced by high resolution seismic data. Since a few years at least the better part of the tidewater glacier retreated onto the island's mainland. It is suggested that such a fundamental change in the fjord's physiography has also changed sedimentation patterns in the area. Potter Cove is characterized by silty-clayey sediments in the deeper inner parts of the cove. Sediments are coarser (fine to coarse sands and boulders) in the shallower areas; they also coarsen from the innermost basin to the mouth of the fjord. Textural structures follow the seabed morphology, i.e. small v-shaped passages through the moraine ridges. The glacier still produces large amounts of turbid melt waters that enter the cove at various places. We presume that very fine-grained sediments fall out from the meltwater plumes and are distributed by mid-depth or even bottom currents, thus suggesting an anti-estuarine circulation pattern. Older sediments that are

  15. Experimental culture of non-indigenous Juncus bufonius from King George Island, South Shetland Island, Antarctica

    Institute of Scientific and Technical Information of China (English)

    Marely Cuba-Díaz; Eduardo Fuentes; Mauricio Rondanelli-Reyes; Ángela Machuca

    2015-01-01

    Juncus bufonius L. (Juncaceae) is recognized by the US Department of Agriculture as a weed or invasive plant. Recently, we reported on J. bufonius L. var. bufonius associated with the native vascular plants Deschampsia antarctica and Colobanthus quitensis in the environs of the Polish Arctowski Station, King George Island, in the Maritime Antarctica. In this study, we evaluated the developmental stages and morphological characteristics of J. bufonius plants cultivated in controlled conditions beginning with seeds obtained from plants of the Antarctic population. Germination occurred at 3 weeks and the germination percentage was low (22.5%). The average time between the anthesis and seed formation was 7 weeks, similar to that reported for other species in the Juncaceae. According to data reported in the literature, Antarctic individuals were significantly smaller than their relatives growing in other conditions, except for the number of inflorescences. The morphological characteristics of a species vary according to its distribution and the edaphoclimatic environment where it occur; cosmopolitan plants shuch as J. bufonius also have reduced stature in cold environments. The low percentage germination may have been due to water availability in the plant chamber in which the study was conducted. J. bufonius is intolerant of dry environments, and once it suffers hydric stress its recovery is very low; thus, a moister environment could be beneficial. J. bufonius has become established amongst native vegetation near Arctowski Station and without careful control or eradication; it may have the potential to spread far beyond the site, as has happened with the alien grass Poa annua as human disturbance and climate warming increase.

  16. Eocene age of the Baranowski Glacier Group at Red Hill, King George Island, West Antarctica

    Directory of Open Access Journals (Sweden)

    Mozer Anna

    2015-12-01

    Full Text Available Radiometric and geochemical studies were carried out at Red Hill in the southern part of King George Island (South Shetland Islands, northern Antarctic Peninsula on the Bransfield Strait coast. The rock succession at Red Hill has been determined to represent the Baranowski Glacier Group that was previously assigned a Late Cretaceous age. Two formations were distinguished within this succession: the lower Llano Point Formation and the upper Zamek Formation. These formations have stratotypes defined further to the north on the western coast of Admiralty Bay. On Red Hill the Llano Point Formation consists of terrestrial lavas and pyroclastic breccia; the Zamek Formation consist predominantly of fine to coarse tuff, pyroclastic breccia, lavas, tuffaceous mud-, silt-, and sandstone, locally conglomeratic. The lower part of the Zamek Formation contains plant detritus (Nothofagus, dicotyledonous, thermophilous ferns and numerous coal seams (vitrinitic composition that confirm the abundance of vegetation on stratovolcanic slopes and surrounding lowlands at that time. Selected basic to intermediate igneous rocks from the succession have been analysed for the whole-rock K-Ar age determination. The obtained results indicate that the Red Hill succession was formed in two stages: (1 from about 51–50 Ma; and (2 46–42 Ma, i.e. during the Early to Middle Eocene. This, in combination with other data obtained from other Baranowski Glacier Group exposures on western coast of Admiralty Bay, confirms the recently defined position of the volcano-clastic succession in the stratigraphic scheme of King George Island. The new stratigraphic position and lithofacies development of the Red Hill succession strongly suggest its correlation with other Eocene formations containing fossil plants and coal seams that commonly occur on King George Island.

  17. Geochemical markers of soil anthropogenic contaminants in polar scientific stations nearby (Antarctica, King George Island).

    Science.gov (United States)

    Prus, Wojciech; Fabiańska, Monika J; Łabno, Radosław

    2015-06-15

    The organic contamination of Antarctic soils and terrestrial sediments from nearby of five polar scientific stations on King George Island (Antarctica) was investigated. Gas chromatography-mass spectrometry (GC-MS) was applied to find composition of dichloromethane extracts of soil and terrestrial sediments. The presence of geochemical markers, such as n-alkanes, steranes, pentacyclic triterpenoids, and alkyl PAHs, their distribution types, and values of their ratios indicates the predominating source of organic fossil fuels and products of their refining rather than from the natural Antarctic environment. Fossil fuel-originated compounds well survived in conditions of Antarctic climate over long times thus enabling to characterize geochemical features of source fossil fuel identified as petroleum expelled from kerogen II of algal/bacterial origins deposited in sub-oxic conditions and being in the middle of catagenesis. Both microbial activity and water leaching play an important role in degradation of terrestrial oil spills in the Antarctica climate, and petroleum alteration occurs lowly over long periods of time. Synthetic anthropogenic compounds found in terrestrial Antarctica sediments included diisopropylnaphthalenes, products of their sulfonates degradation in paper combustion, and organophosporus compounds used as retardants and plasticizers.

  18. Eocene paleosols of King George Island, Maritime Antarctica

    Science.gov (United States)

    Spinola, Diogo; Portes, Raquel; Schaefer, Carlos; Kühn, Peter

    2016-04-01

    Red layers between lava flows on King George Island, Maritime Antarctica, were formed during the Eocene, which was one of the warmest periods on Earth in the Cenozoic. Our hypothesis is that these red layers are paleosols formed in periods of little or no volcanic activity. Therefore, our main objective was to identify the main pedogenic properties and features to distinguish these from diagenetic features formed after the lava emplacement. Additionally, we compared our results with volcanic soils formed under different climates to find the best present analogue. The macromorphological features indicate a pedogenic origin, because of the occurrence of well-defined horizons based on colour and structure. Micromorphological analyses showed that most important pedogenic features are the presence of biological channels, plant residues, anisotropic b-fabric, neoformed and illuvial clay and distinct soil microstructure. Although the paleosols are not strongly weathered, the geochemical data also support the pedogenic origin despite of diagenetic features as the partial induration of the profiles and zeolites filling nearly all voids in the horizons in contact with the overlying lava flow, indicating circulation of hydrothermal fluids. The macromorphological and micromorphological features of these paleosols are similar to the soils formed under seasonal climates. Thus, these paleosol features do not correspond to the other proxies (e.g. sediment, plant fossils), which indicate a wet, non-seasonal climate, as in Valdivian Forest, Chile, during the Eocene in King George Island

  19. Volcanic geology of Admiralty Bay, King George Island, Antarctica

    Institute of Scientific and Technical Information of China (English)

    邢光福; 王德滋; 金庆民; 沈渭洲; 陶奎元

    2002-01-01

    At Admiralty Bay of central King George Island, Keller Peninsula, Ullman Spur and Point Hennequin are main Tertiary volcanic terranes. Field investigation and isotopic datings indicate that, there occurred three periods of eruptions ( three volcanic cycles) and accompanying N-toward migration of the volcanic center on Keller Peninsula. After the second period of eruptions, the crater collapsed and a caldera was formed, then later eruptions were limited at the northern end of the peninsula and finally migrated to Ullman Spur. Thus Keller Peninsula is a revived caldera, and its volcanism migrated toward E with time. Point Hennequin volcanism happened more or less simultaneously with the above two areas, but has no clear relation in chemical evolution with them, frequently it belongs to another independent volcanic center.

  20. UAV-based detection and spatial analyses of periglacial landforms on Demay Point (King George Island, South Shetland Islands, Antarctica)

    Science.gov (United States)

    Dąbski, Maciej; Zmarz, Anna; Pabjanek, Piotr; Korczak-Abshire, Małgorzata; Karsznia, Izabela; Chwedorzewska, Katarzyna J.

    2017-08-01

    High-resolution aerial images allow detailed analyses of periglacial landforms, which is of particular importance in light of climate change and resulting changes in active layer thickness. The aim of this study is to show possibilities of using UAV-based photography to perform spatial analysis of periglacial landforms on the Demay Point peninsula, King George Island, and hence to supplement previous geomorphological studies of the South Shetland Islands. Photogrammetric flights were performed using a PW-ZOOM fixed-winged unmanned aircraft vehicle. Digital elevation models (DEM) and maps of slope and contour lines were prepared in ESRI ArcGIS 10.3 with the Spatial Analyst extension, and three-dimensional visualizations in ESRI ArcScene 10.3 software. Careful interpretation of orthophoto and DEM, allowed us to vectorize polygons of landforms, such as (i) solifluction landforms (solifluction sheets, tongues, and lobes); (ii) scarps, taluses, and a protalus rampart; (iii) patterned ground (hummocks, sorted circles, stripes, nets and labyrinths, and nonsorted nets and stripes); (iv) coastal landforms (cliffs and beaches); (v) landslides and mud flows; and (vi) stone fields and bedrock outcrops. We conclude that geomorphological studies based on commonly accessible aerial and satellite images can underestimate the spatial extent of periglacial landforms and result in incomplete inventories. The PW-ZOOM UAV is well suited to gather detailed geomorphological data and can be used in spatial analysis of periglacial landforms in the Western Antarctic Peninsula region.

  1. Molecular characterisation of anthropogenic sources of sedimentary organic matter from Potter Cove, King George Island, Antarctica.

    Science.gov (United States)

    Dauner, Ana Lúcia L; Hernández, Edgardo A; MacCormack, Walter P; Martins, César C

    2015-01-01

    Although relatively recent, human activities in Antarctica, such as growing tourism, fishery activities, and scientific operations, have affected some areas of this continent. These activities eventually release pollutants, such as petroleum and its derivatives and sewage, into this environment. Located on King George Island (25 de Mayo Island), Potter Cove (62°14'S, 58°39'W) is home to the Argentine Carlini research station. To evaluate the anthropogenic impacts surrounding Potter Cove, sediment samples were collected and analysed for sewage and fuel introduction via the determination of organic markers. The highest concentrations were found in the central portion of the fjords, where fine sediments are deposited and the accumulation of organic molecules is favoured. Aliphatic hydrocarbons were mainly derived from biogenic sources, evidenced by the predominance of odd short-chain n-alkanes. Anthropogenic impacts were evidenced primarily by the presence of PAHs, which were predominantly related to petrogenic sources, such as vessel and boat traffic. Sewage marker concentrations were much lower than those found in other Antarctic regions. These results indicate that oil hydrocarbons and sewage inputs to Potter Cove may be considered low or only slightly influential.

  2. New data on the Late Pleistocene and Holocene glacial, climate and relative sea-level changes at Fildes Peninsula, King George Island (South Shetlands Islands, West Antarctica)

    Science.gov (United States)

    Verkulich, Sergey; Pushina, Zina; Tatur, Andrej

    2010-05-01

    New data on the Late Pleistocene and Holocene glacial, climate and relative sea-level changes at Fildes Peninsula, King George Island (South Shetlands Islands, West Antarctica) Verkulich S. R. (Arctic and Antarctic Research Institute, St. Petersburg, Russia) Pushina Z.V. (Arctic and Antarctic Research Institute, St. Petersburg, Russia) Tatur A. (Department of Antarctic Biology, Polish Academy of Sciences, Warsaw, Poland) During the 2008-2009 austral summer, co-operative Russian - Polish paleogeographical investigations allowed to refine the understanding of the past environmental events at Fildes Peninsula, King George Island. Old marine deposits (ca. 30000 yrs BP) with shells, whale bones and marine algae in situ were found in the western coastal and northern inland territories at the altitudes of 20-40 m a.s.l. that evidences the covering of considerable part of the peninsula by relatively warm sea waters before the Last Glacial Maximum. Quite good preservation of these deposits supposes relatively small thickness and weak erosional potential of ice masses overlying the area during the LGM. The early Holocene phase of the peninsula deglaciation was caused by both climate warming and marine transgression, which left the deposits with fossil flora and fauna at heights up to 15 m a.s.l. (maximum rise of the relative sea-level 7000-8000 yrs BP). During the middle Holocene, glacier contraction in the area continued (on the whole) due to mainly favorable climatic conditions. The presence of marine and terrestrial deposit blocks (with shells, algae, mosses) in moraine ridges on the surface of Collins Ice Cap signifies that this glacier could vanish from the peninsula during climate optimum (ca. 4000-3000 yrs BP). The processes of new formation and growth of the ice cap started probably ca. 2000 yrs BP; within the last 1000 years the limited advance of the glacier occurred (likely corresponding to the Little Ice Age), and was replaced then by modern process of its decay.

  3. THE COMPILATION OF A DTM AND A NEW SATELLITE IMAGE MAP FOR KING GEORGE ISLAND,ANTARCTICA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An improved topographic database for King George Island,one of the most frequently visited regions in Antarctica,is presented.A first step consisted in combining data from differential GPS surveys gained during the austral summers 1997~1998 and 1999~2000,with the current coastline from a SPOT satellite image mosaic,topographic information from existing maps and from the Antarctic Digital Database.From this data sets,a digital terrain model (DTM) was generated using Arc/Info GIS.In a second step,a satellite image map at the scale 1∶100 000 was assembled from contour lines derived from the DTM and the satellite mosaic.A lack of accurate topographic information in the eastern part of the island was identified.Additional topographic surveying or SAR interferometry should be used to improve the data quality in that area.The GIS integrated database will be indispensable for glaciological and climatological studies and administrative and scientific purposes.In future,the application of GIS techniques will be mandatory for environmental impact studies and environmental monitoring as well as for management plans on King George Island.

  4. Polyphenolic substrates and dyes degradation by yeasts from 25 de Mayo/King George Island (Antarctica).

    Science.gov (United States)

    Rovati, José I; Pajot, Hipólito F; Ruberto, Lucas; Mac Cormack, Walter; Figueroa, Lucía I C

    2013-11-01

    Antarctica offers a range of extreme climatic conditions, such as low temperatures, high solar radiation and low nutrient availability, and constitutes one of the harshest environments on Earth. Despite that, it has been successfully colonized by ’cold-loving’ fungi, which play a key role in decomposition cycles in cold ecosystems. However, knowledge about the ecological role of yeasts in nutrient or organic matter recycling/mineralization remains highly fragmentary. The aim of this work was to study the yeast microbiota in samples collected on 25 de Mayo/King George Island regarding the scope of their ability to degrade polyphenolic substrates such as lignin and azo dyes. Sixty-one yeast isolates were obtained from 37 samples, including soil, rocks, wood and bones. Molecular analyses based on rDNA sequences revealed that 35 yeasts could be identified at the species level and could be classified in the genera Leucosporidiella, Rhodotorula, Cryptococcus, Bullera and Candida. Cryptococcus victoriae was by far the most ubiquitous species. In total, 33% of the yeast isolates examined showed significant activity for dye decolorization, 25% for laccase activity and 38% for ligninolytic activity. Eleven yeasts did not show positive activity in any of the assays performed and no isolates showed positive activity across all tested substrates. A high diversity of yeasts were isolated in this work, possibly including undescribed species and conspicuous Antarctic yeasts, most of them belonging to oligotrophic, slow-growing and metabolically diverse basidiomycetous genera.

  5. Ultrastructure of Lobosphaera reniformis (Watanabe) Komárek et Fott (Chlorellales) from King George Island, South Shetland Islands, Antarctica

    OpenAIRE

    A. Massalski; T. Mrozińska; Olech, M.

    2014-01-01

    Lobosphaera reniformis (Wat.) Kom. et Fott (=Chlorella reniformis Wat.) so far known only from Japan, and Papua Island, was for the first time found in Antarctica (King George Island, South Shetland Islands). In laboratory cultures a complete life cycle was obtained, and most of its stages were followed by the electron microscopy. Reproduction is by morphologically different autospores. In some large vegetative cells two Golgi apparatuses lying side by side were observed.

  6. Ultrastructure of Lobosphaera reniformis (Watanabe Komárek et Fott (Chlorellales from King George Island, South Shetland Islands, Antarctica

    Directory of Open Access Journals (Sweden)

    A. Massalski

    2014-01-01

    Full Text Available Lobosphaera reniformis (Wat. Kom. et Fott (=Chlorella reniformis Wat. so far known only from Japan, and Papua Island, was for the first time found in Antarctica (King George Island, South Shetland Islands. In laboratory cultures a complete life cycle was obtained, and most of its stages were followed by the electron microscopy. Reproduction is by morphologically different autospores. In some large vegetative cells two Golgi apparatuses lying side by side were observed.

  7. Isolation and characterization of Campylobacter spp. from Antarctic fur seals (Arctocephalus gazella) at Deception Island, Antarctica.

    Science.gov (United States)

    García-Peña, F J; Pérez-Boto, D; Jiménez, C; San Miguel, E; Echeita, A; Rengifo-Herrera, C; García-Párraga, D; Ortega-Mora, L M; Pedraza-Díaz, S

    2010-09-01

    The presence of Campylobacter spp. was investigated in 41 Antarctic fur seals (Arctocephalus gazella) and 9 Weddell seals (Leptonychotes weddellii) at Deception Island, Antarctica. Infections were encountered in six Antarctic fur seals. The isolates, the first reported from marine mammals in the Antarctic region, were identified as Campylobacter insulaenigrae and Campylobacter lari.

  8. Observation of a mesospheric front in a thermal-doppler duct over King George Island, Antarctica

    Directory of Open Access Journals (Sweden)

    J. V. Bageston

    2011-12-01

    Full Text Available A mesospheric front was observed with an all-sky airglow imager on the night of 9–10 July 2007 at Ferraz Station (62° S, 58° W, located on King George island on the Antarctic Peninsula. The observed wave propagated from southwest to northeast with a well defined wave front and a series of crests behind the main front. The wave parameters were obtained via a 2-D Fourier transform of the imager data providing a horizontal wavelength of 33 km, an observed period of 6 min, and a horizontal phase speed of 92 m s−1. Simultaneous mesospheric winds were measured with a medium frequency (MF radar at Rothera Station (68° S, 68° W and temperature profiles were obtained from the SABER instrument on the TIMED satellite. These wind and temperature profiles were used to estimate the propagation environment of the wave event. A wavelet technique was applied to the wind in the plane of wave propagation at the OH emission height spanning three days centered on the front event to define the dominant periodicities. Results revealed a dominance of near-inertial periods, and semi-diurnal and terdiurnal tides suggesting that the ducting structure enabling mesospheric front propagation occurred on large spatial scales. The observed tidal motions were used to reconstruct the winds employing a least-squares method, which were then compared to the observed ducting environment. Results suggest an important contribution of large-scale winds to the ducting structure, but with buoyancy frequency variations in the vertical also expected to be important. These results allow us to conclude that the wave front event was supported by a duct including contributions from both winds and temperature.

  9. George W. Bush at Goree Island: American Slavery and the Rhetoric of Redemption

    Science.gov (United States)

    Medhurst, Martin J.

    2010-01-01

    On July 8, 2003, at Goree Island, Senegal, George W. Bush delivered the most important speech on American slavery since Abraham Lincoln. As an example of rhetorical artistry, the speech is a masterpiece, putting the brutality of slavery into historical, political, and theological perspective. Although the speech had deliberative effects--it grew…

  10. Modern sedimentation in a rapidly warming fjord: Potter Cove, King George Island, Antarctica

    Science.gov (United States)

    Hass, H. C.; Kuhn, G.; Wittenberg, N.; Wölfl, A.

    2012-04-01

    The northern Antarctic Peninsula belongs to the fastest warming regions on earth. The winter-warming trend was strong and stable over the past 70 years. As a result, Potter Cove, a small fjord that opens into Maxwell Bay (King George Island, South Shetland Islands), shows significant environmental change. A former tidewater glacier (Fourcade Glacier) has retreated onto land exposing bedrock such as a small island close to the glacier front. It is suggested that the warming trend triggered excessive discharge of sediment-laden meltwaters in the form of turbid surface waters. The hypothesis for this study is that very fine-grained materials are present in Potter Cove and that meltwater plumes that exit Potter Cove can be traced downstream in the form of fans of fine-grained materials. In this study we investigate the modern sedimentation patterns in Potter Cove using hydroacoustics and seafloor samples to compare that with conditions from the past as recorded in sediment cores. Surface grain-size distributions reveal a distinct textural pattern in Potter Cove. Cluster analysis suggests 7 classes of sediment types. Four of them are unimodal, three classes show fine-skewed distributions with tendencies to bimodality. The finer sediment classes are found in the central inner part of the cove. The finest class (mode at 16 µm) forms only a small patch in the shelter of a small island. Sediments from close to the glacier front appear to be slightly depleted in fine-grained materials. From the glacier front to the outer fjord the sediments show influence of current sorting, i.e. the coarser mode becomes more significant and sorting increases. A sediment core from the deeper outer basin of Potter Cove reveals only one of the better-sorted, coarser classes that appears to form on the way from the glacier into the basin. There are 5 long sediment cores located less than 10 km off the mouth of Potter Cove in Maxwell Bay. All of which reveal sediments that belong either to the

  11. A 2,000-year record of mercury and ancient civilizations in seal hairs from King George Island, West Antarctica.

    Science.gov (United States)

    Sun, Liguang; Yin, Xuebin; Liu, Xiaodong; Zhu, Renbin; Xie, Zhouqing; Wang, Yuhong

    2006-09-01

    The concentrations of total mercury (Hg(T)) and three bio-essential elements (phosphor, potassium, sodium) were analyzed in Antarctic seal hairs from a lake core spanning the past 2,000 years and collected from King George Island (63 degrees 23'S, 57 degrees 00'W), West Antarctica. The Hg(T) concentration shows a significant fluctuation while the levels of the three bio-essential elements remain almost constant. The rise and fall of the Hg(T) concentration in the seal hairs are found to be closely coincided with ancient activities of gold and silver mining using Hg-amalgamation process around the world, especially in the Southern Hemisphere. Briefly, Hg(T) levels are high during five episodes of extensive gold and silver mining activities--Rome Empire and China Han Dynasty (approximately 18-300 A.D.), Maya period and China Tang (750-900 A.D.), Incas civilization and Christian Kingdom (1200-1500 A.D.), New world (1650-1800 A.D.), and modern industry period (1840 A.D.-present); they are low during four time periods of reduced gold and silver mining activities--the China Han and Rome fall (since 300 A.D.), Maya fall and Wartime period in China (1050-1250 A.D.), Pizarro coming (ca. 1532 A.D.) and Independence War of South America (1800-1830 A.D.). Two profiles of Hg(T) in other two lake cores, one affected by seal excrements and the other by penguin droppings, from the same region are similar to the one in seal hairs. The Hg concentration profile in the seal hairs is significantly correlated with the one in a peat bog of Southern Chile near King George Island. Since Hg is existent mainly at the form of methyl-mercury in seal hairs, this correlation supports a relationship and link between atmospheric mercury concentration and methyl-mercury production. Comparing with samples from American and European continents, the Antarctic seal hairs provide an archive of total mercury concentration in surface seawater of the South Ocean less affected by regional human activities

  12. Sedimentary regimes at Potter Cove, King George Island, maritime Antarctica - from source to sink

    Science.gov (United States)

    Monien, Donata; Monien, Patrick; Brünjes, Robert M.; Widmer, Tatjana; Schnetger, Bernhard; Brumsack, Hans-Jürgen

    2013-04-01

    Increased particle run-off due to recently retreated ice masses along the Antarctic margins may play an important role in fertilizing the high-nutrient-low-chlorophyll regions of the Southern Ocean. At Potter Cove, King George Island, maritime Antarctica, small melt water streams at the south-eastern shoreline (Potter Peninsula) discharge up to 1,500 mg L-1 (av. 110 mg L-1) of suspended particle matter (SPM) per day into the coastal water body during the summer seasons. Apart from potential light limitation of plankton growth by the suspension load, the particle run-off affects benthic feeders, possibly changes the depositional regime and the preservation of chemical proxies in the outlet zones, and exports trace elements offshore. In Potter Cove's water column, the average particle size is low, and extreme turbidity events are restricted to the upper five to seven meters. High particle loads are often associated with low salinities, most probably induced by increased onshore precipitation. Sediment traps installed in the inner and outer cove at 5 and 20 m water depth suggest mass accumulation rates of 0.83 and 0.58 g cm-2 yr-1, and 0.13 and 0.11 g cm-2 yr-1 (considering 183 days of sedimentation), respectively. 210Pb measurements of short sediment cores reveal recent sediment accumulation rates of approximately 0.1 to 0.6 g cm-2 yr-1. The SPM sampled in the melt water streams and plumes is chemically different to surface sediments deposited in Potter Cove. Chemical characteristics suggest a significant impact of particle sorting: SPM and outer cove sediments are more clayey, whereas inner cove sediments contain more heavy minerals. Generally, sediment deposits in Potter Cove exhibit coarser grain sizes and are mainly derived from Barton Peninsula (northern shoreline), whereas the SPM consists of more fine-grained material originating from Potter Peninsula eluviations. Sequential leaching of the SPM by ascorbic acid showed that approximately 0.5 to 2% of the total

  13. Observation of a mesospheric front in a dual duct over King George Island, Antarctica

    Directory of Open Access Journals (Sweden)

    J. V. Bageston

    2011-05-01

    Full Text Available A mesospheric bore was observed with an all-sky airglow imager on the night of 9–10 July 2007 at Ferraz Station (62° S, 58° W, located on King George island on the Antarctic Peninsula. The observed bore propagated from southwest to northeast with a well defined wave front and a series of crests behind the main front. There was no evidence of dissipation during its propagation within the field of view. The wave parameters were obtained via a 2-D Fourier transform of the imager data providing a horizontal wavelength of 33 km, an observed period of 6 min, and a horizontal phase speed of 92 m s−1. Simultaneous mesospheric winds were measured with a medium frequency (MF radar at Rothera Station (68° S, 68° W and temperature profiles were obtained from the SABER instrument on the TIMED satellite. These wind and temperature profiles were used to estimate the propagation environment of the bore. A wavelet technique was applied to the wind in the plane of bore propagation at the OH emission height spanning three days centered on the bore event to define the dominant periodicities. Results revealed a dominance of near-inertial periods, and semi-diurnal and terdiurnal tides suggesting that the ducting structure enabling bore propagation occurred on large spatial scales. The observed tidal motions were used to reconstruct the winds employing a least-squares method, which were then compared to the observed ducting environment. Results suggest an important contribution of large-scale winds to the ducting structure, but with buoyancy frequency variations in the vertical also expected to be important. These results allow us to conclude that the bore was supported by a duct including contributions from both winds and temperature (or stability. A co-located airglow temperature imager operated simultaneously with the all-sky imager confirmed that the bore event was the dominant small-scale wave event during the analysis interval.

  14. Holocene glacier dynamics on James Ross Island, NE Antarctic Peninsula

    Science.gov (United States)

    Davies, B. J.; Glasser, N. F.; Hambrey, M.

    2013-12-01

    The northern Antarctic Peninsula is currently warming very rapidly, which has resulted in ice sheet thinning, ice-shelf collapse, and rapid and widespread glacier recession. These small mountain glaciers are predicted to make a large sea level contribution over the coming century. Reconstructing past rates, volumes and magnitudes of change, particularly with respect to the former configuration of former ice sheets and ice shelves, is vital to contextualise contemporary change and to improve predictions of future ice-sheet behaviour. The aim of this research is therefore to investigate the relationship of deglacial ice sheet thinning and Holocene glacier fluctuations around James Ross Island, northeast Antarctic Peninsula, with temperature changes recorded in the Mount Haddington Ice Core. We use a combination of geomorphological mapping, from field campaigns and remotely sensed images, cosmogenic nuclide ages on glacially transported boulders, and numerical modelling with a simple 1D flowline model. Prior to 18 ka, James Ross Island was inundated by a thick and mainly cold-based ice sheet, which scattered granite erratics across the island. Ice sheet thickness and the rate of thinning is constrained by granite erratics on Terrapin Hill (610 m a.s.l.), and from flat-topped mesas at 370 m a.s.l. on Ulu Peninsula. During deglaciation and a period of rapid warming and eustatic sea level rise, the area was drained by Prince Gustav Ice Stream. The ice sheet reached its current configuration by around 6 ka, with glacier readvances around 4-5 ka. At Boulder Valley, near Terrapin Hill on James Ross Island, a large glacial readvance reached the current shoreline. It pre-dated the Mid-Holocene sea level high-stand, and has shorelines imprinted upon its seaward face. After 5.3 cal. ka BP and post-dating the mid-Holocene sea level high-stand, there was a readvance of at least 7 km by glacier 'IJR-45' on Ulu Peninsula. Rapid glacier recession occurred during a period of

  15. Hydroacoustic habitat mapping in Potter Cove (King George Island, Antarctica)

    Science.gov (United States)

    Hass, H. Christian; Wölfl, Anne-Cathrin; Kuhn, Gerhard; Jerosch, Kerstin; Scharf, Frauke; Abele, Doris

    2016-04-01

    Climate change increasingly affects the coastal areas off Antarctica. Strongest environmental response occurs in the transition zones that mediate between the polar and subpolar latitudes. Potter Cove, a minor fjord at the northern tip of the Antarctic Peninsula is significantly affected by rising temperatures and retreating ice sheets. Large amounts of turbid meltwaters affect both, the seafloor and the water column and cause stress for many biota. There is an increasing demand to monitor the ongoing change and to work out means for comparison with similar coastal ecosystems under pressure. Marine habitat maps provide information on the seafloor characteristics that allow to describe and evaluate the status of the recent coastal ecosystem and to predict its future development. We used a RoxAnn acoustic ground discrimination system, a sidescan sonar, grab samples (grain size and TOC) and underwater video footage to gain habitat information. Supervised and unsupervised classification routines (including fuzzy k-means clustering and LDA) were employed to calculate models ranging from two classes (soft bottom habitat, stone habitat) to 7 classes (including classes of rocks with and without macroalgae as well as classes of gravels, sands and silts). Including organic carbon in the database allowed to identify a carbon-depleted class proximal to the glacier front. Potter Cove reveals features that are related to the climate-controlled environmental change: very rough seafloor topography in a small basin close to the fjord head which was cleared by the retreating tidewater glacier through the past two decades. The increasing distance to the glacier down-fjord causes existing habitats to smooth and mature and new habitats to form. This process will change the terrestrial and marine face of Potter Cove until the ongoing climatic change stops or even reverses. It becomes apparent that the final interpretation of the results benefits significantly from the different

  16. Structural and Chemical Modification of Fe-Rich Smectite Associated with Microbial Fe-Respiration By Psychrophilic Bacteria in King George Island, West Antarctica

    Science.gov (United States)

    Jung, J.; Kim, J.; Lim, H. S.; Yoon, H.; Lee, Y. K.; Park, K.; Lee, J.; Kim, J. W.

    2014-12-01

    Surface soil samples were collected from Antarctic exploration (2010/2011, 2011/2012) at Barton Peninsula, King George Island, West Antarctica to determine the feasible biological alteration of clay minerals in Antarctica where the physical weathering is considered to be a major process. Seven areas (1226-1, 1226-2, 0101-4, 0105-1, 0105-2, 0107-2, 0107-3) from the coast toward the inland were investigated. The duration of exposure of soil samples to the air depending on the retraction of ice to the inland may affect the microbial activity resulting in the biogeochemical mineral alteration. The multiline of techniques for example, X-ray diffraction (XRD), Scanning Electron Microscope (SEM), wet chemistry analysis including the extent of Fe(III) reduction, and batch experiments of microbe-mineral interaction under the low temperature that mimics the Antarctic condition to understand the mechanism of biogeochemical alteration of clay minerals. Clay minerals of smectite, mica, chlorite and kaolinite were detected in the XRD profiles. The variation of relative amount of clay minerals in the regions indicated that the physical/biological alteration might be different depending on the duration of ice retraction. From the batch experiment using Nontronite (NAu-1), moreover, we confirm that Psychrophilic bacteria (Shewanella sp. isolated from King George Island) reduce structural Fe(III) of clay mineral, and occur structural change of smectite at low temperature (4℃ and 15℃). The present study, therefore, would present the feasibility of biological effects on chemical modification through the structural changes in clay mineral in cold environment and suggest a new pathway of Fe-supply into the Antarctic Ocean.

  17. Hydrography of Potter Cove, a Small Fjord-like Inlet on King George Island (South Shetlands)

    Science.gov (United States)

    Klöser, Heinz; Ferreyra, Gustavo; Schloss, Irene; Mercuri, Guillermo; Laturnus, Frank; Curtosi, Antonio

    1994-05-01

    The hydrography of Potter Cove (King George Island, South Shetlands) is described in detail for one summer season. Recorded data are wind, air temperature, water temperature, salinity and water colour. From these, information on surface circulation patterns and dynamics of suspended sediments are derived. Possible sources of sediment input are discussed. As a result, a complex interaction between wind forcing, circulation and seasonal melt of high glacier surfaces emerges.

  18. Diversity and cold adaptation of culturable endophytic fungi from bryophytes in the Fildes Region, King George Island, maritime Antarctica.

    Science.gov (United States)

    Zhang, Tao; Zhang, Yu-Qin; Liu, Hong-Yu; Wei, Yu-Zhen; Li, Hai-Long; Su, Jing; Zhao, Li-Xun; Yu, Li-Yan

    2013-04-01

    Endophytic fungi associated with three bryophyte species in the Fildes Region, King George Island, maritime Antarctica, that is, the liverwort Barbilophozia hatcheri, the mosses Chorisodontium aciphyllum and Sanionia uncinata, were studied by culture-dependent method. A total of 128 endophytic fungi were isolated from 1329 tissue segments of 14 samples. The colonization rate of endophytic fungi in three bryophytes species were 12.3%, 12.1%, and 8.7%, respectively. These isolates were identified to 21 taxa, with 15 Ascomycota, 5 Basidiomycota, and 1 unidentified fungus, based on morphological characteristics and sequence analyses of ITS region and D1/D2 domain. The dominant fungal endophyte was Hyaloscyphaceae sp. in B. hatcheri, Rhizoscyphus sp. in C. aciphyllum, and one unidentified fungus in S. uncinata; and their relative frequencies were 33.3%, 32.1%, and 80.0%, respectively. Furthermore, different Shannon-Weiner diversity indices (0.91-1.99) for endophytic fungi and low endophytic fungal composition similarities (0.19-0.40) were found in three bryophyte species. Growth temperature tests indicated that 21 taxa belong to psychrophiles (9), psychrotrophs (11), and mesophile (1). The results herein demonstrate that the Antarctic bryophytes are an interesting source of fungal endophytes and the endophytic fungal composition is different among the bryophyte species, and suggest that these fungal endophytes are adapted to cold stress in Antarctica.

  19. The Promise and Perils of the Island City of George Town (Penang as a Creative City

    Directory of Open Access Journals (Sweden)

    Suet Leng Khoo

    2015-12-01

    Full Text Available The peripheral and semi-peripheral roles of islands are being challenged and contested as contemporary island cities assume positions as engines of growth and become centres of progress for driving economic development. Notably, island cities around the globe have become instrumental in shaping and influencing the dynamics of urban development as cities now compete with each other to strategically position themselves in today’s competitive global economy that leverages creativity and innovation. Particularly in a creative economy, the availability, quantity, and quality of unique cultures; creative talents; and creative/cultural industries within a city are differentiating and determining factors that can boost a city’s position and subsequently spur economic growth and progress. Against this backdrop, this paper explores the position of the island city of George Town (Penang en route to becoming a Creative City. This paper highlights the island’s urban dynamics as well as discusses the promise and perils of transforming George Town into a Creative City in its own right.

  20. Geology and geochronology of the Sub-Antarctic Snares Islands/Tini Heke, New Zealand

    DEFF Research Database (Denmark)

    Scott, JM; Turnbull, IM; Sagar, MW

    2015-01-01

    The first comprehensive geological map, a summary of lithologies and new radiogenic isotope data (U–Pb, Rb–Sr) are presented for crystalline rocks of the Sub-Antarctic Snares Islands/Tini Heke, 150 km south of Stewart Island. The main lithology is Snares Granite (c. 109 Ma from U–Pb dating of zir...

  1. Geodetic implications on block formation and geodynamic domains in the South Shetland Islands, Antarctic Peninsula

    Science.gov (United States)

    Berrocoso, M.; Fernández-Ros, A.; Prates, G.; García, A.; Kraus, S.

    2016-01-01

    The South Shetland Islands archipelago is dynamically complex due to its tectonic surroundings. Most islands are part of a formerly active volcanic arc, although Deception, Penguin and Bridgeman Islands, as well as several submarine volcanoes, are characterized by active back-arc volcanism. Geodetic benchmarks were deployed and the movement of the lithosphere to which they were fixed measured to provide geodynamic insight for the South Shetland Islands, Bransfield Basin and Antarctic Peninsula area based on surface deformation. These benchmarks' data add spatial and temporal coverage to previous results. The results reveal two different geodynamic patterns, each confined to a distinct part of the South Shetland Islands archipelago. The inferred absolute horizontal velocity vectors for the benchmarks in the northeastern part of the archipelago are consistent with the opening of the Bransfield Basin, while benchmark vectors in the southwestern part of the archipelago are similar to those of the benchmarks on the Antarctic Peninsula. In between, Snow, Deception and Livingston Islands represent a transition zone. In this area, the horizontal velocity vectors relative to the Antarctic plate shift northeastwards from N to NW. Furthermore, the South Shetland Islands benchmarks, except for that at Gibbs (Elephant) Islands, indicate subsidence, which might be a consequence of the slab roll-back at the South Shetland Trench. In contrast, the uplift revealed by the Antarctic Peninsula benchmarks suggests glacial isostatic adjustment after the Larson B ice-shelf breakup.

  2. Environmental monitoring and management proposals for the Fildes Region, King George Island, Antarctica

    Directory of Open Access Journals (Sweden)

    Christina Braun

    2012-05-01

    Full Text Available The Antarctic terrestrial environment is under increasing pressure from human activities. The Fildes Region is characterized by high biodiversity, but is also a major logistic centre for the northern Antarctic Peninsula. Different interests, from scientific research, nature conservation, protection of geological and historical values, station operations, transport logistics and tourism, regularly overlap in space and time. This has led to increasing conflict among the multiple uses of the region and breaches of the legal requirements for environmental protection that apply in the area. The aim of this study was to assess the impacts of human activities in the Fildes Region by monitoring the distribution of bird and seal breeding sites and recording human activities and their associated environmental impacts. Data from an initial monitoring period 2003–06 were compared with data from 2008–10. We observed similar or increased levels of air, land and ship traffic, but fewer violations of overflight limits near Antarctic Specially Protected Area No. 150 Ardley Island. Open waste dumping and oil contamination are still major environmental impacts. Scientific and outdoor leisure activities undertaken by station personnel are more frequent than tourist activities and are likely to have a commensurate level of environmental impact. Despite the initial success of some existing management measures, it is essential that scientific and environmental values continue to be safeguarded, otherwise environmental impacts will increase and the habitat will be further degraded. We argue that the Fildes Region should be considered for designation as an Antarctic Specially Managed Area, a measure that has proven effective for environmental management of vulnerable areas of the Antarctic.

  3. Occurrence, bioaccumulation and long-range transport of short-chain chlorinated paraffins on the Fildes Peninsula at King George Island, Antarctica.

    Science.gov (United States)

    Li, Huijuan; Fu, Jianjie; Zhang, Aiqian; Zhang, Qinghua; Wang, Yawei

    2016-09-01

    As a candidate persistent organic pollutant of the Stockholm Convention, short-chain chlorinated paraffins (SCCPs) have recently received particular attention. In this study, we investigated, for the first time, the concentrations of SCCPs in biota samples collected from the Fildes Peninsula at King George Island and Ardley Island, Antarctica. The concentrations of SCCPs ranged from 3.5 to 256.6ng/g (dry weight, dw), with a mean of 76.6±61.8ng/g dw, which was lower than those detected in mid- and low-latitude regions. The long-range transport behaviour of SCCPs was confirmed by both the detection of SCCPs in Antarctic remote areas and their special congener profiles. Short carbon chain (C10) congeners predominated in the Antarctic samples, which accounted for 56.1% of the total SCCP contamination. Such enrichment of C10 congeners indicated the high potential for the long-range transport of shorter chain congeners. In addition, SCCPs tended to be enriched in the species with high lipid contents. The biomagnification potential of SCCPs was found between Archeogastropoda (Agas) and Neogastropoda (Ngas), and the biomagnification factors of shorter chain congeners of SCCPs were higher than that of the longer chain ones. Considering that the endemic species in polar regions may be sensitive and vulnerable to the adverse effects of environmental contaminants, more attention should be paid on the bioaccumulation and toxicological risks of SCCPs in polar environments.

  4. Preliminary evidence for 17 coastal terraces on Fildes Peninsula, King George Island, Antarctica

    Institute of Scientific and Technical Information of China (English)

    CHU Zhuding; YIN Xuebin; SUN Liguang; WANG Yuhong

    2015-01-01

    This study confirms the presence of 17 coastal terraces on Fildes Peninsula, Antarctica based on field observations and grain size analysis. The terraces formed by isostatic uplift during climate warming and glacier melting, and each level corresponds to a relatively stable period of climate. The grain size characteristics indicate an overlapping sedimentary origin for the sediments on the coastal terraces. The consistency of regional sea level rise, climate change, and glacial area suggest the presence of similar coastal terraces on King George Island since 18.0 ka.

  5. DISCOVERY OF LATE CRETACEOUS PALYNOFLORA FROM FILDES PENINSULA, KING GEORGE ISLAND, ANTARCTICA AND ITS SIGNIFICANCE

    Institute of Scientific and Technical Information of China (English)

    1990-01-01

    This paper makes an analysis and study on altogether 8 palyniferous samples from the volcano-sedimentary rock series in the Half Three Point area of the Fildes Peninsula, King George Island, Antarctica, the rock series being grey tuffaceous siltstone in lithological characters, about 5m in thickness. Only after making a number of analyses, could we find the relatively abundant sporopollen fossils from 4 samples (Nos. GWP 4—7). But the fossils are poorly preserved, and most of them can hardly be identifi...

  6. Environmental conditions of interstadial (MIS 3 and features of the last glacial maximum on the King George island (West Antarctica

    Directory of Open Access Journals (Sweden)

    S. R. Verkulich

    2013-01-01

    Full Text Available The interstadial marine deposits stratum was described in the Fildes Peninsula (King George Island due to field and laboratory investigations during 2008–2011. The stratum fragments occur in the west and north-west parts of peninsula in following forms: sections of soft sediments, containing fossil shells, marine algae, bones of marine animals and rich marine diatom complexes in situ (11 sites; fragments of shells and bones on the surface (25 sites. According to the results of radiocarbon dating, these deposits were accumulated within the period 19–50 ky BP. Geographical and altitude settings of the sites, age characteristics, taxonomy of fossil flora and fauna, and good safety of the soft deposits stratum allow to make following conclusions: during interstadial, sea water covered significant part of King George Island up to the present altitude of 40 m a.s.l., and the King George Island glaciation had smaller size then; environmental conditions for the interstadial deposit stratum accumulation were at least not colder than today; probably, the King George island territory was covered entirely by ice masses of Last glacial maximum not earlier than 19 ky BP; during Last glacial maximum, King George Island was covered by thin, «cold», not mobile glaciers, which contribute to conservation of the soft marine interstadial deposits filled with fossil flora and fauna.

  7. Pre-Fukushima levels of artificial radionuclides activities in maritime samples from King George Island (South Shetlands, Antarctica)

    Energy Technology Data Exchange (ETDEWEB)

    Sobiech-Matura, K. [European Commision DG-JRC Institute for Reference Materials and Measurements, Retieseweg 111, Geel (Belgium); Institute of Botany, Zdzislaw Czeppe Department of Polar Research and Documentation, Jagiellonian University, Kopernika 27, Krakow (Poland); Mietelski, J.W. [The Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, W.E. Radzikowskiego 152, Krakow (Poland); Olech, M.A. [Institute of Botany, Zdzislaw Czeppe Department of Polar Research and Documentation, Jagiellonian University, Kopernika 27, Krakow (Poland); Department of Antarctic Biology, Polish Academy of Sciences, Ustrzycka 10/12, Warsaw (Poland)

    2014-07-01

    Different maritime samples were collected at King George Island during Polish scientific expeditions in years 2005/2006 and 2006/2007. They originated mainly from Admiralty Bay region. Activities of {sup 137}Cs, {sup 238,239+240}Pu, {sup 90}Sr and {sup 241}Am were measured using γ-, β- and α-spectrometry. Our measurements allow estimating the state of radioactive pollution of Antarctic environment directly before the Fukushima accident. Examined samples included different elements of Antarctic marine environment: macro-algae (e.g. Cystosphaera jacquinotii, Ascoseira mirabilis), fishes(e.g. Notothenia coriiceps, Chaenocephalus aceratus), birds (e.g. Pygoscelis adeliae, P. papua), and crustaceans (e.g. Euphausia superba, Waldeckia obesa). Activity concentrations of {sup 137}Cs vary from <0.3 to 21.8 ± 2.1 Bq/kg d.w. In comparison with results obtained for samples of animals and macro-algae previously [1,2] our results are similar or lower. Activity concentrations of {sup 239+240}Pu range from <0.2 to 455 ± 56 mBq/kg d.w. and comparing to previous results [1,2] they were similar or lower. For maritime animals from Terra Nova Bay [3] results are also similar or lower than obtained in present project. Activity concentrations of {sup 238}Pu in samples varied from <0.2 to 79 ± 22 mBq/kg d.w. In comparison to results presented in [1,2,3] our values are similar or higher. Activity concentrations obtained for {sup 90}Sr varied from <1.5 to 73 ± 24 Bq/kg d.w. and are similar or lower then values given in [2,3]. Activity concentrations of {sup 241}Am varied from <9.4 to 29.8 ± 9.3 mBq/kg d.w. and they are similar or higher than values obtained in [3] and similar to that from [1]. Obtained results show that levels of radioactive contamination were very low and in many cases lower than the detection limit. Planned further investigation will allow estimating the environmental condition after the Fukushima accident. (authors)

  8. Quantitative ecological risk assessment of inhabitants exposed to polycyclic aromatic hydrocarbons in terrestrial soils of King George Island, Antarctica

    Science.gov (United States)

    Pongpiachan, S.; Hattayanone, M.; Pinyakong, O.; Viyakarn, V.; Chavanich, S. A.; Bo, C.; Khumsup, C.; Kittikoon, I.; Hirunyatrakul, P.

    2017-03-01

    This study aims to conduct a quantitative ecological risk assessment of human exposure to polycyclic aromatic hydrocarbons (PAHs) in terrestrial soils of King George Island, Antarctica. Generally, the average PAH concentrations detected in King George Terrestrial Soils (KGS) were appreciably lower than those of World Marine Sediments (WMS) and World Terrestrial Soils (WTS), highlighting the fact that Antarctica is one of the most pristine continents in the world. The total concentrations of twelve probably carcinogenic PAHs (ΣPAHs: a sum of Phe, An, Fluo, Pyr, B[a]A, Chry, B[b]F, B[k]F, B[a]P, Ind, D[a,h]A and B[g,h,i]P) were 3.21 ± 1.62 ng g-1, 5749 ± 4576 ng g-1, and 257,496 ± 291,268 ng g-1, for KGS, WMS and WTS, respectively. In spite of the fact that KGS has extremely low ΣPAHs in comparison with others, the percentage contribution of Phe is exceedingly high with the value of 50%. By assuming that incidental ingestion and dermal contact are two major exposure pathways responsible for the adverse human health effects, the cancer and non-cancer risks from environmental exposure to PAHs were carefully evaluated based on the ;Role of the Baseline Risk Assessment in Superfund Remedy Selection Decisions; memorandum provided by US-EPA. The logarithms of cancer risk levels of PAH contents in KGS varied from -11.1 to -7.18 with an average of -7.96 ± 7.73, which is 1790 times and 80,176 times lower than that of WMS and WTS, respectively. All cancer risk levels of PAH concentrations observed in KGS are significantly (p < 0.001) lower than those of WMS and WTS. Despite the Comandante Ferraz Antarctic Station fire occurred in February 25th, 2012, both the cancer and non-cancer risks of environmental exposure to PAHs were found in ;acceptable level;.

  9. Colonization by mites of glacier-free areas in King George Island, Antarctica Colonização por ácaros em áreas livres de geleiras na Ilha Rei George, Antárctica

    Directory of Open Access Journals (Sweden)

    Grzegorz Gryziak

    2009-08-01

    Full Text Available This work aimed to investigate the ratio of colonization by terrestrial mites on ice-free areas created by the ongoing climate-induced melting of Antarctic glaciers. Glacier retreat opens new ice-free areas for the colonization by vegetation and animals. The study was undertaken on the Antarctic Specially Protected Area no. 128 (West Coast of the Admiralty Bay, King George Island, South Shetlands Islands. Transects marked between the Ecology, Baranowski and Windy Glaciers, and a sea shore were used to collect soil samples. Oribatid mites were found only on near-shore areas, on patches of vegetation of more than 30 years of age. The colonization by mite communities is strongly determined by the presence of plants.Este trabalho visou investigar a proporção de colonização, por ácaros terrestres, em áreas de terra seca criadas pelo contínuo derretimento das geleiras antárticas induzido pelas condições climáticas. O recuo das geleiras abre novas áreas livres de gelo para a colonização pela vegetação e por animais. O estudo foi conduzido na Área de Proteção Especial da Antártica número 128 (ASPA nº 128, costa oeste da Baía do Almirantado, Ilha Rei George, Ilhas Shetland do Sul. Transectos marcados entre as geleiras Ecology, Baranowski e Windy e a costa marítima foram utilizados para coletar amostras de solo. Os ácaros oribatídeos foram encontrados somente em áreas próximas da costa em manchas de vegetação com mais de 30 anos de idade. A colonização das áreas de terra pelas comunidades de ácaros é fortemente determinada pela presença de plantas.

  10. At?sea distribution and habitat use in king penguins at sub?Antarctic Marion Island

    OpenAIRE

    Pistorius, Pierre; Hindell, Mark; Crawford, Robert; Makhado, Azwianewi; Dyer, Bruce; Reisinger, Ryan

    2017-01-01

    Abstract King penguins make up the bulk of avian biomass on a number of sub?Antarctic islands where they have a large functional effect on terrestrial and marine ecosystems. The same applies at Marion Island where a substantial proportion of the world population breeds. In spite of their obvious ecological importance, the at?sea distribution and behavior of this population has until recently remained entirely unknown. In addressing this information deficiency, we deployed satellite?linked tra...

  11. Turgidosculum complicatulum on sub-Antarctic Marion Island: carbon acquisition response to climate change

    NARCIS (Netherlands)

    Smith, V.; Gremmen, N.J.M.

    2001-01-01

    The lichen Turgidosculum complicatulum (formerly Mastodia tesselata) occurs in the shore-zone of Marion Island (sub-Antarctic: 47°S,38°E). Net CO2 exchange in the lichen is dominated by a strong temperature-dependence of respiration rate. The light/temperature response of photosynthesis is such that

  12. Soil biogeochemical toxicity end points for sub-Antarctic islands contaminated with petroleum hydrocarbons.

    Science.gov (United States)

    Schafer, Alexis Nadine; Snape, Ian; Siciliano, Steven Douglas

    2007-05-01

    Sub-Antarctic islands have been subjected to petroleum hydrocarbon spills, yet no information is available regarding the toxicity of petroleum hydrocarbons to these subpolar soils. The purpose of the present study was to identify soil biogeochemical toxicity end points for petroleum hydrocarbon contamination in sub-Antarctic soil. Soil from Macquarie Island, a sub-Antarctic island south of Australia, was collected and exposed to 10 concentrations of Special Antarctic Blend (SAB) diesel fuel, ranging from 0 to 50,000 mg fuel/kg soil, for a 21-d period. The sensitivity of nitrification, denitrification, carbohydrate utilization, and total soil respiration to SAB fuel was assessed. Potential nitrification activity was the most sensitive indicator of SAB contamination assessed for nitrogen cycling, with an IC20 (concentration that results in a 20% change from the control response) of 190 mg fuel/ kg soil. Potential denitrification activity was not as sensitive to SAB contamination, with an IC20 of 950 mg fuel/kg soil for nitrous oxide production. Nitrous oxide consumption was unaffected by SAB contamination. Carbohydrate utilization (respiration caused by sucrose) was a more sensitive indicator (IC20, 16 mg fuel/kg soil) of SAB contamination than total respiration (IC20, 220 mg fuel/kg soil). However, total soil respiration was a more responsive measurement end point, increasing soil respiration over a 72-h period by 17 mg of CO2, compared to a change of only 2.1 mg of CO2 for carbohydrate utilization. Our results indicate that IC20s varied between 16 to 950 mg fuel/kg soil for Macquarie Island soil spiked with SAB diesel fuel. These results indicate that current cleanup levels derived from temperate zones may be too liberal for soil contamination in sub-Antarctic islands.

  13. 33 CFR 334.650 - Gulf of Mexico, south of St. George Island, Fla.; test firing range.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Gulf of Mexico, south of St. George Island, Fla.; test firing range. 334.650 Section 334.650 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.650 Gulf of Mexico, south of St....

  14. At-sea distribution and habitat use in king penguins at sub-Antarctic Marion Island.

    Science.gov (United States)

    Pistorius, Pierre; Hindell, Mark; Crawford, Robert; Makhado, Azwianewi; Dyer, Bruce; Reisinger, Ryan

    2017-06-01

    King penguins make up the bulk of avian biomass on a number of sub-Antarctic islands where they have a large functional effect on terrestrial and marine ecosystems. The same applies at Marion Island where a substantial proportion of the world population breeds. In spite of their obvious ecological importance, the at-sea distribution and behavior of this population has until recently remained entirely unknown. In addressing this information deficiency, we deployed satellite-linked tracking instruments on 15 adult king penguins over 2 years, April 2008 and 2013, to study their post-guard foraging distribution and habitat preferences. Uniquely among adult king penguins, individuals by and large headed out against the prevailing Antarctic Circumpolar Current, foraging to the west and southwest of the island. On average, individuals ventured a maximum distance of 1,600 km from the colony, with three individuals foraging close to, or beyond, 3,500 km west of the colony. Birds were mostly foraging south of the Antarctic Polar Front and north of the southern boundary of the Antarctic Circumpolar Current. Habitat preferences were assessed using boosted regression tree models which indicated sea surface temperate, depth, and chorophyll a concentration to be the most important predictors of habitat selection. Interestingly, king penguins rapidly transited the eddy-rich area to the west of Marion Island, associated with the Southwest Indian Ocean Ridge, which has been shown to be important for foraging in other marine top predators. In accordance with this, the king penguins generally avoided areas with high eddy kinetic energy. The results from this first study into the behavioral ecology and at-sea distribution of king penguins at Marion Island contribute to our broader understanding of this species.

  15. Aeolian processes and landforms in the sub-Antarctic: preliminary observations from Marion Island

    Directory of Open Access Journals (Sweden)

    David W. Hedding

    2015-11-01

    Full Text Available Sub-Antarctic Marion Island has a hyperoceanic climate, with cold and wet conditions and consistently strong wind velocities throughout the year. Recent observations recognized the increasing role of aeolian processes as a geomorphic agent, and this paper presents the first data for transport by aeolian processes on a sub-Antarctic island. Data were collected through an intensive and high-resolution measurement campaign at three study sites using Big Spring Number Eight sediment traps and surface sediment samplers in conjunction with an array of climatic and soil logger sensors. Observed aeolian landforms are megaripples, and the data suggest that aeolian processes are also modifying solifluction landforms. The sediment traps and sediment samplers collected wind-blown scoria at all three study sites, and the annual (horizontal aeolian sediment flux extrapolated from this preliminary data is estimated at 0.36–3.85 kg cm−2 y−1. Importantly, plant material of various species was trapped during the study that suggests the efficiency of wind for the dispersal of plants in this sub-Antarctic environment may be underestimated. This paper advocates long-term monitoring of aeolian processes and that the link between aeolian processes and synoptic climate must be established. Furthermore, wind as a means to disperse genetic material on Marion Island should be investigated.

  16. The Quarantine Protection of Sub-Antarctic Australia: Two Islands, Two Regimes

    Directory of Open Access Journals (Sweden)

    Sandra Potter

    2007-11-01

    Full Text Available Sub-Antarctic Heard Island and Macquarie Island are among Australia’s offshore properties susceptible to colonization by species introduced by humans. While both islands share World Heritage status and are IUCN Category Ia Protected Areas (Strict Nature Reserves, different quarantine protection regimes are in operation. Macquarie Island’s biosecurity appears to be less catered for while the means and likelihood of introductions are greater. The administrative, political, practical and geographical contexts within which quarantine management planning takes place variously impact on the level of quarantine protection provided to both islands. These and other remote sites of high conservation value are unlikely to receive heightened protection until the issues associated with such management contexts receive greater attention.

  17. Radon and thoron daughter activities in the environment of the King George Island (West Antarctica

    Directory of Open Access Journals (Sweden)

    A. T. Solecki

    2005-06-01

    Full Text Available Results of 253 gamma spectrometric analyses of radon daughters in soil and bedrocks of the King George Island (West Antarctica are presented. Measured values range from 0.1 to 58.4 Bq/kg, and from 4.9 to 75.5 Bq/kg for 214Bi and 208Tl respectively, but most measurements fall in the lower part of this range due to predominantly basaltic character of the geological basement. Obtained gamma spectrometric data correspond well to very low soil gas radon content measured by means of Kodak LR115 being below 454 Bqm-3. Low soil gas radon content and characteristic type of architecture is responsible for low indoor radon activity in Arctowski Station being as low as 10- 15 Bqm-3. The highest 105 Bqm-3 indoor Rn activity has been measured in the greenhouse bungalow of the station. This increased value was probably connected with the presence of about 1000 kg of imported soil material in the greenhouse room of the bungalow. Local zones of increased uranium and thorium content, discovered as a result of radiometric mapping, can potentaily influence atmospheric radon used for meteorological interpretation.

  18. Occurrence of organochlorine pesticides in the environmental matrices from King George Island, west Antarctica.

    Science.gov (United States)

    Zhang, Qinghua; Chen, Zhaojing; Li, Yingming; Wang, Pu; Zhu, Chaofei; Gao, Guanjun; Xiao, Ke; Sun, Huizhong; Zheng, Shucheng; Liang, Yong; Jiang, Guibin

    2015-11-01

    Antarctica is considered as a final sink of many persistent organic pollutants (POPs). This work aims to investigate the levels, distributions and potential sources of organochlorine pesticides (OCPs) with HRGC/HRMS technique. Twenty-three OCPs were measured in various environmental matrices from King George Island, west Antarctica. The total concentrations (Σ23OCPs) were at quite low levels, ranging 93.6-1260 pg g(-1) dry weight (dw) in soil and sediment, 223-1053 pg g(-1) dw in moss and 373-812 pg g(-1) dw in lichen. Hexachlorobenzene (HCB), dichloro-diphenyl-trichloroethane (DDT) and its metabolites (especially p,p'-DDE) and hexachlorocyclohexanes (HCHs) were the main contaminants in all samples. Lower α-HCH/γ-HCH and higher p,p'-DDE/p,p'-DDT ratios compared with the technical products indicated long-range atmospheric transport (LRAT) of recent lindane and aged technical DDT. Significant dependence of many OCPs concentrations on total organic carbon (TOC) was observed. Apart from LRAT, local biotic activities could also contribute and influence the spatial distribution of the contaminants.

  19. Molecular organic geochemical peculiarities of lacustrine core sediments in Fildes Peninsula, King George Island,Antarctica

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The peculiarities of lipids in lacustrine core sediments from Fildes Peninsula, King George Island, Antarctica, are reported. The origin of high-molecular-weight n-alkanes, alkenes,fatty acids, alcohols is supposed to be related to the abundant moss occurring in the sediments.Abundant iso-and anteiso-fatty acids that occur in the sediments indicate a relatively strong bacterial activity in non-ice-cover zone than in other regions in Antarctica. The C18:2 unsaturated fatty acids mainly originate from autochthonous algae in the sediment pool, and the C18:2/C18:0ratios in the profile are controlled more by paleotemperatures than source assemblies. Long-chain alkenones were identified in freshwater lacustrine sediment in Antarctica for the first time, of which Prymnesiophyceae is assumed to be the source organism. High relative abundance of C37:4honologue in long-chain alkenone well correlates to the severely cold climate in Antarctica.

  20. Morphology and ecology of bivalve molluscs from Admiralty Bay, King George Island, Antarctica

    Directory of Open Access Journals (Sweden)

    Theresinha M. Absher

    1998-08-01

    Full Text Available Bivalve species were collected from shallow coastal areas of King George Island (Martel, Mackellar and Ezcurra Inlets of Admiralty Bay. Twenty one species belonging to 16 genera and 12 families were identified and their morphometric and morphological shell characteristics were described. Three main characteristics were found to be common to the majority of the bivalve species sampled: 1 thin fragile shells; 2 small size of individuals (76%, and 3 the lack of true cardinal teeth (72%. Comparison of calcium data from a tropical estuary and a subantarctic coastal shallow area suggested that the calcium in the sea water was not a constraint to shell building but shell thickness could be an adaptation to the efficiency of energy partitioning. Small individual size and the lack of true cardinal teeth are discussed in relation to a high deposition environment and widespread mud bottoms.Espécies de bivalves foram coletadas na região costeira rasa da Ilha Rei George (Enseadas Martel, Mackellar e Ezcurra da Baía do Almirantado. Vinte e uma espécies pertencentes a 16 gêneros e 12 famílias foram identificadas e as caractrísticas morfológicas e morfométricas das conchas descritas. Destacaram-se 3 características principais comuns à maioria das espécies: 1 conchas finas e frágeis; 2 pequeno tamanho dos indivíduos (76%, e 3 a ausência de dentes cardinais (72%. A comparação entre os dados de cálcio de um estuário tropical e uma região rasa costeira subantártica sugeriu que os valores de cálcio na água do mar não seriam uma restrição à formação das conchas, mas a espessura das conchas poderia ser uma adaptação à eficiência na distribuição da energia. Discute-se a ausência de dentes cardinais e pequeno tamanho dos indivíduos em ralação a um ambiente de alta deposição e abundância de fundos lodosos.

  1. Distribution and characteristics of marine habitats in a subpolar bay based on hydroacoustics and bed shear stress estimates—Potter Cove, King George Island, Antarctica

    Science.gov (United States)

    Wölfl, Anne-Cathrin; Lim, Chai Heng; Hass, H. Christian; Lindhorst, Sebastian; Tosonotto, Gabriela; Lettmann, Karsten Alexander; Kuhn, Gerhard; Wolff, Jörg-Olaf; Abele, Doris

    2014-10-01

    Marine habitats worldwide are increasingly pressurized by climate change, especially along the Antarctic Peninsula. Well-studied areas in front of rapidly retreating tidewater glaciers like Potter Cove are representative for similar coastal environments and, therefore, shed light on habitat formation and development on not only a local but also regional scale. The objective of this study was to provide insights into habitat distribution in Potter Cove, King George Island, Antarctica, and to evaluate the associated environmental processes. Furthermore, an assessment concerning the future development of the habitats is provided. To describe the seafloor habitats in Potter Cove, an acoustic seabed discrimination system (RoxAnn) was used in combination with underwater video images and sediment samples. Due to the absence of wave and current measurements in the study area, bed shear stress estimates served to delineate zones prone to sediment erosion. On the basis of the investigations, two habitat classes were identified in Potter Cove, namely soft-sediment and stone habitats that, besides influences from sediment supply and coastal morphology, are controlled by sediment erosion. A future expansion of the stone habitat is predicted if recent environmental change trends continue. Possible implications for the Potter Cove environment, and other coastal ecosystems under similar pressure, include changes in biomass and species composition.

  2. Kelp gulls, Larus dominicanus (Aves: Laridae, breeding in Keller Peninsula, King George Island, Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Joaquim O. Branco

    2009-09-01

    Full Text Available We examined the distribution, abundance and density of the Kelp Gull, Larus dominicanus (Lichtenstein, 1823, at Keller Peninsula on two occasions during the breeding season of 2007-2008 (once for incubation and once for chick stages and compared our results with previously published data. We present information on the number of eggs, incubation success, and initial development of L. dominicanus chicks in the studied sites. The abundance and density of the species has remained statistically similar in Keller Peninsula over the last 30 years (since 1978-1979. Although the abundance and density were almost unchanged, we recorded alterations in the occupation of the breeding areas by L. dominicanus, mainly the abandonment of breeding sites in the eastern portion of Keller Peninsula. The results of the present study compared with similar previous investigations on the abundance of L. dominicanus indicate that the populations have been in equilibrium over the years.

  3. King George Island ice cap geometry updated with airborne GPR measurements

    Directory of Open Access Journals (Sweden)

    M. Rückamp

    2012-07-01

    Full Text Available Ice geometry is a mandatory requirement for numerical modelling purposes. In this paper we present a consistent data set for the ice thickness, the bedrock topography and the ice surface topography of the King George Island ice cap (Arctowski icefield and the adjacent central part. The new data set is composed of ground based and airborne ground penetrating radar (GPR and differential GPS (DGPS measurements, obtained during several field campaigns. Blindow et al. (2010 already provided a comprehensive overview of the ground based measurements carried out in the safely accessible area of the ice cap. The updated data set incorporates airborne measurements in the heavily crevassed coastal areas. Therefore, in this paper special attention is paid to the airborne measurements by addressing the instrument used, survey procedure, and data processing in more detail. In particular, the inclusion of airborne GPR measurements with the 30 MHz BGR-P30-System developed at the Institute of Geophysics (University of Münster completes the picture of the ice geometry substantially. The compiled digital elevation model of the bedrock shows a rough, highly variable topography with pronounced valleys, ridges, and troughs. Mean ice thickness is 240 ± 6 m, with a maximum value of 422 ± 10 m in the surveyed area. Noticeable are bounded areas in the bedrock topography below sea level where marine based ice exists. The provided data set is required as a basis for future monitoring attempts or as input for numerical modelling experiments. The data set is available from the PANGAEA database at http://dx.doi.org/10.1594/PANGAEA.770567.

  4. Active layer thermal monitoring at Fildes Peninsula, King George Island, Maritime Antarctica

    Directory of Open Access Journals (Sweden)

    R. F. M. Michel

    2014-07-01

    Full Text Available International attention to the climate change phenomena has grown in the last decade; the active layer and permafrost are of great importance in understanding processes and future trends due to their role in energy flux regulation. The objective of the this paper is to present active layer temperature data for one CALM-S site located at Fildes Peninsula, King George Island, Maritime Antarctica over an fifth seven month period (2008–2012. The monitoring site was installed during the summer of 2008 and consists of thermistors (accuracy of ± 0.2 °C, arranged vertically with probes at different depths, recording data at hourly intervals in a~high capacity data logger. A series of statistical analysis were performed to describe the soil temperature time series, including a linear fit in order to identify global trend and a series of autoregressive integrated moving average (ARIMA models were tested in order to define the best fit for the data. The controls of weather on the thermal regime of the active layer have been identified, providing insights about the influence of climate chance over the permafrost. The active layer thermal regime in the studied period was typical of periglacial environment, with extreme variation at the surface during summer resulting in frequent freeze and thaw cycles. The active layer thickness (ALT over the studied period showed variability related to different annual weather conditions, reaching a maximum of 117.5 cm in 2009. The ARIMA model was considered appropriate to treat the dataset, enabling more conclusive analysis and predictions when longer data sets are available. Despite the variability when comparing temperature readings and active layer thickness over the studied period, no warming trend was detected.

  5. King George Island ice cap geometry updated with airborne GPR measurements

    Directory of Open Access Journals (Sweden)

    M. Rückamp

    2011-12-01

    Full Text Available Ice geometry is a mandatory requirement for numerical modelling purposes. In this paper we present a consistent data set for the ice thickness, the bedrock topography and the ice surface topography of the King George Island ice cap (Arctowski Icefield and the adjacent central part. The newly data set is composed of groundbased and airborne Ground Penetrating Radar (GPR and differential GPS (DGPS measurements, obtained during several field campaigns. Blindow et al. (2010 already provided a comprehensive overview of the groundbased measurements carried out in the safely accessible area of the ice cap. The updated data set incorporates airborne measurements in the heavily crevassed coastal areas. Therefore, in this paper special attention is paid to the airborne measurements by addressing the used instrument, survey, and data processing in more detail. In particular, the inclusion of airborne GPR measurements with the 30 MHz BGR-P30-System developed at the Institute of Geophysics (University of Münster completes the picture of the ice geometry substantially. The compiled digital elevation model of the bedrock shows a rough, highly variable topography with pronounced valleys, ridges, and troughs. Mean ice thickness is ~240 m, with a maximum value of ~400 m in the surveyed area. Noticeable are bounded areas in the bedrock topography below sea level where marine based ice exists. The provided data set is required as a basis for future monitoring attempts or as input for numerical modelling experiments. The data set is available from the PANGAEA database at doi:10.1594/PANGAEA.770567.

  6. Regional genetic diversity patterns in Antarctic hairgrass (Deschampsia antartica Desv.)

    NARCIS (Netherlands)

    van de Wouw, M.J.; Van Dijk, P.J.; Huiskes, A.H.L.

    2008-01-01

    Aim To determine patterns in diversity of a major Antarctic plant species, including relationships of Antarctic populations with those outside the Antarctic zone. Location Antarctic Peninsula, Maritime Antarctica, sub-Antarctic islands, Falkland Islands and South America. Methods Amplified fragment

  7. Soil thermal regime on ice-free areas in Livingston Island and James Ross Island, Antarctic Peninsula region

    Science.gov (United States)

    Hrbáček, Filip; Oliva, Marc; Láska, Kamil; Ruiz-Fernández, Jesús; Ángel de Pablo, Miguel; Vieira, Gonçalo; Ramos, Miguel; Nývlt, Daniel

    2016-04-01

    Permafrost and active layer are considered prominent components of the Cryosphere, which react very sensitively to small climate variations. The Antarctic Peninsula (AP) region is considered as one of the fastest warming regions on Earth, where mean annual air temperature locally increased more than 2.5°C over the last 60 years. Significant climate differences are found between the eastern and western sides of the AP. While mean annual air temperatures (MAAT) oscillate around -1 to -2 °C and precipitation reach 800 mm w.e. year-1 in the western AP, the MAAT in the eastern AP are below -6 °C and precipitation does not exceed 500 mm. These differences determine different permafrost thickness and spatial distribution in these two regions, as well as diverse patterns of active layer dynamics. With the purpose to better understand the factors controlling the soil thermal regime in maritime permafrost environments, we examine data from 2014 acquired from several sites in Livingston Island (western AP) and James Ross Island (eastern AP). The study sites show similar characteristics in terms of topography (slope Ross Island ranged from -7.0 to -7.9 °C. Mean soil temperature at 5 cm depth was slightly higher than air temperature in both areas: -0.7 to -1.3 °C in Livingston Island and -6.2 to -6.3 °C in James Ross Island; the same occurred for soil temperature at 75 cm: -0.4 to -0.7 °C in Livingston Island and -6.0 to -6.6 °C James Ross Island. Significantly lower values of mean daily amplitude of soil temperature at 5 cm depth and the freezing n-factor values observed during the freezing season on Livingston Island suggest a pronounced insulating effect of snow cover in this area in comparison to James Ross Island. The mean daily amplitude of soil temperature at 5 cm ranged from 0.9 to 1.7 °C in Livingston Island, while it reached 3.0 to 4.0 °C in James Ross Island. The freezing n-factor reached 0.33 and 0.63 on Livingston Island, while 0.88 and 0.98 were

  8. Foraging segregation of two congeneric diving seabird species breeding on St. George Island, Bering Sea

    Science.gov (United States)

    Kokubun, Nobuo; Yamamoto, Takashi; Sato, Nobuhiko; Watanuki, Yutaka; Will, Alexis; Kitaysky, Alexander S.; Takahashi, Akinori

    2016-04-01

    Subarctic environmental changes are expected to affect the foraging ecology of marine top predators, but the response to such changes may vary among species if they use food resources differently. We examined the characteristics of foraging behavior of two sympatric congeneric diving seabird: common (Uria aalge: hereafter COMUs) and thick-billed (U. lomvia: hereafter TBMUs) murres breeding on St. George Island, located in the seasonal sea-ice region of the Bering Sea. We investigated their foraging trip and flight durations, diel patterns of dive depth, and underwater wing strokes, along with wing morphology and blood stable isotope signatures and stress hormones. Acceleration-temperature-depth loggers were attached to chick-guarding birds, and data were obtained from 7 COMUs and 12 TBMUs. Both species showed similar mean trip duration (13.2 h for COMUs and 10.5 h for TBMUs) and similar diurnal patterns of diving (frequent dives to various depths in the daytime and less frequent dives to shallow depths in the nighttime). During the daytime, the dive depths of COMUs had two peaks in shallow (18.1 m) and deep (74.2 m) depths, while those of TBMUs were 20.2 m and 59.7 m. COMUs showed more frequent wing strokes during the bottom phase of dives (1.90 s-1) than TBMUs (1.66 s-1). Fish occurred more frequently in the bill loads of COMUs (85 %) than those of TBMUs (56 %). The δ15N value of blood was significantly higher in COMUs (14.5 ‰) than in TBMUs (13.1 ‰). The relatively small wing area (0.053 m2) of COMUs compared to TBMUs (0.067 m2) may facilitate their increased agility while foraging and allow them to capture more mobile prey such as larger fishes that inhabit deeper depths. These differences in food resource use may lead to the differential responses of the two murre species to marine environmental changes in the Bering Sea.

  9. Late Cenozoic Bryozoa from diamictites of Cape Lamb, Vega Island, Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Adamonis Susana

    2015-12-01

    Full Text Available Bryozoans were found in upper Cenozoic diamictite debris that crops out at the southwestern tip of Cape Lamb, Vega Island. The diamictite is the youngest deposit on the island and richly composed of foraminifers, brachiopods and scallops. The foraminifera assemblage recovered from the Cape Lamb diamictite and 87Sr/86Sr isotopic age obtained from the pectinid Adamussium colbecki in the nearby locality of Terrapin indicates a Pleistocene age for this deposit. The main goal of this contribution is to present a bryozoan assemblage of Microporella stenoporta Hayward et Taylor, Hippothoa flagellum Manzoni, Ellisina antarctica (Kluge, Micropora notialis Hayward et Ryland and an indeterminate crisiid constituting the first record of these bryozoan taxa in Cenozoic diamictites of the Antarctic Peninsula.

  10. Texture-based classification of sub-Antarctic vegetation communities on Heard Island

    Science.gov (United States)

    Murray, Humphrey; Lucieer, Arko; Williams, Raymond

    2010-06-01

    This study was the first to use high-resolution IKONOS imagery to classify vegetation communities on sub-Antarctic Heard Island. We focused on the use of texture measures, in addition to standard multispectral information, to improve the classification of sub-Antarctic vegetation communities. Heard Island's pristine and rapidly changing environment makes it a relevant and exciting location to study the regional effects of climate change. This study uses IKONOS imagery to provide automated, up-to-date, and non-invasive means to map vegetation as an important indicator for environmental change. Three classification techniques were compared: multispectral classification, texture based classification, and a combination of both. Texture features were calculated using the Grey Level Co-occurrence Matrix (GLCM). We investigated the effect of the texture window size on classification accuracy. The combined approach produced a higher accuracy than using multispectral bands alone. It was also found that the selection of GLCM texture features is critical. The highest accuracy (85%) was produced using all original spectral bands and three uncorrelated texture features. Incorporating texture improved classification accuracy by 6%.

  11. Composition of plagioclases in volcanic rocks of King George Island, Antarctica with reference to the petrogenetic significance

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Plagioclases occur mainly as phenocrysts in volcanic rocks of King George Island, South Shetland Islands, West Antarctica. In basaltic andesites and andesites of Keller Peninsula and Ullman Spur (Admiralty Bay), they are high structure state labradorite-andesines; and in high-A1 basalts and basaltic andesites of Barton and Weaver peninsulas (Maxwell Bay), they are high structure state bytownite-anorthites.∑REE, La/Yb ratios and δEu values of plagioclases from Admiralty Bay are higher than those from Maxwell Bay. All plagioclases have rather identical chondritenormalized transitional element distribution patterns, probably reflecting that crystal structure rather than composition of plagioclase controls their diversity. Compositions of plagioclases depend chiefly on those of their host rocks, compositional differences of plagioclases reveal that basaltic magmas in the Admiralty Bay area are more evolved than in the Maxwell Bay area.

  12. Magnetostratigraphic Dating of Paleogene Sediments in the Seymour Island (Antarctic Peninsula): A Preliminary Chronostratigraphy

    Science.gov (United States)

    Beamud, E.; Montes, M. J.; Santillana, S.; Nozal, F.; Marenssi, S.

    2015-12-01

    Seymour Island is located at 64 º S, close to the northeastern tip of the Antarctic Peninsula. This glacier-free island contains the southernmost exposures of the K/Pg boundary and it has the most complete record of the Paleogene in Antarctica. The base of the Paleogene is represented by the Early Paleocene shallow marine shelf deposits of the Marambio Group; which are unconformably overlain by the Late Paleocene to Late Eocene Seymour Island Group. The Marambio Group is divided into the quartz-rich silty sandstones and mudstones of the López de Bertodano Fm and the mudstones to quartz-rich sandstones of the Sobral Fm. The overlaying Seymour Island Group records the erosion and filling of incised valleys. This group is made up by the Cross Valley-Wiman, La Meseta and the uppermost new Submeseta Formations. Main regressive periods are evidenced by the erosional unconformities and their related time gaps at the base of these three Formations. The La Meseta and Submeseta Formations are composed by poorly consolidated marine sandstones and siltstones deposited in a shallow coastal (possibly estuarine) environment. Several biostratigraphic and isotopic studies have been conducted in the Seymour Island due to its extremely rich fossil record, and the age of the López de Bertodano Fm has been recently refined by magnetostratigraphy. However, the overlying Paleogene formations lack a reliable absolute continuous dating. To solve this problem, a composite magnetostratigraphic section spanning more than 1300 m from the K/Pg boundary up to the top of the Submeseta Fm was conducted, with an average sampling resolution of 3 m per site. Although many samples yielded weak results, a local magnetostratigraphy was obtained which has been correlated to the GPTS. The new derived ages range from Danian (~ 66 Ma) up to Priabonian (~ 34 Ma). These results have been integrated with previous litho-, bio- and isotopic data to build a new Paleogene chronostratigraphy for the Seymour

  13. Mercury in the ecosystem of Admiralty Bay, King George Island, Antarctica: Occurrence and trophic distribution.

    Science.gov (United States)

    Cipro, Caio V Z; Montone, Rosalinda C; Bustamante, Paco

    2017-01-15

    Mercury (Hg) can reach the environment through natural and human-related sources, threatening ecosystems all over the planet due to its well known deleterious effects. Therefore, Antarctic trophic webs, despite being relatively isolated, are not exempt of its influence. To evaluate Hg concentrations in an Antarctic ecosystem, different tissues from 2 species of invertebrates, 2 of fish, 8 of birds, 4 of pinnipeds and at least 5 of vegetation were investigated (n=176). For animals, values ranged from 0.018 to 48.7μgg(-1) dw (whole Antarctic krill and Antarctic Fur Seal liver). They were generally correlated to trophic position (assessed by δ(15)N and δ(13)C) but also to cephalopods and myctophids consumption. For vegetation, values ranged from 0.014 to 0.227μgg(-1) dw (Colobanthus quitensis and an unidentified lichen), with lichens presenting significantly higher values than mosses, likely due to year-round exposure and absorption of animal derived organic matter, as hypothesized by literature.

  14. Up, Down, and All Around: Scale-Dependent Spatial Variation in Rocky-Shore Communities of Fildes Peninsula, King George Island, Antarctica

    Science.gov (United States)

    Valdivia, Nelson; Díaz, María J.; Holtheuer, Jorge; Garrido, Ignacio; Huovinen, Pirjo; Gómez, Iván

    2014-01-01

    Understanding the variation of biodiversity along environmental gradients and multiple spatial scales is relevant for theoretical and management purposes. Hereby, we analysed the spatial variability in diversity and structure of intertidal and subtidal macrobenthic Antarctic communities along vertical environmental stress gradients and across multiple horizontal spatial scales. Since biotic interactions and local topographic features are likely major factors for coastal assemblages, we tested the hypothesis that fine-scale processes influence the effects of the vertical environmental stress gradients on the macrobenthic diversity and structure. We used nested sampling designs in the intertidal and subtidal habitats, including horizontal spatial scales ranging from few centimetres to 1000s of metres along the rocky shore of Fildes Peninsula, King George Island. In both intertidal and subtidal habitats, univariate and multivariate analyses showed a marked vertical zonation in taxon richness and community structure. These patterns depended on the horizontal spatial scale of observation, as all analyses showed a significant interaction between height (or depth) and the finer spatial scale analysed. Variance and pseudo-variance components supported our prediction for taxon richness, community structure, and the abundance of dominant species such as the filamentous green alga Urospora penicilliformis (intertidal), the herbivore Nacella concinna (intertidal), the large kelp-like Himantothallus grandifolius (subtidal), and the red crustose red alga Lithothamnion spp. (subtidal). We suggest that in coastal ecosystems strongly governed by physical factors, fine-scale processes (e.g. biotic interactions and refugia availability) are still relevant for the structuring and maintenance of the local communities. The spatial patterns found in this study serve as a necessary benchmark to understand the dynamics and adaptation of natural assemblages in response to observed and

  15. Up, down, and all around: scale-dependent spatial variation in rocky-shore communities of Fildes Peninsula, King George Island, Antarctica.

    Directory of Open Access Journals (Sweden)

    Nelson Valdivia

    Full Text Available Understanding the variation of biodiversity along environmental gradients and multiple spatial scales is relevant for theoretical and management purposes. Hereby, we analysed the spatial variability in diversity and structure of intertidal and subtidal macrobenthic Antarctic communities along vertical environmental stress gradients and across multiple horizontal spatial scales. Since biotic interactions and local topographic features are likely major factors for coastal assemblages, we tested the hypothesis that fine-scale processes influence the effects of the vertical environmental stress gradients on the macrobenthic diversity and structure. We used nested sampling designs in the intertidal and subtidal habitats, including horizontal spatial scales ranging from few centimetres to 1000s of metres along the rocky shore of Fildes Peninsula, King George Island. In both intertidal and subtidal habitats, univariate and multivariate analyses showed a marked vertical zonation in taxon richness and community structure. These patterns depended on the horizontal spatial scale of observation, as all analyses showed a significant interaction between height (or depth and the finer spatial scale analysed. Variance and pseudo-variance components supported our prediction for taxon richness, community structure, and the abundance of dominant species such as the filamentous green alga Urospora penicilliformis (intertidal, the herbivore Nacella concinna (intertidal, the large kelp-like Himantothallus grandifolius (subtidal, and the red crustose red alga Lithothamnion spp. (subtidal. We suggest that in coastal ecosystems strongly governed by physical factors, fine-scale processes (e.g. biotic interactions and refugia availability are still relevant for the structuring and maintenance of the local communities. The spatial patterns found in this study serve as a necessary benchmark to understand the dynamics and adaptation of natural assemblages in response to

  16. Up, down, and all around: scale-dependent spatial variation in rocky-shore communities of Fildes Peninsula, King George Island, Antarctica.

    Science.gov (United States)

    Valdivia, Nelson; Díaz, María J; Holtheuer, Jorge; Garrido, Ignacio; Huovinen, Pirjo; Gómez, Iván

    2014-01-01

    Understanding the variation of biodiversity along environmental gradients and multiple spatial scales is relevant for theoretical and management purposes. Hereby, we analysed the spatial variability in diversity and structure of intertidal and subtidal macrobenthic Antarctic communities along vertical environmental stress gradients and across multiple horizontal spatial scales. Since biotic interactions and local topographic features are likely major factors for coastal assemblages, we tested the hypothesis that fine-scale processes influence the effects of the vertical environmental stress gradients on the macrobenthic diversity and structure. We used nested sampling designs in the intertidal and subtidal habitats, including horizontal spatial scales ranging from few centimetres to 1000s of metres along the rocky shore of Fildes Peninsula, King George Island. In both intertidal and subtidal habitats, univariate and multivariate analyses showed a marked vertical zonation in taxon richness and community structure. These patterns depended on the horizontal spatial scale of observation, as all analyses showed a significant interaction between height (or depth) and the finer spatial scale analysed. Variance and pseudo-variance components supported our prediction for taxon richness, community structure, and the abundance of dominant species such as the filamentous green alga Urospora penicilliformis (intertidal), the herbivore Nacella concinna (intertidal), the large kelp-like Himantothallus grandifolius (subtidal), and the red crustose red alga Lithothamnion spp. (subtidal). We suggest that in coastal ecosystems strongly governed by physical factors, fine-scale processes (e.g. biotic interactions and refugia availability) are still relevant for the structuring and maintenance of the local communities. The spatial patterns found in this study serve as a necessary benchmark to understand the dynamics and adaptation of natural assemblages in response to observed and

  17. Evaluation of the ground surface Enthalpy balance from bedrock shallow borehole temperatures (Livingston Island, Maritime Antarctic

    Directory of Open Access Journals (Sweden)

    M. Ramos

    2008-03-01

    Full Text Available The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic is studied. The borehole is 2.4 m deep and is located in a quartzite outcrop in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth hourly temperature profiles from: (i the cooling periods of the frost seasons of 2000 to 2005, and (ii the warming periods of the thaw seasons of 2002–2003, 2003–2004 and 2004–2005, were studied. In this modelling approach, heat gains and losses across ground surface are considered to be the causes for the 0°C isotherm movement. A methodological approach to calculate the Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density is considered to be constant in the borehole and initial isothermal conditions at 0°C are assumed to run the model. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima.

  18. A dromaeosaur from the Maastrichtian of James Ross Island and the Late Cretaceous Antarctic dinosaur fauna

    Science.gov (United States)

    Case, Judd A.; Martin, James E.; Reguero, Marcelo

    2007-01-01

    The recovery of material of a small theropod from the Early Maastrichtian, Cape Lamb Member of the Snow Hill Island Formation is an unusual occurrence from primarily marine sediments. The pedal morphology of the specimen that includes a Metatarsal II with a lateral expansion caudal to Metatarsal III, a third metatarsal that is proximally narrow and distally wide, a Metatarsal III with a distal end that is incipiently ginglymoidal and a second pedal digit with sickle-like ungual are all diagnostic of a theropod that belongs to the family of predatory dinosaurs, the Dromaeosauridae. Yet this Antarctic dromaeosaur retains plesiomorphic features in its ankle and foot morphology. As new dromaeosaur species are being recovered from the mid-Cretaceous of South America and the retention of primitive characters in the Antarctic dromaeosaur, a new biogeographic hypothesis on dromaeosaur distribution has been generated. Gondwanan dromaeosaurs are not North America immigrants into South America and Antarctica; rather they are the relicts of a cosmopolitan dromaeosaur distribution, which has been separated by the vicariant break up of Pangea and created an endemic clade of dromaeosaurs in Gondwana.

  19. Evaluation of the ground surface Enthalpy balance from bedrock shallow borehole temperatures (Livingston Island, Maritime Antarctic)

    Science.gov (United States)

    Ramos, M.; Vieira, G.

    2008-03-01

    The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic) is studied. The borehole is 2.4 m deep and is located in a quartzite outcrop in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth) hourly temperature profiles from: (i) the cooling periods of the frost seasons of 2000 to 2005, and (ii) the warming periods of the thaw seasons of 2002-2003, 2003-2004 and 2004-2005, were studied. In this modelling approach, heat gains and losses across ground surface are considered to be the causes for the 0°C isotherm movement. A methodological approach to calculate the Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density is considered to be constant in the borehole and initial isothermal conditions at 0°C are assumed to run the model. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima).

  20. Snow chemistry measurements on James Ross Island (Antarctic Peninsula) showing sea-salt aerosol modifications

    Energy Technology Data Exchange (ETDEWEB)

    Aristarain, A.J. [Instituto Antartico Argentino (Argentina). Lab. de Estratigrafia Glaciar y Geoquimica de la Nieve; Consejo Nacional de Investigaciones Cientificas y Tecnicas, Mendoza (Argentina); Delmas, R.J. [Laboratoire de Glaciologie et Geophysique de l' Environnement du CNRS, St Martin d' Heres (France)

    2002-07-01

    The fractionation of atmospheric sea-salt has been investigated by glaciochemical analysis of the sea-salt deposited on the snow covering the small ice cap of James Ross Island, Antarctic Peninsula, at an elevation of 1640m. The data show that, generally, but not always, the sea-salt deposited at this location most likely originates directly from seawater, as is the case at lower latitudes. It is found that the original chemical composition of the sea-salt aerosol is significantly modified, in particular by the reaction of sea-salt particles in the atmosphere with acid species. A ternary diagram (sodium, chloride, sulfate) is used to enlighten the involved modification processes. The study points out the frequent formation of HCl in the regional atmosphere. (Author)

  1. Shifting baselines in Antarctic ecosystems; ecophysiological response to warming in Lissarca miliaris at Signy Island, Antarctica.

    Science.gov (United States)

    Reed, Adam J; Thatje, Sven; Linse, Katrin

    2012-01-01

    The Antarctic Peninsula has experienced a rapid increase in atmospheric temperature over the last 50 years. Whether or not marine organisms thriving in this cold stenothermal environment are able to cope with warming is of concern. Here, we present changes to the growth and shell characteristics of the ecologically important, small and short lived brooding bivalve Lissarca miliaris from Signy Island, Antarctica. Using material collected from the 1970's to the present day, we show an increase in growth rate and adult shell deterioration accompanied by a decrease in offspring size, associated with an increase in annual average temperatures. Critical changes to the bivalve's ecology seen today evidence the problem of a shift in baseline since the onset of warming recorded in Antarctica. These small bivalves are demonstrating ecophysiological responses to subtle warming that, provided warming continues, could soon surpass a physiological tipping point, adding to warming associated threats such as increased predatory pressure and ocean acidification.

  2. Spatial modelling of periglacial phenomena in Deception Island (Maritime Antarctic): logistic regression and informative value method.

    Science.gov (United States)

    Melo, Raquel; Vieira, Gonçalo; Caselli, Alberto; Ramos, Miguel

    2010-05-01

    Field surveying during the austral summer of 2007/08 and the analysis of a QuickBird satellite image, resulted on the production of a detailed geomorphological map of the Irizar and Crater Lake area in Deception Island (South Shetlands, Maritime Antarctic - 1:10 000) and allowed its analysis and spatial modelling of the geomorphological phenomena. The present study focus on the analysis of the spatial distribution and characteristics of hummocky terrains, lag surfaces and nivation hollows, complemented by GIS spatial modelling intending to identify relevant controlling geographical factors. Models of the susceptibility of occurrence of these phenomena were created using two statistical methods: logistical regression, as a multivariate method; and the informative value as a bivariate method. Success and prediction rate curves were used for model validation. The Area Under the Curve (AUC) was used to quantify the level of performance and prediction of the models and to allow the comparison between the two methods. Regarding the logistic regression method, the AUC showed a success rate of 71% for the lag surfaces, 81% for the hummocky terrains and 78% for the nivation hollows. The prediction rate was 72%, 68% and 71%, respectively. Concerning the informative value method, the success rate was 69% for the lag surfaces, 84% for the hummocky terrains and 78% for the nivation hollows, and with a correspondingly prediction of 71%, 66% and 69%. The results were of very good quality and demonstrate the potential of the models to predict the influence of independent variables in the occurrence of the geomorphological phenomena and also the reliability of the data. Key-words: present-day geomorphological dynamics, detailed geomorphological mapping, GIS, spatial modelling, Deception Island, Antarctic.

  3. Gastrointestinal helminths of Gentoo penguins (Pygoscelis papua) from Stranger Point, 25 de Mayo/King George Island, Antarctica.

    Science.gov (United States)

    Diaz, Julia Inés; Fusaro, Bruno; Longarzo, Lucrecia; Coria, Néstor Rubén; Vidal, Virginia; Jerez, Silvia; Ortiz, Juana; Barbosa, Andrés

    2013-05-01

    The aim of this work is to contribute to the knowledge of gastrointestinal parasites of the Gentoo penguin (Pygoscelis papua) from 25 de Mayo/King George Island (South Shetlands, Antarctica). Gastrointestinal tracts of 37 fresh dead individuals (21 chicks, 10 juveniles, and 6 adults) were collected from December 2006 to February 2012 and examined for macroparasites. Four adult parasite species were found: one Cestoda species (Parorchites zederi), two Nematoda species (Stegophorus macronectes and Tetrameres wetzeli), and one Acanthocephalan (Corynosoma shackletoni). Two species of immature acanthocephalans, Corynosoma hamanni and Corynosoma bullosum, were found in a single host. This is the first record of Tetrameres wetzeli in Gentoo penguins. The low parasite richness observed could be related to the stenophagic and pelagic diet of this host species which feeds almost exclusively on krill.

  4. [Archaeal diversity in permafrost deposits of Bunger Hills Oasis and King George Island (Antarctica) according to the 16S rRNA gene sequencing].

    Science.gov (United States)

    Karaevskaia, E S; Demchenko, L S; Demidov, N É; Rivkina, E M; Bulat, S A; Gilichinskiĭ, D A

    2014-01-01

    Archaeal communities of permafrost deposits of King George Island and Bunger Hills Oasis (Antarctica) differing in the content of biogenic methane were analyzed using clone libraries of two 16S rRNA gene regions. Phylotypes belonging to methanogenic archaea were identified in all horizons.

  5. Terrestrial and submarine evidence for the extent and timing of the Last Glacial Maximum and the onset of deglaciation on the maritime-Antarctic and sub-Antarctic islands

    Science.gov (United States)

    Hodgson, Dominic A.; Graham, Alastair G. C.; Roberts, Stephen J.; Bentley, Michael J.; Cofaigh, Colm Ó.; Verleyen, Elie; Vyverman, Wim; Jomelli, Vincent; Favier, Vincent; Brunstein, Daniel; Verfaillie, Deborah; Colhoun, Eric A.; Saunders, Krystyna M.; Selkirk, Patricia M.; Mackintosh, Andrew; Hedding, David W.; Nel, Werner; Hall, Kevin; McGlone, Matt S.; Van der Putten, Nathalie; Dickens, William A.; Smith, James A.

    2014-09-01

    This paper is the maritime and sub-Antarctic contribution to the Scientific Committee for Antarctic Research (SCAR) Past Antarctic Ice Sheet Dynamics (PAIS) community Antarctic Ice Sheet reconstruction. The overarching aim for all sectors of Antarctica was to reconstruct the Last Glacial Maximum (LGM) ice sheet extent and thickness, and map the subsequent deglaciation in a series of 5000 year time slices. However, our review of the literature found surprisingly few high quality chronological constraints on changing glacier extents on these timescales in the maritime and sub-Antarctic sector. Therefore, in this paper we focus on an assessment of the terrestrial and offshore evidence for the LGM ice extent, establishing minimum ages for the onset of deglaciation, and separating evidence of deglaciation from LGM limits from those associated with later Holocene glacier fluctuations. Evidence included geomorphological descriptions of glacial landscapes, radiocarbon dated basal peat and lake sediment deposits, cosmogenic isotope ages of glacial features and molecular biological data. We propose a classification of the glacial history of the maritime and sub-Antarctic islands based on this assembled evidence. These include: (Type I) islands which accumulated little or no LGM ice; (Type II) islands with a limited LGM ice extent but evidence of extensive earlier continental shelf glaciations; (Type III) seamounts and volcanoes unlikely to have accumulated significant LGM ice cover; (Type IV) islands on shallow shelves with both terrestrial and submarine evidence of LGM (and/or earlier) ice expansion; (Type V) Islands north of the Antarctic Polar Front with terrestrial evidence of LGM ice expansion; and (Type VI) islands with no data. Finally, we review the climatological and geomorphological settings that separate the glaciological history of the islands within this classification scheme.

  6. The effect of environmental change on vascular plant and cryptogam communities from the Falkland Islands and the Maritime Antarctic

    Directory of Open Access Journals (Sweden)

    Convey Peter

    2007-12-01

    Full Text Available Abstract Background Antarctic terrestrial vegetation is subject to one of the most extreme climates on Earth. Currently, parts of Antarctica are one of the fastest warming regions on the planet. During 3 growing seasons, we investigated the effect of experimental warming on the diversity and abundance of coastal plant communities in the Maritime Antarctic region (cryptogams only and the Falkland Islands (vascular plants only. We compared communities from the Falkland Islands (51°S, mean annual temperature 7.9°C, with those of Signy Island (60°S, -2.1°C and Anchorage Island (67°S, -2.6°C, and experimental temperature manipulations at each of the three islands using Open Top Chambers (OTCs. Results Despite the strong difference in plant growth form dominance between the Falkland Islands and the Maritime Antarctic, communities across the gradient did not differ in total diversity and species number. During the summer months, the experimental temperature increase at 5 cm height in the vegetation was similar between the locations (0.7°C across the study. In general, the response to this experimental warming was low. Total lichen cover showed a non-significant decreasing trend at Signy Island (p Conclusion These results suggest that small temperature increases may rapidly lead to decreased soil moisture, resulting in more stressful conditions for plants. The more open plant communities (grass and lichen appeared more negatively affected by such changes than dense communities (dwarf shrub and moss.

  7. Bryozoan diversity around the Falkland and South Georgia Islands: Overcoming Antarctic barriers.

    Science.gov (United States)

    Figuerola, Blanca; Barnes, David K A; Brickle, Paul; Brewin, Paul E

    2017-05-01

    There are a number of remote archipelagos distributed between 45 and 60 °S. The biota of these islands provide useful information to describe and understand patterns in biodiversity and biogeography as well as potential impacts of climate change on marine ecosystems. They are in key locations either side of the Polar Front but also have limited influence from human activities. Here we investigate one taxon, bryozoans, on South Atlantic shelf habitats of the Falkland (FI) and the sub-Antarctic island of South Georgia (SG). We present new data on spatial distribution in these islands, as well as an analysis of the bryozoological similarities between these and neighbouring regions. A total of 85 species of cheilostome bryozoans (351 samples) were found, belonging to 33 genera, including 18 potentially new genera and 23 new species. Remarkably 65% and 41% of species were reported for the first time at FI and SG, respectively. The highest and the lowest value of species richness and species/genus ratio were found at East (EFI) and West Falkland (WFI), respectively, likely showing a tendency for stronger intrageneric competition. New data from this study were jointly analysed with data from the literature and existing databases, revealing new bathymetric ranges in 32 species. The biogeographic affinities of the bryozoans found give further evidence of the hypothesis of sequential separation of Gondwana and support the changing concept that although the Polar Front acts as a circumpolar biogeographic barrier it is not as impermeable as originally thought. Potential dispersal mechanisms are also discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Insights into accumulation variability over the last 2000 years at James Ross Island, Antarctic Peninsula

    Science.gov (United States)

    Massam, A.; Mulvaney, R.; McConnell, J.; Abram, N.; Arienzo, M. M.; Whitehouse, P. L.

    2016-12-01

    The James Ross Island ice core, drilled to 364 m on the northern tip of the Antarctic Peninsula, preserves a climate record that spans beyond the Holocene period to the end of the last glacial maximum (LGM). Reanalysis of the ice core using high-resolution continuous flow analysis (CFA) highlighted errors in the identification of events of known age that had been used to constrain the earlier chronology. The new JRI2 chronology is annual layer counted to 300 years, with the remaining profile reconstructed using a new age-depth model that is tied to age horizons identified in the annual-layer counted WAIS Divide ice core record. An accurate age-depth profile requires reliable known-age horizons along the ice core profile. In addition, these allow us to determine a solution for the accumulation history and rate of compaction due to vertical strain. The accuracy of the known-age constraints used in JRI2 allows only a small uncertainty in the reconstruction of the most recent 2000 years of accumulation variability. Independently, the surface temperature profile has been estimated from the stable water isotope profile and calibrated to borehole temperature observations. We present the accumulation, vertical thinning and temperature history interpreted from the James Ross Island ice core for the most recent 2000 years. JRI2 reconstructions show accumulation variability on a decadal to centennial timescale up to 20% from the present-day mean annual accumulation rate of 0.63 m yr-1. Analysis of the accumulation profile for James Ross Island offers insight into the sensitivity of accumulation to a change in surface temperature, as well as the reliability of the assumed relationship between accumulation and surface temperature in climate reconstructions using stable water isotope proxies.

  9. Evaluation of the ground surface Enthalpy balance from bedrock temperatures (Livingston Island, Maritime Antarctic)

    Science.gov (United States)

    Ramos, M.; Vieira, G.

    2009-05-01

    The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic) is studied. The borehole is 2.4 m deep and is located in a massive quartzite outcrop with negligible water content, in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth) hourly temperature profiles from: (i) the cooling periods of the frost season of 2000 to 2005, and (ii) the warming periods of the thaw season of 2002-2003, 2003-2004 and 2004-2005, were studied. In this modelling approach, heat gains and losses across the ground surface are assumed to be the causes for the 0°C isotherm movement. A methodological approach to calculate the ground Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change into the rock is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density and thermal conductivity are considered to be constant and initial isothermal conditions at 0°C are assumed (based in collected data and local meteorological conditions in this area) to run the model in the beginning of each season. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima). The application of this method avoids error propagation induced by the heat exchange calculations from multiple sensors using the Fourier method.

  10. Evaluation of the ground surface Enthalpy balance from bedrock temperatures (Livingston Island, Maritime Antarctic

    Directory of Open Access Journals (Sweden)

    M. Ramos

    2009-05-01

    Full Text Available The annual evolution of the ground temperatures from Incinerador borehole in Livingston Island (South Shetlands, Antarctic is studied. The borehole is 2.4 m deep and is located in a massive quartzite outcrop with negligible water content, in the proximity of the Spanish Antarctic Station Juan Carlos I. In order to model the movement of the 0°C isotherm (velocity and maximum depth hourly temperature profiles from: (i the cooling periods of the frost season of 2000 to 2005, and (ii the warming periods of the thaw season of 2002–2003, 2003–2004 and 2004–2005, were studied. In this modelling approach, heat gains and losses across the ground surface are assumed to be the causes for the 0°C isotherm movement. A methodological approach to calculate the ground Enthalpy change based on the thermodynamic analysis of the ground during the cooling and warming periods is proposed. The Enthalpy change into the rock is equivalent to the heat exchange through the ground surface during each season, thus enabling to describe the interaction ground-atmosphere and providing valuable data for studies on permafrost and periglacial processes. The bedrock density and thermal conductivity are considered to be constant and initial isothermal conditions at 0°C are assumed (based in collected data and local meteorological conditions in this area to run the model in the beginning of each season. The final stages correspond to the temperatures at the end of the cooling and warming periods (annual minima and maxima. The application of this method avoids error propagation induced by the heat exchange calculations from multiple sensors using the Fourier method.

  11. The marine epilithic diatom Melosira brandinii sp. nov. (Bacillariophyta) from Elephant Island, Antarctic Peninsula, with comments on some related species

    OpenAIRE

    Fernandes, Luciano F.; Souza-Mosimann,Roseli M. de

    2001-01-01

    A new species of epilithic diatom is described from samples collected near Elephant Island, Antarctic Peninsula. The cells of Melosira brandinii sp. nov. are joined in filamentous chains and attached by means of long mucilaginous stalks. The valves are circular with the valvar surface composed of irregularly arranged pentagonal Ioculi. Each loculus bears 6-12 pores on the external surface, opening to the innerside through rotae. The corona is only composed of coarse granules. A mantle is well...

  12. The geomorphic action of wind-blown snow in the Maritime Antarctic. Preliminary results from Livingston Island.

    Science.gov (United States)

    Vieira, Gonçalo; Trindade, Alexandre; Mora, Carla; Ramos, Miguel

    2010-05-01

    Wind-blown snow may cause a significant geomorphic action on exposed rock surfaces in polar and mountain environments, a process known as niveo-aeolian corrasion. Livingston Island (South Shetlands, Antarctic Peninsula region) shows a polar maritime climate with mean annual air temperatures at sea-level of ca. -2°C. 90% of the island is covered by glaciers, but several peninsulas area glacier-free with large areas of exposed bedrock terrain. Observations from Hurd Peninsula, a metasedimentary area with quartzites and shales (flysch facies) and frequent dolerite dykes, show that wind erosion is an active process on present-day geomorphological dynamics. Effects of corrasion have been observed on boulder surfaces and rock outcrops, as well as on moss covers. Painted poles have been installed at several sites in order to detect the direction of erosive winds. For obtaining snow and wind data a meteorological station has been installed in the vicinity of the Bulgarian Antarctic Station St. Kliment Ohridski, as well as air/snow temperature loggers and time-lapse cameras close to the Spanish Antarctic Station Juan Carlos I. ASAR satellitte imagery provides a regional scale overview of snow cover. In this poster we present a first overview of the observations, preliminary results and discuss the methodology for the future systematical assessment of niveo-aeolian corrasion in Livingston Island.

  13. Cephalopoda as prey of juvenile Southern elephant seals at Isla 25 de Mayo/King George, South Shetland Islands

    Directory of Open Access Journals (Sweden)

    Luciana Burdman

    2015-03-01

    Full Text Available The aim of the present study was to enhance the knowledge of the feeding habits of the juvenile component of the population of Southern elephant seals [Mirounga leonina (Linnaeus, 1758] from Isla 25 de Mayo, South Shetland Islands, age class whose diet information is scarce. A total of 60 individuals were stomach lavaged in the spring - summer seasons of three consecutive years (2003, 2004 and 2005 of which 53.3 % (n = 32 presented food remnants. The Antarctic glacial squid Psychroteuthis glacialis Thiele, 1921 was the dominant prey taxon in terms of frequency of occurrence (68.7%, numerical abundance (60.1% and biomass (51.5%, contributing 84.1% to the total relative importance index. Other squid prey species of importance were Slosarczykovia circumantartica Lipinski, 2001 in terms of occurrence (37.5% and numerical abundance (14% and Moroteuthis knipovitchi Filippova, 1972 in terms of biomass (16%. All identified cephalopod prey taxa are distributed south of the Antarctic Polar Front, except for the squid Martialia hyadesi Rochebrune & Mabille, 1889 which has a circumpolar distribution associated to the Polar Frontal Zone. No significant differences in the sizes of P. glacialis preyed upon by elephant seals were found between sexes and years. However, significant interannual differences were found in the taxonomical composition of their diet. This would be associated with temporal changes in food availability at the foraging areas of seals, which in turn may have been influenced by changes in oceanographic conditions as a result of the El Niño Southern Oscillation (ENSO phenomenon that occurred during part of the study period. Furthermore, a differential response of males and females to this temporal variation was observed, with the former being also associated to a predation on octopods. This would suggest a sexual segregation in foraging habits of this species from the early stages of its life cycle.

  14. Sulphate reducing activity detected in soil samples from Antarctica, Ecology Glacier Forefield, King George Island.

    Science.gov (United States)

    Wolicka, Dorota; Zdanowski, Marek K; Żmuda-Baranowska, Magdalena J; Poszytek, Anna; Grzesiak, Jakub

    2014-01-01

    We determined sulphate-reducing activities in media inoculated with soils and with kettle lake sediments in order to investigate their potential in geomicrobiological processes in low-temperature, terrestrial maritime Antarctic habitats. Soil and sediment samples were collected in a glacier valley abandoned by Ecology Glacier during the last 30 years: from a new formed kettle lake sediment and forefield soil derived from ground moraine. Inoculated with these samples, liquid Postgate C and minimal media supplemented with various carbon sources as electron donors were incubated for 8 weeks at 4°C. High rates of sulphate reduction were observed only in media inoculated with soil. No sulphate reduction was detected in media inoculated with kettle lake sediments. In soil samples culture media calcite and elemental sulphur deposits were observed, demonstrating that sulphate-reducing activity is associated with a potential to mineral formation in cold environments. Cells observed on scanning microscopy (SEM) micrographs of post-culture-soil deposits could be responsible for sulphate-reducing activity.

  15. A paleomagnetic study of the Antarctic Peninsula

    Science.gov (United States)

    Poblete, F.; Arriagada, C.; Roperch, P.

    2009-05-01

    In the Paleozoic, South America, South Africa and Antarctica were part of Gondwana. The Weddell Sea began to form at about 146 Ma, after rifting between the Antarctic Peninsula and southernmost South America. Much uncertainty still exists about the geometrical fit and subsequent drift history between Patagonia and Antarctica. Geophysical and geological data which describe the tectonic history are sparsely distributed and often of poor quality. During the last two years we have collected more than 1000 paleomagnetic samples from 70 sites at several localities (King George Island, Robert Island, Yankee Bay, Half Moon Island, Byers Peninsula and Snow Island) from the South Shetland Islands and Anderson Island in the northern tip of Antarctic Peninsula. Our main objective was to provide first-order constraints on latitudinal displacements and the amount of tectonic rotations as an essential test of published tectonic models. Paleomagnetic results were obtained from 50 sites. All samples from sites in volcanic and intrusive rocks have well-defined univectorial magnetizations. Unfortunately, all sites in late Paleozoic sediments have been remagnetized and the magnetizations are often unstable upon thermal demagnetization. Cretaceous and Cenozoic units display very little apparent polar wander. Results from intrusive rocks of expected Jurassic age do not confirm the expected relative rotation betwen the Antarctic Peninsula and East Antarctica. Further radiometric dating are needed to confirm the age of these units.

  16. A new sediment-dwelling pholadid bivalve from Oligocene glaciomarine sediments of King George Island, West Antarctica

    Directory of Open Access Journals (Sweden)

    Krzysztof Hryniewicz

    2016-12-01

    Full Text Available We present a re-description of the pholadid bivalve from the Oligocene Polonez Cove Formation, King George Island, West Antarctica, previously identified as Penitella sp. The study is based on a collection of 210 specimens, preserved exclusively in life position in flask-shaped Gastrochaenolites type borings which have been subsequently buried by glaciomarine diamictite. The systematic study showed that this pholadid is a new species belonging to the genus Pholadidea rather than to Penitella and we name it Pholadidea gradzinskii sp. nov. The species is one of very few Late Cretaceous–Paleogene pholadids that we could safely identify as Pholadidea. All of them are known exclusively from the southern Pacific and adjacent areas (New Zealand, Antarctica, and Patagonia. We demonstrate that the genus attained its Recent broad distribution before the middle Miocene, when the first species of Pholadidea appeared in the Northern Hemisphere. The mass occurrence of P. gradzinskii in the Oligocene of West Antarctica results from favourable living condition in a shallow marine environment. Low sedimentation rate allowed the settlement of numerous larvae and their subsequent metamorphosis, growth, and maturity terminated by the mass mortality caused by the burial by marine diamictite. The sediment-boring Paleogene species of Pholadidea, among them P. gradzinskii, follow the wood-boring Late Cretaceous species P. (Hatasia wiffenae, which reflects a general pattern of evolution of substrate selection among pholadoid bivalves.

  17. Holocene environmental change according to lake core in Fildes Peninsula of King George Island, Antarctica

    Institute of Scientific and Technical Information of China (English)

    李小梅; 袁宝印; 赵俊琳

    2002-01-01

    Lake core sampled from Xihu in Fildes Peninsula of King Gorge Island, Antarctica could reveal the environmental change of the district. The lake core(GA7) , 9.28 meters long ,was sectioned at an interval of 2 cm. Through measuring the organic carbon, magnetic susceptibility, granularity and organic carbon isotope of GA7, by use of 14C age it was estimated that there were four periods of high temperature in Fildes Peninsula: 4800-4400 aB.P., 3600-3350 aB.P.,2100-1800 aB.P. and 900 aB.P. - present. Meanwhile, results showed that there was a strikingly positive correlation between the content of organic carbon and that of organic carbon isotope(δC13org) which could be the substitute indicators of environmental temperature.

  18. Microbial biomass and basal respiration in Sub-Antarctic and Antarctic soils in the areas of some Russian polar stations

    Directory of Open Access Journals (Sweden)

    E. Abakumov

    2014-03-01

    Full Text Available Antarctica is the unique place for pedological investigations. Soils of Antarctica have been studied intensively during the last century. Antarctic logistic provides the possibility to scientists access the terrestrial landscapes mainly in the places of polar stations. That is why the main and most detailed pedological investigations were conducted in Mc Murdo Valleys, Transantarctic Mountains, South Shetland Islands, Larsemann hills and Schirmacher Oasis. Investigations were conducted during the 53rd and 55th Russian Antarctic expeditions on the base of soil pits and samples collected in Sub-Antarctic and Antarctic regions. Soils of diverse Antarctic landscapes were studied with aim to assess the microbial biomass level, basal respiration rates and metabolic activity of microbial communities. The investigation conducted shows that soils of Antarctic are quite different in profile organization and carbon content. In general, Sub-Antarctic soils are characterized by more developed humus (sod organo-mineral horizons as well as the upper organic layer. The most developed organic layers were revealed in peat soils of King-George Island, where its thickness reach even 80 cm. These soils as well as soils under guano are characterized by the highest amount of total organic carbon (TOC 7.22–33.70%. Coastal and continental soils of Antarctic are presented by less developed Leptosols, Gleysols, Regolith and rare Ornhitosol with TOC levels about 0.37–4.67%. The metabolic ratios and basal respiration were higher in Sub-Antarctic soils than in Antarctic ones which can be interpreted as result of higher amounts of fresh organic remnants in organic and organo-mineral horizons. Also the soils of King-George island have higher portion of microbial biomass (max 1.54 mg g−1 than coastal (max 0.26 mg g−1 and continental (max 0.22 mg g−1 Antarctic soils. Sub-Antarctic soils mainly differ from Antarctic ones in increased organic layers thickness and total

  19. Marine bird colony and other data from land platforms on St. George Island as part of the Outer Continental Shelf Environmental Assessment Program (OCSEAP) from 20 June 1975 to 08 August 1975 (NODC Accession 7700108)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Marine bird colony and other data were collected from land platforms on St. George Island from 20 June 1975 to 08 August 1975. Data were collected by the University...

  20. The Brazilian research contribution to knowledge of the plant communities from Antarctic ice free areas

    Directory of Open Access Journals (Sweden)

    ANTONIO B. PEREIRA

    2013-09-01

    Full Text Available This work aims to summarize the results of research carried out by Brazilian researchers on the plant communities of Antarctic ice free areas during the last twenty five years. Since 1988 field work has been carried out in Elephant Island, King George Island, Nelson Island and Deception Island. During this period six papers were published on the chemistry of lichens, seven papers on plant taxonomy, five papers on plant biology, two studies on UVB photoprotection, three studies about the relationships between plant communities and bird colonies and eleven papers on plant communities from ice free areas. At the present, Brazilian botanists are researching the plant communities of Antarctic ice free areas in order to understand their relationships to soil microbial communities, the biodiversity, the distribution of the plants populations and their relationship with birds colonies. In addition to these activities, a group of Brazilian researchers are undertaking studies related to Antarctic plant genetic diversity, plant chemistry and their biotechnological applications.

  1. Novel flame retardants (N-FRs), polybrominated diphenyl ethers (PBDEs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in fish, penguin, and skua from King George Island, Antarctica.

    Science.gov (United States)

    Wolschke, Hendrik; Meng, Xiang-Zhou; Xie, Zhiyong; Ebinghaus, Ralf; Cai, Minghong

    2015-07-15

    Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), are frequently detected in biota from Antarctica, whereas no data are available for their replacements, such as novel flame retardants (N-FRs). This study presented the occurrence of several N-FRs, PBDEs, and PCBs in tissue samples of an Antarctic rock cod (Trematomus bernacchii), a young gentoo penguin (Pygoscelis papua), and a brown skua (Stercorarius antarcticus) collected from King George Island. The total concentrations of N-FRs (ΣN-FRs; mean: 931 pg/g dry weight (dw)) were comparable to PBDEs (Σ8PBDEs; 681 pg/gdw), which were much lower than PCBs (ΣDL-PCBs; 12,800 pg/gdw). Overall, skua contained two to three orders of magnitude higher contamination than penguin and fish. In the future, more attention should be focused on the fate of N-FRs in Antarctica, where usages have increased since PBDEs were banned. To our knowledge, this is the first report of N-FRs in biota from Antarctica.

  2. Monitoring of land-based glaciers on James Ross Island, Antarctic Peninsula

    Science.gov (United States)

    Laska, Kamil; Nyvlt, Daniel; Engel, Zbynek; Stachon, Zdenek

    2015-04-01

    Antarctic Peninsula has been considered one of the most rapidly warming parts of our planet during the second half of the 20th century. Therefore, James Ross Island located near the northern tip of the Antarctic Peninsula, represents a unique place to study the sensitivity of glacier systems to regional atmospheric warming. Since 2006, an integrated multidisciplinary study of glaciers and terrestrial ecosystems has been carried out in the northern part of Ulu Peninsula, James Ross Island. In this contribution, glacier monitoring network consisting of four dominant land-based glaciers at the Ulu Peninsula is presented. Davies Dome (DD) is an ice dome, which originates on the surface of a flat volcanic mesa at >400 m a.s.l. and terminates as a single 700 m wide outlet in Whisky Bay. In 2006, Davies Dome had an area of 6.5 km2 and lay in the altitude range 0-514 m a.s.l. Whisky Glacier (WG) is a cold-based land-terminating valley glacier, which is surrounded by an extensive area of debris-covered ice. WG covered an area of 2.4 km2 and ranged from 215 to 520 m a.s.l. Triangular Glacier (TG) is a southwest-facing land-terminating glacier with an area of 0.6 km2 ranging from 302 to 107 m a.s.l. with well-developed ice-cored terminal moraine. San Jose Glacier (SJG) is a south-facing land-terminating piedmont glacier rejuvenated from the above lying Lachman Crags Dome (~640 m a.s.l.). SJG covers an area of 0.6 km2 and extends between 138 and 310 m a.s.l. Moreover, monitoring network consists of five automatic weather stations (AWS) placed in the central and marginal parts of the selected glaciers. Each AWS was equipped with the EMS33 air temperature and humidity probes placed inside the radiation shields. Apart from that, additional instruments, e.g. albedometer, propeller anemometer, snow depth sensors were installed on the central part of DD and WG. Since 2009, annual mass balance measurements have been realized on the DD, WG and TG glaciers. In 2010, ice thickness and

  3. Thermal regime of active layer at two lithologically contrasting sites on James Ross Island, Antarctic Peninsula.

    Science.gov (United States)

    Hrbáček, Filip; Nývlt, Daniel; Láska, Kamil

    2016-04-01

    Antarctic Peninsula region (AP) represents one of the most rapidly warming parts of our planet in the last 50 years. Despite increasing research activities along both western and eastern sides of AP in last decades, there is still a lot of gaps in our knowledge relating to permafrost, active layer and its thermal and physical properties. This study brings new results of active layer monitoring on James Ross Island, which is the largest island in northern AP. Its northern part, Ulu Peninsula, is the largest ice-free area (more than 200 km2) in the region. Due its large area, we focused this study on sites located in different lithologies, which would affect local thermal regime of active layer. Study site (1) at Abernethy Flats area (41 m a.s.l.) lies ~7 km from northern coast. Lithologically is formed by disintegrated Cretaceous calcareous sandstones and siltstones of the Santa Marta Formation. Study site (2) is located at the northern slopes of Berry Hill (56 m a.s.l.), about 0.4 km from northern coastline. Lithology is composed of muddy to intermediate diamictites, tuffaceous siltstones to fine grained sandstones of the Mendel Formation. Data of air temperature at 2 meters above ground and the active layer temperatures at 75 cm deep profiles were obtained from both sites in period 1 January 2012 to 31 December 2014. Small differences were found when comparing mean air temperatures and active temperatures at 5 and 75 cm depth in the period 2012-2014. While the mean air temperatures varied between -7.7 °C and -7.0 °C, the mean ground temperatures fluctuated between -6.6 °C and -6.1 °C at 5 cm and -6.9 °C and -6.0 °C at 75 cm at Abernethy Flats and Berry Hill slopes respectively. Even though ground temperature differences along the profiles weren't pronounced during thawing seasons, the maximum active layer thickness was significantly larger at Berry Hill slopes (80 to 82 cm) than at Abernethy Flats (52 to 64 cm). We assume this differences are affected by

  4. Microbial biomass and basal respiration of selected Sub-Antarctic and Antarctic soils in the areas of some Russian polar stations

    Science.gov (United States)

    Abakumov, E.; Mukhametova, N.

    2014-07-01

    Antarctica is a unique place for soil, biological, and ecological investigations. Soils of Antarctica have been studied intensively during the last century, when different national Antarctic expeditions visited the sixth continent with the aim of investigating nature and the environment. Antarctic investigations are comprised of field surveys mainly in the terrestrial landscapes, where the polar stations of different countries are situated. That is why the main and most detailed soil surveys were conducted in the McMurdo Valleys, Transantarctic Mountains, South Shetland Islands, Larsemann Hills and the Schirmacher Oasis. Our investigations were conducted during the 53rd and 55th Russian Antarctic expeditions in the base of soil pits, and samples were collected in Sub-Antarctic and Antarctic regions. Sub-Antarctic or maritime landscapes are considered to be very different from Antarctic landscapes due to differing climatic and geogenic conditions. Soils of diverse zonal landscapes were studied with the aim of assessing the microbial biomass level, basal respiration rates and metabolic activity of microbial communities. This investigation shows that Antarctic soils are quite diverse in profile organization and carbon content. In general, Sub-Antarctic soils are characterized by more developed humus (sod) organo-mineral horizons as well as by an upper organic layer. The most developed organic layers were revealed in peat soils of King George Island, where its thickness reach, in some cases, was 80 cm. These soils as well as soils formed under guano are characterized by the highest amount of total organic carbon (TOC), between 7.22 and 33.70%. Coastal and continental Antarctic soils exhibit less developed Leptosols, Gleysols, Regolith and rare Ornhitosol, with TOC levels between 0.37 and 4.67%. The metabolic ratios and basal respiration were higher in Sub-Antarctic soils than in Antarctic ones, which can be interpreted as a result of higher amounts of fresh organic

  5. Per- and polyfluoroalkyl substances in snow, lake, surface runoff water and coastal seawater in Fildes Peninsula, King George Island, Antarctica.

    Science.gov (United States)

    Cai, Minghong; Yang, Haizhen; Xie, Zhiyong; Zhao, Zhen; Wang, Feng; Lu, Zhibo; Sturm, Renate; Ebinghaus, Ralf

    2012-03-30

    The multi-matrices samples from snow (n=4), lake water (n=4), surface runoff water (SRW) (n=1) and coastal seawater (n=10) were collected to investigate the spatial distribution and the composition profiles of per- and polyfluoroalkyl substances (PFASs) in Fildes Peninsula, King George Island, Antarctica in 2011. All samples were prepared by solid-phase extraction and analyzed by using high performance liquid chromatography/negative electrospray ionization-tandem mass spectrometry (HPLC/(-)ESI-MS/MS). 14 PFASs in snow, 12 PFASs in lake water, 9 PFASs in SRW and 13 PFASs in coastal seawater were quantified, including C(4), C(7), C(8), C(10) PFSAs, C(4)-C(9), C(11)-C(14), C(16) PFCAs, and FOSA. PFOA was detected in all samples with the highest concentration (15,096 pg/L) in coastal seawater indicating a possible influence of local sewage effluent. High concentration and mostly frequency of PFBA occurred in snow (up to 1112 pg/L), lake water (up to 2670 pg/L) and SRW (1431 pg/L) while detected in the range of method detection limited (MDL) in the coastal seawaters indicate that PFBA is mainly originated from atmospheric dust contamination and also affected by the degradation of their precursors. No geographical differences in PFOS concentrations (n=8, 18 ± 3 pg/L) were measured in all snow and lake water samples also suggests that PFOS could be originated from the degradation of their precursors which can transported by long-range atmospheric route, but in a very low level.

  6. Feeding ecology of chinstrap penguins Pygoscelis antarctica at Livingston Island (Antarctic)

    OpenAIRE

    Dimitrijević, Danijela

    2015-01-01

    Dissertação de mestrado em Ecologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra Antarctic and Southern Ocean marine ecosystems have been changing for the past 30 years, along with the global climate change. The most evident changes are on the Western Antarctic Peninsula, which is warming four times faster than the average rate of Earth‘s overall warming. Within the Antarctic Peninsula region, one of the penguin species u...

  7. Snow cover regime in Livingston and Deception Islands (Maritime Antarctic) using multitemporal analysis of ASAR imagery from 2009.

    Science.gov (United States)

    Mora, Carla; Vieira, Gonçalo; Ramos, Miguel

    2010-05-01

    ASAR images from Envisat (WSW and IMM) are analyzed to study the snow cover regime of Deception and Livingston Islands (South Shetlands, Antarctic Peninsula) during 2009. The study is part of the project PERMANTAR focusing on monitoring and modeling the thermal regime of permafrost. For a GIS-based spatial modelling of snow cover distribution, spatially distributed data is required and the exploration of microwave remote sensing is the most suitable technique for mapping the snow cover characteristics and regime. This becomes especially true due to the long winter night and unstable weather conditions of the northern Antarctic Peninsula region. For this purpose a multitemporal ASAR imagery analysis was conducted in order to distinguish wet snow cover from snow free terrain using the absorption dependency of the radar signal on the liquid water content of the snow to set a threshold on the differential backscatter between scenes. The imagery was analyzed using the processing chains from NEST (ESA SAR Toolbox). Preliminary results of the analysis of the time-series show strong seasonal changes in the backscattering due to the variations of liquid water content in snow. Validation of the results obtained from the microwave imagery is done using the ground truth data. In January and February 2009 we have installed in Livingston and Deception islands time-lapse camera in key-areas, ultra-sonic sensors of the snow thickness and probes with snow temperature mini-loggers. This data will be collected from field sites n January 2010 and used for the calibration of the results. Satellite immagery is provided by the European Space Agency in the framework of the Proposal Category-1: Snow cover characteristics and regime in the South Shetlands (Maritime Antarctic) - SnowAntar.

  8. Controls and variability of solute and sedimentary fluxes in Antarctic and sub-Antarctic Environments

    Science.gov (United States)

    Zwolinski, Zbigniew

    2015-04-01

    The currently prepared SEDIBUD Book on "Source-to-Sink Fluxes in Undisturbed Cold Environments" (edited by Achim A. Beylich, John C. Dixon and Zbigniew Zwolinski and published by Cambridge University Press) is summarizing and synthesizing the achievements of the International Association of Geomorphologists` (I.A.G./A.I.G.) Working Group SEDIBUD (Sediment Budgets in Cold Environments), which has been active since 2005 (http://www.geomorph.org/wg/wgsb.html). The book comprises five parts. One of them is part about sub-Antarctic and Antarctic Environments. This part "Sub-Antarctic and Antarctic Environments" describes two different environments, namely oceanic and continental ones. Each part contains results of research on environmental drivers and rates of contemporary solute and sedimentary fluxes in selected sites. Apart from describing the environmental conditions of the whole continent of Antarctica and sub-Antarctic islands (Zb.Zwolinski, M.Kejna, A.N.Lastochkin, A.Zhirov, S.Boltramovich) this part of the book characterizes terrestrial polar oases free from multi-year ice and snow covers (Zb.Zwolinski). The detailed results of geoecological and sedimentological research come from different parts of Antarctica. Antarctic continental shelf (E.Isla) is an example of sub-Antarctic oceanic environment. South Shetlands, especially King George Island (Zb.Zwolinski, M.Kejna, G.Rachlewicz, I.Sobota, J.Szpikowski), is an example of sub-Antarctic terrestrial environment. Antarctic Peninsula (G.Vieira, M.Francelino, J.C.Fernandes) and surroundings of McMurdo Dry Valleys (W.B.Lyons, K.A.Welch, J.Levy, A.Fountain, D.McKnight) are examples of Antarctic continental environments. The key goals of the Antarctic and sub-Antarctic book chapters are following: (i) identify the main environmental drivers and rates of contemporary solute and sedimentary fluxes, and (ii) model possible effects of projected climate change on solute and sedimentary fluxes in cold climate environments

  9. Spatial distribution and characteristics of permafrost in Hurd Peninsula, Livingston Island, Maritime Antarctic

    Science.gov (United States)

    Vieira, G.; Ramos, M.; Trindade, A.; Gruber, S.; Hauck, C.; Mora, C.; Batista, V.; Neves, M.; Pimpirev, C.; Kenderova, R.

    2009-04-01

    The Antarctic Peninsula is one of Earth's regions experiencing a faster increase on temperatures, with Mean Annual Air Temperatures (MAAT) rising ca. 2.5 °C in the last 50 years. The northerly location of the Antarctic Peninsula in respect to the Antarctic and its oceanic setting originate a milder and moister climate than in the Antarctic continent. The Northern Antarctic Peninsula is roughly located between the isotherms of MAAT of -1 °C to -8 °C at sea-level and therefore the northern tip and especially the South Shetlands are close to the limits of permafrost occurrence. If the observed warming trend is to continue in the near future, the region might suffer widespread permafrost degradation. Research on the permafrost environment of Hurd Peninsula has been taking place with systematical measurements by our group since January 2000 and currently we are able to provide a good overview of the spatial distribution and characteristics of permafrost terrain in Hurd Peninsula. Our research is based on shallow boreholes (Collado Ramos (115m). In 2006 Electrical Tomography Resistivity and refraction seismic profiles have been performed, providing us with a good overview of the general conditions of the permafrost terrain in the area. Air temperatures are measured at different sites accounting for altitude since a few years and during 3 summer campaigns the radiation balance was monitored continuously at two sites. Detailed geomorphological mapping of periglacial features has been conducted at a scale 1:5,000 providing important information about the geomorphological dynamics. Using the data gathered since 2000 it is now possible to present the general characteristics of the permafrost distribution in Hurd Peninsula as a first step towards a more comprehensive approach that is now starting that involves empirico-statistical modeling, remote sensing, as well as downscaling of mesoscale climate data.

  10. Climate Change Impacts in the sub-Antarctic Islands Technical Report N.2 of ONERC; Impacts du changement climatique dans les iles subantarctiques. Rapport Technique N.2 de l'ONERC

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Difficult to apprehend as a whole, the polar regions constitute the Arctic to the North, an ocean surrounded by emerged lands, and the Antarctic to the South, a continent bordered by the Austral Ocean where a belt of sub Antarctic islands lies. Climate change impacts on sub Antarctic islands are varied, direct and indirect: glacier retreat, more favourable conditions for introduced species, marine biodiversity modification, etc. This report discusses the French, British, Australian, South African and New Zealand sub Antarctic islands, the climatic evolutions and the resulting impacts, focused especially on biodiversity. The Observatoire National sur les Effets du Rechauffement Climatique and the International Polar Foundation have been joined in this endeavour by the French polar institute Paul-Emile Victor, the administration of the French Southern and Antarctic Lands (TAAF in French) and the International Union for the Conservation of Nature. (authors)

  11. A Biophysical and Economic Profile of South Georgia and the South Sandwich Islands as Potential Large-Scale Antarctic Protected Areas.

    Science.gov (United States)

    Rogers, Alex D; Yesson, Christopher; Gravestock, Pippa

    2015-01-01

    The current hiatus in the establishment of a network of marine protected areas (MPAs) in the Antarctic means that other routes to conservation are required. The protection of overseas territories in the Antarctic and sub-Antarctic represents one way to advance the initiation of such a network. This review of the physical and biological features of the United Kingdom (U.K.) overseas territories of South Georgia and South Sandwich Islands (SGSSI) is undertaken to estimate the importance of the islands in terms of marine conservation in the Southern Ocean and globally. The economy and management of SGSSI are also analysed, and the question of whether the islands already have sufficient protection to constitute part of an Antarctic network of MPAs is assessed. The SGSSI comprise unique geological and physical features, a diverse marine biota, including a significant proportion of endemic species and globally important breeding populations of marine predators. Regardless of past exploitation of biotic resources, such as seals, whales and finfish, SGSSI would make a significant contribution to biological diversity in an Antarctic network of MPAs. At present, conservation measures do not adequately protect all of the biological features that render the islands so important in terms of conservation at a regional and global level. However, a general lack of data on Antarctic marine ecosystems (particularly needed for SGSSSI) makes it difficult to assess this fully. One barrier to achieving more complete protection is the continuing emphasis on fishing effort in these waters by U.K. government. Other non-U.K. Antarctic overseas territories of conservation importance are also compromised as MPAs because of the exploitation of fisheries resources in their waters. The possible non-use values of SGSSI as well as the importance of ecosystem services that are indirectly used by people are outlined in this review. Technology is improving the potential for management of remote MPAs

  12. Antifouling activity in some benthic Antarctic invertebrates by "in situ" experiments at Deception Island, Antarctica.

    Science.gov (United States)

    Angulo-Preckler, Carlos; Cid, Cristina; Oliva, Francesc; Avila, Conxita

    2015-04-01

    Competition for space is a remarkable ecological force, comparable to predation, producing a strong selective pressure on benthic invertebrates. Some invertebrates, thus, possess antimicrobial compounds to reduce surface bacterial growth. Antimicrobial inhibition is the first step in avoiding being overgrown by other organisms, which may have a negative impact in feeding, respiration, reproduction … The in situ inhibition of bacterial biofilm was used here as an indicator of antifouling activity by testing hydrophilic extracts of twelve Antarctic invertebrates. Using two different approaches (genetics and confocal techniques) different levels of activity were found in the tested organisms. In fact, differences within body parts of the studied organisms were determined, in agreement with the Optimal Defense Theory. Eight out of 15 extracts tested had negative effects on fouling after 28 days submerged in Antarctic waters. Thus, although chemical defenses may be quite species-specific in their ecological roles, these results suggest that different chemical strategies exist to deal with space competition.

  13. Moss-inhabiting diatom communities from Heard Island, sub-Antarctic

    NARCIS (Netherlands)

    VandeVijver, B.; Beyens, L.; Vincke, S.; Gremmen, N.J.M.

    2004-01-01

    In this paper, we list 192 diatom taxa, collected from bryophyte samples from Heard Island (52degrees05'S, 73degrees30'E). The Heard Island diatom flora shows a marked similarity to those of the Crozet and Kerguelen archipelagos, and is quite dissimilar to the moss-dwelling diatom flora of Macquarie

  14. Transport of nutrients and contaminants from ocean to island by emperor penguins from Amanda Bay, East Antarctic.

    Science.gov (United States)

    Huang, Tao; Sun, Liguang; Wang, Yuhong; Chu, Zhuding; Qin, Xianyan; Yang, Lianjiao

    2014-01-15

    Penguins play important roles in the biogeochemical cycle between Antarctic Ocean and land ecosystems. The roles of emperor penguin Aptenodytes forsteri, however, are usually ignored because emperor penguin breeds in fast sea ice. In this study, we collected two sediment profiles (EPI and PI) from the N island near a large emperor penguin colony at Amanda Bay, East Antarctic and performed stable isotope and element analyses. The organic C/N ratios and carbon and nitrogen isotopes suggested an autochthonous source of organic materials for the sediments of EPI (C/N = 10.21 ± 0.28, n = 17; δ(13)C = -13.48 ± 0.50‰, δ(15)N = 8.35 ± 0.55‰, n = 4) and an allochthonous source of marine-derived organic materials for the sediments of PI (C/N = 6.15 ± 0.08, δ(13)C = -26.85 ± 0.11‰, δ(15)N = 21.21 ± 2.02‰, n = 20). The concentrations of total phosphorus (TP), selenium (Se), mercury (Hg) and zinc (Zn) in PI sediments were much higher than those in EPI, the concentration of copper (Cu) in PI was a little lower, and the concentration of element lead (Pb) showed no difference. As measured by the geoaccumulation indexes, Zn, TP, Hg and Se were from moderately to very strongly enriched in PI, relative to local mother rock, due to the guano input from juvenile emperor penguins. Because of its high trophic level and transfer efficiency, emperor penguin can transport a large amount of nutrients and contaminants from ocean to land even with a relatively small population, and its roles in the biogeochemical cycle between ocean and terrestrial environment should not be ignored. © 2013.

  15. Monitoring of active layer thermal regime and depth on CALM-S site, James Ross Island, Eastern Antarctic Peninsula

    Science.gov (United States)

    Hrbáček, Filip; Kňažková, Michaela; Nývlt, Daniel; Láska, Kamil; Mueller, Carsten W.; Ondruch, Jakub

    2017-04-01

    Active layer thickness and its dynamic are considered one of the key parameters of permafrost-affected ground. They variability are very sensitive to specific local conditions, especially climate, vegetation, snow cover or soil texture and moisture. To better understand the local variability of active layer thickness in Antarctica, the original Circumpolar Active Layer Monitoring protocol (CALM) was adapted as its southern form (CALM-S) with respect to specific conditions of Antarctica. To date, almost 40 CALM-S sites were registered across the Antarctic continent with the highest density on western Antarctic Peninsula (South Shetlands) and Victoria Land in East Antarctica (McMurdo region). On James Ross Island, CALM-S site was established in February 2014 as the first CALM-S in the eastern Antarctic Peninsula region. The CALM-S site is located near the Johann Gregor Mendel Station on the northern coast of James Ross Island. The area delimited to 80 × 70 m is elevated at 8 to 11 m asl. Geologically it consists of a Holocene marine terrace ( 80% of CALM-S area) with typical sandy material and passes to lithified to poorly disintegrated sedimentary rocks of Cretaceous Whisky Bay Formation ( 20% of CALM-S area) with a more muddy material and a typical bimodal composition. For both geologically different parts of CALM-S site, ground temperature was measured at two profiles at several levels up to 200 cm depth using resistance thermometers Pt100/8 (accuracy ± 0.15 °C). The air temperature at 2 m above surface was monitored at the automatic weather station near Johann Gregor Mendel Station using resistance thermometer Pt100/A (accuracy ± 0.15 °C). Data used in this study were obtained during the period from 1 March 2013 to 6 February 2016. Mechanical probing of active layer depth was performed in 72 grid points at the end of January, or beginning of February in 2014 to 2016. During the whole study period, mean annual air temperature varied between -7.0 °C (2013

  16. Baseline concentrations of faecal sterols and assessment of sewage input into different inlets of Admiralty Bay, King George Island, Antarctica.

    Science.gov (United States)

    Martins, César C; Aguiar, Sabrina N; Wisnieski, Edna; Ceschim, Liziane M M; Figueira, Rubens C L; Montone, Rosalinda C

    2014-01-15

    The Antarctic region is one of the best preserved environments in the world. However, human activities such as the input of sewage result in the alteration of this pristine site. We report baseline values of faecal sterols in Admiralty Bay, Antarctica. Four sediment cores were collected during the 2006/2007 austral summer at the Ezcurra (THP and BAR), Mackelar (REF) and Martel (BTP) inlets. Concentrations of faecal sterols (coprostanol+epicoprostanol) were sterols in core layers for THP, BAR, REF and BTP, were 0.04 ± 0.02, 0.03 ± 0.01, 0.07 ± 0.01 and 0.04 ± 0.02 μg g(-1), respectively. These results established as natural contributions of faecal sterols, suggesting that these markers can be useful indicators of human-derived faecal input and contributing to monitoring programs to prevent anthropogenic impacts. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Generative reproduction of Antarctic grasses, the native species Deschampsia antarctica Desv. and the alien species Poa annua L.

    OpenAIRE

    Giełwanowska Irena; Kellmann−Sopyła Wioleta

    2015-01-01

    The embryology of two species, Deschampsia antarctica, a native species, and Poa annua, an alien species in the Antarctic we studied. Flowering buds of plants growing in their natural habitats on King George Island and generative tissues of both plant species grown in a greenhouse were analyzed. Adaptations to autogamy and anemogamy were observed in the flower anatomy of both species. The microsporangia of the evaluated grasses produce a small number of three−celled pollen grains. Numerous po...

  18. Geomorphological dynamics of Deception Island (Maritime Antarctic): a GIS based analysis of the Cerro de la Cruz - Crater Lake area

    Science.gov (United States)

    Melo, R.; Vieira, G.; Rocha, J.; Caselli, A.; Batista, V.; Ramos, M.

    2009-04-01

    This study, based on field surveying from the austral summer of 2007-2008, presents the first results of the detailed geomorphological mapping of Deception Island (South Shetlands, Antarctic Peninsula). The main objective is to provide new geomorphological observations aiming to understand: i) how climate change is affecting permafrost, ii) the interactions between volcanoes and permafrost and also, iii) the present-day geomorphological dynamics in an area of high environmental sensitivity. The detailed geomorphological mapping was made in the area between the Argentinean base of Decepción and the Spanish Base Gabriel de Castilla, corresponding to 4 km2, as well as in the vicinity of the ruins of the Chilean Refuge. Mapping focused on landforms and deposits that may be indicators of permafrost dynamics, such as rockfalls, gullies, debris flows, thermokarst depressions and lag surfaces. Active layer thickness was monitored during the summer in two sites with different topographic conditions using mechanical probing. The spatial distribution of the geomorphological processes and landforms was studied using a GIS, with the objective to study the controls of several independent variables, such as altitude, aspect, slope, topographical parameters and net summer radiation.

  19. Glacial evolution in King George and Livingston Islands (Antarctica) since the Last Glacial Maximum based on cosmogenic nuclide dating and glacier surface reconstruction - CRONOANTAR project

    Science.gov (United States)

    Ruiz Fernández, Jesús; Oliva, Marc; Fernández Menéndez, Susana del Carmen; García Hernández, Cristina; Menéndez Duarte, Rosa Ana; Pellitero Ondicol, Ramón; Pérez Alberti, Augusto; Schimmelpfennig, Irene

    2017-04-01

    CRONOANTAR brings together researchers from Spain, Portugal, France and United Kingdom with the objective of spatially and temporally reconstruct the deglaciation process at the two largest islands in the South Shetlands Archipelago (Maritime Antarctica), since the Global Last Glacial Maximum. Glacier retreat in polar areas has major implications at a local, regional and even planetary scale. Global average sea level rise is the most obvious and socio-economically relevant, but there are others such as the arrival of new fauna to deglaciated areas, plant colonisation or permafrost formation and degradation. This project will study the ice-free areas in Byers and Hurd peninsulas (Livingston Island) and Fildes and Potter peninsulas (King George Island). Ice-cap glacier retreat chronology will be revealed by the use of cosmogenic isotopes (mainly 36Cl) on glacially originated sedimentary and erosive records. Cosmogenic dating will be complemented by other dating methods (C14 and OSL), which will permit the validation of these methods in regions with cold-based glaciers. Given the geomorphological evidences and the obtained ages, a deglaciation calendar will be proposed and we will use a GIS methodology to reconstruct the glacier extent and the ice thickness. The results emerging from this project will allow to assess whether the high glacier retreat rates observed during the last decades were registered in the past, or if they are conversely the consequence (and evidence) of the Global Change in Antarctica. Acknowledgements This work has been funded by the Spanish Ministry of Economy, Industry and Competitiveness (Reference: CTM2016-77878-P).

  20. Heavy metals in Antarctic notothenioid fish from South Bay, Livingston Island, South Shetlands (Antarctica).

    Science.gov (United States)

    Beltcheva, Michaela; Metcheva, Roumiana; Peneva, Vesela; Marinova, Margarita; Yankov, Yordan; Chikova, Vania

    2011-06-01

    The Pb, Cd, Cu, Zn, and Mn contents of the liver, spleen, muscle, bones, scales, gills, and the whole body of 3- to 7-year-old notothenioid Antarctic cod (Notothenia coriiceps, Richardson, 1844) were measured. The highest heavy metal concentrations obtained are as follows: Cd in liver, the mean value was 1.36 ± 0.19 mg/kg dry weight (wt); Pb and Zn in spleen, the mean values were 3.33 ± 0.86 and 143.97 ± 16.17 mg/kg dry wt, respectively; Cu in gills, 3.76 ± 1.16 mg/kg dry wt; and Mn in scales, 14.80 ± 4.77 mg/kg dry wt. The comparison with the data reported up to now shows that the metal concentrations varied within relative wide ranges. These first data obtained could be used as a baseline to investigate further relationships among metal contents in fish, their diet, and habitat.

  1. West Antarctic Ice Sheet retreat from Pine Island Bay during the Holocene: New insights into forcing mechanisms

    Science.gov (United States)

    Hillenbrand, Claus-Dieter; Smith, James; Kuhn, Gerhard; Poole, Chris; Hodell, David; Elderfield, Harry; Kender, Sev; Williams, Mark; Peck, Victoria; Larter, Robert; Klages, Johann; Graham, Alastair; Forwick, Matthias; Gohl, Karsten

    2013-04-01

    The Amundsen Sea sector of the largely marine-based and therefore conditionally unstable West Antarctic Ice Sheet (WAIS) contains enough ice to raise global sea level by ca. 1.5 metres. At present, ice streams draining this sector into the Southern Ocean, especially glaciers flowing into Pine Island Bay in the eastern Amundsen Sea embayment, are undergoing considerable mass loss characterised by major thinning, flow acceleration and rapid grounding-line retreat. Sub-ice shelf melting by relatively warm Circumpolar Deep Water (CDW) upwelling onto the continental shelf is held responsible for these dynamical changes but atmospheric warming in West Antarctica may also have contributed to them. In contrast to the modern situation, the long-term history of the Amundsen Sea sector and the mechanisms forcing its deglaciation during the Holocene are only poorly constrained. We will present new palaeoenvironmenal data obtained from marine sediment cores collected in Pine Island Bay. The cores targeted shallow sites on the inner continental shelf and successfully recovered sedimentary sequences bearing calcareous microfossils. Radiocarbon ages on these microfossils demonstrate that the grounding line of the WAIS retreated to within ~100 km of its modern position before ca. 10 kyr BP (thousand years before present), which is consistent with an early WAIS retreat from near-coastal locations in the western Amundsen Sea embayment. Currently, there is no evidence that the grounding line had retreated landward of its modern position during the Holocene. Therefore, the chronological constraints may imply that during the last 10 kyr any episodes of fast grounding-line retreat similar to those observed today were short-lived and rare. Preliminary geochemical data from benthic and planktonic foraminifera tests in the cores from Pine Island Bay reveals that intense CDW upwelling coincided with and may have forced the deglaciation of the inner continental shelf. Furthermore, we observe

  2. Brain and sense organ anatomy and histology of the Falkland Islands mullet, Eleginops maclovinus (Eleginopidae), the sister group of the Antarctic notothenioid fishes (Perciformes: Notothenioidei).

    Science.gov (United States)

    Eastman, Joseph T; Lannoo, Michael J

    2008-01-01

    The perciform notothenioid fish Eleginops maclovinus, representing the monotypic family Eleginopidae, has a non-Antarctic distribution in the Falkland Islands and southern South America. It is the sister group of the five families and 103 species of Antarctic notothenioids that dominate the cold shelf waters of Antarctica. Eleginops is the ideal subject for documenting the ancestral morphology of nervous and sensory systems that have not had historical exposure to the unusual Antarctic thermal and light regimes, and for comparing these systems with those of the phyletically derived Antarctic species. We present a detailed description of the brain and cranial nerves of Eleginops and ask how does the neural and sensory morphology of this non-Antarctic notothenioid differ from that seen in the phyletically derived Antarctic notothenioids? The brain of Eleginops is similar to those of visually oriented temperate and tropical perciforms. The tectum is smaller but it has well-developed olfactory and mechanoreceptive lateral line areas and a large, caudally projecting corpus cerebellum. Eye diameter is about twofold smaller in Eleginops than in many Antarctic species. Eleginops has a duplex (rod and cone) retina with single and occasional twin cones conspicuous centrally. Ocular vascular structures include a large choroid rete mirabile and a small lentiform body; a falciform process and hyaloid arteries are absent. The olfactory rosette is oval with 50-55 lamellae, a large number for notothenioids. The inconspicuous bony canals of the cephalic lateral line system are simple with membranous secondary branches that lack neuromasts. In Antarctic species, the corpus cerebellum is the most variable brain region, ranging in size from large and caudally projecting to small and round. "Stalked" brains showing reduction in the size of the telencephalon, tectum, and corpus cerebellum are present in the deep-living artedidraconid Dolloidraco longedorsalis and in most of the deep

  3. Geoenvironments from the vicinity of Arctowski Station, Admiralty Bay, King George Island, Antarctica: vulnerability and valuation assessment

    Science.gov (United States)

    Schaefer, Carlos Ernesto G.R.; Santana, Rogério Mercandelle; Simas, Felipe Nogueira Bello; Francelino, Márcio R.; Filho, Elpídio Inácio Fernandes; Albuquerque, Miriam Abreu; Calijuri, Maria Lúcia

    2007-01-01

    The use of a geographic information system (GIS) allows the mapping and quantification of biotic and physical features of importance to the environmental planning of Antarctic areas. In this paper we examined the main aspects of the geoenvironments of Arctowski Station vicinity (Admiralty bay, Maritime Antartica), by means of a photointerpretation of an orthomosaic at 1:6000 scale, produced by non-conventional aerial photographs obtained by the Brazilian Cryosols project. We carried out a preliminary environmental valuation and vulnerability assessment of the area. Hence, geoenvironments were classified and ranked according with their biological valuation and vulnerability (fragility), mapping 20 units covering approximately 150 ha. The most fragile geoenvironmental units were former and present penguin rookeries with different vegetation covers, all very prone to degradation by over-trampling and human perturbations. The relationships between each geoenvironment were also explored, emphasizing the ecological aspects and their valuation. In quantitative terms, the most vulnerable and fragile units (classes 4 and 5) occupy nearly 22 % of the total area, being highly concentrated near the coastal areas. There, ornithogenic input is an important factor favoring the vegetation development.

  4. Molecular identification larvae of Onchobothrium antarcticum (Cestoda: Tetraphyllidea) from marbled rockcod, Notothenia rossii, in Admiralty Bay (King George Island, Antarctica).

    Science.gov (United States)

    Laskowski, Zdzislaw; Rocka, Anna

    2014-10-01

    Antarctic bony fishes are infected with cestode larvae belonging to the order Tetraphyllidea (parasites as adults in chondrichthyans). Larvae of the Tetraphyllidea differ from each other in the morphology of their scoleces and represent five forms. There are larvae with bothridia subdivided into one, two and three loculi, bothridia sac-like in shape and bothridia undivided with hook-like projections. Only one species of the family Onchobothriidae, Onchobothrium antarcticum, has been described from Antarctica and larvae with trilocular bothridia were assigned to this cestode species. In this study, ten larvae obtained from Notothenia rossii and three adult specimens of Onchobothrium antarcticum isolated from Bathyraja eatonii were examined. A partial sequence of cytochrome c oxidase subunit 1 of three adult specimens and four larvae was identical. The remaining six larval sequences differed from the sequences obtained from adult cestodes. Partial sequences of lsrDNA of all analyzed larvae were identical. These results confirm the taxonomic affiliation of the larvae with trilocular bothridia parasitizing marbled rockcod in Antarctica as Onchobothrium antarcticum.

  5. Climate change effects on organic matter decomposition rates in ecosystems from the Maritime Antarctic and Falkland Islands

    NARCIS (Netherlands)

    Bokhorst, S.F.; Huiskes, A.H.L.; Convey, P.; Aerts, R.A.M.

    2007-01-01

    Antarctic terrestrial ecosystems have poorly developed soils and currently experience one of the greatest rates of climate warming on the globe. We investigated the responsiveness of organic matter decomposition in Maritime Antarctic terrestrial ecosystems to climate change, using two study sites in

  6. Climate change effects on organic matter decomposition rates in ecosystems from the Maritime Antarctic and Falkland Islands

    NARCIS (Netherlands)

    Bokhorst, S.F.; Huiskes, A.H.L.; Convey, P.; Aerts, R.A.M.

    2007-01-01

    Antarctic terrestrial ecosystems have poorly developed soils and currently experience one of the greatest rates of climate warming on the globe. We investigated the responsiveness of organic matter decomposition in Maritime Antarctic terrestrial ecosystems to climate change, using two study sites in

  7. [Myxomatosis in the sub-antarctic islands of Kerguelen, without vectors, thirty years after its introduction].

    Science.gov (United States)

    Chapuis, J L; Chantal, J; Bijlenga, G

    1994-02-01

    Myxoma virus was introduced into the Kerguelen archipelago in 1955-1956. Thirty years after its introduction, the virus is present in most areas inhabited by rabbits. Rabbit fleas and mosquitoes are absent from this group of islands and the disease is transmitted by contact. The timing of the beginning of new myxomatosis outbreaks, the absence of real epizootics as well as the higher percentage of infected males over females are specific observations in favour of this mode of transmission. The majority of 34 isolates tested between 1984 and 1988 are of intermediate virulence (Grades IIIA-IIIB). In these conditions, the impact of myxomatosis virus on rabbit populations estimated on two sites is low. Myxomatosis therefore plays only a minor role in the regulation of rabbit populations.

  8. Satellite remote sensing of the island mass effect on the Sub-Antarctic Kerguelen Plateau, Southern Ocean

    Science.gov (United States)

    Jena, Babula

    2016-09-01

    The presence of the Kerguelen Plateau and surrounding bathymetric features has a strong influence on the persistently eastward flowing Antarctic Circumpolar Current (ACC), resulting in enhancement of surface chlorophyll-a (Chl- a) in the downstream section of the plateau along the polar front (PF). The phenomenon is reported in this paper as the island mass effect (IME). Analysis of climatological Chl- a datasets from Aqua- Moderate Resolution Imaging Spectroradiometer (Aqua- MODIS) and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) shows distinct bloomy plumes (Chl- a>0.5 mg/m3) during austral spring-summer spreading as far as ~1800 km offshore up to 98°E along the downstream of the north Kerguelen Plateau (NKP). Similar IME phenomena is apparent over the south Kerguelen Plateau (SKP) with the phytoplankton bloom extending up to 96.7°E, along the southern boundary of ACC. The IME phenomena are pronounced only during austral spring-summer period with the availability of light and sedimentary source of iron from shallow plateau to sea surface that fertilizes the mixed layer. The NKP bloom peaks with a maximum areal extent of 1.315 million km2 during December, and the SKP bloom peaks during January with a time lag of one month. The blooms exist for at least 4 months of a year and are significant both as the base of regional food web and for regulating the biogeochemical cycle in the Southern Ocean. Even though the surface water above the Kerguelen Plateau is rich in Chl- a, an exception of an oligotrophic condition dominated between NKP and SKP due to apparent intrusion of iron limited low phytoplankton regime waters from the Enderby basin through the northeastward Fawn Trough Current.

  9. Habitat associations and distribution of the hyperbenthic shrimp, Nauticaris marionis, around the sub-Antarctic Prince Edward Islands

    Science.gov (United States)

    Haley, Craig; von der Meden, Charles; Atkinson, Lara; Reed, Cecile

    2017-09-01

    The association of organisms with particular habitats and habitat-forming organisms, can strongly influence species distributions, interactions and wider ecosystem services. At the sub-Antarctic Prince Edward Islands, the caridean shrimp Nauticaris marionis is a principal part of the benthic ecosystem, occurring between ca. 50 m and 600 m. Its role as a trophic link between the primary productivity and higher predators is established, but little is understood of its in situ habitat usage and associations or of how these structure patterns of abundance. We investigated these aspects directly using a benthic camera sled, sampling 27 stations between 50 m and 500 m. Substratum type was characterised, and estimates of percentage cover of the 13 main groups of habitat-forming epibenthic taxa were made, alongside absolute counts of N. marionis within 'digital quadrats' drawn from 300 m transects. The distribution of N. marionis was influenced by depth, substratum type and overall biogenic cover, being limited to habitats between 50 and 160 m depth on mud or gravel substrata only, and having > 50% biogenic cover. The presence/absence of N. marionis related to significantly different epibenthic assemblages (termed biogenic habitats), but this effect was contingent on depth. Likewise, densities of N. marionis were significantly affected by biogenic habitat type, identifying an association with two biogenic habitat groups, one dominated by red-algae, the other by structurally complex bryozoan species. These associations likely relate to the structural complexity of the two habitat groups, rather than the specific taxa involved. The apparent absence of N. marionis at depths > 160 m contrasts with earlier records and poses questions about the trophic importance of the shrimp in deeper habitats.

  10. Levels and pattern of polybrominated diphenyl ethers in eggs of Antarctic seabirds: Endemic versus migratory species

    Energy Technology Data Exchange (ETDEWEB)

    Yogui, G.T. [Geochemical and Environmental Research Group, College of Geosciences, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: gtyogui@ocean.tamu.edu; Sericano, J.L. [Geochemical and Environmental Research Group, College of Geosciences, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: jsericano@gerg.tamu.edu

    2009-03-15

    Chinstrap and gentoo penguins are endemic species that live year round south of the Antarctic Convergence. South polar skua is a migratory seabird that can be observed in Antarctica during the breeding season (i.e., austral summer). This study compares concentration and pattern of polybrominated diphenyl ethers (PBDEs) in eggs of seabirds breeding at King George Island, Antarctic Peninsula. PBDEs in south polar skua eggs are approximately 20 times higher than in penguin eggs suggesting that skuas are more exposed to contaminants during the non-breeding season when they migrate to waters of the northern hemisphere. The pattern of PBDE congeners also differs between south polar skua and penguin eggs. The latter exhibited a pattern similar to that found in the local biota. In contrast, the congener pattern in south polar skua eggs suggests that birds breeding at King George Island may winter in the northwestern Pacific Ocean. - Skua and penguin eggs collected at King George Island have different concentration and pattern of PBDEs.

  11. Denaturing gradient gel electrophoresis fingerprinting of soil bacteria in the vicinity of the Chinese Great Wall Station, King George Island, Antarctica.

    Science.gov (United States)

    Pan, Qi; Wang, Feng; Zhang, Yang; Cai, Minghong; He, Jianfeng; Yang, Haizhen

    2013-08-01

    Bacterial diversity was investigated in soil samples collected from 13 sites around the Great Wall Station, Fildes Peninsula, King George Island, Antarctica, using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes. The classes alpha-, beta-, and gamma-Proteobacteria, as well as the phylum Actinobacteria, were found to be the dominant bacteria in the soils around the Great Wall Station. Although the selected samples were not contaminated by oil, a relationship between soil parameters, microbial biodiversity, and human impact was still seen. Sample sites in human impacted areas showed lower bacterial biodiversity (average H' = 2.65) when compared to non-impacted sites (average H' = 3.05). There was no statistically significant correlation between soil bacterial diversity and total organic carbon (TOC), total nitrogen, or total phosphorus contents of the soil. Canonical correlation analysis showed that TOC content was the most important factor determining bacterial community profiles among the measured soil parameters. In conclusion, microbial biodiversity and community characteristics within relatively small scales (1.5 km) were determined as a function of local environment parameters and anthropogenic impact.

  12. Denaturing gradient gel electrophoresis fingerprinting of soil bacteria in the vicinity of the Chinese Great Wall Station, King George Island, Antarctica

    Institute of Scientific and Technical Information of China (English)

    Qi Pan; Feng Wang; Yang Zhang; Minghong Cai; Jianfeng He; Haizhen Yang

    2013-01-01

    Bacterial diversity was investigated in soil samples collected from 13 sites around the Great Wall Station,Fildes Peninsula,King George Island,Antarctica,using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA genes.The classes α-,β-,and γ-Proteobacteria,as well as the phylum Actinobacteria,were found to be the dominant bacteria in the soils around the Great Wall Station.Although the selected samples were not contaminated by oil,a relationship between soil parameters,microbial biodiversity,and human impact was still seen.Sample sites in human impacted areas showed lower bacterial biodiversity (average H' =2.65) when compared to non-impacted sites (average H' =3.05).There was no statistically significant correlation between soil bacterial diversity and total organic carbon (TOC),total nitrogen,or total phosphorus contents of the soil.Canonical correlation analysis showed that TOC content was the most important factor determining bacterial community profiles among the measured soil parameters.In conclusion,microbial biodiversity and community characteristics within relatively small scales (1.5 km) were determined as a function of local environment parameters and anthropogenic impact.

  13. COMPILATION OF GEOMORPHOLOGICAL MAP FOR RECONSTRUCTING THE DEGLACIATION OF ICE-FREE AREAS IN THE MARTEL INLET, KING GEORGE ISLAND, ANTARCTICA

    Directory of Open Access Journals (Sweden)

    Kátia Kellem Rosa

    2014-03-01

    Full Text Available We compiled a geomorphological map and a reconstruction map of glacier extension and ice-free areas in the Martel Inlet, located in King George Island, South Shetlands, Antarctica. Glacier extension data were derived of the digitized over a orthophotomosaic (2003, SPOT (February, 1988; March, 1995 and 2000, Quickbird (October, 2006 and Cosmo-Skymed (February, 2011 images. This mapping was supported by fieldworks carried out in the summers of 2007, 2010 and 2011, and by topographic surveys and geomorphic map in the proglacial area. Several types of glacial deposits were identified in the study area, such as frontal and lateral moraines, flutes, meltwater channels and erosional features like rock moutonnés, striations and U-shaped valleys. These features allowed reconstructing the evolution of the deglaciation environment in the Martel Inlet ice-free areas, which has been affected by a regional climate warming trend. The mapped data indicated the glaciers in study area lost about 0.71 km² of their ice masses (13.2% of the 50.3 km² total area, without any advances during 1979-2011. Since those years these glaciers receded by an average of 25.9 m a-1. These ice-free areas were susceptible to rapid post-depositional changes.

  14. The state of permafrost surrounding "Gabriel de Castilla" Spanish Antarctic Station (Deception Island, Antarctica): Studying the possible degradation due to the infrastructures heating effect.

    Science.gov (United States)

    Recio, Cayetana; Ángel de Pablo, MIguel; Ramos, MIguel; Molina, Antonio

    2015-04-01

    Permafrost degradation is one of the effects of the global warming. Many studies reveal the increase of active layer and reduction on permafrost table thickness, also in Antarctica. However, these trends on permafrost can be accelerated by the human activities, as the heating produced by the Antarctic stations infrastructures when they are not properly isolated from the ground. In Deception island, South Shetland Archipelago, we started 3 years ago a monitoring program at the 26 years old "Gabriel de Castilla" Spanish Antarctic Station (SAS), It is focused on charactering the state of permafrost, since in the coastal scarps at tens of meters from the station an increase on erosion had been detected. Although the main cause of the erosion of this coastal volcanoclastic materials is the 2 meters thick icefield which forms during the winter in the inner sea of this volcanic island, we want to detect any possible contribution to the coastal erosion caused by the permafrost degradation related to the SAS presence. We present our preliminary analysis based on three years of continuous ground temperature data, monitored at a shallow borehole (70 cm deep) in the SAS edge, together with the active layer thickness measured around the station and their vicinities in two thawing seasons. We complete this study with the analysis of the continuous temperature data taken inside the SAS and the air and ground temperatures below the station, acquired during the last Antarctic Campaign (December 2014-February 2015). These preliminary results are fundamental 1) to discard any contribution from the SAS presence, and to help to improve its thermal isolation, 2) to help improve our knowledge about the thermal state of permafrost in the area, and 3) to help to understand the causes of the coastal erosion in the volcanic Deception Island.

  15. [Microbiological analysis of terrestrial biotopes of the Antarctic region].

    Science.gov (United States)

    Tashirev, A B; Romanovskaia, V A; Rokitko, P V; Shilin, S O; Chernaia, N A; Tashireva, A A

    2010-01-01

    Microbiological analysis has been made of 120 samples from biotopes of the western coast of the Antarctic peninsula (Rasmussen cope, Tuxen cope, Waugh mountain), Argentine archipelago islands (Galindez, Skua, Corner, Barchans, Irizar, Uruguay, Cluls, Three Little Pigs, King-George), as well as neighbouring islands (Petermann--on the north, a group of Jalour islands--on the east, Berthelot--on the south-east); and more remote islands (Darboux, Lippmann, Booth). It was found out that the total number of chemoorganotrophic aerobic microorganisms was 10(6) - 10(8) cells/g of soil, that was by 2-3 orders lower than in the regions with temperate climate. One can observe a tendency of decreasing the quantity of chemoorganotrophic microorganisms in the Antartic biotopes (cells/g of a sample) in the following order: soil (1 x 10(7) - 8 x 10(8)), underground part of moss (1 x 10(6) - 5 x 10(7)), grass Deschampsia antarctica (10(6) - 10(8), slit of fresh-water reservoir (10(5) - 10(7)), ground part of moss (10(3) - 10(6)), lichens (10(3) - 10(6)). Representatives of several phylogenetic lines: Proteobacteria (genera Pseudomonas, Methylobacterium, Enterobacter), Firmicutes (genera Bacillus, Staphylococcus), Actinobacteria (genera Brevibacterium, Actinomyces, Streptomyces) have been found in the Antarctic samples. As a rule, genera of bacteria found in the Antarctic Region are widely distributed in different regions of the Earth with temperate climate. Microorganisms similar to the species Exophiala nigra (Issatsch.) Haats et de Hoog 1999, which was first detected 100 years ago by Academician B.L. Isachenko in the Arctic region water, were also isolated from biofilms on vertical rocks of the Galindez Island as well as from the soil of the Irizar Island.

  16. Concentration of trace elements in feathers of three Antarctic penguins: Geographical and interspecific differences

    Energy Technology Data Exchange (ETDEWEB)

    Jerez, Silvia [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Motas, Miguel, E-mail: motas@um.es [Area de Toxicologia, Facultad de Veterinaria, Universidad de Murcia, Campus de Espinardo, 30100 Murcia (Spain); Palacios, Maria Jose; Valera, Francisco [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Cuervo, Jose Javier; Barbosa, Andres [Departamento de Ecologia Funcional y Evolutiva, Estacion Experimental de Zonas Aridas, CSIC, Carretera de Sacramento s/n, 04120 La Canada de San Urbano, Almeria (Spain); Departamento de Ecologia Evolutiva, Museo Nacional de Ciencias Naturales, CSIC, C/Jose Gutierrez Abascal 2, 28006 Madrid (Spain)

    2011-10-15

    Antarctica is often considered as one of the last pristine regions, but it could be affected by pollution at global and local scale. Concentrations of Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and Pb were determinated by ICP-MS in feathers (n = 207 individuals) of gentoo, chinstrap and Adelie penguin collected in 8 locations throughout the Antarctic Peninsula (2006-2007). The highest levels of several elements were found in samples from King George Island (8.08, 20.29 and 1.76 {mu}g g{sup -1} dw for Cr, Cu and Pb, respectively) and Deception Island (203.13, 3.26 and 164.26 {mu}g g{sup -1} dw for Al, Mn and Fe, respectively), where probably human activities and large-scale transport of pollutants contribute to increase metal levels. Concentrations of Cr, Mn, Cu, Se or Pb, which are similar to others found in different regions of the world, show that some areas in Antarctica are not utterly pristine. - Highlights: > We study levels of trace elements in feathers of Antarctic penguins. > Eight different rookeries throughout the Antarctic Peninsula were sampled. > Interspecific (gentoo, chinstrap, Adelie) and geographical differences were tested. > Relatively high metal levels were found in areas with major human presence. > Penguin feather can be useful for metals monitoring in the Antarctic environment. - Trace element levels in feathers of three penguin species from the Antarctic Peninsula indicate the presence of pollution in certain locations.

  17. Joint Antarctic School Expedition - An International Collaboration for High School Students and Teachers on Antarctic Science

    Science.gov (United States)

    Botella, J.; Warburton, J.; Bartholow, S.; Reed, L. F.

    2014-12-01

    The Joint Antarctic School Expedition (JASE) is an international collaboration program between high school students and teachers from the United States and Chile aimed at providing the skills required for establishing the scientific international collaborations that our globalized world demands, and to develop a new approach for science education. The National Antarctic Programs of Chile and the United States worked together on a pilot program that brought high school students and teachers from both countries to Punta Arenas, Chile, in February 2014. The goals of this project included strengthening the partnership between the two countries, and building relationships between future generations of scientists, while developing the students' awareness of global scientific issues and expanding their knowledge and interest in Antarctica and polar science. A big component of the project involved the sharing by students of the acquired knowledge and experiences with the general public. JASE is based on the successful Chilean Antarctic Science Fair developed by Chile´s Antarctic Research Institute. For 10 years, small groups of Chilean students, each mentored by a teacher, perform experimental or bibliographical Antarctic research. Winning teams are awarded an expedition to the Chilean research station on King George Island. In 2014, the Chileans invited US participation in this program in order to strengthen science ties for upcoming generations. On King George Island, students have hands-on experiences conducting experiments and learning about field research. While the total number of students directly involved in the program is relatively small, the sharing of the experience by students with the general public is a novel approach to science education. Research experiences for students, like JASE, are important as they influence new direction for students in science learning, science interest, and help increase science knowledge. We will share experiences with the

  18. Active layer monitoring at CALM-S site near J.G.Mendel Station, James Ross Island, eastern Antarctic Peninsula.

    Science.gov (United States)

    Hrbáček, Filip; Kňažková, Michaela; Nývlt, Daniel; Láska, Kamil; Mueller, Carsten W; Ondruch, Jakub

    2017-12-01

    The Circumpolar Active Layer Monitoring - South (CALM-S) site was established in February 2014 on James Ross Island as the first CALM-S site in the eastern Antarctic Peninsula region. The site, located near Johann Gregor Mendel Station, is labelled CALM-S JGM. The grid area is gently sloped (<3°) and has an elevation of between 8 and 11ma.s.l. The lithology of the site consists of the muddy sediments of Holocene marine terrace and clayey-sandy Cretaceous sedimentary rocks, which significantly affect the texture, moisture content, and physical parameters of the ground within the grid. Our objective was to study seasonal and interannual variability of the active layer depth and thermal regime at the CALM-S site, and at two ground temperature measurement profiles, AWS-JGM and AWS-CALM, located in the grid. The mean air temperature in the period March 2013 to February 2016 reached -7.2°C. The mean ground temperature decreased with depth from -5.3°C to -5.4°C at 5cm, to -5.5°C to -5.9°C at 200cm. Active layer thickness was significantly higher at AWS-CALM and ranged between 86cm (2014/15) and 87cm (2015/16), while at AWS-JGM it reached only 51cm (2013/14) to 65cm (2015/16). The mean probed active layer depth increased from 66.4cm in 2013/14 to 78.0cm in 2014/15. Large differences were observed when comparing the minimum (51cm to 59cm) and maximum (100cm to 113cm) probed depths. The distribution of the active layer depth and differences in the thermal regime of the uppermost layer of permafrost at CALM-S JGM clearly show the effect of different lithological properties on the two lithologically distinct parts of the grid. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. The marine epilithic diatom Melosira brandinii sp. nov. (Bacillariophyta from Elephant Island, Antarctic Peninsula, with comments on some related species

    Directory of Open Access Journals (Sweden)

    Luciano F. Fernandes

    2001-01-01

    Full Text Available A new species of epilithic diatom is described from samples collected near Elephant Island, Antarctic Peninsula. The cells of Melosira brandinii sp. nov. are joined in filamentous chains and attached by means of long mucilaginous stalks. The valves are circular with the valvar surface composed of irregularly arranged pentagonal Ioculi. Each loculus bears 6-12 pores on the external surface, opening to the innerside through rotae. The corona is only composed of coarse granules. A mantle is well developed, presenting rimoportulae and bearing coarse granules, which are more concentrated at the mantle edge. Comparisons with the related species Melosira arctica, M. moniliformis and M. nummuloides are made. Additionally, photomicrographs of M. arctica from the type material and Barents Sea, and of M. moniliformis from estuaries of Southern Brazil are included.Uma nova espécie de diatomácea eplítica é descrita sob microscopia eletrônica, a partir de amostras coletadas próximo à Ilha Elefante, Península Antártica. As células de Melosira brandinii sp. nov. encontram-se reunidas em cadeias filamentosas através de longos tubos mucilaginosos. As valvas são circulares, com superfície valvar provida de lóculos pentagonais arranjados irregularmente. Cada lóculo possui 6-12 poros na superfície externa, abrindo-se para o interior através de aréolas do tipo rota. A corona é composta exclusivamente por grânulos grosseiros, os quais estão mais concentrados na borda do manto. Comparações com as espécies próximas Melosira arctica, M. moniliformis e M. nummuloides foram realizadas. Adicionalmente, são fornecidas fotomicrografias de M. arctica provenientes do material tipo e do Mar de Barents (Ártico, e de M. moniliformis de estuários do Sul do Brasil.

  20. Pygoscelis antarcticus feathers as bioindicator of trace element risk in marine environments from Barton Peninsula, 25 de Mayo (King George) Island, Antarctica.

    Science.gov (United States)

    Catán, Soledad Perez; Bubach, Debora; Di Fonzo, Carla; Dopchiz, Laura; Arribére, Maria; Ansaldo, Martin

    2017-04-01

    We report the contents of elements in feathers of Chinstrap penguin (Pygoscelis antarcticus), which had not been informed up to now, such as silver and bromine and others listed as hazardous by the United States Environmental Protection Agency as arsenic, cobalt, chromium, and mercury. Analyses of the element concentrations in feathers, adult and chicken, from Barton Peninsulas at 25 de Mayo (King George) Island, South Shetlands, were made by Instrumental Neutron Activation Analysis. Samarium, lanthanum a, thorium, and uranium concentrations in Chinstrap penguin feathers were below 0.1 mg/kg. This suggests that the elements in feather do not come from atmospheric particles surface deposition. Arsenic (0.120 ± 0.050 mg/kg) and cobalt (0.030 ± 0.020 mg/kg) concentrations were lower than the reports for other colony of Chinstrap penguins, and essential elements as iron (26 ± 12 mg/kg), zinc (78.0 ± 5.3 mg/kg), and chromium (0.51 ± 0.27 mg/kg) were in the same range while Se (2.90 ± 0.65 mg/kg) content were the lowest reported. Mercury (0.43 ± 0.21 mg/kg), chromium (0.210 ± 0.060 mg/kg), and silver (0.083 ± 0.003 mg/kg) in chicks tended to be lower than in adults. Iron, cobalt, and arsenic concentrations in feathers found in this study were the lowest compared to measurements were in several penguin species in Antarctica. These results confirm to feathers like effective indicators for the trace elements incorporated in the penguins and it provide a data set which can adds to the baseline for bioindication studies using feathers.

  1. Foraging segregation of two congeneric diving seabird species (common and thick-billed murres breeding on St. George Island, Bering Sea

    Directory of Open Access Journals (Sweden)

    N. Kokubun

    2015-11-01

    Full Text Available Sub-arctic environmental changes are expected to affect the ecology of marine top predators. We examined the characteristics of foraging behavior of two sympatric congeneric diving seabirds, common (Uria aalge: hereafter COMU and thick-billed (U. lomvia: hereafter TBMU murres breeding on St. George Island located in the seasonal sea-ice region of the Bering Sea. We investigated their flight duration, diel patterns of dive depth, and underwater wing strokes, along with morphology and blood stable isotopes. Acceleration-temperature-depth data loggers were attached to chick-guarding birds, and behavioral data were obtained from 7 COMU and 12 TBMU. Both species showed similar trip duration (13.21 ± 4.79 h for COMU and 10.45 ± 7.09 h for TBMU and similar diurnal patterns of diving (frequent dives to various depths in the daytime and less frequent dives to shallow depths in the nighttime. During the daytime, dive depths of COMU had two peaks in shallow (18.1 ± 6.0 m and deep (74.2 ± 8.7 m depths, while those of TBMU were 20.2 ± 7.4 m and 59.7 ± 7.9 m. COMU showed more frequent wing strokes during the bottom phase of dives (1.90 ± 0.11 s−1 than TBMU (1.66 ± 0.15 s−1. Fishes occurred with higher proportion in the bill-loads brought back to chicks in COMU (85 % than in TBMU (56 %. δ15N value of blood was significantly higher in COMU (14.47 ± 0.27 ‰ than in TBMU (13.14 ± 0.36 ‰. Relatively small wing area (0.053 ± 0.007 m2 of COMU compared to TBMU (0.067 ± 0.007 m2 may make them more agile underwater and thus enable them to target more mobile prey including larger fishes that inhabit deeper depths. These differences in foraging behavior between COMU and TBMU might explain the differences in their responses to long-term marine environmental changes.

  2. Holoceno marino en la península Potter, Isla 25 de Mayo, Antártida Marine sediments of the early Holocene in the Potter Península, King George Island, Southern Shetland, Antarctica

    Directory of Open Access Journals (Sweden)

    R.A. del Valle

    2007-11-01

    Full Text Available La sucesión sedimentaria del Holoceno temprano expuesta en la terraza marina de 3,77 m s.n.m. en la costa sur de la caleta Potter (Isla 25 de Mayo/King George Island, islas Shetland del Sur, Antártida contiene invertebrados marinos, algas y huesos de foca y pingüino. Dataciones por radiocarbono de huesos de pingüino obtenidos en esta sucesión dieron edades de 7.562 a cal AP (años calibrados antes del Presente y 7.414 a cal AP. Las dataciones indican que los huesos están entre los restos de vertebrados más antiguos del Holoceno hallados en las Islas Shetland del Sur, y pueden ser consideradas como edades mínimas de ocupación por estas aves de las costas de las islas en el Holoceno temprano. Esto indica condiciones interglaciales en esa época, con situación clima/hielo marino similar a la presente y condiciones marinas estacionalmente abiertas.The early Holocene sedimentary succession exposed at the 3.77 m-high marine terrace on the south coast of Potter Cove (King George Island/Isla 25 de Mayo, South Shetland Islands, Antarctica contains marine invertebrates, seaweed and bones of seals and penguins. Radiocarbon dating on penguin bones from this succession yielded 7,562 cal yr BP and 7,414 cal yr BP. These dates suggest that the bones are among the oldest remains of Holocene vertebrates found in South Shetland Islands, and may be considered as minimum ages of penguin occupation of coastal areas on the islands during the early Holocene. This indicates interglacial conditions in this time, with climate/sea ice situation similar to the present and seasonally open marine conditions.

  3. The 1997 GLE as seen by the Antarctic Laboratory for Cosmic Rays

    Science.gov (United States)

    Massetti, Stefano

    The first relativistic solar cosmic-ray event of the on-going solar activity cycle (n. 23) occurred on November 6, 1997. Data, obtained with the standard neutron monitor (6-NM-64) of LARC (Antarctic Laboratory for Cosmic Rays - South Shetlands - King George Island - Ardley Cove: 62°12'09" S, 58°57'42" W; geomagnetic rigidity cut-off about 3 GV), are reported to show the ground level enhancement (GLE) registered by the Chile/Italy collaboration in the frame of the International Decade for Scientific Cooperation in Antarctica (1991-2000).

  4. Georges Duby

    OpenAIRE

    Arnoux, Mathieu; Beaucage, Benoît; Braunstein, Philippe; Chiva, Isac; Comet, Georges; DUBY, Georges; Feller, Laurent; Lamaison, Pierre; La Rochefoucauld, Jean-Dominique de; Lévi-Strauss, Claude; Rösener, Werner

    2005-01-01

    Études rurales rend hommage à l'un des fondateurs de la revue, héritier de la géographie humaine, qui fit ses premières rencontres avec la vie des campagnes européennes il y a quarante ans. Des historiens d'aujourd'hui tentent, à la lumière de leurs propres recherches, de situer les apports d'une pensée féconde à une vision économique, technique et sociale du monde rural ancien. Tous les aspects de l'oeuvre de Georges Duby sont évoqués au gré des interviews, des témoignages et des réflexions...

  5. Diversity of the aerobic anoxygenic phototrophy genepufM in Arctic and Antarctic coastal seawaters

    Institute of Scientific and Technical Information of China (English)

    ZENG Yinxin; DONG Peiyan; QIAO Zongyun; ZHENG Tianling

    2016-01-01

    Aerobic anoxygenic phototrophic (AAP) bacteria serve important functions in marine carbon and energy cycling because of their capability to utilize dissolved organic substrates and harvest light energy. AAP bacteria are widely distributed in marine environments, and their diversity has been examined in marine habitats. However, information about AAP bacteria at high latitudes remains insufficient to date. Therefore, this study determined the summer AAP bacterial diversity in Arctic Kongsfjorden and in the Antarctic coastal seawater of King George Island on the basis ofpufM, a gene that encodes a pigment-binding protein subunit of the reaction center complex. FourpufM clone libraries were constructed, and 674 positive clones were obtained from four investigated stations (two in Kongsfjorden and two in the Antarctic Maxwell Bay). Arctic clones were clustered within theAlphaproteobacteria, whereas Antarctic clones were classified into theAlphaproteobacteria and Betaproteobacteria classes.Rhodobacteraceae-likepufM genes dominated in all samples. In addition, sequences closely related topufM encoded on a plasmid inSulfitobacter guttiformis were predominant in both Arctic and Antarctic samples. This result indicates the transpolar or even global distribution ofpufM genes in marine environments. Meanwhile, differences between the Arctic and Antarctic sequences may prove polar endemism. These results indicate the important role ofRhodobacteraceae as AAP bacteria in bipolar coastal waters.

  6. Revealing past environmental changes on the Antarctic Peninsula by analyzing high resolution sedimentary records from Lake Esmeralda, Vega Island

    Science.gov (United States)

    Píšková, Anna; Nývlt, Daniel; Roman, Matěj; Lirio, Juan Manuel; Kopalová, Kateřina

    2017-04-01

    Topographically and climatically, the environment of the Antarctic Peninsula (AP) differs significantly from Continental Antarctica. The AP forms an unbroken chain of rugged, alpine topography, which forms a climatic barrier separating the warmer Bellingshausen Sea on the western coast from the colder Weddell Sea on the east. The AP has experienced one of the highest temperature increases on Earth in the second half of the 20th century as a response to the ongoing global warming (Turner et al., 2005). However, the last decade was colder and a significant decrease in air temperature was detected especially in the north-eastern part of the AP (Turner et al., 2016; Oliva et al., 2017). The extreme sensitivity of the area to climate change represents exceptional potential for AP palaeoclimatic records either from marine, lacustrine, or ice cores. We have analysed several sedimentary cores from yet unstudied Lake Esmeralda, which was formed as a result of the last deglaciation during the Pleistocene/Holocene transition. We here focus on the longest (177 cm) core that could record environmental changes of the past millennia. In order to describe both inorganic and organic components of the sediment we used a combination of the following methods: XRF, XRD, magnetic susceptibility measurement, chemical analysis for determination of cation exchange capacity, grain size analysis, geochemical analysis (TIC, TOC, TS), high pressure liquid chromatography (HPLC) and diatom community analysis. This combination of methods gave us an insight in the past environmental changes in the lake catchment as well as in the lake body. More specifically it enabled us to define periods of enhanced weathering and to distinguish colder and warmer phases. The preliminary results will be completed with age-depth model resulting in a high resolution multi-proxy record that will contribute to a better, more detailed picture of the past climatic and environmental changes in the north-eastern AP

  7. Potential changes in feeding behavior of Antarctic fish, Pseudotrematomus bernacchii (Boulenger, 1902) on the East Ongul Island, Antarctica

    Science.gov (United States)

    Chavanich, Suchana; Viyakarn, Voranop; Nomura, Daiki; Watanabe, Kentaro

    2015-12-01

    The feeding habits of the Antarctic fish Pseudotrematomus bernacchii (Previous name: Trematomus bernacchii) under the fast ice around Japanese Syowa Station were investigated in the summers of 2004/2005 and 2009/2010. The results showed that amphipods and krill were the major prey. However, there was a significant difference in the proportions of larger invertebrates such as squids, octopus and other crustaceans found in the fish stomachs between 2009/2010 and the previous years. Moreover, the percentage of amphipods and krill in fish stomachs declined over the 5-year period in all fish size classes. Several factors including sea ice melting, habitat and environmental changes might have influenced the pattern of feeding behavior.

  8. Biodiversity and biogeography of Antarctic and sub-Antarctic mollusca

    Science.gov (United States)

    Linse, Katrin; Griffiths, Huw J.; Barnes, David K. A.; Clarke, Andrew

    2006-04-01

    For many decades molluscan data have been critical to the establishment of the concept of a global-scale increase in species richness from the poles to the equator. Low polar diversity is key to this latitudinal cline in diversity. Here we investigate richness patterns in the two largest classes of molluscs at both local and regional scales throughout the Southern Ocean. We show that biodiversity is very patchy in the Southern Ocean (at the 1000-km scale) and test the validity of historical biogeographic sub-regions and provinces. We used multivariate analysis of biodiversity patterns at species, genus and family levels to define richness hotspots within the Southern Ocean and transition areas. This process identified the following distinct sub-regions in the Southern Ocean: Antarctic Peninsula, Weddell Sea, East Antarctic—Dronning Maud Land, East Antarctic—Enderby Land, East Antarctic—Wilkes Land, Ross Sea, and the independent Scotia arc and sub Antarctic islands. Patterns of endemism were very different between the bivalves and gastropods. On the basis of distributional ranges and radiation centres of evolutionarily successful families and genera we define three biogeographic provinces in the Southern Ocean: (1) the continental high Antarctic province excluding the Antarctic Peninsula, (2) the Scotia Sea province including the Antarctic Peninsula, and (3) the sub Antarctic province comprising the islands in the vicinity of the Antarctic Circumpolar Current.

  9. Bacterial diversity of autotrophic enriched cultures from remote, glacial Antarctic, Alpine and Andean aerosol, snow and soil samples

    Science.gov (United States)

    González-Toril, E.; Amils, R.; Delmas, R. J.; Petit, J.-R.; Komárek, J.; Elster, J.

    2009-01-01

    Four different communities and one culture of autotrophic microbial assemblages were obtained by incubation of samples collected from high elevation snow in the Alps (Mt. Blanc area) and the Andes (Nevado Illimani summit, Bolivia), from Antarctic aerosol (French station Dumont d'Urville) and a maritime Antarctic soil (King George Island, South Shetlands, Uruguay Station Artigas), in a minimal mineral (oligotrophic) media. Molecular analysis of more than 200 16S rRNA gene sequences showed that all cultured cells belong to the Bacteria domain. Phylogenetic comparison with the currently available rDNA database allowed sequences belonging to Proteobacteria Alpha-, Beta- and Gamma-proteobacteria), Actinobacteria and Bacteroidetes phyla to be identified. The Andes snow culture was the richest in bacterial diversity (eight microorganisms identified) and the marine Antarctic soil the poorest (only one). Snow samples from Col du Midi (Alps) and the Andes shared the highest number of identified microorganisms (Agrobacterium, Limnobacter, Aquiflexus and two uncultured Alphaproteobacteria clones). These two sampling sites also shared four sequences with the Antarctic aerosol sample (Limnobacter, Pseudonocardia and an uncultured Alphaproteobacteriaclone). The only microorganism identified in the Antarctica soil (Brevundimonas sp.) was also detected in the Antarctic aerosol. Most of the identified microorganisms had been detected previously in cold environments, marine sediments soils and rocks. Air current dispersal is the best model to explain the presence of very specific microorganisms, like those identified in this work, in environments very distant and very different from each other.

  10. Climate change and glacier retreat drive shifts in an Antarctic benthic ecosystem.

    Science.gov (United States)

    Sahade, Ricardo; Lagger, Cristian; Torre, Luciana; Momo, Fernando; Monien, Patrick; Schloss, Irene; Barnes, David K A; Servetto, Natalia; Tarantelli, Soledad; Tatián, Marcos; Zamboni, Nadia; Abele, Doris

    2015-11-01

    The Antarctic Peninsula (AP) is one of the three places on Earth that registered the most intense warming in the last 50 years, almost five times the global mean. This warming has strongly affected the cryosphere, causing the largest ice-shelf collapses ever observed and the retreat of 87% of glaciers. Ecosystem responses, although increasingly predicted, have been mainly reported for pelagic systems. However, and despite most Antarctic species being benthic, responses in the Antarctic benthos have been detected in only a few species, and major effects at assemblage level are unknown. This is probably due to the scarcity of baselines against which to assess change. We performed repeat surveys of coastal benthos in 1994, 1998, and 2010, analyzing community structure and environmental variables at King George Island, Antarctica. We report a marked shift in an Antarctic benthic community that can be linked to ongoing climate change. However, rather than temperature as the primary factor, we highlight the resulting increased sediment runoff, triggered by glacier retreat, as the potential causal factor. The sudden shift from a "filter feeders-ascidian domination" to a "mixed assemblage" suggests that thresholds (for example, of tolerable sedimentation) and alternative equilibrium states, depending on the reversibility of the changes, could be possible traits of this ecosystem. Sedimentation processes will be increasing under the current scenario of glacier retreat, and attention needs to be paid to its effects along the AP.

  11. Impact of the variability of the seasonal snow cover on the ground surface regimes in Hurd Peninsula (Livingston Island, Antarctic)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2014-05-01

    Seasonally snow cover has a great impact on the thermal regime of the active layer and permafrost. Ground temperatures over a year are strongly affected by the timing, duration, thickness, structure and physical and thermal properties of snow cover. The purpose of this communication is to characterize the shallow ground thermal regimes, with special reference to the understanding of the influence snow cover in permafrost spatial distribution, in the ice-free areas of the north western part of Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". We have analyzed and ground temperatures as well as snow thickness data in four sites distributed along an altitudinal transect in Hurd Peninsula from 2007 to 2013: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). At each study site, data loggers were installed for the monitoring of air temperatures (at 1.5 m high), ground temperatures (5, 20 and 40 cm depth) and for snow depth (2, 5, 10, 20, 40, 80 and 160 cm) at 4-hour intervals. The winter data suggests the existence of three types of seasonal stages regarding the ground surface thermal regime and the thickness of snow cover: (a) shallow snow cover with intense ground temperatures oscillations; (b) thick snow cover and low variations of soil temperatures; and (c) stability of ground temperatures. Ground thermal conditions are also conditioned by a strong variability. Winter data indicates that Nuevo Incinerador site experiences more often thicker snow cover with higher ground temperatures and absence of ground temperatures oscillations. Collado Ramos and Ohridski show frequent variations of snow cover thickness, alternating between shallow snow cover with high ground temperature fluctuation and thick snow cover and low ground temperature fluctuation. Reina Sofia in all the years has thick snow cover with little variations in soil

  12. Differential adaptations between cold-stenothermal environments in the bivalve Lissarca cf. miliaris (Philobryidae) from the Scotia Sea islands and Antarctic Peninsula

    Science.gov (United States)

    Reed, Adam J.; Linse, Katrin; Thatje, Sven

    2014-04-01

    The cold stenothermal nature of the Southern Ocean, and highly adapted fauna living within, raises the question of how much intra-specific variation there is among invertebrate populations, and how variation may have a role in speciation processes through ecological divergence, natural selection, and reproductive isolation. Despite decades of collecting biological material, this question remains largely unanswered, and many studies compare ‘populations' of pooled material from wide geographic ranges to compensate for sampling constraints. In this study, variations in ecophysiological traits are explored by measuring growth, reproduction, and shell morphology among six populations of the small bivalve Lissarca cf. miliaris (Philippi, 1845) from the Southern Ocean, which experience subtle differences in temperature, disturbance, and food availability. There are significant differences in shell morphology and growth among different populations and slower growth rates at higher latitude populations. Prodissoconch sizes show an inverse ‘U' shaped relationship with latitude, and are correlated with egg size at South Georgia and King George Island's Potter Cove. Higher brood sizes at the South Georgia population represent a trade-off with lower egg size, and correlate with shell morphology by offering lower internal capacity to brood young. Lower investment into offspring and morphological variations in L. cf. miliaris highlight the importance of local scale environmental variations on species' ecology. These variations in physical traits appear to be underestimated in the Southern Ocean, but may be important drivers of ecological divergence and speciation, which should be considered in future genetic investigations on different invertebrate populations.

  13. Antarctic clouds

    OpenAIRE

    Lachlan-Cope, Tom

    2010-01-01

    Sensitivity studies with global climate models show that, by their influence on the radiation balance, Antarctic clouds play a major role in the climate system, both directly at high southern latitudes and indirectly globally, as the local circulation changes lead to global teleconnections. Unfortunately, observations of cloud distribution in the Antarctic are limited and often of low quality because of the practical difficulty in observing clouds in the harsh Antarctic environment. The best ...

  14. Geographic names of the Antarctic

    Science.gov (United States)

    ,; ,; ,; ,; Alberts, Fred G.

    1995-01-01

    This gazetteer contains 12,710 names approved by the United States Board on Geographic Names and the Secretary of the Interior for features in Antarctica and the area extending northward to the Antarctic Convergence. Included in this geographic area, the Antarctic region, are the off-lying South Shetland Islands, the South Orkney Islands, the South Sandwich Islands, South Georgia, Bouvetøya, Heard Island, and the Balleny Islands. These names have been approved for use by U.S. Government agencies. Their use by the Antarctic specialist and the public is highly recommended for the sake of accuracy and uniformity. This publication, which supersedes previous Board gazetteers or lists for the area, contains names approved as recently as December 1994. The basic name coverage of this gazetteer corresponds to that of maps at the scale of 1:250,000 or larger for coastal Antarctica, the off-lying islands, and isolated mountains and ranges of the continent. Much of the interior of Antarctica is a featureless ice plateau. That area has been mapped at a smaller scale and is nearly devoid of toponyms. All of the names are for natural features, such as mountains, glaciers, peninsulas, capes, bays, islands, and subglacial entities. The names of scientific stations have not been listed alphabetically, but they may appear in the texts of some decisions. For the names of submarine features, reference should be made to the Gazetteer of Undersea Features, 4th edition, U.S. Board on Geographic Names, 1990.

  15. Structural and chemical modification of Fe-rich smectite associated with microbial Fe-respiration by psychrophilic bacteria in King George Island, West Antarctica

    Science.gov (United States)

    Jung, J.; Kim, J. Y.; Lim, H. S.; Lee, Y. K.; Kim, O. S.; Park, K.; Lee, J.; Yoon, H.; Kim, J. W.

    2015-12-01

    Biotic/abiotic redox reaction is a ubiquitous process in a mineral alteration and an elemental cycling in the sediments/ocean. The role of psychrophiles in clay mineral alteration was tested in the soil for the seven sites from the coast to the inland at Barton Peninsula. Batch experiments of microbe-mineral interaction under the various temperatures (4 ℃, 15 ℃) that mimics the Antarctic condition were performed to understand the mechanism of biogeochemical alteration of clay minerals. After 12 months incubation of the bulk surface soil samples in the M1 minimal medium, the extent of Fe reduction was reached up to 49 and 42 % at 4 ℃ and 15 ℃. The increase in CEC corresponds to the extent of Fe reduction. Moreover, precipitations of secondary phase mineral such as vivianite were observed only in 12 months enrichment samples at 4 ℃ and 15 ℃. Sulfate reducing bacteria and Fe-reducing bacteria capable of reducing Fe were identified by 16S rRNA pyrosequencing. The Fe reduction coupled to oxidation of organic matter might be enhanced by cooperation of a consortium of Sulfate reducing bacteria and Fe-reducing bacteria. Moreover, Nitrate reducing bacteria which have an ability to oxidize ferrous iron anaerobically with nitrate reduction were identified at 15 ℃. The lower values observed in the extent of Fe reduction at 15 ℃ may be associated with Fe-oxidation induced by nitrate reduction.In order to verify the mechanism of microbial Fe reduction in clay minerals at low temperatures (4 and 15 ℃), Fe-rich Nontronite (NAu-1) and Psychrophilic bacteria were incubated for 4 months in anaerobic condition. Total structural Fe in NAu-1 is 16.4 % and 99.6 % of the total Fe is ferric. The extent of Fe reduction in nontronite was reached up to 11.5 % and 11 % at 4 ℃ and 15 ℃, respectively. The structural modification of biologically Fe-reduced nontronite was observed in the (001) peak shift to the lower 2 theta indicating the layer collapse associated with K

  16. Comparison of glacial isostasy contribution to the sea level changes during the Holocene in West and East Antarctic regions.

    Science.gov (United States)

    Poleshchuk, Ksenia; Verkulich, Sergey; Pushina, Zina

    2016-04-01

    Antarctica as geographically completed and tectonically compound continent is an interesting object for study of glacial isostatic adjustment (GIA) and sea level changes in the Holocene. The analysis of relative sea level curves is one of the most indicative approaches for glacio-isostasy estimation. The present study focuses on two different regions of Antarctic margin which sea-level changes are well researched. We compare our relative sea-level curves for Bunger Oasis (East Antarctica) and King George Island (West Antarctica) that were obtained from new geomorphological, paleogeographical and micropaleontological data. The results showed notable difference: the maximum relative water altitude had occurred between 8 000 - 6 000 yr BP and had reached 12 m a. s. l. in the Bunger Oasis and 18-20 m a. s. l. in King George Island. Furthermore, the research of other Antarctic regions revealed significant differences in sea-level altitudes. Following analysis of constructed curves and computative GIA models allow us to estimate the possible extent of glacial isostatic adjustment. Besides, this observation has indicated the importance of deglaciation rates and local tectonic features. The reported study was funded by RFBR according to the research project No. 16-35-00346 mol_a.

  17. First results with a new-generation meteor radar on King George Island: Mean and Tidal Wind and Gravity Wave Momentum Flux Measurements over the Drake Passage

    Science.gov (United States)

    Fritts, D.; Janches, D.; Iimura, H.; Hocking, W. K.; Bageston, J. V.; Leme, N. P.

    2011-12-01

    A new-generation meteor radar was installed at the Brazilian Antarctic Comandante Ferraz Base (62.1S) in March 2010. This talk describes the motivations for the radar location, its measurement capabilities, and comparisons of measured mean winds, tides, and gravity wave momentum fluxes from April to June of 2010 and 2011 with those by a similar radar on Tierra del Fuego (53.8S). Motivations for the radars include the "hotspot" of small-scale gravity wave activity extending from the troposphere into the mesosphere and lower thermosphere (MLT) centered over the Drake Passage, the maximum of the semidiurnal tide at these latitudes, and the lack of other MLT wind measurements in this latitude band. Mean winds are seen to be strongly modulated at planetary wave and longer periods and to exhibit strong coherence over the two radars at shorter time scales as well as systematic seasonal variations. The semidiurnal tide contribute most to the large-scale winds over both radars, with maximum tidal amplitudes during May and maxima at the highest altitudes varying from ~20 to >70 m/s. In contrast, the diurnal tide and various planetary waves achieve maximum winds of ~10 to 20 m/s. Monthly-mean gravity wave momentum fluxes appear to reflect the occurrence of significant sources at lower altitudes, with relatively small zonal fluxes over both radars, but with significant, and opposite, meridional momentum fluxes below ~85 km. These suggest gravity waves propagating away from the Drake Passage at both sites, and may indicate an important source region accounting in part for this "hotspot".

  18. The seasonal evolution of shelf water masses around Bouvetøya, a sub-Antarctic island in the mid-Atlantic sector of the Southern Ocean, determined from an instrumented southern elephant seal

    Directory of Open Access Journals (Sweden)

    Andrew D. Lowther

    2016-10-01

    Full Text Available Our study makes use of a fortuitous oceanographic data set collected around the remote sub-Antarctic island of Bouvetøya by a conductivity–temperature–depth recorder (CTD integrated with a satellite-relayed data logger deployed on an adult female southern elephant seal (Mirounga leonina to describe the seasonal evolution of the western shelf waters. The instrumented seal remained in waters over the shelf for 259 days, collecting an average of 2.6 (±0.06 CTD profiles per day, providing hydrographic data encompassing the late austral summer and the entire winter. These data document the thermal stratification of the upper water layer due to summer surface heating of the previous year's Antarctic Surface Water, giving way to a cold subsurface layer at about 100 m as the austral winter progressed, with a concomitant increase in salinity of the upper layer. Upper Circumpolar Deep Water was detected at a depth of approximately 200 m along the western shelf of Bouvetøya throughout the year. These oceanographic data represent the only seasonal time series for this region and the second such animal–instrument oceanographic time series in the sub-Antarctic domain of the Southern Ocean.

  19. Implications of biological factors on accumulation of persistent organic pollutants in Antarctic notothenioid fish.

    Science.gov (United States)

    Ríos, J M; Lana, N B; Ciocco, N F; Covaci, A; Barrera-Oro, E; Moreira, E; Altamirano, J C

    2017-11-01

    In the present study, the possible associations between selected persistent organic pollutants (POPs) and biological factors were assessed in different tissues of two Antarctic notothenioid fish: Notothenia rossii (NOR) and Trematomus newnesi (TRN) collected at Potter Cove, King George Island/Isla 25 de Mayo, South Shetland Islands. Specifically, association patterns between biological factors (body size, lipid content, body condition) and POP concentrations (polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT) and metabolites, polybrominated diphenyl ethers (PBDEs), and hexachlorocyclohexane (HCH), hexachlorobenzene (HCB), chlordanes (CHLs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs)), were explored by using two approaches: multivariate analyses (principal component analysis: PCA) and intraspecific correlations. Integrating results suggest that biological factors such as size, KI and tissue type seemed to be associated to selective accumulation of POPs for immature specimens of N. rossii, and KI and tissue type for mature specimens of T. newnesi. Each particular factor should be considered when choosing N. rossii or T. newnesi as sentinels for POPs pollution in Antarctic marine environments. Further, both nototheniids showed a selective accumulation pattern in their gonads of penta-chlorinated biphenyls (penta-CBs; 55.5 and 29ngg(-1) lw for N. rossii and T. newnesi, respectively) and organochlorine pesticides such as DDTs (199 and 13.3ngg(-1) lw, for N. rossii and T. newnesi respectively), and of polybrominated diphenyl ethers (PBDEs) in gills (97.2 and 22.1 for ngg(-1) lw, for N. rossii and T. newnesi, respectively), highlighting the importance of these tissues in monitoring studies of pollution in fish. The current study expands the knowledge concerning the biological factors to be investigated when specific pollutants are monitored and supports the importance of tissue type for the selective accumulation of POPs in Antarctic

  20. Antarctic Fishes.

    Science.gov (United States)

    Eastman, Joseph T.; DeVries, Arthur L.

    1986-01-01

    Explains the adaptations to Antarctic waters that Notothenioidei, a group of advanced bony fishes, have exhibited. Discusses the fishes' mechanisms of production of antifreeze properties and their capacities for neutral buoyancy in water. (ML)

  1. Reading the Club as Colonial Island in E.M. Forster’s A Passage to India and George Orwell’s Burmese Days

    Directory of Open Access Journals (Sweden)

    Ralph Crane

    2011-05-01

    Full Text Available This paper examines the “island effect” in two enormously influential colonial fictions published in the final decades of the British Empire in India. Through a detailed analysis of the Club scene in Forster’s A Passage to India (1924 and Orwell’s pervasive use of the Kyauktada Club in Burmese Days (1934, this paper brings critical focus to the phenomenon of the Club in British India. It explores the way the Club functions as an ‘island’ microcosm within a larger framework of colonial isolation, and the way intimate colonial relations prevail within its walls and sustain an isolated community which fears for its survival outside its enclosing border.

  2. Molecular and morphological analysis of an Antarctic tardigrade, Acutuncus antarcticus

    Directory of Open Access Journals (Sweden)

    Hiroshi Kagoshima

    2013-03-01

    Full Text Available We isolated a species of tardigrade from moss samples collected from Langhovde and Skarvsnes, near Syowa station, East Antarctic, from which we cultured a parthenogenetic strain in Petri dishes with co-occurring cyanobacteria or green algae. This culture was maintained at both 4 and 10ºC, though the latter proved more suitable for growth. Eggs were laid free, rather than in exuviae. We isolated the 18S rRNA sequences from this tardigrade, identical to that of Acutuncus antarcticus from King George island, South Shetland islands. Morphological analyses via both light and scanning electron microscopy also show general agreement with characteristics of A. antarcticus: dorsal and ventral apophyses for the insertion of stylet muscles and dorsal longitudinal thickening on the anterior part of buccal tube; presence of pharyngeal apophyses, two macroplacoids and absence of a microplacoid; the surface structure of egg; and claw shape. Peribuccal lamellae were absent, but six oval swellings surrounded the mouth opening. An additional study of moss pillars from lake Hotoke-ike, Skarvsnes, proved the existence of the same tardigrade taxon living at the bottom of the lake.

  3. Antarctic Crustal Thickness from Gravity Inversion

    Science.gov (United States)

    Vaughan, A. P.; Kusznir, N. J.; Ferraccioli, F.; Jordan, T. A.

    2013-12-01

    around the Amundsen Ridges. Thin crust is predicted under the Ross Sea and beneath the West Antarctic Ice Sheet and delineates the regional extent of the broad West Antarctic Rift System (WARS). Crustal thicknesses from gravity inversion are compared with independent seismic estimates, which are still relatively sparse over Antarctica. The large crustal thicknesses under part of East Antarctica predicted from gravity inversion are consistent with seismic estimates. A substantial mantle thermal anomaly is required under Marie Byrd Land to reconcile gravity and seismic estimates. Crustal thickness and lithosphere thinning derived from gravity inversion also allows the determination of circum-Antarctic ocean-continent transition structure and the mapping of continent-ocean boundary location. Superposition of illuminated satellite gravity data onto crustal thickness maps from gravity inversion provides improved determination of Southern Ocean rift orientation, pre-breakup rifted margin conjugacy and continental breakup trajectory. The new maps produced by this study support the hypothesis that one branch of the WARS links through to the De Gerlache sea-mounts and Peter I Island in the Bellingshausen Sea region, while another branch may link to the George V Sound Rift in the Antarctic Peninsula region.

  4. X-RAY FLUORESCENT ANALYSIS OF THE 6 SPECIES OF BRYOPHYTE IN THE KING GEORGE ISLAND, ANTARCTICA%南极乔治王岛六种苔藓植物的X荧光分析

    Institute of Scientific and Technical Information of China (English)

    黄宇营; 巨新; 康士秀; 吴自勤; 沈显生; 孙立广; 尹雪斌; 张莉

    2001-01-01

    在无标样条件下,我们利用微束X荧光分析法对南极乔治王岛的6种苔藓植物的叶和茎进行重元素分析。它们是:Andreaea regularis, Bryum muehlenbeckii, Drepanocladus uncinatus, Brachythecium subpilosum, Tortula saxiola, Ditrichum austro-georgicum。研究结果发现,不同苔藓植物对各种不同重元素的吸收能力不同,即使是同一种植物,叶和茎中的重元素成分也有差异。在6种苔藓中,Andreaea regularis 体内的重元素种类最少,但其对Fe有较强的吸收。由于南极环境条件优越,在苔藓植物体内,尚未发现大量有毒重金属元素的存在。%Without a standard specimen, we analysed the heavy element content of 6 moss species in the King George Island of Antarctica by XRF. They are Andreaea regularis, Bryum muehlenbeckii, Drepanocladus uncinatus, Brachythecium subpilosum, Tortula saxiola and Ditrichum austro-georgicum. We found that various plants absorbed varied heavy elements. Even if the same moss, there are the different elements in leaves and stems. Andreaea regularis is possessed of the fewest heavy element varieties in 6 species of bryophyte, but it absorbs Fe more powerfully. Owing to superior environment, we didn't find a lot of poisonous heavy metal elements in bryophyte of Antarctica.

  5. Sr, Nd, Pb and Li isotope geochemistry and Ar-Ar dating of alkaline lavas from northern James Ross Island (Antarctic Peninsula) - implications for back-arc magma formation

    Science.gov (United States)

    Kosler, J.; Magna, T.; Mlcoch, B.; Mixa, P.; Hendriks, B. W. H.; Holub, F. V.; Nyvlt, D.

    2009-04-01

    The elemental and isotopic (Sr, Nd, Pb and Li) composition of Cenozoic back-arc alkaline basalts emplaced east of the Antarctic Peninsula in James Ross Island Volcanic Group (JRIVG) is different from the compositions of the fore-arc alkaline volcanic rocks in Southern Shetlands and nearby Bransfield Strait. The variability in elemental and isotopic composition is not consistent with the JRIVG derivation from a single mantle source but rather it suggests that the magma was mainly derived from a depleted mantle with subordinate OIB-like enriched mantle component (EM II). The isotopic data are consistent with mantle melting during extension and possible roll-back of the subducted lithosphere of the Antarctic plate in Miocene to Pliocene times, as indicated by the existing geochronological data and the new Ar-Ar age determinations. Magma contamination by Triassic - Early Tertiary clastic sediments deposited in the back-arc basin was only localized and affected Li isotopic composition in two of the samples, while most of the basalts show very little variation in delta 7Li values, as anticipated for "mantle-driven" Li isotopic composition. These variations are difficult to resolve with radiogenic isotope systematics but Li isotopes may prove sensitive in tracking complex geochemical processes acting through the oceanic crust pile, including hydrothermal leaching and seawater equilibration.

  6. Environmental contamination in Antarctic ecosystems.

    Science.gov (United States)

    Bargagli, R

    2008-08-01

    Although the remote continent of Antarctica is perceived as the symbol of the last great wilderness, the human presence in the Southern Ocean and the continent began in the early 1900s for hunting, fishing and exploration, and many invasive plant and animal species have been deliberately introduced in several sub-Antarctic islands. Over the last 50 years, the development of research and tourism have locally affected terrestrial and marine coastal ecosystems through fuel combustion (for transportation and energy production), accidental oil spills, waste incineration and sewage. Although natural "barriers" such as oceanic and atmospheric circulation protect Antarctica from lower latitude water and air masses, available data on concentrations of metals, pesticides and other persistent pollutants in air, snow, mosses, lichens and marine organisms show that most persistent contaminants in the Antarctic environment are transported from other continents in the Southern Hemisphere. At present, levels of most contaminants in Antarctic organisms are lower than those in related species from other remote regions, except for the natural accumulation of Cd and Hg in several marine organisms and especially in albatrosses and petrels. The concentrations of organic pollutants in the eggs of an opportunistic top predator such as the south polar skua are close to those that may cause adverse health effects. Population growth and industrial development in several countries of the Southern Hemisphere are changing the global pattern of persistent anthropogenic contaminants and new classes of chemicals have already been detected in the Antarctic environment. Although the Protocol on Environmental Protection to the Antarctic Treaty provides strict guidelines for the protection of the Antarctic environment and establishes obligations for all human activity in the continent and the Southern Ocean, global warming, population growth and industrial development in countries of the Southern

  7. Evaluation of soil bioremediation techniques in an aged diesel spill at the Antarctic Peninsula.

    Science.gov (United States)

    de Jesus, Hugo E; Peixoto, Raquel S; Cury, Juliano C; van Elsas, Jan D; Rosado, Alexandre S

    2015-12-01

    Many areas on the Antarctic continent already suffer from the direct and indirect influences of human activities. The main cause of contamination is petroleum hydrocarbons because this compound is used as a source of energy at the many research stations around the continent. Thus, the current study aims to evaluate treatments for bioremediation (biostimulation, bioaugmentation, and bioaugmentation + biostimulation) using soils from around the Brazilian Antarctic Station "Comandante Ferraz" (EACF), King George Island, Antarctic Peninsula. The experiment lasted for 45 days, and at the end of this period, chemical and molecular analyses were performed. Those analyses included the quantification of carbon and nitrogen, denaturing gradient gel electrophoresis (DGGE) analysis (with gradient denaturation), real-time PCR, and quantification of total hydrocarbons and polyaromatics. Molecular tests evaluated changes in the profile and quantity of the rrs genes of archaea and bacteria and also the alkB gene. The influence of the treatments tested was directly related to the type of soil used. The work confirmed that despite the extreme conditions found in Antarctic soils, the bacterial strains degraded hydrocarbons and bioremediation treatments directly influenced the microbial communities present in these soils even in short periods. Although the majority of the previous studies demonstrate that the addition of fertilizer seems to be most effective at promoting bioremediation, our results show that for some conditions, autochthonous bioaugmentation (ABA) treatment is indicated. This work highlights the importance of understanding the processes of recovery of contaminated environments in polar regions because time is crucial to the soil recovery and to choosing the appropriate treatment.

  8. Bacterial diversity of autotrophic enriched cultures from remote, glacial Antarctic, Alpine and Andean aerosol, snow and soil samples

    Directory of Open Access Journals (Sweden)

    E. González-Toril

    2009-01-01

    Full Text Available Four different communities and one culture of autotrophic microbial assemblages were obtained by incubation of samples collected from high elevation snow in the Alps (Mt. Blanc area and the Andes (Nevado Illimani summit, Bolivia, from Antarctic aerosol (French station Dumont d'Urville and a maritime Antarctic soil (King George Island, South Shetlands, Uruguay Station Artigas, in a minimal mineral (oligotrophic media. Molecular analysis of more than 200 16S rRNA gene sequences showed that all cultured cells belong to the Bacteria domain. Phylogenetic comparison with the currently available rDNA database allowed sequences belonging to Proteobacteria Alpha-, Beta- and Gamma-proteobacteria, Actinobacteria and Bacteroidetes phyla to be identified. The Andes snow culture was the richest in bacterial diversity (eight microorganisms identified and the marine Antarctic soil the poorest (only one. Snow samples from Col du Midi (Alps and the Andes shared the highest number of identified microorganisms (Agrobacterium, Limnobacter, Aquiflexus and two uncultured Alphaproteobacteria clones. These two sampling sites also shared four sequences with the Antarctic aerosol sample (Limnobacter, Pseudonocardia and an uncultured Alphaproteobacteriaclone. The only microorganism identified in the Antarctica soil (Brevundimonas sp. was also detected in the Antarctic aerosol. Most of the identified microorganisms had been detected previously in cold environments, marine sediments soils and rocks. Air current dispersal is the best model to explain the presence of very specific microorganisms, like those identified in this work, in environments very distant and very different from each other.

  9. KING GEORGE ISLAND SPATIAL DATA MODEL

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Distribution,interoperability,interactivity,component are four main features of distributed GIS.Based on the principle of hypermap,hypermedia and distributed database,the paper comes up with a kind of distributed spatial data model which is in accordance with those features of distributed GIS.The model takes catalog service as the outline of spatial information globalization,and defines data structure of hypermap node in different level.Based on the model,it is feasible to manage and process distributed spatial information,and integrate multi_source,heterogeneous spatial data into a framework.Traditionally,to retrieve and access spatial data via Internet is only by theme or map name.With the concept of the model,it is possible to retrieve,load,and link spatial data by vector_based graphics on the Internet.

  10. George's cosmic treasure hunt

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2009-01-01

    George and Annie explore the galaxy in this cosmic adventure from Stephen Hawking and Lucy Hawking, complete with essays from Professor Hawking about the latest in space travel. George is heartbroken when he learns that his friend Annie and her father are moving to the US. Eric has a new job working for the space program, looking for signs of life in the Universe. Eric leaves George with a gift—a book called The User’s Guide to the Universe. But Annie and Eric haven’t been gone for very long when Annie believes that she is being contacted by aliens, who have a terrible warning for her. George joins her in the US to help her with her quest—and before he knows it, he, Annie, Cosmos, and Annie’s annoying cousin Emmett have been swept up in a cosmic treasure hunt, spanning the whole galaxy and beyond. Lucy Hawking's own experiences in zero-gravity flight and interviews with astronauts at Cape Kennedy and the Johnson Space Center lend the book a sense of realism and excitement that is sure to fire up ima...

  11. Baker & Taylor's George Coe

    Science.gov (United States)

    Fialkoff, Francine

    2009-01-01

    In his 30 years as a library wholesaler, first as VP and general manager of Brodart Books, Library, and School Automation divisions and since 2000 as president of the Library & Education division of Baker & Taylor (B&T), George Coe has been instrumental in a whole host of innovations. They go way beyond the selection, processing, and delivery of…

  12. Who Framed George Lakoff?

    Science.gov (United States)

    Goldstein, Evan R.

    2008-01-01

    In this article, a noted linguist reflects on his tumultuous foray into politics. For years George P. Lakoff has been at the center of some of the biggest intellectual disagreements in linguistics (most famously with Noam Chomsky) and has helped create an important interdisciplinary field of study, cognitive linguistics, that is reshaping people's…

  13. Who Framed George Lakoff?

    Science.gov (United States)

    Goldstein, Evan R.

    2008-01-01

    In this article, a noted linguist reflects on his tumultuous foray into politics. For years George P. Lakoff has been at the center of some of the biggest intellectual disagreements in linguistics (most famously with Noam Chomsky) and has helped create an important interdisciplinary field of study, cognitive linguistics, that is reshaping people's…

  14. Photosynthesis in a sub-Antarctic shore-zone lichen

    NARCIS (Netherlands)

    Smith, V.; Gremmen, N.J.M.

    2001-01-01

    Photosynthetic responses to moisture, light, temperature, salinity and inorganic nitrogen fertilization are reported for a shore-zone lichen Turgidiusculum complicatulum (formerly Mastodia tesselata), a possible recent introduction to sub-Antarctic Marion Island. Optimum moisture contents for net ph

  15. Photosynthesis in a sub-Antarctic shore-zone lichen

    NARCIS (Netherlands)

    Smith, V.; Gremmen, N.J.M.

    2001-01-01

    Photosynthetic responses to moisture, light, temperature, salinity and inorganic nitrogen fertilization are reported for a shore-zone lichen Turgidiusculum complicatulum (formerly Mastodia tesselata), a possible recent introduction to sub-Antarctic Marion Island. Optimum moisture contents for net

  16. The Antarctic Geospatial Information Center: Three Years of Supporting Antarctic Science and Operations

    Science.gov (United States)

    Herried, B.; Morin, P. J.; Larue, M.; Porter, C.; Niebuhr, S.; Antarctic Geospatial Information Center

    2010-12-01

    Founded in 2007, the Antarctic Geospatial Information Center (AGIC) is dedicated to supporting and promoting the United States Antarctic Program (USAP) by providing geospatial information to Antarctic science, operations, and education communities. Since its inception, AGIC contributes to Antarctic science in four significant ways: 1) by direct geospatial support of research groups to advance science, 2) by authoring maps and creating applications to facilitate better logistical support, 3) by serving as a data repository and clearinghouse for Antarctic geospatial data, 4) by providing expertise, analysis, and education to researchers, support staff, and students. This poster will showcase several products, tools, and services developed by AGIC in the past three years, including a collection of 150 ground control points in the McMurdo Dry Valleys and Ross Island, highly accurate maps in the McMurdo Sound region using satellite imagery, and an archive of historical USGS aerial photography accessed through a web-based search application.

  17. Complex Geodetic Research in Ukrainian Antarctic Station "Academician Vernadsky" (Years 2002 - 2005, 2013-2014)

    Science.gov (United States)

    Tretyak, Kornyliy; Hlotov, Volodymyr; Holubinka, Yuriy; Marusazh, Khrystyna

    2016-06-01

    In this paper is given an information about complex geodetic research in Ukrainian Antarctic station "Academician Vernadsky". Research were carried by Lviv polytechnic scientists, during Antarctic expeditions in years 2002 - 2005, 2013, 2014. Main objectives of the studies were: (a) study of the islands glaciers surface volumes changes in Antarctic archipelago and Antarctic Peninsula using terestrial laser scaning and digital terrestrial stereophotogrammetry survey; (b) investigation of Penola strain tectonic fault, using the results of precise GNSS observations.

  18. High Prevalence of Gammaproteobacteria in the Sediments of Admiralty Bay and North Bransfield Basin, Northwestern Antarctic Peninsula

    Science.gov (United States)

    Franco, Diego C.; Signori, Camila N.; Duarte, Rubens T. D.; Nakayama, Cristina R.; Campos, Lúcia S.; Pellizari, Vivian H.

    2017-01-01

    Microorganisms dominate most Antarctic marine ecosystems, in terms of biomass and taxonomic diversity, and play crucial role in ecosystem functioning due to their high metabolic plasticity. Admiralty Bay is the largest bay on King George Island (South Shetland Islands, Antarctic Peninsula) and a combination of hydro-oceanographic characteristics (bathymetry, sea ice and glacier melting, seasonal entrance of water masses, turbidity, vertical fluxes) create conditions favoring organic carbon deposition on the seafloor and microbial activities. We sampled surface sediments from 15 sites across Admiralty Bay (100–502 m total depth) and the adjacent North Bransfield Basin (693–1147 m), and used the amplicon 454-sequencing of 16S rRNA gene tags to compare the bacterial composition, diversity, and microbial community structure across environmental parameters (sediment grain size, pigments and organic nutrients) between the two areas. Marine sediments had a high abundance of heterotrophic Gammaproteobacteria (92.4% and 83.8% inside and outside the bay, respectively), followed by Alphaproteobacteria (2.5 and 5.5%), Firmicutes (1.5 and 1.6%), Bacteroidetes (1.1 and 1.7%), Deltaproteobacteria (0.8 and 2.5%) and Actinobacteria (0.7 and 1.3%). Differences in alpha-diversity and bacterial community structure were found between the two areas, reflecting the physical and chemical differences in the sediments, and the organic matter input. PMID:28210255

  19. Antarctic Cosmic Ray Astronomy

    Science.gov (United States)

    Duldig, Marc

    Cosmic ray observations related to Antarctica commenced in the austral summer of 1947-48 from sub-Antarctic Heard and Macquarie Islands and from the HMAS Wyatt Earp. Muon telescope observations from Mawson station Antarctica commenced in 1955. The International Geophysical Year was the impetus for the installation of a number of neutron monitors around Antarctica observing the lowest energy cosmic rays accessible by ground based instruments. In 1971 a new observatory was built at Mawson including the only underground muon telescope system at polar latitudes in either hemisphere. In the 1980s the South Pole Air Shower Experiment (SPASE) opened the highest energy cosmic ray window over Antarctica and this was followed by the in-ice neutrino experiment AMANDA. Over more than half a century cosmic ray astronomy has been undertaken from Antarctica and its surrounding regions and these observations have been critical to our growing understanding of nearby astrophysical structures. For example the Parker spiral magnetic field of the sun was confirmed through Mawson observations of a Solar flare induced Ground Level Enahncement in 1960 long before spacecraft were able to directly observe the interplanetary magnetic field. A summary of the Antarctic instrumental developments and the scientific advances that resulted will be presented.

  20. Antarctic Genomics

    Directory of Open Access Journals (Sweden)

    Alex D. Rogers

    2006-03-01

    Full Text Available With the development of genomic science and its battery of technologies, polar biology stands on the threshold of a revolution, one that will enable the investigation of important questions of unprecedented scope and with extraordinary depth and precision. The exotic organisms of polar ecosystems are ideal candidates for genomic analysis. Through such analyses, it will be possible to learn not only the novel features that enable polar organisms to survive, and indeed thrive, in their extreme environments, but also fundamental biological principles that are common to most, if not all, organisms. This article aims to review recent developments in Antarctic genomics and to demonstrate the global context of such studies.

  1. CERN honours Georges Charpak

    CERN Multimedia

    2009-01-01

    CERN pays tribute to the work of Georges Charpak at a colloquium in honour of his 85th birthday. var flash_video_player=get_video_player_path(); insert_player_for_external('Video/Public/Movies/2009/CERN-MOVIE-2009-008/CERN-MOVIE-2009-008-0753-kbps-480x360-25-fps-audio-64-kbps-44-kHz-stereo', 'mms://mediastream.cern.ch/MediaArchive/Video/Public/Movies/2009/CERN-MOVIE-2009-008/CERN-MOVIE-2009-008-Multirate-200-to-753-kbps-480x360.wmv', 'false', 480, 360, 'https://mediastream.cern.ch/MediaArchive/Video/Public/Movies/2009/CERN-MOVIE-2009-008/CERN-MOVIE-2009-008-posterframe-480x360-at-10-percent.jpg', '1167500', true, 'Video/Public/Movies/2009/CERN-MOVIE-2009-008/CERN-MOVIE-2009-008-0600-kbps-maxH-360-25-fps-audio-128-kbps-48-kHz-stereo.mp4'); Watch the video conference of Georges Charpak.   On 9 March CERN’s Main Auditorium was the venue for a fascinating and moving celebration marking the 85th birthday of Georges Charpak, who was awarded the Nobel Prize for Physics in 1992 for his inven...

  2. George Wald memorial talk.

    Science.gov (United States)

    Hubbard, R; Wald, E

    1999-01-01

    George Wald was born in 1906 in New York City to immigrant parents. An early and voracious reader, he soon developed a wide range of interests and entered New York University as a pre-law student, the first in his family to attend college. Shortly shifting to pre-medicine, he graduated college in biology. For graduate work, he joined the laboratory of Selig Hecht, a pioneer in vision research, at Columbia University. In 1932, four months before Hitler came to power, George went to Berlin to do postdoctoral work in the laboratory of Otto Warburg and there found vitamin A in the retina. This launched his life-long explorations of the molecular basis of vision for which he received the Nobel Prize in Physiology or Medicine in 1967. During the 1960s, George became increasingly involved in anti-war and anti-nuclear activities, writing and travelling widely, including multiple trips to commemorations of the bombings of Hiroshima and Nagasaki sponsored by Japanese colleagues. He considered these activities part of being a biologist, someone concerned with life. In his final years, he turned to questions about consciousness, writing and speaking about 'Life and Mind in the Universe'.

  3. Bivalves Antárticos e Subantárticos coletados durante as Expedições Científicas Brasileiras à Antártica I a IX (1982-1991 Antarctic and Subantarctic bivalves collected during the Scientific, Brazilian Expeditions to Antarctica I-IX (1982-1991

    Directory of Open Access Journals (Sweden)

    Walter Narchi

    2002-09-01

    Full Text Available The bivalves collected in the Western Antarctic and Subantarctic waters by scientists of the Instituto Oceanográfico - USP during the Scientific Brazilian Expeditions to Antarctical-IX are characterised through its conchiliological features, illustrated and their occurrence plotted in maps. A species of bivalve collected by scuba divers of the IO-USP on the Napier Rock, Admiralty Bay, King George Island during the Expeditions XV and XVI is also considered in this work. The material identified is representative of 25 species distributed among three families and four genera of Protobranchia, three farnilies and five genera of Pteriornorpha, five families and six genera of Heterodonta, and four families and four genera of Anomalo desmata. The main scope of this work is to provide searchers dealing with macrobenthic fauna with an ease identification guide to the bivalved molluscs of the sampled region.

  4. A consistent data set of Antarctic ice sheet topography, cavity geometry, and global bathymetry

    Directory of Open Access Journals (Sweden)

    R. Timmermann

    2010-12-01

    Full Text Available Sub-ice shelf circulation and freezing/melting rates in ocean general circulation models depend critically on an accurate and consistent representation of cavity geometry. Existing global or pan-Antarctic topography data sets have turned out to contain various inconsistencies and inaccuracies. The goal of this work is to compile independent regional surveys and maps into a global data set. We use the S-2004 global 1-min bathymetry as the backbone and add an improved version of the BEDMAP topography (ALBMAP bedrock topography for an area that roughly coincides with the Antarctic continental shelf. The position of the merging line is individually chosen in different sectors in order to capture the best of both data sets. High-resolution gridded data for ice shelf topography and cavity geometry of the Amery, Fimbul, Filchner-Ronne, Larsen C and George VI Ice Shelves, and for Pine Island Glacier are carefully merged into the ambient ice and ocean topographies. Multibeam survey data for bathymetry in the former Larsen B cavity and the southeastern Bellingshausen Sea have been obtained from the data centers of Alfred Wegener Institute (AWI, British Antarctic Survey (BAS and Lamont-Doherty Earth Observatory (LDEO, gridded, and blended into the existing bathymetry map. The resulting global 1-min Refined Topography data set (RTopo-1 contains self-consistent maps for upper and lower ice surface heights, bedrock topography, and surface type (open ocean, grounded ice, floating ice, bare land surface. The data set is available in NetCDF format from the PANGAEA database at doi:10.1594/pangaea.741917.

  5. RTOPO-1: A consistent dataset for Antarctic ice shelf topography and global ocean bathymetry

    Science.gov (United States)

    Timmermann, Ralph

    2010-05-01

    Sub-ice shelf circulation and freezing/melting rates depend critically on an accurate and consistent representation of cavity geometry (i.e. ice-shelf draft and ocean bathymetry). Existing global or pan-Antarctic data sets have turned out to contain various inconsistencies and inaccuracies. The goal of this work is to compile independent regional fields into a global data set. We use the S-2004 global 1-minute bathymetry as the backbone and add an improved version of the BEDMAP topography for an area that roughly coincides with the Antarctic continental shelf. Locations of the merging line have been carefully adjusted in order to get the best out of each data set. High-resolution gridded data for the Amery, Fimbul, Filchner-Ronne, Larsen C and George VI Ice Shelves and for Pine Island Glacier have been carefully merged into the ambient ice and ocean topographies. Multibeam ship survey data for bathymetry in the former Larsen B cavity and the southeastern Bellingshausen Sea have been obtained from the data centers of Alfred Wegener Institute (AWI), British Antarctic Survey (BAS) and Lamont-Doherty Earth Observatory (LDEO), gridded, and again carefully merged into the existing bathymetry map. The resulting global 1-minute data set contains consistent masks for open ocean, grounded ice, floating ice, and bare land surface. The Ice Shelf Cavern Geometry Team: Anne Le Brocq, Tara Deen, Eugene Domack, Pierre Dutrieux, Ben Galton-Fenzi, Dorothea Graffe, Hartmut Hellmer, Angelika Humbert, Daniela Jansen, Adrian Jenkins, Astrid Lambrecht, Keith Makinson, Fred Niederjasper, Frank Nitsche, Ole Anders Nøst, Lars Henrik Smedsrud, and Walter Smith

  6. Georges Didi-Huberman

    OpenAIRE

    Hagelstein, Maud

    2012-01-01

    Georges Didi-Huberman est un philosophe et un historien de l'art français né à Saint-Étienne le 13 juin 1953. Il a été pensionnaire à l'Académie de France à Rome (Villa Médicis) et résident à la Fondation Berenson de la Villa I Tatti à Florence. Il enseigne à l’École des hautes études en sciences sociales où il est maître de conférences depuis 1990. Bibliographie Invention de l’hystérie. Charcot et l’Iconographie photographique de la Salpêtrière, sur l'École de la Salpêtrière, Macula, 1982. M...

  7. Complex Geodetic Research in Ukrainian Antarctic Station “Academician Vernadsky” (Years 2002 - 2005, 2013-2014)

    OpenAIRE

    2016-01-01

    In this paper is given an information about complex geodetic research in Ukrainian Antarctic station “Academician Vernadsky”. Research were carried by Lviv polytechnic scientists, during Antarctic expeditions in years 2002 - 2005, 2013, 2014. Main objectives of the studies were: (a) study of the islands glaciers surface volumes changes in Antarctic archipelago and Antarctic Peninsula using terestrial laser scaning and digital terrestrial stereophotogrammetry survey; (b) investigation of Penol...

  8. Complex Geodetic Research in Ukrainian Antarctic Station “Academician Vernadsky” (Years 2002 - 2005, 2013-2014

    Directory of Open Access Journals (Sweden)

    Tretyak Kornyliy

    2016-06-01

    Full Text Available In this paper is given an information about complex geodetic research in Ukrainian Antarctic station “Academician Vernadsky”. Research were carried by Lviv polytechnic scientists, during Antarctic expeditions in years 2002 - 2005, 2013, 2014. Main objectives of the studies were: (a study of the islands glaciers surface volumes changes in Antarctic archipelago and Antarctic Peninsula using terestrial laser scaning and digital terrestrial stereophotogrammetry survey; (b investigation of Penola strain tectonic fault, using the results of precise GNSS observations.

  9. Persistent organic pollutants and polycyclic aromatic hydrocarbons in penguins of the genus Pygoscelis in Admiralty Bay - An Antarctic specially managed area.

    Science.gov (United States)

    Montone, Rosalinda C; Taniguchi, Satie; Colabuono, Fernanda I; Martins, César C; Cipro, Caio Vinícius Z; Barroso, Hileia S; da Silva, Josilene; Bícego, Márcia C; Weber, Rolf R

    2016-05-15

    Persistent organic pollutants were assessed in fat samples of the Gentoo (Pygoscelis papua), Chinstrap (Pygoscelis antarcticus) and Adélie (Pygoscelis adeliae) penguins collected during the austral summers of 2005/06 and 2006/07 in Admiralty Bay, King George Island, Antarctica. The predominant organic pollutants were PCB (114 to 1115), polycyclic aromatic hydrocarbons (PAHs) (60.1 to 238.7), HCB (organic pollutants were similar among the three species of penguins. Chicks of all three species showed similar profiles of PCB congeners, with predominance of lower chlorinated compounds. The distribution of PAHs was similar in all birds, with a predominance of naphthalene and alkyl-naphthalene, which are the main constituents of arctic diesel fuel. These data contribute to the monitoring of the continued exposure to organic pollutants in the Antarctic biota. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Neogene to Quaternary stratigraphic evolution of the Antarctic Peninsula, Pacific Margin offshore of Adelaide Island: Transitions from a non-glacial, through glacially-influenced to a fully glacial state

    Science.gov (United States)

    Hernández-Molina, F. Javier; Larter, Robert D.; Maldonado, Andrés

    2017-09-01

    A detailed morphologic and seismic stratigraphic analysis of the continental margin offshore of Adelaide Island on the Pacific Margin of the Antarctic Peninsula (PMAP) is described based on the study of a regular network of reflection multichannel seismic profiles and swath bathymetry. We present an integrated study of the margin spanning the shelf to the continental rise, establish novel chronologic constraints and offer new interpretations on tectonic evolution and environmental changes affecting the PMAP. The stratigraphic stacking patterns record major shifts in the depositional style of the margin that outline three intervals in its evolution. The first non-glacial interval (Early Cretaceous to middle Miocene) encompasses a transition from an active to a passive margin (early Miocene). The second glacially-influenced interval (middle to late Miocene) is marked by pronounced aggradational sedimentary stacking and subsidence. Ice sheets advanced over the middle shelf of the margin at the end of this second interval, while the outer shelf experienced rare progradational events. The third, fully glaciated interval shows clear evidence of glacially dominated conditions on the margin. This interval divides into three minor stages. During the first stage (late Miocene to the beginning of the Pliocene), frequent grounded ice advances to the shelf break began, depositing an initial progradational unit. A major truncation surface marked the end of this stage, which coincided with extensive mass transport deposits at the base of the slope. During the second progradational glacial margin stage (early Pliocene to middle Pleistocene), stacking patterns record clearly prograding glacial sequences. The beginning of the third aggradational glacial margin stage (middle Pleistocene to present) corresponded to an important shift in global climate during the Mid-Pleistocene Transition. Morphosedimentary characteristics observed along the margin today began to develop during the

  11. Superstitions of George Bartisch.

    Science.gov (United States)

    Blanchard, Donald L

    2005-01-01

    George Bartisch was a 16th century German ophthalmologist who published the first ophthalmology textbook in the vernacular for laymen and non-university-trained practitioners. His treatments and understanding of diseases rested firmly on Greek tradition, but he also was very involved in the superstitions of the day. This essay looks at the man and his mores. Bartisch believed that much of the suffering of patients had to do with sins they had committed, and that the devil was the active force in the world inflicting this punishment. Often, he believed, witches would carry out the devil's hexes, in the form of either hot or cold witchcraft. Bartisch also felt that astrology played a major role in the outcome of surgery. Because of that he practiced only during certain astrological signs, and in the proper waxing and waning phases of the moon. He also linked many common problems to sins. For example, presbyopia was presented as due to excessive use of alcohol. Glasses were to be avoided because he felt they destroyed vision in themselves. Despite these superstitions and misconceptions, Bartisch was an honorable professional and his books give insight into the making of a good ophthalmologist.

  12. The lichen and bryophyte vegetation of Cuverville Island, Antarctica

    NARCIS (Netherlands)

    de Leeuw, C; Aptroot, A; van Zanten, B

    1998-01-01

    In the Antarctic summer of 1993 the vegetation of Cuverville Island, a small island near the west coast of the Antarctic Peninsula, was mapped and described. Eleven different plant communities of algae, lichens, bryophytes and spermatophytes have been distinguished. The 51 species Vary from endemic

  13. [History of Polish botanical and mycological researches on sheets of land of Antarctic and Sub-Antarctic in the years 1977-2009].

    Science.gov (United States)

    Köhler, Piotr; Olech, Maria

    2011-01-01

    The work includes a description of the period from the moment of setting up Polish Polar Station on King George Island (1977) to the end of International Polar Year IV in 2009. Researches on flower plants focused, among others, on plants' morphology, morphological composition of the pollen and anatomical ultra-structure of the leaves. There were also carried out biochemical and other searches for the internal mutability. Within physiological studies one concentrated on the problem of reaction to temperature stress. Biological researches focused mainly on solving taxonomic and bio-geographic problems. Finally, were published several monographs and, among others, the first in history complete description of moss' flora of the whole of Antarctic (2008). Research works over algae included also such issues as floristics, bio-geography, taxonomy and ecology (for instance, the rookery's impact on distribution of algae, or the influence of inanimate factors on dynamics of condensing the Diatoma in different water and soil-bound tanks). Up till now, within mycological investigations has been identified a variety of lichen fungi that for the most part of Antarctic are a novelty. There were scientifically described new for science genera and species of Western Antarctic. Lichenological studies were made in the field of taxonomy, geography, lichenometry, biochemistry of lichens, lichenoindication, ecophysiology and from the point of analysis of base metals' content. There were also described new for science species. Since 1991, were published the results of searches for the base metals' content and vestigial chemical elements in lichens' thallus. Ecophysiological researches concerned both micro-climatic conditions' impact on primary production and lichens' adaptation to a very cold climate. One discovered a mechanism of two-phase hydratization/dehydratization of lichens' thallus. On the ground of palaeobotanical analyzes was reconstructed a development of flora in Western

  14. Environmental assessment of proposed dredging and disposal activities at the St. George small boat harbor, reconnaissance stage: Planning aid report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Types of environmental impacts possibly resulting from dredging and disposal activities at the St. George Island small boat harbor include: 1) bottom topographic and...

  15. Q&A: George Smoot

    Science.gov (United States)

    Hodson, Richard

    2016-09-01

    George Smoot shared the 2006 Nobel Prize in Physics for the discovery of small temperature variations in the cosmic microwave background radiation, providing support for Big Bang theory. Smoot spoke to Nature about last year's big cosmological discovery, gravitational waves.

  16. George and the big bang

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2012-01-01

    George has problems. He has twin baby sisters at home who demand his parents’ attention. His beloved pig Freddy has been exiled to a farm, where he’s miserable. And worst of all, his best friend, Annie, has made a new friend whom she seems to like more than George. So George jumps at the chance to help Eric with his plans to run a big experiment in Switzerland that seeks to explore the earliest moment of the universe. But there is a conspiracy afoot, and a group of evildoers is planning to sabotage the experiment. Can George repair his friendship with Annie and piece together the clues before Eric’s experiment is destroyed forever? This engaging adventure features essays by Professor Stephen Hawking and other eminent physicists about the origins of the universe and ends with a twenty-page graphic novel that explains how the Big Bang happened—in reverse!

  17. Entrevista com Georges Bertin

    Directory of Open Access Journals (Sweden)

    Bertin, Georges

    2011-01-01

    Sociólogo, antropólogo, doutor em Ciências da Educação, Georges Bertin pesquisa as questões que envolvem o imaginário, os mitos, o simbolismo e a antropologia do esoterismo. É diretor de pesquisas em Ciências Sociais do CNAM Pays-de-la-Loire e dirige em Angers e em Mans o Ciclo de Pesquisas Antropológicas sobre o Imaginário (CRAI, o qual fundou em 1992. Presidente fundador da associação CENA em 1973, da qual é hoje presidente em exercício, também exerce, desde 2006, o cargo de diretor executivo da revista internacional de sociologia Esprit Critique. O pesquisador participou do XI Seminário Internacional da Comunicação na PUCRS, em 2011, com a palestra “Antropologia do Imaginário e Estruturas da Comunicação: abordagens cruzadas”, na qual estabelece uma convergência entre as posturas reflexivas de François Rabelais e Marshall McLuhan a respeito do papel das mídias e das rupturas do sentido da comunicação induzidas pelas estruturas sociais, e as reflexões propostas por autores modernos e pós-modernos, interessados pelas rupturas de significações imaginárias sociais, como Régis Debray, Manuel Castells, Cornélius Castoriadis e Michel Maffesoli, de forma a questionar o sentido desta Nova Era da comunicação que hoje se apresenta sob nossos olhos e em nossas vidas

  18. 45 CFR 670.29 - Designation of Antarctic Specially Protected Areas, Specially Managed Areas and Historic Sites...

    Science.gov (United States)

    2010-10-01

    ... 134Cierva Point and offshore islands, Danco Coast, Antarctic Peninsula ASPA 135North-eastern Bailey..., South Shetland Islands ASMA 5Amundsen-Scott South Pole Station, South Pole ASMA 6Larsemann Hills, East... Inexpressible Island, Terra Nova Bay, Scott Coast HSM 15Hut at Cape Royds, Ross Island HSM 16Hut at Cape Evans...

  19. Climate signals in Late Holocene sediments from Maxwell Bay and English Strait (South Shetland Islands, Antarctica)

    Science.gov (United States)

    Hass, H. Christian; Schröder, Simon; Kuhn, Gerhard

    2017-04-01

    Climate fluctuations of the past two millennia such as the Little Ice Age and the Medieval Warm Period are reported mainly from the Northern Hemisphere. Evidence from Antarctica is comparably sparse and reveals regional and temporal differences, which are particularly evident at the western and eastern sides of the Antarctic Peninsula. High-resolution coastal-marine sediment cores from the northernmost tip of the West Antarctic Peninsula reveal periods dominated by finer sediments between periods that lack the finer sediment component. In Maxwell Bay this fine sediment (grain size mode around 16 µm) has been traced back to sediment related to the occurrence of glacial meltwater. It was found in sheltered places and meltwater creeks of Potter Cove, a small tributary fjord to Maxwell Bay. In the sediment core this sediment occurs predominantly between 600 and 1250 AD (Medieval Warm Period) whereas it is only sparsely affecting the record between 1450 and 1900 AD (Little Ice Age). The temporal pattern is very similar to global-temperature reconstructions and even resembles temperature reconstructions from the Northern Hemisphere. To avoid local effects that may occur in Maxwell Bay more sediment cores were taken from bays and straits further south of King George Island during Cruise PS97 of RV "Polarstern" in 2016. A core from English Strait reveals completely different sedimentary conditions with no detectable meltwater signal (16 µm). However, the mean grain size record resembles that of the cores from Maxwell Bay. The lack of a clear-cut meltwater sediment class as it occurs further north is likely the result of a much smaller hinterland (Greenwich and Robert islands) when compared to Maxwell Bay between Nelson Island and the much bigger King George Island where glaciers and ice sheets discharge large quantities of very turbid meltwater directly into the bay. It is concluded that during the warmer climate periods a large amount of meltwater was released along the

  20. First record of massive blooming of benthic diatoms and their association with megabenthic filter feeders on the shallow seafloor of an Antarctic Fjord: Does glacier melting fuel the bloom?

    Science.gov (United States)

    Ahn, In-Young; Moon, Hye-Won; Jeon, Misa; Kang, Sung-Ho

    2016-03-01

    We report a conspicuous benthic diatom bloom on an Antarctic fjord shallow seafloor, which has not been reported elsewhere in Antarctica. A thick and massive growth of benthic diatoms was covering or being entangled with a variety of common benthic megafauna such as stalked ascidians, sponges, tubedwelling polychaetes, gastropods, bryozoans, and others. This finding is an outcome of recent investigations on benthic communities in Marian Cove, King George Island, where glacier retreat has been proceeding quickly for the past several decades. Dominance of benthic diatoms during the austral summer has been frequently reported in shallow Antarctic nearshore waters, which in turn indicates their potential as a primary food item for secondary producers living in this harsh environment. However, previous blooming records of the benthic diatoms were primarily based on data from water column samples. We are the first to report observational evidence of shallow seafloor substrates, including the massive blooming of benthic diatoms and their associations with common benthic megafauna in an Antarctic fjord.

  1. In honour of Georges Charpak

    CERN Multimedia

    More than 40 years ago, Georges Charpak invented the multi-wire proportional chamber, which revolutionized the detection of particles and which found applications in medicine. He was awarded the Nobel Prize in physics for this invention in 1992. On March 9, there will be a conference here at CERN to celebrate Georges Charpak’s 85th birthday and to pay tribute to his groundbreaking work. After an introduction by Rolf Heuer, CERN Director-General, Georges Charpak will give a short speech by videoconference. This will be followed by a talk on the invention of the multi-wire proportional chamber by Ioanis Giomataris of CEA-Saclay. You are invited to attend this special conference in the Main Auditorium, from 4.00 pm to 6.00 pm: http://indico.cern.ch/conferenceDisplay.py?confId=53188

  2. Antarctic fish in a changing world: metabolic, osmoregulatory and endocrine stress response

    Directory of Open Access Journals (Sweden)

    Pedro Miguel Guerreiro

    2015-10-01

    Full Text Available Fish around Antarctic Peninsula are exposed to the fastest climate change rate in the planet, up to ten times higher than the global average. The evolution in extreme stenothermal isolation was a strong selective pressure for the development of a highly endemic fish fauna, with likely structural and functional constraints. To which extent can coastal notothenioid fish adjust to the conditions forecasted by the models of climate change? Experiments were run in the Arctowski (PL station at Admiralty Bay, King George Island, in 2012/13. Fish, Notothenia rossii and N. coriiceps, were collected by boat at 5-25 meter deep using fishing poles and were transferred to experimental tanks in cold rooms acclimated to natural temperatures (0-2°C. Fish were exposed to rapid/ gradual changes in water temperature or/and salinity (to 6-8°C using thermostat-controlled heaters, to 20-10‰ by addition of freshwater to recirculating tanks, over a period of up to 10 days to evaluate the response of several physiological processes. The stress endocrine axis was tested by injecting known blockers/ agonists of cortisol release and receptors. Exposure to altered conditions had no effect in immediate mortality. Increased temperature reduced overall activity and behavioral response to stimuli, although it had no clear effect on mobilization of energetic substrate. Both cortisol and gene expression of metabolic-related proteins and glucocorticoid- and mineralocorticoid receptors were modified after heat shock, but that the cortisol response to handling was reduced. The rise in temperature induced a dependent decrease in plasma osmolality while increasing branchial Na+/K+-ATPase activity, thus decreasing osmoregulatory efficiency. In conclusion, Antarctic fish are reactive to environmental change, but that their ability to accommodate rapid or adaptive responses may be compromised.

  3. Wastewater contamination in Antarctic melt-water streams evidenced by virological and organic molecular markers.

    Science.gov (United States)

    Tort, L F L; Iglesias, K; Bueno, C; Lizasoain, A; Salvo, M; Cristina, J; Kandratavicius, N; Pérez, L; Figueira, R; Bícego, M C; Taniguchi, S; Venturini, N; Brugnoli, E; Colina, R; Victoria, M

    2017-12-31

    Human activities in the Antarctica including tourism and scientific research have been raised substantially in the last century with the concomitant impact on the Antarctic ecosystems through the release of wastewater mainly from different scientific stations activities. The aim of this study was to assess the wastewater contamination of surface waters and sediments of three melt-water streams (11 sites) by leaking septic tanks located in the vicinity of the Uruguayan Scientific Station in the Fildes Peninsula, King George Island, Antarctica, during summer 2015. For this purpose, we combined the analysis of fecal steroids in sediments by using gas chromatography and six enteric viruses in surface waters by quantitative and qualitative PCR. Coprostanol concentrations (from 0.03 to 3.31μgg(-1)) and fecal steroids diagnostic ratios indicated that stations C7 and C8 located in the kitchen stream presented sewage contamination. Rotavirus was the only enteric virus detected in five sites with concentration ranging from 1.2×10(5)gcL(-)(1) to 5.1×10(5)gcL(-)(1) being three of them located downstream from the leaking AINA and Kitchen septic tanks. This study shows for the first time the presence of both virological and molecular biomarkers of wastewater pollution in surface waters and sediments of three melt-water streams in the vicinity of a scientific station in the Antarctica. These results highlight the importance of the complementation of these biomarkers in two different matrices (surface waters and sediments) to assess wastewater pollution in an Antarctic environment related to anthropogenic activities in the area. Copyright © 2017. Published by Elsevier B.V.

  4. Bacterial diversity in rhizosphere soil from Antarctic vascular plants of Admiralty Bay, maritime Antarctica.

    Science.gov (United States)

    Teixeira, Lia C R S; Peixoto, Raquel S; Cury, Juliano C; Sul, Woo Jun; Pellizari, Vivian H; Tiedje, James; Rosado, Alexandre S

    2010-08-01

    The Antarctic is a pristine environment that contributes to the maintenance of the global climate equilibrium. The harsh conditions of this habitat are fundamental to selecting those organisms able to survive in such an extreme habitat and able to support the relatively simple ecosystems. The DNA of the microbial community associated with the rhizospheres of Deschampsia antarctica Desv (Poaceae) and Colobanthus quitensis (Kunth) BartI (Caryophyllaceae), the only two native vascular plants that are found in Antarctic ecosystems, was evaluated using a 16S rRNA multiplex 454 pyrosequencing approach. This analysis revealed similar patterns of bacterial diversity between the two plant species from different locations, arguing against the hypothesis that there would be differences between the rhizosphere communities of different plants. Furthermore, the phylum distribution presented a peculiar pattern, with a bacterial community structure different from those reported of many other soils. Firmicutes was the most abundant phylum in almost all the analyzed samples, and there were high levels of anaerobic representatives. Also, some phyla that are dominant in most temperate and tropical soils, such as Acidobacteria, were rarely found in the analyzed samples. Analyzing all the sample libraries together, the predominant genera found were Bifidobacterium (phylum Actinobacteria), Arcobacter (phylum Proteobacteria) and Faecalibacterium (phylum Firmicutes). To the best of our knowledge, this is the first major bacterial sequencing effort of this kind of soil, and it revealed more than expected diversity within these rhizospheres of both maritime Antarctica vascular plants in Admiralty Bay, King George Island, which is part of the South Shetlands archipelago.

  5. George and the unbreakable code

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2014-01-01

    George and his best friend Annie haven't had any space adventures for a while and they're missing the excitement. But not for long . . . Seriously strange things start happening. Banks are handing out free money; supermarkets can't charge for their produce so people are getting free food; and aircraft are refusing to fly. It looks like the world's biggest and best computers have all been hacked. George and Annie will travel further into space than ever before in order to find out who is behind it.

  6. Seasonal proliferation rates and the capacity to express genes involved in cell cycling and maintenance in response to seasonal and experimental food shortage in Laternula elliptica from King George Island.

    Science.gov (United States)

    Husmann, G; Philipp, E E R; Abele, D

    2016-07-01

    Melting of coastal glaciers at the West Antarctic Peninsula (WAP) causes shorter winter sea ice duration, intensified ice scouring, sediment erosion and surface freshening in summer, which alters coastal productivity and feeding conditions for the benthos. The soft shell clam Laternula elliptica is a fast growing and abundant filter feeder in coastal Antarctica and a key element for bentho-pelagic carbon recycling. Our aim was to assess the cellular growth and maintenance capacity of small and large clams during natural winter food shortage (seasonal sampling) and in response to experimental starvation exposure. We measured tissue specific proliferation rates, the expression of cell cycling genes, and the iron binding protein Le-ferritin in freshly collected specimens in spring (Nov 2008) and at the end of summer (March 2009). For the experimental approach, we focused on 14 cell cycling and metabolic genes using the same animal size groups. Mantle tissue of young bivalves was the only tissue showing accelerated proliferation in summer (1.7% of cells dividing per day in March) compared to 0.4% dividing cells in animals collected in November. In mantle, siphon and adductor muscle proliferation rates were higher in younger compared to older individuals. At transcript level, Le-cyclin D was upregulated in digestive gland of older animals collected in spring (Nov) compared to March indicating initiation of cell proliferation. Likewise, during experimental starvation Le-cyclin D expression increased in large clam digestive gland, whereas Le-cyclin D and the autophagic factor beclin1 decreased in digestive gland of smaller starved clams. The paper corroborates earlier findings of size and age dependent differences in the metabolic response and gene expression patterns in L. elliptica under energetic deprivation. Age structure of shallow water populations can potentially change due to differences in cellular response between young and old animals as environmental stress

  7. Pigments from UV-resistant Antarctic bacteria as photosensitizers in Dye Sensitized Solar Cells.

    Science.gov (United States)

    Órdenes-Aenishanslins, N; Anziani-Ostuni, G; Vargas-Reyes, M; Alarcón, J; Tello, A; Pérez-Donoso, J M

    2016-09-01

    Here we report the use of pigments produced by UV-resistant Antarctic bacteria as photosensitizers in Dye Sensitized Solar Cells (DSSCs). Pigments were obtained from red and yellow colored psychrotolerant bacteria isolated from soils of King George Island, Antarctica. Based on metabolic characteristics and 16s DNA sequence, pigmented bacteria were identified as Hymenobacter sp. (red) and Chryseobacterium sp. (yellow). Pigments produced by these microorganisms were extracted and classified as carotenoids based on their spectroscopic and structural characteristics, determined by UV-Vis spectrophotometry and infrared spectroscopy (FTIR), respectively. With the purpose of develop green solar cells based on bacterial pigments, the photostability and capacity of these molecules as light harvesters in DSSCs were determined. Absorbance decay assays determined that bacterial carotenoids present high photostability. In addition, solar cells based on these photosensitizers exhibit an open circuit voltage (VOC) of 435.0 [mV] and a short circuit current density (ISC) of 0.2 [mA·cm(-2)] for the red pigment, and a VOC of 548.8 [mV] and a ISC of 0.13 [mA·cm(-2)] for the yellow pigment. This work constitutes the first approximation of the use of pigments produced by non-photosynthetic bacteria as photosensitizers in DSSCs. Determined photochemical characteristics of bacterial pigments, summed to their easy obtention and low costs, validates its application as photosensitizers in next-generation biological solar cells.

  8. Microplastics in the Antarctic marine system: An emerging area of research.

    Science.gov (United States)

    Waller, Catherine L; Griffiths, Huw J; Waluda, Claire M; Thorpe, Sally E; Loaiza, Iván; Moreno, Bernabé; Pacherres, Cesar O; Hughes, Kevin A

    2017-11-15

    It was thought that the Southern Ocean was relatively free of microplastic contamination; however, recent studies and citizen science projects in the Southern Ocean have reported microplastics in deep-sea sediments and surface waters. Here we reviewed available information on microplastics (including macroplastics as a source of microplastics) in the Southern Ocean. We estimated primary microplastic concentrations from personal care products and laundry, and identified potential sources and routes of transmission into the region. Estimates showed the levels of microplastic pollution released into the region from ships and scientific research stations were likely to be negligible at the scale of the Southern Ocean, but may be significant on a local scale. This was demonstrated by the detection of the first microplastics in shallow benthic sediments close to a number of research stations on King George Island. Furthermore, our predictions of primary microplastic concentrations from local sources were five orders of magnitude lower than levels reported in published sampling surveys (assuming an even dispersal at the ocean surface). Sea surface transfer from lower latitudes may contribute, at an as yet unknown level, to Southern Ocean plastic concentrations. Acknowledging the lack of data describing microplastic origins, concentrations, distribution and impacts in the Southern Ocean, we highlight the urgent need for research, and call for routine, standardised monitoring in the Antarctic marine system. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Isolation and characterization of an Antarctic Flavobacterium strain with agarase and alginate lyase activities

    Directory of Open Access Journals (Sweden)

    Lavín Paris

    2016-09-01

    Full Text Available Several bacteria that are associated with macroalgae can use phycocolloids as a carbon source. Strain INACH002, isolated from decomposing Porphyra (Rhodophyta, in King George Island, Antarctica, was screened and characterized for the ability to produce agarase and alginate-lyase enzymatic activities. Our strain INACH002 was identified as a member of the genus Flavobacterium, closely related to Flavobacterium faecale, using 16S rRNA gene analysis. The INACH002 strain was characterized as psychrotrophic due to its optimal temperature (17ºC and maximum temperature (20°C of growth. Agarase and alginate-lyase displayed enzymatic activities within a range of 10°C to 50°C, with differences in the optimal temperature to hydrolyze agar (50°C, agarose (50°C and alginate (30°C during the first 30 min of activity. Strain Flavobacterium INACH002 is a promising Antarctic biotechnological resource; however, further research is required to illustrate the structural and functional bases of the enzymatic performance observed during the degradation of different substrates at different temperatures.

  10. Antarctic bacterial isolates that produce cold-active extracellular proteases at low temperature but are active and stable at high temperature

    Directory of Open Access Journals (Sweden)

    Cecilia Martínez-Rosales

    2011-04-01

    Full Text Available We report the isolation and identification of bacteria that produce extracellular cold-active proteases, obtained from water samples collected near the Uruguayan Antarctic Base on King George Island, South Shetlands. The bacteria belonged to the genera Pseudomonas (growth between 4 and 30 °C and Flavobacterium (growth between 4 and 18 °C. In all cases, extracellular protease production was evident when reaching the stationary phase at 18 and 4 °C but was not detected at 30 °C. The zymogram revealed the secretion of one extracellular protease per isolate, each with different relative electrophoretic mobility. The extracellular proteases produced at 4 °C showed thermal activity and stability at 30 °C. Both activity and stability at a temperature higher that 10 °C have no physiological meaning because the isolates do not experience such temperatures in the Antarctic environment; however, the possible ecological value of cold-active and -stable extracellular proteases is discussed.

  11. George Sandi "Consuelo" / Ott Ojamaa

    Index Scriptorium Estoniae

    Ojamaa, Ott, 1926-1996

    2010-01-01

    Arvustus: Sand, George, pseud. Consuelo. 1-2. : romaan / [prantsuse keelest tõlkinud Leili-Maria Kask järelsõna ja märkused: Ott Ojamaa]. Tallinn : Eesti Riiklik Kirjastus, 1961. (Suuri sõnameistreid). 2. tr. ilmus 1988. a.

  12. George Hampton (1920-2004)

    CERN Multimedia

    2004-01-01

    George Hampton, who died recently, was CERN's Director of Administration in the 1960s and an important member of the team who managed the growth of CERN as it left the construction period and became a world-class physics laboratory. George came to CERN in the 1963, when the laboratory was just starting its main research activities after the intense period of construction for the Proton Synchrotron (PS). At that time the laboratory was passing through a major budget crisis, and the new Director-general, Viki Weisskopf, was faced with a completely new structure set up by his predecessor John Adams, with 12 divisions for running the laboratory reporting directly to him, and with four Directors. With the renewal of the position of Director of Administration in 1963, Weisskopf selected George Hampton from candidates from the Member States. He came from the UK Atomic Energy Authority, but had worked earlier as a delegate to the international Civil Aviation Organization. George's position at the start was to hel...

  13. Postmodernist Prose and George Orwell

    Science.gov (United States)

    Roney, Stephen K.

    2002-01-01

    George Orwell, in the essay "Politics and the English Language," criticized pretentious doublespeak and technobabble that numb the consciousness and hide political power plays. Judith Butler defends the "nuanced" prose of her fellow postmodernists as necessary to convey the complexity of their thoughts. Stephen Roney contrasts the two and…

  14. Georges Canguilhem, 1904-1995

    OpenAIRE

    Robbins, Derek

    2006-01-01

    An extract from The Cambridge Dictionary of Sociology which outlines the work and influence of Georges Canguilhem. Canguilhem made important contributions to epistemology and his discussions of health and disease relate as pertinently to the societal as to the individual condition.

  15. George Sandi "Consuelo" / Ott Ojamaa

    Index Scriptorium Estoniae

    Ojamaa, Ott, 1926-1996

    2010-01-01

    Arvustus: Sand, George, pseud. Consuelo. 1-2. : romaan / [prantsuse keelest tõlkinud Leili-Maria Kask järelsõna ja märkused: Ott Ojamaa]. Tallinn : Eesti Riiklik Kirjastus, 1961. (Suuri sõnameistreid). 2. tr. ilmus 1988. a.

  16. Mathilde Prager und Georg Brandes

    DEFF Research Database (Denmark)

    Bang, Karin

    2004-01-01

    I størstedelen af deres 30-årige forbindelse havde Mathilde Prager og Georg Brandes et fint samarbejde, men forholdet mellem dem var meget ulige, og det pinte Mathilde Prager, at hun i mange år ikke måtte stå som oversætter af de arbejder, der blev offentliggjort i de tysktalende lande. Brandes...

  17. A Post-Modern George.

    Science.gov (United States)

    Hunter, Robert S.

    2000-01-01

    Presents an art project in which students create postmodern portraits of George Washington in the style of Andy Warhol's pop-art portraits. Each portrait incorporates a fact and six symbols associated with Washington. Describes the project in detail and lists the materials and project objectives. (CMK)

  18. Parasites of the Antarctic toothfish (Dissostichus mawsoni Norman, 1937 (Perciformes, Nototheniidae in the Pacific sector of the Antarctic

    Directory of Open Access Journals (Sweden)

    Ilya I. Gordeev

    2016-06-01

    Full Text Available The Antarctic toothfish (Dissostichus mawsoni Norman, 1937 is one of the main target species of commercial fisheries in the Antarctic. It is an endemic and is found along the shelf of Antarctica, as well as on the slopes of seamounts, underwater elevations and islands in the sub-Antarctic. It feeds on a variety of fish and cephalopods and can be an intermediate/paratenic host of some helminthes, whose final hosts are whales, seals, large rays and sharks. This article presents new data on toothfish infection in the Pacific sector of the Antarctic. Specimens were examined during commercial longline fishing in the Ross Sea and the Amundsen Sea in January–February 2013. Fourteen species of parasites were found using standard parasitological methods and genetic analysis.

  19. Adjustment of pigment composition in Desmarestia (Desmarestiaceae species along a sub-Antarctic to Antarctic latitudinal gradient

    Directory of Open Access Journals (Sweden)

    Andrés Mansilla

    2016-08-01

    Full Text Available Photosynthesis at high latitudes demands efficient strategies of light utilization to maintain algal fitness and performance. The fitness, and physiological adaptation, of a plant or algae species depends in part on the abundance and efficiency of the pigments it can produce to utilize the light resource from its environment. We quantified pigment composition and concentration in six species of the brown macroalgal genus Desmarestia, collected from sub-Antarctic sites (Strait of Magellan, Beagle Channel–Cape Horn Province and sites on the Antarctic Peninsula and adjacent islands. Sub-Antarctic Desmarestia species exhibited lower concentrations of chlorophyll a, chlorophyll c and fucoxanthin than endemic Antarctic species. Antarctic samples of D. menziesii and D. antarctica collected along a decreasing latitudinal gradient showed spatial and interspecific differences in light-harvesting pigment composition. Our results suggest distinct physiological adjustments in Desmarestia species in response to heterogeneous abiotic environmental conditions. The marine sub-Antarctic and Antarctic ecosystems are characterized by harsh environments (e.g., extreme irradiance, photoperiod, temperature, salinity to which the physiology of macroalgal species must adapt.

  20. Polyphasic characterization of 10 selected ecologically relevant filamentous cyanobacterial strains from the South Shetland Islands, Maritime Antarctica.

    Science.gov (United States)

    Jancusova, Miroslava; Kovacik, Lubomir; Pereira, Antonio Batista; Dusinsky, Roman; Wilmotte, Annick

    2016-07-01

    The evolutionary relationships of 10 Antarctic cyanobacterial strains of the order Oscillatoriales isolated from King George and Deception Islands, South Shetland Islands were studied by a polyphasic approach (morphology, 16S rRNA and internal transcribed spacer sequences). The studied taxa are characteristic of coastal Antarctic biotopes, where they form distinct populations and ecologically delimited communities. They were isolated from terrestrial habitats: microbial mats in seepages; crusts on soil, rocks, bones and mosses; mud, sometimes close to bird colonies; and from guano. Based on major phenotypic features, the strains were divided into four distinct morphotypes: Leptolyngbya borchgrevinkii (A), Leptolyngbya frigida (B), Microcoleus sp. (C) and Wilmottia murrayi (D). This morphological identification was in agreement with the phylogenetic relationships. For the first time, the 16S rRNA gene sequence of a strain corresponding to the L. borchgrevinkii morphotype was determined. Morphotype B is most related to sequences assigned to L. frigida isolated from microbial mats of coastal lakes in East Antarctica. Morphotype C belongs to a cluster including strains with morphotypes corresponding to Microcoleus attenuatus, Microcoleus favosus and Microcoleus sp., which are from Antarctica and other continents. Morphotype D is grouped with sequences assigned to W. murrayi mostly isolated from Antarctica.

  1. Georg filmis ja elus / Marvi Taggo

    Index Scriptorium Estoniae

    Taggo, Marvi

    2007-01-01

    Peeter Simmi mängufilm Georg Otsast "Georg" (stsenaristid Mati Põldre ja Aleksandr Borodjanski). Kolleegid ja sõbrad-tuttavad Elonna Spriit, Jaak Jõekallas, Eino Baskin võrdlevad elus tuntud Georg, Asta ja Karl Otsa, Garibaldi Kivisalu filmis näitlejate Marko Matvere, Anastasija Makejeva, Renars Kaupersi, Tõnu Kargi loodud tegelaskujudega

  2. The impacts of local human activities on the Antarctic environment

    Science.gov (United States)

    Tin, T.; Fleming, Z. L.; Hughes, K. A.; Ainley, D. G.; Convey, P.; Moreno, C. A.; Pfeiffer, S.; Scott, J.; Snape, I.

    2009-04-01

    An overview of a recently published review of the scientific literature from the past decade on the impacts of human activities on the Antarctic environment is presented. An assessment of the cumulative effects of scientists and accompanying base construction, tourists and fishery activities in Antarctica is timely given a decade since the Protocol on Environmental Protection to the Antarctic Treaty came into force in 1998 and the increasing attention given to and human presence in Antarctica during this 2007-2009 IPY. A range of impacts has been identified at a variety of spatial and temporal scales. Chemical contamination and sewage disposal on the continent have been found to be long-lived, with contemporary sewage management practices at many coastal stations insufficient to prevent local contamination. Human activities, particularly construction and transport, have affected Antarctic flora and fauna and a small number of non-indigenous plant and animal species has become established on some of the Antarctic Peninsula and sub Antarctic islands. There is little indication of recovery of overexploited fish stocks, and ramifications of fishing activity on bycatch species and the ecosystem could also be far-reaching. The Antarctic Treaty System and its instruments, in particular the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the Environmental Protocol, provide a framework within which management of human activities take place. In order to ensure comprehensive protection of the Antarctic environment, including its intrinsic, wilderness and scientific values in the face of the continuing expansion of human activities in Antarctica, a more effective implementation of a wide range of measures is essential. These include effective environmental impact assessments, long-term monitoring, mitigation measures for non-indigenous species, ecosystem-based management of living resources, and increased regulation of National Antarctic

  3. George and the blue moon

    CERN Document Server

    Hawking, Lucy

    2016-01-01

    George and his best friend, Annie have been selected as junior astronauts - part of a programme that trains up young people for a trip to Mars in the future. This is everything they've ever wanted - they get to be a part of up-to-the minute space discoveries and meet a bunch of new friends who are as fascinated by the universe as they are. But when they arrive at space camp, George and Annie quickly learn that strange things are happening - on Earth as well as up in our skies. Mysterious space missions are happening in secret, and the astronaut training they're undertaking gets scarier and scarier . . . The fifth adventure in this series by Lucy and Stephen Hawking - also containing up-to-the-minute scientific facts and information by the world's leading scientists.

  4. Nutritional advice from George Orwell

    DEFF Research Database (Denmark)

    Larsen, Morten Hedegaard

    2015-01-01

    Despite of a general consensus and recognition of the importance of the “social gradient” on nutritional standards and ultimately people's health, (WHO 2013, Marmot & Wilkinson 1999, Marmot et.al 1991, Budrys 2003, Ross & Wu 1995), the body of literature identifying and describing the actual...... is historical descriptions (in the form of excerpts) from George Orwell's 1937 book “The Road to Wigan Pier” on the living conditions of the British working classes. These descriptions will be aligned with results from contemporary research into nutritional behaviour. Strong similarities are identified between...... George Orwell's historical descriptions of the working-class's unhealthy diet and the findings from contemporary research into nutritional behaviour of people with a low socio-economic status. The article, on this basis, argues that certain social mechanisms influencing nutritional choices are readily...

  5. In Search of George Mallory

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    George Mallory(1886-1924),a graduate ofCambridge Universi-ty,was a middleschool teacher, andAndrew lrvine(1902-1924)was a third-year student ofCambridge University, whenboth of them climbedQomolangmo for the thirdtime as members of a UKmountaineering team in 1924.Sadly, they disappeared whileclimbing the highest peak inthe world from the Tibetanslope,leaving unsolved to thisday the question of whetherthey reached the summit.

  6. Georg Cantor: habitar lo eterno

    Directory of Open Access Journals (Sweden)

    Juan Manuel Rodríguez Penagos

    Full Text Available Este artículo pone en discusión la relación entre estructura psíquica y la producción lógica del delirio; para ello, parte de un matemático alemán llamado Georg Cantor. Aquí se discute la relación entre la producción matemática y la instalación de su psicosis.

  7. Carbon and Nitrogen Use Efficiency in Microbial Communities in Antarctic Soils

    Science.gov (United States)

    Prommer, Judith; Spohn, Marie; Klaus, Karoline; Kusch, Stephanie; Wanek, Wolfgang; Dercon, Gerd; Richter, Andreas

    2016-04-01

    Terrestrial ecosystems in the Antarctic experience harsh environmental conditions including very low temperatures and a low carbon input leading to poorly developed ecosystems with low diversity and a low soil organic matter content, which may be vulnerable to perturbations in a future climate. Microbial transformation and decomposition of soil organic matter under the extreme climatic conditions in the Antarctic has received little attention so far. Specifically, little is known about microbial process rates and how they might be affected by climate warming. We here report on C and N transformation rates and their corresponding microbial use efficiencies in two soil horizons of two sites on King George Island, the maritime Antarctica. We used novel isotope techniques to estimate microbial carbon use efficiency (CUE; based on incorporation of 18O from water into DNA) and nitrogen use efficiency (NUE; based on a 15N isotope pool dilution assays). The investigated two contrasting sites at marine terraces on basaltic rocks that were characterized by a stable surface. While both sites were similar in exposition, distance from sea and elevation, they differed in their vegetation cover and several biogeochemical parameters, such as soil pH and soil organic carbon and nitrogen content. Surprisingly, we found low soil C:N ratios at both sites and for both horizons, i.e. below 12 in the organic crust and below 8 in the first mineral horizon. This indicates a low carbon availability relative to nitrogen and would thus imply a high microbial CUE. However, our results showed also a low CUE at both sites and in both horizons (CUE of 24% and 9% in the organic crust and mineral layer, respectively). In contrast, NUE was very high in organic layers (98%), pointing towards a strong nitrogen limitation, while in the mineral horizons, NUE was lower (between 84% and 72%), as expected for soil horizons with a C:N ratio below 8. Thus, the NUE pattern followed stoichiometric theory (i

  8. Redox conditions and trace metal cycling in coastal sediments from the maritime Antarctic

    Science.gov (United States)

    Monien, Patrick; Lettmann, Karsten Alexander; Monien, Donata; Asendorf, Sanja; Wölfl, Anne-Cathrin; Lim, Chai Heng; Thal, Janis; Schnetger, Bernhard; Brumsack, Hans-Jürgen

    2014-09-01

    Redox-sensitive trace metals (Mn, Fe, U, Mo, Re), nutrients and terminal metabolic products (NO3-, NH4+, PO43-, total alkalinity) were investigated for the first time in pore waters of Antarctic coastal sediments. The results of this study reveal a high spatial variability in redox conditions in surface sediments from Potter Cove, King George Island, western Antarctic Peninsula. Particularly in the shallower areas of the bay the significant correlation between sulphate depletion and total alkalinity, the inorganic product of terminal metabolism, indicates sulphate reduction to be the major pathway of organic matter mineralisation. In contrast, dissimilatory metal oxide reduction seems to be prevailing in the newly ice-free areas and the deeper troughs, where concentrations of dissolved iron of up to 700 μM were found. We suggest a combination of several factors to be responsible for the domination of metal oxide reduction over sulphate reduction in these areas. These include the increased accumulation of fine-grained material with high amounts of reducible metal oxides, a reduced availability of metabolisable organic matter and an enhanced physical and biological disturbance by bottom water currents, ice scouring and burrowing organisms. Based on modelled iron fluxes we calculate the contribution of the Antarctic shelf to the pool of potentially bioavailable iron (Feb) to be 6.9 × 103 to 790 × 103 t yr-1. Consequently, these shelf sediments would provide an Feb flux of 0.35-39.5 mg m-2 yr-1 (median: 3.8 mg m-2 yr-1) to the Southern Ocean. This contribution is in the same order of magnitude as the flux provided by icebergs and significantly higher than the input by aeolian dust. For this reason suboxic shelf sediments form a key source of iron for the high nutrient-low chlorophyll (HNLC) areas of the Southern Ocean. This source may become even more important in the future due to rising temperatures at the WAP accompanied by enhanced glacier retreat and the

  9. Georges et le big bang

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2011-01-01

    Georges et Annie, sa meilleure amie, sont sur le point d'assister à l'une des plus importantes expériences scientifiques de tous les temps : explorer les premiers instants de l'Univers, le Big Bang ! Grâce à Cosmos, leur super ordinateur, et au Grand Collisionneur de hadrons créé par Éric, le père d'Annie, ils vont enfin pouvoir répondre à cette question essentielle : pourquoi existons nous ? Mais Georges et Annie découvrent qu'un complot diabolique se trame. Pire, c'est toute la recherche scientifique qui est en péril ! Entraîné dans d'incroyables aventures, Georges ira jusqu'aux confins de la galaxie pour sauver ses amis...Une plongée passionnante au coeur du Big Bang. Les toutes dernières théories de Stephen Hawking et des plus grands scientifiques actuels.

  10. Georges Charpak street sign unveiled

    CERN Multimedia

    Paola Catapano

    2011-01-01

    While it might not be the only French street named in honour of the late Georges Charpak, who passed away in September 2010 at the age of 87, the street chosen by the mayor of Saint-Genis-Pouilly is certainly the only one located directly opposite the CERN "campus". The road overlooks buildings on the CERN Meyrin site, where Georges Charpak spent most of his career as a physicist, conducting the research that won him the Nobel Prize in Physics in 1992.   From left to right: Sigurd Lettow, Dominique Charpak and the mayor of Saint-Genis-Pouilly. The unveiling took place on 17 October and was organised by the mayor of Saint-Genis-Pouilly. George Charpak’s wife, Dominique, and Sigurd Lettow, CERN Director of Administration and General Infrastructure, attended what was an intimate and touching ceremony. The mayor’s speech at the event praised Georges’ commitment to scientific education. The highlight of the event, however, was a witty and humorous ...

  11. Benthic Trophic Interactions in an Antarctic Shallow Water Ecosystem Affected by Recent Glacier Retreat.

    Science.gov (United States)

    Pasotti, Francesca; Saravia, Leonardo Ariel; De Troch, Marleen; Tarantelli, Maria Soledad; Sahade, Ricardo; Vanreusel, Ann

    2015-01-01

    The western Antarctic Peninsula is experiencing strong environmental changes as a consequence of ongoing regional warming. Glaciers in the area are retreating rapidly and increased sediment-laden meltwater runoff threatens the benthic biodiversity at shallow depths. We identified three sites with a distinct glacier-retreat related history and different levels of glacial influence in the inner part of Potter Cove (King George Island, South Shetland Islands), a fjord-like embayment impacted since the 1950s by a tidewater glacier retreat. We compared the soft sediment meio- and macrofauna isotopic niche widths (δ13C and δ15N stable isotope analysis) at the three sites to investigate possible glacier retreat-related influences on benthic trophic interactions. The isotopic niches were locally shaped by the different degrees of glacier retreat-related disturbance within the Cove. Wider isotopic niche widths were found at the site that has become ice-free most recently, and narrower niches at the older ice-free sites. At an intermediate state of glacier retreat-related disturbance (e.g. via ice-growler scouring) species with different strategies could settle. The site at the earliest stage of post-retreat development was characterized by an assemblage with lower trophic redundancy. Generally, the isotopic niche widths increased with increasing size spectra of organisms within the community, excepting the youngest assemblage, where the pioneer colonizer meiofauna size class displayed the highest isotopic niche width. Meiofauna at all sites generally occupied positions in the isotopic space that suggested a detrital-pool food source and/or the presence of predatory taxa. In general ice scour and glacial impact appeared to play a two-fold role within the Cove: i) either stimulating trophic diversity by allowing continuous re-colonization of meiofaunal species or, ii) over time driving the benthic assemblages into a more compact trophic structure with increased

  12. The potential macroalgae habitat shifts in an Antarctic Peninsula fjord due to climate change

    Science.gov (United States)

    Jerosch, Kerstin; Scharf, Frauke; Deregibus, Dolores; Campana, Gabriela; Zacher, Katharina; Hass, Christian; Quartino, Liliana; Abele, Doris

    2016-04-01

    The Western Antarctic Peninsula (WAP) region is one of the most rapidly warming on earth since the last 50 yr. The WAP glaciers currently contribute one third of the melt water to global sea level rise. Climate warming is supposed to induce important changes in polar ecosystems, from microbial communities to apex predators' levels. Macroalgae are the main biomass producers in Potter Cove located at King George Island, the biggest island of the South Shetland Arc. They are sensitive to climate change factors such as suspended particulate matter (SPM). Macroalgae presence and absence data were used to test SDMs suitability and, simultaneously, to assess the environmental response of macroalgae as well as to model four scenarios of distribution shifts by varying SPM conditions due to climate change. Species distribution models (SDM) predict species occurrence based on statistical relationships with environmental conditions. The R-package 'biomod2' which includes 10 different SDM techniques and 10 different evaluation methods was used in this study. According to the averaged evaluation scores of Relative Operating Characteristics (ROC) and True scale statistics (TSS) by models, those methods based on a multitude of decision trees such as Random Forest and Classification Tree Analysis, reached the highest predictive power followed by generalized boosted models (GBM) and maximum-entropy approaches (Maxent). The final ensemble model (EM) used 135 of 200 calculated models (TSS > 0.7) and identified hard substrate and SPM as the most influencing parameters followed by distance to glacier, total organic carbon (TOC), bathymetry and slope. The modeled current status of macroalgae distribution results in only 18.25% of earlier estimated areas populated by macroalgae in Potter Cove. The climate change scenarios show an invasive reaction of the macroalgae in case of less SPM and a retreat of the macroalgae in case of higher assumed SPM values.

  13. Benthic Trophic Interactions in an Antarctic Shallow Water Ecosystem Affected by Recent Glacier Retreat.

    Directory of Open Access Journals (Sweden)

    Francesca Pasotti

    Full Text Available The western Antarctic Peninsula is experiencing strong environmental changes as a consequence of ongoing regional warming. Glaciers in the area are retreating rapidly and increased sediment-laden meltwater runoff threatens the benthic biodiversity at shallow depths. We identified three sites with a distinct glacier-retreat related history and different levels of glacial influence in the inner part of Potter Cove (King George Island, South Shetland Islands, a fjord-like embayment impacted since the 1950s by a tidewater glacier retreat. We compared the soft sediment meio- and macrofauna isotopic niche widths (δ13C and δ15N stable isotope analysis at the three sites to investigate possible glacier retreat-related influences on benthic trophic interactions. The isotopic niches were locally shaped by the different degrees of glacier retreat-related disturbance within the Cove. Wider isotopic niche widths were found at the site that has become ice-free most recently, and narrower niches at the older ice-free sites. At an intermediate state of glacier retreat-related disturbance (e.g. via ice-growler scouring species with different strategies could settle. The site at the earliest stage of post-retreat development was characterized by an assemblage with lower trophic redundancy. Generally, the isotopic niche widths increased with increasing size spectra of organisms within the community, excepting the youngest assemblage, where the pioneer colonizer meiofauna size class displayed the highest isotopic niche width. Meiofauna at all sites generally occupied positions in the isotopic space that suggested a detrital-pool food source and/or the presence of predatory taxa. In general ice scour and glacial impact appeared to play a two-fold role within the Cove: i either stimulating trophic diversity by allowing continuous re-colonization of meiofaunal species or, ii over time driving the benthic assemblages into a more compact trophic structure with

  14. Leeches (Hirudinida: Piscicolidae)--parasites of Antarctic fish from Channichthyidae family.

    Science.gov (United States)

    Bielecki, Aleksander; Rokicka, Magdalena; Ropelewska, Ewa; Dziekońska-Rynko, Janina

    2008-01-01

    There has hitherto been very few research projects focusing on ectoparasites of Antarctic fishes. The presently reported study provides data on the prevalence and the intensity of leeches (Hirudinida: Piscicolidae) infecting fishes. The materials were collected in December-February 1986/87 off the Elephant Island, South Georgia, Joinville Island, and South Shetlands. The following leech taxa were recorded in the Antarctic fishes of the family Channichthyidae: Trulliobdella capitis (Brinkmann, 1947); Cryobdella antarctica Epstein, 1970; Nototheniobdella sawyeri Utevsky, 1997; and Cryobdella sp. The above findings constitute new geographic records from off Elephant and Joinville Island and South Georgia.

  15. Particularidades genéticas de glaciares de roca en la isla James Ross, Península Antártica Genetic peculiarities of the rock glaciers in the James Ross Island, Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    J.A. Strelin

    2007-12-01

    morphostructural and morphogenetic environmental conditions. The most important morphostructural condition is the presence of basaltic mesas that provide the raw material for the debris cover of the rock glaciers. The morphogenetic conditions involve small polithermal glaciers that due to little summer temperature variations, subtle reduction in the precipitations, and/or changes in the intensity and direction of the main regional winds, become debris covered. An important factor related to the debris cover, particularly to the nearly homogenous debris distribution over the whole glacier surface, is related to the so called oscillation of the regelation front. Under stable climatic conditions, after the debris cover reaches a thickness similar to that of the active layer, the ice core ablation diminishes markedly, remaining only the own plastic deformation of the ice core. The debris cover of the rock glaciers studied in James Ross Island reaches around 0.3 m in thickness close to the valley head, increasing the thickness to more than 1 m in the fronts. The ice cores rarely exceed 80 m in thickness, and close to the central part of the rock glacier the horizontal flow velocity amounts about 0.15 m per year. The formation of these rock glaciers, and some ice cored moraines, goes back to the climatic change that finished the Little Ice Age. The severe climatic warming verified in the last 15 years in the northern sector of Antarctic Peninsula accelerated the collapse of some of these landforms.

  16. La biophilosophie de Georges Canguilhem

    OpenAIRE

    Charles T. Wolfe

    2017-01-01

    The eminent French biologist and historian of biology, François Jacob, once notoriously declared «On n’interroge plus la vie dans les laboratoires»: laboratory research no longer inquires into the notion of “Life”. Certain influential French philosophers of science of the mid‐century such as Georges Canguilhem would disagree, or at least seek to resist some of Jacob’s diagnosis. Not by imposing a different kind of research program in laboratories, but by an...

  17. Georges Condominas (1921-2011)

    OpenAIRE

    Jean Baffie

    2012-01-01

    Georges Condominas s’est toujours considéré comme un ethnologue plutôt que comme un anthropologue. Au cours de son séminaire ou dans ses conférences, il manquait rarement de rappeler qu’ethnographie, ethnologie et anthropologie constituaient pour lui trois moments bien précis. Si l’ethnographie était le travail de terrain, essentiellement descriptif, la restitution des faits observés, l’ethnologie était la réflexion à partir des matériaux recueillis par l’ethnographe et les premières synthèse...

  18. George Washington: A Grounded Leader

    Science.gov (United States)

    2011-04-08

    Westmoreland County, Virginia.· In this area, there were strict laws against breaking.the Sabbath, having contempt for the Bible, disrespecting its...estates of .his children go to Mary Ball so as ’to remain ill. their mother~s guardianship as long as they were minors. ·Therefore, George’s...same book to· her grandchildren, who re~alled it gratefully. We know this from her grandson Robert Lewis and his ,son-in- law E. C. ) . . . . M’Guire

  19. EVA: Evryscopes for the Arctic and Antarctic

    Science.gov (United States)

    Richichi, A.; Law, N.; Tasuya, O.; Fors, O.; Dennihy, E.; Carlberg, R.; Tuthill, P.; Ashley, M.; Soonthornthum, B.

    2017-06-01

    We are planning to build Evryscopes for the Arctic and Antarctic (EVA), which will enable the first ultra-wide-field, high-cadence sky survey to be conducted from both Poles. The system is based on the successful Evryscope concept, already installed and operating since 2015 at Cerro Tololo in Chile with the following characteristics: robotic operation, 8,000 square degrees simultaneous sky coverage, 2-minute cadence, milli-mag level photometric accuracy, pipelined data processing for real-time analysis and full data storage for off-line analysis. The initial location proposed for EVA is the PEARL station on Ellesmere island; later also an antarctic location shall be selected. The science goals enabled by this unique combination of almost full-sky coverage and high temporal cadence are numerous, and include among others ground-breaking forays in the fields of exoplanets, stellar variability, asteroseismology, supernovae and other transient events. The EVA polar locations will enable uninterrupted observations lasting in principle over weeks and months. EVA will be fully robotic. We discuss the EVA science drivers and expected results, and present the logistics and the outline of the project which is expected to have first light in the winter of 2018. The cost envelope can be kept very competitive thanks to R&D already employed for the CTIO Evryscope, to our experience with both Arctic and Antarctic locations, and to the use of off-the-shelf components.

  20. The megazoobenthos of the Scotia Arc islands

    Directory of Open Access Journals (Sweden)

    Ana Ramos

    1999-12-01

    Full Text Available Megabenthic epifauna composition and distribution from the Scotia Arc islands based on data collected during the Antarctic summer of 1986-87 is presented. Samples were taken from bottom trawl catches at 345 stations (29 at Shag Rocks, 104 at South Georgia, 8 at the South Sandwich Islands, 93 at the South Orkney Islands, 46 at Elephant Island, and 65 at the South Shetland Islands, from 26 to 643 m depth. Among the most striking features of the faunistic composition of the area, pointed out by multivariate analysis, are the singularity of Shag Rocks, closer to the Magellan region, and of the volcanic South Sandwich Islands, as well as the similarity of South Georgia and the South Orkney Islands and that of the islands nearest to the Antarctic continent, especially Elephant Island and the South Shetlands Islands. This similarity is due to the higher frequency and abundance of the most characteristic taxa in the Antarctic epibenthos, such as sessile suspension feeders (sponges, calcareous bryozoans, pennatulids, crinoids, and motile fauna with a wide variety of trophic strategies (asteroids, holothurians, pycnogonids, large isopods and gammarids. These data confirm the fact that the long-lived suspension-feeder communities, demosponges and hexactinellids, characteristic of the Antarctic epibenthos stretch to the eastern shelf of South Georgia without reaching the north-west of this island, the South Sandwich Islands, and Shag Rocks. Some of the zones with rich communities of sessile filter-feeders, long-lived sponges or reef formations of calcareous bryozoans or serpulids should be proposed as Specially Protected Areas.

  1. Health aspects of Antarctic tourism.

    Science.gov (United States)

    Prociv, P

    1998-12-01

    Increasing numbers of seaborne tourists are visiting Antarctica, with most coming from the United States (3503 in 1996-97), Germany (777), and Australia (680; cf. 356 in 1994-95 and 410 in 1995-96). The impression among travel medicine clinicians is that, each year, more prospective travelers seek advice about the health demands of this type of adventure, mostly relating to fitness for travel, exposure to extreme cold, hazards in ice and snow, and other potential health risks. This is a recent phenomenon. While a regular shipping service had been established between the Falklands and the subantarctic islands of South Georgia and the South Shetlands by 1924, the first documented tourists accompanied an Argentine expedition to the South Orkneys in 1933.1 Commercial airline flights over these islands and the Antarctic Peninsula began in 1956, from Chile, and recreational cruises to the Peninsula began in 1958. Tourist numbers subsequently grew slowly, for what was clearly an exclusive and very expensive undertaking, with few ships available for these hazardous voyages. From 1957 to 1993, 37,000 tourists visited by sea, most seeing only the Peninsula.2 The dramatic recent growth in numbers is a consequence of the collapse of the Soviet Union. The small fleet of ice-strengthened research vessels and working icebreakers, which was made redundant by withdrawal of central government support from isolated communities and military activities along the northern coast of Siberia (and from Antarctic research bases), now accounts for the bulk of charter-cruise tourism to Antarctica, at competitive prices. According to the International Association of Antarctica Tour Operators,3 7322 people traveled to Antarctica on commercially organized voyages in the 1996-97 season, and a record 10,000 shipborne visitors were expected for the 1997-98 season (November-March), traveling mainly from South America to the Peninsula on 15 ice-reinforced vessels, each carrying between 36 and 180

  2. The ARM West Antarctic Radiation Experiment (AWARE)

    Science.gov (United States)

    Lubin, Dan; Bromwich, David; Vogelmann, Andrew; Verlinde, Johannes; Russell, Lynn

    2016-04-01

    West Antarctica is one of the most rapidly warming regions on Earth, and its changing climate in both atmosphere and ocean is linked to loss of Antarctic ice mass and global sea level rise. The specific mechanisms for West Antarctic Ice Sheet (WAIS) warming are not fully understood, but are hypothesized to involve linkage between moisture from Southern Ocean storm tracks and the surface energy balance over the WAIS, and related teleconnections with subtropical and tropical meteorology. This present lack of understanding has motivated a climate science and cloud physics campaign jointly supported by the US National Science Foundation (NSF) and Department of Energy (DOE), called the Atmospheric Radiation Measurement Program (ARM) West Antarctic Radiation Experiment (AWARE). The DOE's second ARM Mobile Facility (AMF2) was deployed to McMurdo Station on Ross Island in November 2015 and will operate through December 2016. The AMF2 includes (1) cloud research radars, both scanning and zenith, operating in the Ka- and X-bands, (2) high spectral resolution and polarized micropulse lidars, and (3) a suite of shortwave and longwave broadband and spectral radiometers. A second suite of instruments is deployed at the WAIS Divide Ice Camp on the West Antarctic plateau during December 2015 and January 2016. The WAIS instrument suite provides (1) measurement of all surface energy balance components, (2) a polarized micropulse lidar and shortwave spectroradiometer, (3) microwave total water column measurement, and (4) four times daily rawinsonde launches which are the first from West Antarctica since 1967. There is a direct linkage between the WAIS instrument suite and the AMF2 at McMurdo, in that air masses originating in Southern Ocean storm tracks that are driven up over the WAIS often subsequently descend over the Ross Ice Shelf and arrive at Ross Island. Preliminary data are already illustrating the prevalence of mixed-phase clouds and their role in the surface energy balance

  3. Modelling the Antarctic Ice Sheet

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Holm, A.

    2015-01-01

    The Antarctic ice sheet is a major player in the Earth’s climate system and is by far the largest depository of fresh water on the planet. Ice stored in the Antarctic ice sheet (AIS) contains enough water to raise sea level by about 58 m, and ice loss from Antarctica contributed significantly...... Science) Antarctic Ice Sheet (DAIS) model (Shaffer 2014) is forced by reconstructed time series of Antarctic temperature, global sea level and ocean subsurface temperature over the last two glacial cycles. In this talk a modelling work of the Antarctic ice sheet over most of the Cenozoic era using...

  4. The ARM West Antarctic Radiation Experiment (AWARE)

    Science.gov (United States)

    Scott, R. C.; Lubin, D.; Bromwich, D. H.; Vogelmann, A. M.; Verlinde, J.; Russell, L. M.

    2016-12-01

    West Antarctica is one of the most rapidly warming regions on Earth, and its changing climate in both atmosphere and ocean is linked to loss of Antarctic ice mass and global sea level rise. The specific mechanisms for West Antarctic Ice Sheet (WAIS) warming are not fully understood, but are hypothesized to involve linkage between moisture from Southern Ocean storm tracks and the surface energy balance over the WAIS, and related teleconnections with subtropical and tropical meteorology. This present lack of understanding has motivated a climate science and cloud physics campaign jointly supported by the US National Science Foundation (NSF) and Department of Energy (DOE), called the Atmospheric Radiation Measurement Program (ARM) West Antarctic Radiation Experiment (AWARE). The DOE's second ARM Mobile Facility (AMF2) was deployed to McMurdo Station on Ross Island in November 2015 and will operate through December 2016. The AMF2 includes (1) cloud research radars, both scanning and zenith, operating in the Ka- and X-bands, (2) high spectral resolution and polarized micropulse lidars, and (3) a suite of shortwave and longwave broadband and spectral radiometers. A second suite of instruments is deployed at the WAIS Divide Ice Camp on the West Antarctic plateau during December 2015 and January 2016. The WAIS instrument suite provides (1) measurement of all surface energy balance components, (2) a polarized micropulse lidar and shortwave spectroradiometer, (3) microwave total water column measurement, and (4) four times daily rawinsonde launches which are the first from West Antarctica since 1967. There is a direct linkage between the WAIS instrument suite and the AMF2 at McMurdo, in that air masses originating in Southern Ocean storm tracks that are driven up over the WAIS often subsequently descend over the Ross Ice Shelf and arrive at Ross Island. Preliminary data are already illustrating (1) the prevalence of single- versus mixed-phase clouds and their role in the

  5. Georges et le code secret

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2015-01-01

    À Foxbridge, Georges et Annie s'ennuient, ils rêvent de repartir dans l'espace pour de nouvelles aventures intergalactiques. Pourtant, sur la terre ferme, il se passe des choses étranges... L'argent s'envole des distributeurs de billets, les avions refusent de décoller et les caisses enregistreuses des supermarchés ne fonctionnent plus... Quel chaos ! Il semblerait qu'un bug planétaire ait déréglé tous les systèmes informatiques. S'ils veulent découvrir ce qui se cache derrière tout ça, les deux amis devront voyager plus loin que jamais dans l'espace...

  6. [Georges Canguilhem the medical historian].

    Science.gov (United States)

    Grond-Ginsbach, C

    1996-01-01

    The work of the French philosopher Georges Canguilhem is inroduced here. Medical historiography is not the ultimate aim of Canguilhems work, but rather a tool for the analysis ef epistemological questions. These questions are to be investigated, as well as the art of medical history that Canguilhem consideres to be helpful for such investigations. French "epistemology", a direction of philosophy of science to which Cangilhem belongs, is discussed first. Canguilhem's epistemology does not aim at a rational reconstruction of decontextualized scientific results, but at an historical reconstruction of science. It analyses the functioning of scientific concepts in relation of their historical context. The main themes of Canguilhems work (biological normality, scientific ideology and history of physiology) are summarized in a second part of this study. Finally we investigate the importance of Canguilhem for modern research in history of medicine.

  7. Temperature adaptation of soil bacterial communities along an Antarctic climate gradient: predicting responses to climate warming

    DEFF Research Database (Denmark)

    Rinnan, Riikka; Rousk, Johannes; Yergeau, Etienne;

    2009-01-01

    the leucine incorporation technique, in order to predict future changes in temperature sensitivity of resident soil bacterial communities. Soil samples were collected along a climate gradient consisting of locations on the Antarctic Peninsula (Anchorage Island, 67 °34'S, 68 °08'W), Signy Island (60 °43'S, 45......Soil microorganisms, the central drivers of terrestrial Antarctic ecosystems, are being confronted with increasing temperatures as parts of the continent experience considerable warming. Here we determined short-term temperature dependencies of Antarctic soil bacterial community growth rates, using...... °38'W) and the Falkland Islands (51 °76'S 59 °03'W). At each location, experimental plots were subjected to warming by open top chambers (OTCs) and paired with control plots on vegetated and fell-field habitats. The bacterial communities were adapted to the mean annual temperature of their environment...

  8. Antarctic sponges (Porifera, Demospongiae of the South Shetland Islands and vicinity: part I. Spirophorida, Astrophorida, Hadromerida, Halichondrida and Haplosclerida Esponjas Antárticas (Porifera, Demospongiae das Ilhas Shetland do Sul e áreas próximas: parte I. Spirophorida, Astrophorida, Hadromerida, Halichondrida e Haplosclerida

    Directory of Open Access Journals (Sweden)

    Maurício Campos

    2007-01-01

    Full Text Available The aim of this work is to redescribe 11 species of sponges collected through the Brazilian Antarctic Program (PROANTAR, at the South Shetland Islands and vicinity. New information is provided on the Antarctic sponge fauna, in regard to species richness and the geographical and bathymetric distributions of identified species. The following species were identified and are here illustrated and fully described: Cinachyra antarctica (Carter, 1872, Cinachyra barbata Sollas, 1886, Craniella leptoderma (Sollas, 1886, Tethyopsis longispinum (Lendenfeld, 1907, Polymastia invaginata Kirkpatrick, 1907, Homaxinella balfourensis (Ridley & Dendy, 1886, Suberites montiniger Carter, 1880, Halichondria (Eumastia attenuata (Topsent, 1915, Haliclona (Soestella chilensis (Thiele, 1905, Hemigellius bidens (Topsent, 1901 and Calyx arcuarius (Topsent, 1913. Two new records are given for the Antarctic continent: Halichondria (Eumastia attenuata (Topsent, 1915 and Haliclona (Soestella chilensis (Thiele, 1905. Tethyopsis longispinum (Lendenfeld, 1907, Suberites montiniger Carter, 1880 and Hemigellius bidens (Topsent, 1901 represent the first records for this sector of the continent. Bathymetric data are extended for T. longispinum and H. attenuata.O objetivo deste trabalho é redescrever 11 espécies de esponjas coletadas através do Programa Antártico Brasileiro (PROANTAR, nas Is. Shetland do Sul e áreas próximas. Nnovas informações são fornecidas acerca do conhecimento da fauna de poríferos da Antártica, tanto para a riqueza específica como para os dados referentes às distribuições geográfica e batimétrica das espécies identificadas. As seguintes espécies foram identificadas e são aqui ilustradas e amplamente descritas: Cinachyra antarctica (Carter, 1872, Cinachyra barbata Sollas, 1886, Craniella leptoderma (Sollas, 1886, Tethyopsis longispinum (Lendenfeld, 1907, Polymastia invaginata Kirkpatrick, 1907, Homaxinella balfourensis (Ridley & Dendy, 1886

  9. Assessment of trace metals in droppings of Adélie penguins (Pygoscelis adeliae) from different locations of the Antarctic Peninsula area

    Institute of Scientific and Technical Information of China (English)

    Jos E Celis; Winfred Espejo; Ricardo Barra; Daniel Gonzalez-Acua; Francisca Gonzalez; Solange Jara

    2015-01-01

    In recent decades, polar regions of the planet have witnessed an increase in human presence. Antarctica is considered one of the most pristine regions of the world, but it could be affected by pollution owing to anthropogenic activities, particularly in the Antarctic Peninsula. Human presence can increase the levels of some trace metals in Antarctic environments, an issue that needs to be evaluated. To acquire data of trace metal contamination in the Antarctic Peninsula region, concentrations (dry weight) of Cd, Pb, As, Cu, Hg and Zn in fresh excrement of Adélie penguins were determined by atomic absorption spectrophotometry. During the 2012/2013 austral summer, samples were collected from four important nesting sites on the Antarctic Peninsula:Arctowski Base, Kopaitic Island (both sites in the northern Antarctic Peninsula), Yalour Island and Avian Island (both sites in the southern Antarctic Peninsula). Data showed that Adélie penguin excreta had significantly higher levels (mg·kg-1) of As, Cd, Hg, Pb and Cu at Arctowski Base and Kopaitic Island, both sites that have major anthropogenic activities that probably contributed to increased metal levels. The levels of trace metals in Adélie penguins were similar to those reported in excreta of Antarctic species in previous studies, and lower than those in excreta of other Antarctic animals. Data suggest that metals ingested by these penguin species that feed in the sea, end up in terrestrial ecosystems.

  10. Antarctic science preserve polluted

    Science.gov (United States)

    Simarski, Lynn Teo

    Geophysicists are alarmed at the electromagnetic pollution of a research site in the Antarctic specifically set aside to study the ionosphere and magnetosphere. A private New Zealand communications company called Telecom recently constructed a satellite ground station within the boundaries of this Site of Special Scientific Interest (SSSI), protected since the mid-1970s. The placement of a commercial facility within this site sets an ominous precedent not only for the sanctity of other SSSIs, but also for Specially Protected Areas—preserves not even open to scientific research, such as certain penguin rookeries.The roughly rectangular, one-by-one-half mile site, located at Arrival Heights not far from McMurdo Station, is one of a number of areas protected under the Antarctic treaty for designated scientific activities. Many sites are set aside for geological or biological research, but this is the only one specifically for physical science.

  11. Viruses in Antarctic lakes

    Science.gov (United States)

    Kepner, R. L. Jr; Wharton, R. A. Jr; Suttle, C. A.; Wharton RA, J. r. (Principal Investigator)

    1998-01-01

    Water samples collected from four perennially ice-covered Antarctic lakes during the austral summer of 1996-1997 contained high densities of extracellular viruses. Many of these viruses were found to be morphologically similar to double-stranded DNA viruses that are known to infect algae and protozoa. These constitute the first observations of viruses in perennially ice-covered polar lakes. The abundance of planktonic viruses and data suggesting substantial production potential (relative to bacteria] secondary and photosynthetic primary production) indicate that viral lysis may be a major factor in the regulation of microbial populations in these extreme environments. Furthermore, we suggest that Antarctic lakes may be a reservoir of previously undescribed viruses that possess novel biological and biochemical characteristics.

  12. Biological Interactions and Simulated Climate Change Modulates the Ecophysiological Performance of Colobanthus quitensis in the Antarctic Ecosystem

    Science.gov (United States)

    Torres-Díaz, Cristian; Gallardo-Cerda, Jorge; Lavin, Paris; Oses, Rómulo; Carrasco-Urra, Fernando; Atala, Cristian; Acuña-Rodríguez, Ian S.; Convey, Peter; Molina-Montenegro, Marco A.

    2016-01-01

    Most climate and environmental change models predict significant increases in temperature and precipitation by the end of the 21st Century, for which the current functional output of certain symbioses may also be altered. In this context we address the following questions: 1) How the expected changes in abiotic factors (temperature, and water) differentially affect the ecophysiological performance of the plant Colobanthus quitensis? and 2) Will this environmental change indirectly affect C. quitensis photochemical performance and biomass accumulation by modifying its association with fungal endophytes? Plants of C. quitensis from King George Island in the South Shetland archipelago (62°09′ S), and Lagotellerie Island in the Antarctic Peninsula (65°53′ S) were put under simulated abiotic conditions in growth chambers following predictive models of global climate change (GCC). The indirect effect of GCC on the interaction between C. quitensis and fungal endophytes was assessed in a field experiment carried out in the Antarctica, in which we eliminated endophytes under contemporary conditions and applied experimental watering to simulate increased precipitation input. We measured four proxies of plant performance. First, we found that warming (+W) significantly increased plant performance, however its effect tended to be less than watering (+W) and combined warming and watering (+T°+W). Second, the presence of fungal endophytes improved plant performance, and its effect was significantly decreased under experimental watering. Our results indicate that both biotic and abiotic factors affect ecophysiological performance, and the directions of these influences will change with climate change. Our findings provide valuable information that will help to predict future population spread and evolution through using ecological niche models under different climatic scenarios. PMID:27776181

  13. Development of generative structures of polar Caryophyllaceae plants: the Arctic Cerastium alpinum and Silene involucrata, and the Antarctic Colobanthus quitensis

    Directory of Open Access Journals (Sweden)

    Kellmann-Sopyła Wioleta

    2017-03-01

    Full Text Available The embryology of three polar flowering plants of the family Caryophyllaceae was studied using the methods and techniques of the light, normal and fluorescence microscopes, and the electron microscopes, scanning and transmission. The analyzed species were Colobanthus quitensis of West Antarctic (King George Island, South Shetlands Islands as well as Cerastium alpinum and Silene involucrata of the Arctic (Spitsbergen, Svalbard. In all evaluated species, flowering responses were adapted to the short Arctic and Australian summer, and adaptations to autogamy and anemogamy were also observed. The microsporangia of the analyzed plants produced small numbers of microspore mother cells that were differentiated into a dozen or dozens of trinucleate pollen grains. The majority of mature pollen grains remained inside microsporangia and germinated in the thecae. The monosporous Polygonum type (the most common type in angiosperms of embryo sac development was observed in the studied species. The egg apparatus had an egg cell and two synergids with typical polarization. A well-developed filiform apparatus was differentiated in the micropylar end of the synergids. In mature diaspores of the analyzed plants of the family Caryophyllaceae, a large and peripherally located embryo was, in most part, adjacent to perisperm cells filled with reserve substances, whereas the radicle was surrounded by micropylar endosperm composed of a single layer of cells with thick, intensely stained cytoplasm, organelles and reserve substances. The testae of the analyzed plants were characterized by species-specific primary and secondary sculpture, and they contained large amounts of osmophilic material with varied density. Seeds of C. quitensis, C. alpinum and S. involucrata are very small, light and compact shaped.

  14. George Robert Tilton (1923-2010)

    Science.gov (United States)

    Mattinson, James; Hopson, Clifford

    2011-05-01

    George Robert Tilton, professor emeritus of geochemistry at the University of California, Santa Barbara, passed away 12 October 2010 at age 87 in Eugene, Oreg. George was among those exceptionally versatile scientists whose research and teaching effectively bridged two main disciplines: chemistry and geology. He was recognized internationally as a leader in lead isotope geochemistry and uranium-lead (U-Pb) geochronology, fields that he helped pioneer and revolutionize. George combined analytical chemistry and mass spectrometry to attack a wide range of geological problems, particularly those concerning the age, origin, and evolution of the Earth, Moon, and solar system.

  15. George Combe and common sense.

    Science.gov (United States)

    Dyde, Sean

    2015-06-01

    This article examines the history of two fields of enquiry in late eighteenth- and early nineteenth-century Scotland: the rise and fall of the common sense school of philosophy and phrenology as presented in the works of George Combe. Although many previous historians have construed these histories as separate, indeed sometimes incommensurate, I propose that their paths were intertwined to a greater extent than has previously been given credit. The philosophy of common sense was a response to problems raised by Enlightenment thinkers, particularly David Hume, and spurred a theory of the mind and its mode of study. In order to succeed, or even to be considered a rival of these established understandings, phrenologists adapted their arguments for the sake of engaging in philosophical dispute. I argue that this debate contributed to the relative success of these groups: phrenology as a well-known historical subject, common sense now largely forgotten. Moreover, this history seeks to question the place of phrenology within the sciences of mind in nineteenth-century Britain.

  16. GEORG CANTOR’UN SONSUZLARI

    OpenAIRE

    Güney, Zekeriya; KORKMAZ, Nebiye

    2014-01-01

     Özet Georg Cantor, kümeler kuramı ve matematiksel biçimciliğin öncüsüdür. Cantor’un özellikle sonsuzluklarla ilgili çalışmaları matematikte devrim niteliğindedir ve başta topoloji olmak üzere matematiğin çeşitli alanlarında önemli gelişmelere yol açmıştır. Cantor Kuramı’nın pür matematiksel karakteri, matematiğe ve matematik eğitimine yeni bir bakış açısı getirmiş ve matematiğin asıl eğitimsel öneminin, bir zihin jimnastiği olmasından geldiği daha iyi anlaşılır olmuştur. Matematiğin, herhang...

  17. La biophilosophie de Georges Canguilhem

    Directory of Open Access Journals (Sweden)

    Charles T. Wolfe

    2017-06-01

    Full Text Available The eminent French biologist and historian of biology, François Jacob, once notoriously declared «On n’interroge plus la vie dans les laboratoires»: laboratory research no longer inquires into the notion of “Life”. Certain influential French philosophers of science of the mid‐century such as Georges Canguilhem would disagree, or at least seek to resist some of Jacob’s diagnosis. Not by imposing a different kind of research program in laboratories, but by an unusual combination of historical and philosophical inquiry into the foundations of the life sciences (particularly medicine, physiology and the cluster of activities that were termed “biology” in the early 1800s. Canguilhem speaks of «defending vitalist biology» and declares that Life cannot be grasped by logic (or at least, «la vie déconcerte la logique». Is this history and philosophy of biology? Is it vitalism? It definitely is a different project from current philosophy of biology. One short‐lived term for it was “biophilosophy”. In this paper I explore the content of this term as it relates to the above questions.

  18. Georges Charpak: 1924-2010

    CERN Multimedia

    2010-01-01

    All of CERN was deeply saddened to learn the news that our friend and colleague, Georges Charpak, passed away on 29 September 2010.   There are few people who can honestly be said to have changed the world, but Charpak was one of them. Born in Dabrovika, Poland on 8 March 1924, Charpak fled the Nazi regime under a false identity and moved to France where he joined the resistance. Arrested and deported to Dachau, he returned to France after the war and took French nationality in 1946. A student of Frédéric Joliot-Curie at the Collège de France, he joined CERN in 1959, just five years after the Organization’s foundation, and he certainly left his mark. From the start, Charpak applied himself to the development of new particle detector techniques. His outstanding and pioneering efforts revolutionised particle physics, taking the field into the electronic age. It is fair to say that without the developments pioneered by him, particularly the invention of t...

  19. Analyzing Street Art to Present the Heritage of George Town, Malaysia

    Directory of Open Access Journals (Sweden)

    Seyedehelham Sadatiseyedmahalleh

    2015-08-01

    Full Text Available Street art comprises all kinds of art developed in public locations. This form of art has spread to all heritage streets in George Town, the capital of Penang Island, which is also a known UNESCO World Heritage Site. However, instead of its heritage, food, and interesting past life and structure, the rapid multiplication of street art in George Town has created a new and unusual art that attracts tourists. Street art has spread to small roads and heritage streets in the city. This art increases the awareness of spectators by introducing them to the rich history of these streets and inducing a lively concept in the inner city of George Town. Accordingly, the impact of iron rod sculptures and murals, which comprises approximately 90% of street art in George Town, were determined to explore and identify the effects of this street art on this world heritage site. The findings were obtained from 263 out of 306 questionnaires accomplished by tourists in George Town. The results confirm that tourists prefer murals over iron rod sculptures. Iron rod sculptures are designed to tell the history of the street, whereas murals are designed to create aesthetic value. The findings indicated that similar to iron rod sculptures, more control should be exercised on the subjects of murals.

  20. Soil micromorphology, geochemistry and microbiology at two sites on James Ross Island, Maritime Antarctica

    Science.gov (United States)

    Meier, Lars A.; Krauze, Patryk; Prater, Isabel; Scholten, Thomas; Wagner, Dirk; Kühn, Peter; Mueller, Carsten W.

    2017-04-01

    Referring to the fundamental question in ecosystem research, how biotic and abiotic processes interact, only a few studies exist for polar regions that integrate microbiological and soil scientific studies . Soils comprise the complex structure and environment that fosters water storage and nutrient cycling determined by its unique chemical, physical and biological properties with respect to the specific climate and parent material. In the extreme environment of Antarctica, soil biological processes are primarily controlled by microbial communities (Bacteria, Archaea and Fungi), and thus microbiota may also determine soils chemical and physical properties in a landscape lacking higher plants at an average air temperature below 0°C. James Ross Island, Maritime Antarctica, offers a pristine laboratory and an exceptional opportunity to study pedogenesis without the influence of vascular plants and burrowing animals. We analysed micromorphological features, chemical and microbiological measures at two sites on James Ross Island (Brandy Bay and St. Martha Cove) with similar substrates (mostly fine-grained calcareous sandstones and siltstones of the Alpha Member of the Santa Martha Formation with varying amounts of conglomerates and mudstones) at similar topographic positions (small plateaus at similar elevation (80m a.s.l.)). The sites represent luv- and leeward conditions with respect to the main southwesterly winds. The climate on James Ross Island is to be described as semi-arid polar-continental, which is in clear contrast to the Southern Shetlands (e.g. King George Island) north of the Antarctic Peninsula. We will present first results of soil physical (bulk density, soil moisture and grains size distribution), pedochemical (SOC, total N and S, pH, CECeff, and pedogenic oxides) micromorphological and microbial analyses (Microbial DNA content, microbial abundances).

  1. Antarctic, Sub-Antarctic and cold temperate echinoid database

    Directory of Open Access Journals (Sweden)

    Benjamin Pierrat

    2012-06-01

    Full Text Available This database includes spatial data of Antarctic, Sub-Antarctic and cold temperate echinoid distribution (Echinodermata: Echinoidea collected during many oceanographic campaigns led in the Southern Hemisphere from 1872 to 2010. The dataset lists occurrence data of echinoid distribution south of 35°S latitude, together with information on taxonomy (from species to genus level, sampling sources (cruise ID, sampling dates, ship names and sampling sites (geographic coordinates and depth. Echinoid occurrence data were compiled from the Antarctic Echinoid Database (David et al., 2005a, which integrates records from oceanographic cruises led in the Southern Ocean until 2003. This database has been upgraded to take into account data from oceanographic cruises led after 2003. The dataset now reaches a total of 6160 occurrence data that have been checked for systematics reliability and consistency. It constitutes today the most complete database on Antarctic and Sub-Antarctic echinoids.

  2. George Orwell, Grunts and Freshman Composition.

    Science.gov (United States)

    Stine, Peter

    1983-01-01

    Uses the Vietnamese War as a metaphor for student and instructor approaches to language in composition classes. Explores George Orwell's "Politics and the English Language" in its relationship to the rhetoric surrounding United States intervention. (MM)

  3. Student trainee report of George K. Hetzel

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The summer experiences on Malheur National Wildlife Refuge of first year student trainee George Kyle Hetzel are summarized in this report. These experiences varied...

  4. George W. Bushi "intellektuaalne armuromaan" / Urmas Kiil

    Index Scriptorium Estoniae

    Kiil, Urmas

    2005-01-01

    Paljude poliitikute arvates kinnitab USA presidendi George Bushi vaimustus Natan Sharanski raamatust "The Case of Democracy: The Power of Freedom to Overcome Tyranny and Terror " fakti, et midagi pole tema poliitikas muutunud ka teisel ametiajal

  5. Georges Pereci ammendamatu kirjandus / Janar Ala

    Index Scriptorium Estoniae

    Ala, Janar, 1979-

    2009-01-01

    Arvustus: Perec, Georges. Mõelda/liigitada ja teisi tekste / koostanud, [toimetanud ja järelsõna:] Marek Tamm ; prantsuse keelest tõlkinud Anti Saar, Marek Tamm, Marike Tammet. Tallinn : Varrak, 2008

  6. EAARL Topography George Washington Birthplace National Monument

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model or DEM) of George Washington Birthplace National Monument was produced from remotely-sensed,...

  7. George W. Bushi "intellektuaalne armuromaan" / Urmas Kiil

    Index Scriptorium Estoniae

    Kiil, Urmas

    2005-01-01

    Paljude poliitikute arvates kinnitab USA presidendi George Bushi vaimustus Natan Sharanski raamatust "The Case of Democracy: The Power of Freedom to Overcome Tyranny and Terror " fakti, et midagi pole tema poliitikas muutunud ka teisel ametiajal

  8. Johann Georg Eisen / Indrek Jürjo

    Index Scriptorium Estoniae

    Jürjo, Indrek, 1956-2009

    1999-01-01

    Rets. rmt.: Johann Georg Eisen (1717-1779). Ausgewählte Schriften. Deutsche Volksaufklärung und Leibeigenschaft im Russischen Reich. Hrsg. von Roger Bartlett und Erich Donnert. Marburg : IHerder-Institut, 1998

  9. EAARL Topography George Washington Birthplace National Monument

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model or DEM) of George Washington Birthplace National Monument was produced from remotely-sensed,...

  10. Georges Pereci ammendamatu kirjandus / Janar Ala

    Index Scriptorium Estoniae

    Ala, Janar, 1979-

    2009-01-01

    Arvustus: Perec, Georges. Mõelda/liigitada ja teisi tekste / koostanud, [toimetanud ja järelsõna:] Marek Tamm ; prantsuse keelest tõlkinud Anti Saar, Marek Tamm, Marike Tammet. Tallinn : Varrak, 2008

  11. Severe dystrophy in DiGeorge syndrome

    Institute of Scientific and Technical Information of China (English)

    Barnabás Rózsai; (A)kos Kiss; Gy(o)rgyi Csábi; Márta Czakó; Tamás Decsi

    2009-01-01

    We present the case history of a 3-year-old girl who was examined because of severe dystrophy. In the background, cow's milk allergy was found, but her body weight was unchanged after eliminating milk from her diet. Other types of malabsorption were excluded. Based on nasal regurgitation and facial dysmorphisms, the possibility of DiGeorge syndrome was suspected and was confirmed by fluorescence in situ hybridization. The authors suggest a new feature associated with DiGeorge syndrome.

  12. George Bataille - Historien om øjet

    OpenAIRE

    Faaborg, Ida Selvejer; Sloan, Patrick Alexander Raaby; Hansen, Cecilie Bjørn Roland; Strange, Gustav Valdemar; Barington, Oliver

    2015-01-01

    This project contains a literary analysis of the fictional text The Story of the Eye by the French philosopher and writer Georges Bataille, first issued in 1928 under the pseudonym Lord Auch. Through a broad selection of literary and linguistic theories, we analyze different aspects of the text including its narrative structure and dynamics, literary style and use of imagery figures and metaphors. With the use of Georges Bataille’s nonfictional philosophical theories, predominantly from his b...

  13. George's secret key to the universe

    CERN Document Server

    Hawking, Lucy; Galfard, Christophe; Parsons, Gary

    2007-01-01

    In their bestselling book for young readers, noted physicist Stephen Hawking and his daughter, Lucy, provide a grand and funny adventure that explains fascinating information about our universe, including Dr. Hawking's latest ideas about black holes. It's the story of George, who's taken through the vastness of space by a scientist, his daughter, and their super-computer named Cosmos. George's Secret Key to the Universe was a New York Times bestseller and a selection of Al's Book Club on the Today show.

  14. Heterolobosean amoebae from Arctic and Antarctic extremes: 18 novel strains of Allovahlkampfia, Vahlkampfia and Naegleria.

    Science.gov (United States)

    Tyml, Tomáš; Skulinová, Kateřina; Kavan, Jan; Ditrich, Oleg; Kostka, Martin; Dyková, Iva

    2016-10-01

    The diversity of heterolobosean amoebae, important members of soil, marine and freshwater microeukaryote communities in the temperate zones, is greatly under-explored in high latitudes. To address this imbalance, we studied the diversity of this group of free-living amoebae in the Arctic and the Antarctic using culture dependent methods. Eighteen strain representatives of three heterolobosean genera, Allovahlkampfia Walochnik et Mulec, 2009 (1 strain), Vahlkampfia Chatton et Lalung-Bonnaier, 1912 (2) and Naegleria Alexeieff, 1912 (15) were isolated from 179 samples of wet soil and fresh water with sediments collected in 6 localities. The Allovahkampfia strain is the first representative of the genus from the Antarctic; 14 strains (7 from the Arctic, 7 from the Antarctic) of the highly represented genus Naegleria complete the 'polar' cluster of five Naegleria species previously known from the Arctic and Sub-Antarctic regions, whereas one strain enriches the 'dobsoni' cluster of Naegleria strains of diverse origin. Present isolations of Naegleria polarisDe Jonckheere, 2006 from Svalbard, in the Arctic and Vega Island, in the Antarctic and N. neopolarisDe Jonckheere, 2006 from Svalbard and Greenland in the Arctic, and James Ross Island, the Antarctic demonstrate their bipolar distribution, which in free-living amoebae has so far only been known for Vermistella Morand et Anderson, 2007.

  15. Consistent Richness-Biomass Relationship across Environmental Gradients in a Marine Macroalgal-Dominated Subtidal Community on the Western Antarctic Peninsula

    Science.gov (United States)

    Valdivia, Nelson; Díaz, María José; Garrido, Ignacio; Gómez, Iván

    2015-01-01

    Biodiversity loss has spurred the biodiversity-ecosystem functioning research over a range of ecosystems. In Antarctica, however, the relationship of taxonomic and functional diversity with ecosystem properties (e.g., community biomass) has received less attention, despite the presence of sharp and dynamic environmental stress gradients that might modulate these properties. Here, we investigated whether the richness-biomass relationship in macrobenthic subtidal communities is still apparent after accounting for environmental stress gradients in Fildes Bay, King George Island, Antarctica. Measurements of biomass of mobile and sessile macrobenthic taxa were conducted in the austral summer 2013/4 across two environmental stress gradients: distance from nearest glaciers and subtidal depth (from 5 to 30 m). In general, community biomass increased with distance from glaciers and water depth. However, generalised additive models showed that distance from glaciers and depth accounted for negligible proportions of variation in the number of functional groups (i.e., functional richness) and community biomass when compared to taxonomic richness. Functional richness and community biomass were positive and saturating functions of taxonomic richness. Large endemic, canopy-forming brown algae of the order Desmarestiales dominated the community biomass across both gradients. Accordingly, differences in the composition of taxa accounted for a significant and large proportion (51%) of variation in community biomass in comparison with functional richness (10%). Our results suggest that the environmental factors here analysed may be less important than biodiversity in shaping mesoscale (several km) biomass patterns in this Antarctic system. We suggest that further manipulative, hypothesis-driven research should address the role of biodiversity and species’ functional traits in the responses of Antarctic subtidal communities to environmental variation. PMID:26381149

  16. Consistent Richness-Biomass Relationship across Environmental Gradients in a Marine Macroalgal-Dominated Subtidal Community on the Western Antarctic Peninsula.

    Science.gov (United States)

    Valdivia, Nelson; Díaz, María José; Garrido, Ignacio; Gómez, Iván

    2015-01-01

    Biodiversity loss has spurred the biodiversity-ecosystem functioning research over a range of ecosystems. In Antarctica, however, the relationship of taxonomic and functional diversity with ecosystem properties (e.g., community biomass) has received less attention, despite the presence of sharp and dynamic environmental stress gradients that might modulate these properties. Here, we investigated whether the richness-biomass relationship in macrobenthic subtidal communities is still apparent after accounting for environmental stress gradients in Fildes Bay, King George Island, Antarctica. Measurements of biomass of mobile and sessile macrobenthic taxa were conducted in the austral summer 2013/4 across two environmental stress gradients: distance from nearest glaciers and subtidal depth (from 5 to 30 m). In general, community biomass increased with distance from glaciers and water depth. However, generalised additive models showed that distance from glaciers and depth accounted for negligible proportions of variation in the number of functional groups (i.e., functional richness) and community biomass when compared to taxonomic richness. Functional richness and community biomass were positive and saturating functions of taxonomic richness. Large endemic, canopy-forming brown algae of the order Desmarestiales dominated the community biomass across both gradients. Accordingly, differences in the composition of taxa accounted for a significant and large proportion (51%) of variation in community biomass in comparison with functional richness (10%). Our results suggest that the environmental factors here analysed may be less important than biodiversity in shaping mesoscale (several km) biomass patterns in this Antarctic system. We suggest that further manipulative, hypothesis-driven research should address the role of biodiversity and species' functional traits in the responses of Antarctic subtidal communities to environmental variation.

  17. Antarctic Mapping Tools for MATLAB

    Science.gov (United States)

    Greene, Chad A.; Gwyther, David E.; Blankenship, Donald D.

    2017-07-01

    We present the Antarctic Mapping Tools package, an open-source MATLAB toolbox for analysis and plotting of Antarctic geospatial datasets. This toolbox is designed to streamline scientific workflow and maximize repeatability through functions which allow fully scripted data analysis and mapping. Data access is facilitated by several dataset-specific plugins which are freely available online. An open architecture has been chosen to encourage users to develop and share plugins for future Antarctic geospatial datasets. This toolbox includes functions for coordinate transformations, flight line or ship track analysis, and data mapping in georeferenced or projected coordinates. Each function is thoroughly documented with clear descriptions of function syntax alongside examples of data analysis or display using Antarctic geospatial data. The Antarctic Mapping Tools package is designed for ease of use and allows users to perform each step of data processing including raw data import, data analysis, and creation of publication-quality maps, wholly within the numerical environment of MATLAB.

  18. Widespread Antarctic glaciation during the Late Eocene

    Science.gov (United States)

    Carter, Andrew; Riley, Teal R.; Hillenbrand, Claus-Dieter; Rittner, Martin

    2017-01-01

    Marine sedimentary rocks drilled on the southeastern margin of the South Orkney microcontinent in Antarctica (Ocean Drilling Program Leg 113 Site 696) were deposited between ∼36.5 Ma to 33.6 Ma, across the Eocene-Oligocene climate transition. The recovered rocks contain abundant grains exhibiting mechanical features diagnostic of iceberg-rafted debris. Sand provenance based on a multi-proxy approach that included petrographic analysis of over 275,000 grains, detrital zircon geochronology and apatite thermochronometry rule out local sources (Antarctic Peninsula or the South Orkney Islands) for the material. Instead the ice-transported grains show a clear provenance from the southern Weddell Sea region, extending from the Ellsworth-Whitmore Mountains of West Antarctica to the coastal region of Dronning Maud Land in East Antarctica. This study provides the first evidence for a continuity of widespread glacier calving along the coastline of the southern Weddell Sea embayment at least 2.5 million yrs before the prominent oxygen isotope event at 34-33.5 Ma that is considered to mark the onset of widespread glaciation of the Antarctic continent.

  19. Shackleton: His Antarctic Writings

    Science.gov (United States)

    Dalrymple, Paul C.

    Two books entitled “Shackleton” were published in the United Kingdom in recent years. The one entitled Shackleton: His Antarctic Writings, Selected and Introduced by Christopher Ralling was published by the British Broadcasting Corporation (BBC) in 1983; the other, by Roland Huntford and simply entitled Shackleton, was published by Hodder and Stoughton (London) in November 1985. The only two things that these books have in common are their title and home publication base: The BBC book is essentially excerpts from two well-known books written by Shackleton, with a strong assist from a New Zealand reporter, Edward Saunders (who served as Shackleton's amanuensis), whereas Huntford's book is an outstanding polar biography.

  20. Antarctic Glacial Retreats and the Records of Sea Level Change in Deposits at the North Bank of the Shenzhen Bay,South China

    Institute of Scientific and Technical Information of China (English)

    郑洪汉; 黄宝林

    1997-01-01

    In view of the huge ice cover of 24.5×106 km3 in Antarctica,which accounts for over 90% by volume of the ice body on earth,the movement of Antarctic glaciers is a major control on global sea-level change and climatic fluctuation.As recorded in the Quaternary de posits in King George Island,West Antarctica,Three rapid ablations can be recognized at 11000,9000and 6100 years ago and the global climate within the past 6000 years is characterized by small-amplitude warm-cold fluctuation.Intertibal deposits at the north bank of the Shenzhen Bay suggest a periodic variation in sea level in about every 670 years over the last 6000 years with low sea levels recorded in the periods of 5500-4900,3900-3600,2400-2200and 1300-1200 years ago.Between these periods the sea level rised for about 80 cm on average.The modern warming climate in the last century corresponds with a rise of sea level at the rate of 2-3mm/a.

  1. Metagenomic analysis of a Southern Maritime Antarctic soil

    Directory of Open Access Journals (Sweden)

    David Anthony Pearce

    2012-12-01

    Full Text Available Our current understanding of Antarctic soils is derived from direct culture on selective media, biodiversity studies based on clone library construction and analysis, quantitative PCR amplification of specific gene sequences and the application of generic microarrays for microbial community analysis. Here, we investigated the biodiversity and functional potential of a soil community at Mars Oasis on Alexander Island in the southern Maritime Antarctic, by applying 454 pyrosequencing technology to a metagenomic library constructed from soil genomic DNA. The results suggest that the commonly cited range of phylotypes used in clone library construction and analysis of 78-730 OTUs (de-replicated to 30-140 provides low coverage of the major groups present (~5%. The vast majority of functional genes (>77% were for structure, carbohydrate metabolism and DNA/RNA processing and modification. This study suggests that prokaryotic diversity in Antarctic terrestrial environments appears to be limited at the generic level, with Proteobacteria, Actinobacteria being common. Cyanobacteria were surprisingly under-represented at 2.6% of sequences, although ~1% of the genes identified were involved in CO2 fixation. At the sequence level there appeared to be much greater heterogeneity, and this might be due to high divergence within the relatively restricted lineages which have successfully colonized Antarctic terrestrial environments.

  2. Mass Gains of the Antarctic Ice Sheet Exceed Losses

    Science.gov (United States)

    Zwally, H. Jay; Li, Jun; Robbins, John; Saba, Jack L.; Yi, Donghui; Brenner, Anita; Bromwich, David

    2012-01-01

    During 2003 to 2008, the mass gain of the Antarctic ice sheet from snow accumulation exceeded the mass loss from ice discharge by 49 Gt/yr (2.5% of input), as derived from ICESat laser measurements of elevation change. The net gain (86 Gt/yr) over the West Antarctic (WA) and East Antarctic ice sheets (WA and EA) is essentially unchanged from revised results for 1992 to 2001 from ERS radar altimetry. Imbalances in individual drainage systems (DS) are large (-68% to +103% of input), as are temporal changes (-39% to +44%). The recent 90 Gt/yr loss from three DS (Pine Island, Thwaites-Smith, and Marie-Bryd Coast) of WA exceeds the earlier 61 Gt/yr loss, consistent with reports of accelerating ice flow and dynamic thinning. Similarly, the recent 24 Gt/yr loss from three DS in the Antarctic Peninsula (AP) is consistent with glacier accelerations following breakup of the Larsen B and other ice shelves. In contrast, net increases in the five other DS of WA and AP and three of the 16 DS in East Antarctica (EA) exceed the increased losses. Alternate interpretations of the mass changes driven by accumulation variations are given using results from atmospheric-model re-analysis and a parameterization based on 5% change in accumulation per degree of observed surface temperature change. A slow increase in snowfall with climate waRMing, consistent with model predictions, may be offsetting increased dynamic losses.

  3. Address of U.S. President George W. Bush / George W. Bush

    Index Scriptorium Estoniae

    Bush, George W., 1946-

    2005-01-01

    Ilmunud ka: Eesti Päevaleht : Mõte 10. juuni lk. 9-11. Ameerika Ühendriikide presidendi George Bushi Läti visiidi ajal 7. mail peetud kõne. Ajal. Eesti Päevaleht : Möte toodud ka George W. Bushi CV. Ajal. The Baltic Times lüh.

  4. Address of U.S. President George W. Bush / George W. Bush

    Index Scriptorium Estoniae

    Bush, George W., 1946-

    2005-01-01

    Ilmunud ka: Eesti Päevaleht : Mõte 10. juuni lk. 9-11. Ameerika Ühendriikide presidendi George Bushi Läti visiidi ajal 7. mail peetud kõne. Ajal. Eesti Päevaleht : Möte toodud ka George W. Bushi CV. Ajal. The Baltic Times lüh.

  5. Stable isotopes and Antarctic moss banks: Plants and soil microbes respond to recent warming on the Antarctic Peninsula

    Science.gov (United States)

    Royles, Jessica; Amesbury, Matthew; Ogée, Jérôme; Wingate, Lisa; Convey, Peter; Hodgson, Dominic; Griffiths, Howard; Leng, Melanie; Charman, Dan

    2014-05-01

    The Antarctic Peninsula is one of the most rapidly warming regions on Earth, with air temperature increases of as much as 3°C recorded since the 1950s. However, the longer-term context of this change is limited and existing records, largely relying on ice core data, are not suitably located to be able to trace the spatial signature of change over time. We are working on a project exploiting stable isotope records preserved in moss peat banks spanning 10 degrees of latitude along the Antarctic Peninsula as an archive of late Holocene climate variability. Here we present a unique time series of past moss growth and soil microbial activity that has been produced from a 150 year old moss bank at Lazarev Bay, Alexander Island (69°S), a site at the southern limit of significant plant growth in the Antarctic Peninsula region. These moss banks are ideal archives for palaeoclimate research as they are well-preserved by freezing, generally monospecific, easily dated by radiocarbon techniques, and have sufficiently high accumulation rates to permit decadal resolution. We use accumulation rates, cellulose δ13C and fossil testate amoebae to show that growth rates, assimilation and microbial productivity rose rapidly in the 1960s, consistent with temperature change, although recently may have stalled, concurrent with other evidence. The increase in biological activity is unprecedented in the last 150 years. Along with work completed on Signy Island (60°S), in the South Orkney Islands, in which we used carbon isotope evidence to show recent climate-related enhancement of CO2 assimilation and peat accumulation rates in Antarctica, the observed relationships between moss growth, microbial activity and climate suggests that moss bank records have the potential to test the regional expression of temperature variability shown by instrumental data on the Antarctic Peninsula over centennial to millennial timescales, by providing long-term records of summer growth conditions

  6. Massalongia olechiana (Massalongiaceae, Peltigerales), a new lichen spcies from the Antarctic

    DEFF Research Database (Denmark)

    Alstrup, Vagn; Søchting, Ulrik

    2011-01-01

    A new species of lichenized ascomycete, Massalongia olechiana Alstrup et Søchting, sp. nov. (Massalongiaceae) is described from the South Shetland Islands and the Antarctic Peninsula. The species is distinguished by laminal isidia and 5-7-septate ascospores. The relationships with the other species...

  7. Massalongia olechiana (Massalongiaceae, Peltigerales), a new lichen spcies from the Antarctic

    DEFF Research Database (Denmark)

    Alstrup, Vagn; Søchting, Ulrik

    2011-01-01

    A new species of lichenized ascomycete, Massalongia olechiana Alstrup et Søchting, sp. nov. (Massalongiaceae) is described from the South Shetland Islands and the Antarctic Peninsula. The species is distinguished by laminal isidia and 5-7-septate ascospores. The relationships with the other species...

  8. Heat Islands

    Science.gov (United States)

    EPA's Heat Island Effect Site provides information on heat islands, their impacts, mitigation strategies, related research, a directory of heat island reduction initiatives in U.S. communities, and EPA's Heat Island Reduction Program.

  9. Metazoan Parasites of Antarctic Fishes.

    Science.gov (United States)

    Oğuz, Mehmet Cemal; Tepe, Yahya; Belk, Mark C; Heckmann, Richard A; Aslan, Burçak; Gürgen, Meryem; Bray, Rodney A; Akgül, Ülker

    2015-06-01

    To date, there have been nearly 100 papers published on metazoan parasites of Antarctic fishes, but there has not yet been any compilation of a species list of fish parasites for this large geographic area. Herein, we provide a list of all documented occurrences of monogenean, cestode, digenean, acanthocephalan, nematode, and hirudinean parasites of Antarctic fishes. The list includes nearly 250 parasite species found in 142 species of host fishes. It is likely that there are more species of fish parasites, which are yet to be documented from Antarctic waters.

  10. Scleractinian corals recorded in the Argentinean Antarctic expeditions between 2012 and 2014, with comments on Flabellum (Flabellum areum Cairns, 1982

    Directory of Open Access Journals (Sweden)

    Laura Schejter

    2016-07-01

    Full Text Available In this contribution, we provide a list of the scleractinian corals recorded during the Argentinean Antarctic expeditions on board the oceanographic vessel Puerto Deseado (Argentina in the austral summers in 2012, 2013 and 2014. The identified taxa consist of six solitary species (Flabellum impensum, F. flexuosum, F. areum, Caryophyllia antarctica, Paraconotrochus antarcticus and Javania antarctica, recorded from 19 sampling sites located off the Antarctic Peninsula and South Shetland and South Orkney islands. We also update the information of F. areum, previously known only from south-west Atlantic waters, extending its distribution range to Antarctic waters and its upper bathymetric range to 218 m.

  11. Ecosystem function decays by fungal outbreaks in Antarctic microbial mats.

    Science.gov (United States)

    Velázquez, David; López-Bueno, Alberto; Aguirre de Cárcer, Daniel; de los Ríos, Asunción; Alcamí, Antonio; Quesada, Antonio

    2016-03-14

    Antarctica harbours a remarkably diverse range of freshwater bodies and terrestrial ecosystems, where microbial mats are considered the most important systems in terms of biomass and metabolic capabilities. We describe the presence of lysis plaque-like macroscopic blighted patches within the predominant microbial mats on Livingston Island (Antarctic Peninsula). Those blighting circles are associated with decay in physiological traits as well as nitrogen depletion and changes in the spatial microstructure; these alterations were likely related to disruption of the biogeochemical gradients within the microbial ecosystem caused by an unusually high fungal abundance and consequent physical alterations. This phenomenon has been evidenced at a time of unprecedented rates of local warming in the Antarctic Peninsula area, and decay of these ecosystems is potentially stimulated by warmer temperatures.

  12. Airborne Radar Observations of Hurricane Georges during Landfall over the Dominican Republic

    Science.gov (United States)

    Geerts, B.; Heymsfield, G.; Tian, L.

    1999-01-01

    On 22 September 1998 hurricane Georges made landfall on the Dominican Republic (DR). Georges cost the DR at least 500 lives, made more than 155,000 people homeless and caused extensive damage to the country's main industries, tourism and agriculture. There was considerable wind damage, with wind gusts up to 58 m/s in Santa Domingo on the south coast, but most of the damage and deaths resulted from mudslides and the flooding of rivers. While this may have been the worst natural disaster to strike the DR, the sustained rapid storm movement saved the island from worse damage. Georges had previously affected several islands in the Lesser Antilles and Puerto Rico, but it had retained much of its circulation strength. Forty raingauge stations across the DR measured rainfall totals from Georges between 0.7 and 41 cm, the latter at the capital Santo Domingo, located on the south coast. At Herrera the maximum 1 h rainfall rate was 72 mm/h. It is suspected that much higher rain rates occurred in DR's mountainous interior. Before landfall the eye was clearly evident in satellite imagery. When the eye moved over southeastern DR, it filled rapidly, and the cloud top height decreased in all storm sectors except in the southern inflow sector, where a long-lived MCS, with a diameter larger than that of the eyewall, slowly became enwrapped in the hurricane circulation. The eye closure was most rapid between 16-18 UTC, when the eyewall circulation felt the mountainous terrain of the Cordillera Central, which rises up to 3,093 m. The estimated central pressure increased from 962 hPa at 15 UTC to 986 hPa at 03Z on 23 Sept, and the maximum sustained surface wind speed decreased from 54 to 36 in s-1 during the same period. The island of Hispaniola has a cross-track width of about 250 km, much wider than the diameter of the eyewall anvil (about 100 km before landfall). So the event can truly be considered to be a landfalling case, even though Georges recovered after crossing Hispaniola

  13. Antarctic crabs: invasion or endurance?

    Science.gov (United States)

    Griffiths, Huw J; Whittle, Rowan J; Roberts, Stephen J; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the "invasion hypothesis".

  14. On the Teachings of George Grant

    Science.gov (United States)

    Pinar, William F.

    2014-01-01

    One of Canada's greatest public intellectuals, George Grant (1918-1988) studied history as an undergraduate, focusing on concepts and themes rather than minutiae. That same intellectual disposition surfaced later at Oxford, where he had gone on a Rhodes scholarship to study law. Returning to Oxford after the war, he left law to study…

  15. Plaster People...A La George Segal.

    Science.gov (United States)

    Boulay, Michele

    2003-01-01

    Describes an art project used with eleventh- and twelfth-grade students in which they created plaster self-portraits inspired by the work of George Segal. Includes directions for the casting and lists the art materials needed for the lesson. Explains that the project requires half a semester to complete. (CMK)

  16. George Lakoff's New Happiness: Politics after Rationality

    Science.gov (United States)

    Parrott, John B.

    2009-01-01

    Berkeley professor of linguistics and cognitive science George Lakoff is among the handful of current faculty members in the United States to have successfully recast himself as a significant figure in national politics. Though his views place rather far on the progressive left, he has, unlike some other scholar-activists, focused most of his…

  17. George Wilbur: Otto Rank and Hanns Sachs.

    Science.gov (United States)

    Roazen, Paul

    2006-01-01

    George Wilbur, a pioneering Cape Cod psychoanalytic psychiatrist, was a long-standing editor of the journal "American Imago," and an excellent source of information about the Viennese analysts Otto Rank and Hanns Sachs. Wilbur was also knowledgeable about the early reception of psychoanalysis in the Boston community.

  18. Generative reproduction of Antarctic grasses, the native species Deschampsia antarctica Desv. and the alien species Poa annua L.

    Directory of Open Access Journals (Sweden)

    Giełwanowska Irena

    2015-09-01

    Full Text Available The embryology of two species, Deschampsia antarctica, a native species, and Poa annua, an alien species in the Antarctic we studied. Flowering buds of plants growing in their natural habitats on King George Island and generative tissues of both plant species grown in a greenhouse were analyzed. Adaptations to autogamy and anemogamy were observed in the flower anatomy of both species. The microsporangia of the evaluated grasses produce a small number of three−celled pollen grains. Numerous pollen grains do not leave the microsporangium and germinate in the thecae. Deschampsia antarctica and P. annua plants harvested in Antarctica developed a particularly small number of microspores in pollen chambers. In D. antarctica, male gametophytes were produced at a faster rate: generative cells in pollen did not become detached from the wall of the pollen grain, they were not embedded in the cytoplasm of vegetative cells, and they divided into two sperm cells situated close to the wall. The monosporous Polygonum type of embryo sac development was observed in the studied species. The egg apparatus had typical polarization, and the filiform apparatus did not develop in synergids. Large antipodals with polyploidal nuclei were formed in the embryo sacs of D. antarctica and P. annua. Poa annua was characterized by numerous antipodal cells which formed antipodal tissue in the chalazal region of the embryo sac. Three distinct antipodals with atypical, lateral position in the vicinity of the egg apparatus were observed in D. antarctica. The diaspores of the investigated grass species were characterized by small size, low weight and species-specific primary and secondary sculpture of the testa and caryopsis coat.

  19. Characterizing proteases in an Antarctic Janthinobacterium sp. isolate:Evidence of a protease horizontal gene transfer event

    Institute of Scientific and Technical Information of China (English)

    Cecilia Martinez-Rosales; Juan Jos Marizcurrena; Andrs Iriarte; Natalia Fullana; Hctor Musto; Susana Castro-Sowinski

    2015-01-01

    We report the isolation of a cold-adapted bacterium belonging to the genus Janthinobacterium (named AU11), from a water sample collected in Lake Uruguay (King George Island, South Shetlands). AU11 (growth between 4°C and 30°C) produces a single cold-active extracellular protease (ExPAU11), differentially expressed at low temperature. ExPAU11 was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS) as an alkaline metallo-protease (70% coverage with an extracellular protease of Janthinobacterium sp. PI12), and by protease-inhibitor screening identified as a serine-protease. To the best of our knowledge this is the first experimental evidence of a cold-active extracellular protease produced by Janthinobacterium. Furthermore, we identified a serine-protease gene (named JSP8A) showing 60% identity (98%query coverage) to subtilisin peptidases belonging to the S8 family (S8A subfamily) of many cyanobacteria. A phylogenetic analysis of the JSP8A protease, along with related bacterial protein sequences, confirms that JSP8A clusters with S8A subtilisin sequences from different cyanobacteria, and is clearly separated from S8A bacterial sequences of other phyla (including its own). An analysis of the genomic organization around JSP8A suggests that this protease gene was acquired in an event that duplicated a racemase gene involved in transforming L- to D-amino acids. Our results suggest that AU11 probably acquired this subtilisin-like protease gene by horizontal gene transfer (HGT) from a cyanobacterium. We discuss the relevance of a bacterial protease-HGT in the Antarctic environment in light of this hypothesis.

  20. In vitro antioxidant capacities of two benzonaphthoxanthenones: ohioensins F and G, isolated from the Antarctic moss Polytrichastrum alpinum.

    Science.gov (United States)

    Bhattarai, Hari Datta; Paudel, Babita; Lee, Hong Kum; Oh, Hyuncheol; Yim, Joung Han

    2009-01-01

    Antioxidant agents against reactive oxygen species can be used for several cosmetic and medicinal applications. This study's objective was to evaluate the antioxidant activities of Polytrichastrum alpinum (Hedw.) G. L. Sm. (Polytrichaceae), an Antarctic moss species collected from King George Island (Antarctica). The identification of the moss species was performed on the basis of morphological characteristics and molecular sequencing of the 18S rRNA gene. Two benzonaphthoxanthenones: ohioensins F and G, were isolated from the extract after several chromatographic procedures. The various in vitro antioxidant capacities of a methanolic extract of P. alpinum and the isolated compounds were evaluated by analyzing the scavenging capacities of free radicals of 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH), the total phenol assay with Folin-Ciocalteu reagent, the ferric ion (Fe3+) reducing power and the nitric oxide (NO) scavenging activity and compared to those of commercial standards for each assay. The experimental data showed that even the crude extract of P. alpinum exhibited potent antioxidant activity. The antioxidant activity was increased two- to seven-fold for the purified compounds. The antioxidant activities of both purified compounds were found to be more or less the same in all experiments. However, the obtained data showed that the Fe3+ reducing power of the purified compounds and crude methanolic extract was almost the same suggesting the presence of other stronger reducing agents in the methanolic extract which could not be isolated in the present experiment. Therefore, further work on the isolation of these stronger antioxidant agents from this moss specimen of the extreme environment is warranted. Developments of laboratory mass culture techniques are anticipated to achieve bulk production of the active constituents for commercial application.

  1. Dr. George Koob: "Alcohol Use Disorders Are a Major Problem..."

    Science.gov (United States)

    ... please turn JavaScript on. Feature: Rethinking Drinking Dr. George Koob: "Alcohol use disorders are a major problem …" Past Issues / Spring 2014 Table of Contents George Koob, Ph.D., is Director of the NIH's ...

  2. The philosophy of Hans-Georg Gadamer / Wolfgang Drechsler

    Index Scriptorium Estoniae

    Drechsler, Wolfgang, 1963-

    1998-01-01

    Rets.rmt.: The philosophy of Hans-Georg Gadamer : a review of the philosophy of Hans-Georg Gadamer / Lewis Edwin Hahn, ed. Chicago and La Salle, IL: Open Court, 1997. (The Library of Living Philosophers, vol. XXIV)

  3. The philosophy of Hans-Georg Gadamer / Wolfgang Drechsler

    Index Scriptorium Estoniae

    Drechsler, Wolfgang, 1963-

    1998-01-01

    Rets.rmt.: The philosophy of Hans-Georg Gadamer : a review of the philosophy of Hans-Georg Gadamer / Lewis Edwin Hahn, ed. Chicago and La Salle, IL: Open Court, 1997. (The Library of Living Philosophers, vol. XXIV)

  4. Islands, Island Studies, Island Studies Journal

    Directory of Open Access Journals (Sweden)

    Godfrey Baldacchino

    2006-05-01

    Full Text Available Islands are sites of innovative conceptualizations, whether of nature or human enterprise, whether virtual or real. The study of islands on their own terms today enjoys a growing and wide-ranging recognition. This paper celebrates the launch of Island Studies Journal in the context of a long and thrilling tradition of island studies scholarship.

  5. Penguin eggshell membranes reflect homogeneity of mercury in the marine food web surrounding the Antarctic Peninsula

    Energy Technology Data Exchange (ETDEWEB)

    Brasso, Rebecka L., E-mail: rlb1196@uncw.edu [University of North Carolina Wilmington, Department of Biology and Marine Biology, 601 South College Road, Wilmington, NC 28403 (United States); Polito, Michael J. [University of North Carolina Wilmington, Department of Biology and Marine Biology, 601 South College Road, Wilmington, NC 28403 (United States); Lynch, Heather J. [Ecology and Evolution Department, 640 Life Sciences Bldg., Stony Brook University, Stony Brook, NY 11794 (United States); Naveen, R. [Oceanites Inc., PO Box 15259, Chevy Chase, MD 20825 (United States); Emslie, Steven D. [University of North Carolina Wilmington, Department of Biology and Marine Biology, 601 South College Road, Wilmington, NC 28403 (United States)

    2012-11-15

    Remote regions such as the Antarctic have become increasingly important for investigations into far-reaching anthropogenic impacts on the environment, most recently in regard to the global mercury cycle. Spatial patterns of mercury availability in four regions of the Antarctic Peninsula were investigated using three species of sympatrically breeding Pygoscelis penguins as biomonitors. Eggshells with intact membranes from Adelie, Gentoo, and Chinstrap penguins were collected at 24 breeding colonies in the South Orkney Islands, South Shetland Islands, eastern Antarctic Peninsula, and western Antarctic Peninsula during the 2006/2007 austral summer. In addition, we compared eggshell membrane mercury concentrations with eggshell stable isotope values ({delta}{sup 15}N and {delta}{sup 13}C) to determine if species-specific trophic or foraging habitat preferences influenced female mercury exposure prior to breeding. With few exceptions, mercury concentrations were found to be fairly homogeneous throughout the Antarctic Peninsula suggesting little spatial variation in the risk of exposure to dietary mercury in this food web. Mercury concentrations in Gentoo and Adelie penguins were similar while Chinstrap penguins tended to have higher eggshell membrane mercury concentrations than their congeners. However, inter and intra-specific differences in eggshell membrane mercury concentration were not related to eggshell {delta}{sup 15}N or {delta}{sup 13}C values, a likely result of all three species foraging at similar trophic positions. The lack of regional-scale differences in mercury availability in this marine ecosystem may be a reflection of generally uniform atmospheric deposition and upwelling of regionally homogeneous deep water rather than from geographically distinct point sources. -- Highlights: Black-Right-Pointing-Pointer We examined regional patterns of mercury availability in the Antarctic Peninsula. Black-Right-Pointing-Pointer Three species of Pygoscelis

  6. Treatment and prevention of infection following bites of the Antarctic fur seal (Arctocephalus gazella

    Directory of Open Access Journals (Sweden)

    Kouliev T

    2015-04-01

    Full Text Available Timur Kouliev,1 Victoria Cui2 1Beijing United Family Hospital, Beijing, People's Republic of China; 2Department of Biological Sciences, Columbia University, New York, NY, USA Abstract: In recent decades, an increasing number of people have traveled to sub-Antarctic and Antarctic regions each year for research, tourism, and resource exploitation. Hunting of Antarctic fur seals (Arctocephalus gazella almost pushed the species to extinction in the early 1900s, but populations have since shown rapid and substantial recovery. The species' range has re-expanded to include several islands south of the Antarctic Convergence, most notably South Georgia, and now overlaps with many popular Antarctic travel destinations. Both male and female fur seals can become extremely aggressive when provoked, and their bites, if not properly treated, pose a significant risk of infection by microorganisms not usually encountered in cases of animal bites. In this report, we present the case of a patient treated for a fur seal bite during an Antarctic expedition cruise, review the literature concerning seal bites, and suggest the use of antibiotic prophylaxis to prevent complications. Keywords: zoonotic, polar tourism, prophylaxis, seal finger, expedition medicine

  7. [Resistance to UV radiation of microorganisms isolated from the rock biotopes of the Antarctic region].

    Science.gov (United States)

    Romanovskaia, V A; Tashirev, A B; Shilin, S O; Chernaia, N A

    2010-01-01

    Microbiological analysis of terrestrial biotopes of the Antarctic Region has shown, that vertical rocks of the Antarctic islands open for the Sun were characterized by special microcenoses. The wide distribution of pigmented microorganisms in the rock Antarctic samples, a higher frequency of their occurrence, the total number and biologic diversity, than in other Antarctic biotopes, has been demonstrated. For the first time the presence of bacteria and yeast, resistant to high doses of UV radiation on the vertical rocks in the Antarctic Region was shown. The lethal doze of UV radiation for the Antarctic pink pigmented Methylobacterium strains exceeded 200-300 J/m2, for coal-black yeast--500-800 J/m2, for red yeast--1200-1500 J/m2. The distinctions in lethal UV effect against strains of Methylobacterium isolated from the regions with different climate have not been found. Probably, adaptation of the rock microcenosis to extreme factors of the environment proceeds by natural selection of microorganisms, which resistance to this factor is genetically determined.

  8. George Washington and the Politics of War and Revolution

    Science.gov (United States)

    2015-05-23

    58 Higginbotham, George Washington and the American Military Tradition, 8. 59 George Washington to Robert Dinwiddie, 18 July 1755, The...University, 1914): 144; quoted in Hughes, George Washington: The Rebel and The Patriot, 201. 26 the radical camp. Robert Nicholas Carter, on 24...Continental Army (Washington, DC: Center for Military History, 1983), 11. 76 George Washington to Robert Mackenzie, 9 October 1774, WGW, 3:245-246

  9. Investigations of fungal diversity in wooden structures and soils at historic sites on the Antarctic Peninsula.

    Science.gov (United States)

    Arenz, Brett E; Blanchette, Robert A

    2009-01-01

    Investigations of microbial diversity in Antarctic are important to begin to understand ecosystem functioning and decomposition processes. This study documents fungi at 9 historic sites on the Antarctic Peninsula collected from wooden structures, other organic materials, and soils during a joint National Science Foundation and British Antarctic Survey expedition in 2007. Many of these sites had wooden structures built by the British during the World War II Operation Tabarin, but others visited included the American "East Base" on Stonington Island and the Swedish hut on Snow Hill Island. Fungi were cultured on several different media and pure cultures were obtained and identified by DNA sequencing of the internal transcribed spacer region. Cadophora species previously found to attack historic wooden structures on Ross Island, Antarctica, were found at all but 1 location sampled in the Peninsula region. Fungi causing decay in the historic wooden structures and artifacts and those causing mold problems inside the structures are of great concern, and conservation efforts are urgently needed to help preserve these important polar heritage structures. The results presented also expand our knowledge on the identity of fungi present throughout the Antarctic Peninsula region and provide insights into the organisms responsible for decomposition and nutrient recycling.

  10. Moessbauer study of thermal metamorphosed Antarctic meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Scorzelli, R.B. (Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, RJ (Brazil)); Galvao da Silva, E. (Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, RJ (Brazil) Dept. de Fisica, Univ. Federal de Minas Gerais, Belo Horizonte (Brazil)); Souza Azevedo, I. (Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, RJ (Brazil))

    1994-02-01

    In this paper we report on variable temperature Moessbauer spectroscopy measurements on Yamato-82162 and Yamato-86720. These Antarctic carbonaceous chondrites contrast with other non-Antarctic carbonaceous chondrites in which no evidences of thermal metamorphism have been found. (orig.)

  11. Virtual Visit to the ATLAS Control Room by St George`s School for Girls in Edinburgh

    CERN Multimedia

    2013-01-01

    St George`s School for Girls is in the heart of Edinburgh, the capital of Scotland and home to Peter Higgs. It is an all-through school, with students as young as two and as old as eighteen. St George`s is a flexible and open learning community where students grow and develop at their own pace and in their own direction.

  12. Antarctic sponges (Porifera, Demospongiae of the South Shetland Islands and vicinity: part II. Poecilosclerida Esponjas Antárticas (Porifera, Demospongiae das Ilhas Shetland do Sul e áreas próximas: parte II. Poecilosclerida

    Directory of Open Access Journals (Sweden)

    Maurício Campos

    2007-01-01

    Full Text Available In the present study 16 species are registered for the South Shetland Islands and vicinity: Acanthorhabdus fragilis Burton, 1929, Iophon unicornis Topsent, 1907, Clathria (Axosuberites flabellata (Topsent, 1916, Clathria (Axosuberites nidificata (Kirkpatrick, 1907, Kirkpatrickia variolosa (Kirkpatrick, 1907, Myxodoryx hanitschi (Kirkpatrick, 1907, Iotroata somovi (Koltun, 1964, Tedania (Tedaniopsis charcoti (Topsent, 1907, Tedania (Tedaniopsis vanhoffeni (Hentschel, 1914, Tedania (Tedaniopsis oxeata (Topsent, 1916, Isodictya kerguelenensis (Ridley & Dendy, 1886, Isodictya lankesteri (Kirkpatrick, 1907, Isodictya toxophila Burton, 1932, Isodictya bentarti Ríos, Cristobo & Urgorri, 2004, Latrunculia (Latrunculia brevis Ridley & Dendy, 1886 and Latrunculia (Latrunculia biformis (Kirkpatrick, 1908. Amongst the identified species, five are new occurrences for the studied region, three have their bathymetric limit extended and the others are confirmed for the studied area.No presente estudo 16 espécies são registradas para as Ilhas Shetland do Sul e áreas próximas: Acanthorhabdus fragilis Burton, 1929, Iophon unicornis Topsent, 1907, Clathria (Axosuberites flabellata (Topsent, 1916, Clathria (Axosuberites nidificata (Kirkpatrick, 1907, Kirkpatrickia variolosa (Kirkpatrick, 1907, Myxodoryx hanitschi (Kirkpatrick, 1907, Iotroata somovi (Koltun, 1964, Tedania (Tedaniopsis charcoti (Topsent, 1907, Tedania (Tedaniopsis vanhoffeni (Hentschel, 1914, Tedania (Tedaniopsis oxeata (Topsent, 1916, Isodictya kerguelenensis (Ridley & Dendy, 1886, Isodictya lankesteri (Kirkpatrick, 1907, Isodictya toxophila Burton, 1932, Isodictya bentarti Ríos, Cristobo & Urgorri, 2004, Latrunculia (Latrunculia brevis Ridley & Dendy, 1886 e Latrunculia (Latrunculia biformis (Kirkpatrick, 1908. Dentre as espécies identificadas, cinco são novas ocorrências para a região estudada, três têm seu limite batimétrico ampliado e as demais são confirmadas para a área de estudo.

  13. Regulating Antarctic Tourism and the Precautionary Principle

    NARCIS (Netherlands)

    Bastmeijer, C.J.; Roura, R.

    2004-01-01

    On the basis of an overview of the developments in Antarctic tourism since 1956, this current development note examines the issue of international regulation of Antarctic tourism. After discussing one of the main management issues in respect of Antarctic tourism ¿ the assessment and prevention of cu

  14. EDITORIAL: George W Series Memorial Essays

    Science.gov (United States)

    Dodd, J. N.

    1997-01-01

    I would like to recall my experiences when I joined George Series when on study leave from the University of Otago in 1959. Like George, we had decided, some years previously, to pursue the line of research opened up by the double-resonance experiment of Brossel and Bitter. Up to that time both groups had been applying the new technique to traditional spectroscopic problems, those of measuring the fine structure, hyperhe structure, g-factors and nuclear moments. But here, in Oxford, was something new and exciting - experiments that studied the nature of light itself, questioning some long-held views. George had come to the view that, in a double-resonance experiment, one could demonstrate the inner coherence that could exist between superposition states of an atom. He, and his students Wilf Fox and Mike Taylor, had already obtained promising evidence; but he needed more definite results if he was going to allay the doubts and suspicions of some others in the Clarendon. At the time, people generally thought that light, being a superposition of radiations from many atoms with no obvious phase relation to each other, was an incoherent wave phenomenon. One could observe small scale coherence (for example, in the Young interference experiment) but it would be largely concealed by the incoherent nature of the radiation from many atoms in a source. In the experiments that had been performed the coherence was introduced between a pair of excited states (Zeeman sub-states) by the application of an oscillating magnetic field - was it not likely, according to the doubters, that the modulation observed in the fluorescence was due to "pick-up" in the amplifiers from the source of oscillations? George had to prove that this was not the cause. I well remember him saying at the time "I have a hunch that I am correct". That typified his approach to physics. The work of 1959 demonstrated beyond all doubt that substantial coherence, manifested as strong beats in the intensity of the

  15. Distant Fathers: Disjointed World of George Eliot

    Directory of Open Access Journals (Sweden)

    Tahira Jabeen

    2014-01-01

    Full Text Available The article discusses distant fathers in the novels of George Eliot within the context of the nineteenth century. In the nineteenth-century Britain, the father’s role is best defined by Nelson, “authority, guidance and financial support”. (Natalie 2011, p.155 The article is devoted to explore the distant or absent fathers, which means no guidance, protection, and financial support to the children. The absence might be the consequences of many aspects relating to fathers. The father could be absent either physically or emotionally. The article argues that Eliot seeks and yearns for a perfect fatherhood by showing some shortcomings of the father and its effects on the lives of their children. Keywords: George Eliot, distant fathers, nineteenth century

  16. Crustal architecture of the oblique-slip conjugate margins of George V Land and southeast Australia

    Science.gov (United States)

    Stagg, H.M.J.; Reading, A.M.

    2007-01-01

    A conceptual, lithospheric-scale cross-section of the conjugate, oblique-slip margins of George V Land, East Antarctica, and southeast Australia (Otway Basin) has been constructed based on the integration of seismic and sample data. This cross-section is characterised by asymmetry in width and thickness, and depth-dependent crustal extension at breakup in the latest Maastrichtian. The broad Antarctic margin (~360 km apparent rift width) developed on thick crust (~42 km) of the Antarctic craton, whereas the narrow Otway margin (~220 km) developed on the thinner crust (~31 km) of the Ross–Delamerian Orogen. The shallow basement (velocities ~5.5 km.s-1) and the deep continental crust (velocities >6.4 km.s-1) appear to be largely absent across the central rift, while the mid-crustal, probably granitic layer (velocities ~6 km.s-1) is preserved. Comparison with published numerical models suggests that the shallow basement and deep crust may have been removed by simple shear, whereas the mid-crust has been ductilely deformed.

  17. THE ONEIRIC AUTOBIOGRAPHY OF GEORGES PEREC.

    Science.gov (United States)

    Schwartz, Henry P

    2016-01-01

    Georges Perec's book La Boutique Obscure (1973; translated into English in 2012) serves as the basis for this paper. The book is a collection of dreams that its author dreamed from May 1968 to August 1972. The present author treats these dreams as chapters in a bizarre autobiography, elaborating Perec's life through a discussion of those dreams and using them as a starting point with which to discuss his views of dream interpretation and the role of dreams in psychoanalysis.

  18. Apontamentos para uma leitura de Georg Simmel

    Directory of Open Access Journals (Sweden)

    Simone Costa

    2010-05-01

    Full Text Available Este artigo tem por objetivo descrever e analisar algumas questões centrais para a compreensão do pensamento de Georg Simmel. Discute-se como esse importante expoente da sociologia alemã percebe a relação estabelecida entre os indivíduos e a sociedade e as influências que ele exerce sobre intelectuais como Max Weber e Erving Goffman.

  19. Two new species of Ammothea (Pycnogonida, Ammotheidae) from Antarctic waters

    Science.gov (United States)

    Cano, Esperanza; López-González, Pablo J.

    2013-06-01

    Two new species of the genus Ammothea are described from Elephant Island and the South Shetlands Islands, Antarctica. The material was captured during the Polarstern cruise XXIII/8 to the Antarctic Peninsula area. The main features of Ammothea pseudospinosa n. sp. are a proboscis distinctly trilobulated distally with a constriction at 2/3 of its length and dimorphism between the propodi of the anterior (first and second) and posterior (third and fourth) legs, and a trunk: proboscis length ratio of about 1.5. The main features of Ammothea childi n. sp. are a cylindrical proboscis, longer than trunk length, and adults with functional chelifores. These species are compared with their closest congeners from the Southern Ocean: A. pseudospinosa n. sp. with Ammothea spinosa and Ammothea allopodes; A. childi n. sp. with Ammothea gigantea, Ammothea bicorniculata and Ammothea hesperidensis.

  20. Major advance of South Georgia glaciers during the Antarctic Cold Reversal following extensive sub-Antarctic glaciation

    Science.gov (United States)

    Graham, Alastair G. C.; Kuhn, Gerhard; Meisel, Ove; Hillenbrand, Claus-Dieter; Hodgson, Dominic A.; Ehrmann, Werner; Wacker, Lukas; Wintersteller, Paul; Dos Santos Ferreira, Christian; Römer, Miriam; White, Duanne; Bohrmann, Gerhard

    2017-03-01

    The history of glaciations on Southern Hemisphere sub-polar islands is unclear. Debate surrounds the extent and timing of the last glacial advance and termination on sub-Antarctic South Georgia in particular. Here, using sea-floor geophysical data and marine sediment cores, we resolve the record of glaciation offshore of South Georgia through the transition from the Last Glacial Maximum to Holocene. We show a sea-bed landform imprint of a shelf-wide last glacial advance and progressive deglaciation. Renewed glacier resurgence in the fjords between c. 15,170 and 13,340 yr ago coincided with a period of cooler, wetter climate known as the Antarctic Cold Reversal, revealing a cryospheric response to an Antarctic climate pattern extending into the Atlantic sector of the Southern Ocean. We conclude that the last glaciation of South Georgia was extensive, and the sensitivity of its glaciers to climate variability during the last termination more significant than implied by previous studies.

  1. First record of Babesia sp. in Antarctic penguins.

    Science.gov (United States)

    Montero, Estrella; González, Luis Miguel; Chaparro, Alberto; Benzal, Jesús; Bertellotti, Marcelo; Masero, José A; Colominas-Ciuró, Roger; Vidal, Virginia; Barbosa, Andrés

    2016-04-01

    This is the first reported case of Babesia sp. in Antarctic penguins, specifically a population of Chinstrap penguins (Pygoscelis antarctica) in the Vapour Col penguin rookery in Deception Island, South Shetlands, Antarctica. We collected peripheral blood from 50 adult and 30 chick Chinstrap penguins. Examination of the samples by microscopy showed intraerythrocytic forms morphologically similar to other avian Babesia species in 12 Chinstrap penguin adults and seven chicks. The estimated parasitaemias ranged from 0.25×10(-2)% to 0.75×10(-2)%. Despite the low number of parasites found in blood smears, semi-nested PCR assays yielded a 274 bp fragment in 12 of the 19 positive blood samples found by microscopy. Sequencing revealed that the fragment was 97% similar to Babesia sp. 18S rRNA from Australian Little Penguins (Eudyptula minor) confirming presence of the parasite. Parasite prevalence estimated by microscopy in adults and chicks was higher (24% vs. 23.3%, respectively) than found by semi-nested PCR (16% vs. 13.3% respectively). Although sampled penguins were apparently healthy, the effect of Babesia infection in these penguins is unknown. The identification of Babesia sp. in Antarctic penguins is an important finding. Ixodes uriae, as the only tick species present in the Antarctic Peninsula, is the key to understanding the natural history of this parasite. Future work should address the transmission dynamics and pathogenicity of Babesia sp. in Chinstrap penguin as well as in other penguin species, such as Gentoo penguin (Pygoscelis papua) and Adélie penguin (Pygoscelis adeliae), present within the tick distribution range in the Antarctic Peninsula. Copyright © 2016 Elsevier GmbH. All rights reserved.

  2. Life between tides: Spatial and temporal variations of an intertidal macroalgal community at Potter Peninsula, South Shetland Islands, Antarctica

    Science.gov (United States)

    Marcías, María Laura; Deregibus, Dolores; Saravia, Leonardo Ariel; Campana, Gabriela Laura; Quartino, María Liliana

    2017-03-01

    Intertidal zones are one of the most studied habitats in the world. However, in Antarctica, further studies are needed for a more complete understanding of these systems. When conspicuous Antarctic intertidal communities occur, macroalgae are a key component. Given that intertidal communities have a fast response to variations in environmental conditions and could reflect climate fluctuations, we conducted a non-destructive study with photographic transects in an intertidal zone at Potter Peninsula, Isla 25 de Mayo/King George Island, over four years and during five months of the warm season. We tested the general hypothesis that macroalgal intertidal communities are mainly structured by the vertical stress gradient and that changes in temperature between seasons and between years have a great influence in the macroalgal community structure. Spatial, seasonal and inter-annual variations were studied using GLM, quantile regression and NMDS ordinations. The vertical stress gradient was the main factor that explained macroalgal cover. The Low and the Middle level shared similarities, but the latter was more variable. The High level had the lowest cover, richness and diversity. The dominant species here was the endemic red alga Pyropia endiviifolia, which is strongly adapted to extreme conditions. At the Middle level, there was a significant increase in macroalgal cover during spring months, and it stabilized in summer. Inter-annual variations showed that there is a strong variation in the total macroalgal cover and community structure over the studied years. Environmental conditions have a significant effect in shaping the studied intertidal community, which is very sensitive to climate oscillations. An increase in temperature produced a decrease of annual ice foot cover, number of snow days and - as a result - an increase in macroalgal cover. In a global climate-change scenario, a shift in species composition could also occur. Species with wide physiological

  3. Factors that affect the nearshore aggregations of Antarctic krill in a biological hotspot

    Science.gov (United States)

    Bernard, Kim S.; Cimino, Megan; Fraser, William; Kohut, Josh; Oliver, Matthew J.; Patterson-Fraser, Donna; Schofield, Oscar M. E.; Statscewich, Hank; Steinberg, Deborah K.; Winsor, Peter

    2017-08-01

    Antarctic krill, Euphausia superba, is a highly abundant and ecologically important zooplankton species in the Southern Ocean. Regions of elevated Antarctic krill biomass exist around Antarctica, often as a result of the concentrating effect of bathymetry and ocean currents. Such areas are considered biological hotspots and are key foraging grounds for numerous top predators in the region. A hotspot of Antarctic krill biomass exists off the southern extent of Anvers Island, Western Antarctic Peninsula, and supports a population of Adélie penguins that feed almost exclusively on it, as well as numerous other top predators. We investigated the spatio-temporal variability in Antarctic krill biomass and aggregation structure over four consecutive summer seasons, identifying environmental factors that were responsible. We identified three distinct krill aggregation types (Large-dense, Small-close and Small-sparse), and found that the relative proportion of each type to total aggregation numbers varied significantly between survey days. Large-dense aggregations occurred more frequently when westerly winds predominated and when the local mixed tide was in the diurnal regime. Small-close aggregations were also more frequent during diurnal tides and were negatively correlated with phytoplankton biomass. Small-sparse aggregations, on the other hand, were more prevalent when the mixed tide was in the semi-diurnal phase. We suggest that, under certain conditions (i.e. diurnal tides and westerly winds), the biological hotspot in the nearshore waters off Palmer Station, Anvers Island, functions as a zone of accumulation, concentrating krill biomass. Our findings provide important information on the dynamics of Antarctic krill at the local scale.

  4. Extent of the Antarctic Continent.

    Science.gov (United States)

    Press, F; Dewart, G

    1959-02-20

    Group velocities of eartquake-generated Love and Rayleigh waves for certain transantarctic paths are abnormally high when compared with data from other continents. For these paths, the data indicate that at most only three-fourths of the antarctic ice sheet is underlain by continent, the remaining area being oceanic in structure.

  5. Principles of the Antarctic Treaty

    Science.gov (United States)

    Candidi, M.

    The operation of any base or expedition to Antarctica is regulated by the mutual agreement among nations in the “Antarctic Treaty”. This treaty deals with the major aspects of life in Antarctica and its main principles and provisions are described in what follows.

  6. Special Stamps:Antarctic Scenery

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In July 2002, the State Postal Bureau issued a set of three stamps, whose theme is Antarctic scenery.The first stamp depicts an iceberg. Antarctica is where 90 percent of the world’s ice exists. Each year countless icebergs float majestically through the sea, and are a magnificent scenic feature of Antarctica.

  7. Terrestrial habitats on sub-Antarctic Marion Islan: their vegetation, edaphic attibutes, distribution and resonse to climate change

    NARCIS (Netherlands)

    Smith, V.; Steenkamp, M.; Gremmen, N.J.M.

    2001-01-01

    The vegetation, soil chemistry characteristics and altitudinal distributions of 23 habitats in 7 habitat complexes on sub-Antarctic Marion Island (47°S, 38°E) are described. The habitat complexes (number of habitats in complex) are: Coastal Salt-spray Complex (2); Fellfield Complex (2); Slope Comple

  8. Terrestrial habitats on sub-Antarctic Marion Islan: their vegetation, edaphic attibutes, distribution and resonse to climate change

    NARCIS (Netherlands)

    Smith, V.; Steenkamp, M.; Gremmen, N.J.M.

    2001-01-01

    The vegetation, soil chemistry characteristics and altitudinal distributions of 23 habitats in 7 habitat complexes on sub-Antarctic Marion Island (47°S, 38°E) are described. The habitat complexes (number of habitats in complex) are: Coastal Salt-spray Complex (2); Fellfield Complex (2); Slope

  9. Antarctic volcanoes: A remote but significant hazard

    Science.gov (United States)

    Geyer, Adelina; Martí, Alex; Folch, Arnau; Giralt, Santiago

    2017-04-01

    Ash emitted during explosive volcanic eruptions can be dispersed over massive areas of the globe, posing a threat to both human health and infrastructures, such as the air traffic. Some of the last eruptions occurred during this decade (e.g. 14/04/2010 - Eyjafjallajökull, Iceland; 24/05/2011-Grímsvötn, Iceland; 05/06/2011-Puyehue-Cordón Caulle, Chile) have strongly affected the air traffic in different areas of the world, leading to economic losses of billions of euros. From the tens of volcanoes located in Antarctica, at least nine are known to be active and five of them have reported volcanic activity in historical times. However, until now, no attention has been paid to the possible social, economical and environmental consequences of an eruption that would occur on high southern latitudes, perhaps because it is considered that its impacts would be minor or local, and mainly restricted to the practically inhabited Antarctic continent. We show here, as a case study and using climate models, how volcanic ash emitted during a regular eruption of one of the most active volcanoes in Antarctica, Deception Island (South Shetland Islands), could reach the African continent as well as Australia and South America. The volcanic cloud could strongly affect the air traffic not only in the region and at high southern latitudes, but also the flights connecting Africa, South America and Oceania. Results obtained are crucial to understand the patterns of volcanic ash distribution at high southern latitudes with obvious implications for tephrostratigraphical and chronological studies that provide valuable isochrones with which to synchronize palaeoclimate records. This research was partially funded by the MINECO grants VOLCLIMA (CGL2015-72629-EXP)and POSVOLDEC(CTM2016-79617-P)(AEI/FEDER, UE), the Ramón y Cajal research program (RYC-2012-11024) and the NEMOH European project (REA grant 34 agreement n° 289976).

  10. Ciliate biogeography in Antarctic and Arctic freshwater ecosystems: endemism or global distribution of species?

    Science.gov (United States)

    Petz, Wolfgang; Valbonesi, Alessandro; Schiftner, Uwe; Quesada, Antonio; Cynan Ellis-Evans, J

    2007-02-01

    Ciliate diversity was investigated in situ in freshwater ecosystems of the maritime (South Shetland Islands, mainly Livingston Island, 63 degrees S) and continental Antarctic (Victoria Land, 75 degrees S), and the High Arctic (Svalbard, 79 degrees N). In total, 334 species from 117 genera were identified in both polar regions, i.e. 210 spp. (98 genera) in the Arctic, 120 spp. (73 genera) in the maritime and 59 spp. (41 genera) in the continental Antarctic. Forty-four species (13% of all species) were common to both Arctic and Antarctic freshwater bodies and 19 spp. to both Antarctic areas (12% of all species). Many taxa are cosmopolitans but some, e.g. Stentor and Metopus spp., are not, and over 20% of the taxa found in any one of the three areas are new to science. Cluster analysis revealed that species similarity between different biotopes (soil, moss) within a study area was higher than between similar biotopes in different regions. Distinct differences in the species composition of freshwater and terrestrial communities indicate that most limnetic ciliates are not ubiquitously distributed. These observations and the low congruence in species composition between both polar areas, within Antarctica and between high- and temperate-latitude water bodies, respectively, suggest that long-distance dispersal of limnetic ciliates is restricted and that some species have a limited geographical distribution.

  11. Integrated Science and Logistical Planning to Support Big Questions in Antarctic Science

    Science.gov (United States)

    Vaughan, D. G.; Stockings, T. M.

    2015-12-01

    Each year, British Antarctic Survey (BAS) supports an extensive programme of science at five Antarctic and sub-Antarctic stations, ranging from the tiny Bird Island Research Station at 54°S in the South Atlantic, to the massive, and fully re-locatable, Halley Research Station on Brunt Ice Shelf at 75°S. The BAS logistics hub, Rothera Research Station on the Antarctic Peninsula supports deployment of deep-field and airborne field campaigns through much of the Antarctic continent, and an innovative new UK polar research vessel is under design, and planned to enter service in the Southern Ocean in 2019. BAS's core science programme covering all aspects of physical, biological and geological science is delivered by our own science teams, but every year many other UK scientists and overseas collaborators also access BAS's Antarctic logistics to support their own programmes. As an integrated science and logistics provider, BAS is continuously reviewing its capabilities and operational procedures to ensure that the future long-term requirements of science are optimally supported. Current trends are towards providing the capacity for heavier remote operations and larger-scale field camps, increasing use of autonomous ocean and airborne platforms, and increasing opportunities to provide turnkey solutions for low-cost experimental deployments. This talk will review of expected trends in Antarctic science and the opportunities to conduct science in Antarctica. It will outline the anticipated logistic developments required to support future stakeholder-led and strategically-directed science programmes, and the long-term ambitions of our science communities indentified in several recent horizon-scanning activities.

  12. George Eliot's interrogation of physiological future knowledge.

    Science.gov (United States)

    Claggett, Shalyn

    2011-01-01

    This essay tracks George Eliot's sustained interest in the epistemological problems surrounding the Victorian tendency to envision the future through the body's materiality. It argues that her nuanced criticism of phrenology in "The Lifted Veil" (1859) and "A Minor Prophet" (1865) addresses the delimiting psychological and social effects that attend an applied theory of physiological determinism. Returning to this problem in Daniel Deronda (1876), Eliot offers Mordecai's plan to posit Deronda's body as a living emblem as a radical alternative to racial iconography and typological meaning—a move that allowed her to reconcile the body's legibility with a future beyond socially inscribed possibilities.

  13. George Sand [Reseña

    OpenAIRE

    Jack, Belinda; Thomas, Florence

    2002-01-01

    Belinda Jack nos cuenta en ese libro la vida de George Sand (de su verdadero nombre Aurora Dupin), esa mujer libertaria del siglo XIX, lo años de su nacimiento, su infancia, su adolescencia y su vida adulta. Una vida tan llena tanto por sus luchas interiores -Sand es una mujer que desde su adolescencia tratará de romper los fatalismos ligados a la condición de mujer del siglo XIX, un siglo profundamente familista y maternalista- como por su inmensa obra literaria que cuenta más de cincuenta n...

  14. George Williams, theoretician and guerilla environmentalist.

    Science.gov (United States)

    Low, Bobbi S

    2005-03-01

    George Williams is rightly honored for his contributions to basic biological theory. In addition, however, his thought and contribution paved the way for much needed integration of basic evolutionary theory and modern environmental problems. Specifically, his contributions to the levels of selection" debate, and his application of these contributions to the "Gaia" approach to ecological problems, may help us improve our ability to move past untested prescriptions to a thoughtful matching of the characteristics of the problem and solution, and thus improve our effectiveness.

  15. Molecular clock evidence for survival of Antarctic cyanobacteria (Oscillatoriales, Phormidium autumnale) from Paleozoic times.

    Science.gov (United States)

    Strunecký, Otakar; Elster, Josef; Komárek, Jiří

    2012-11-01

    Cyanobacteria are well adapted to freezing and desiccation; they have been proposed as possible survivors of comprehensive Antarctic glaciations. Filamentous types from the order Oscillatoriales, especially the species Phormidium autumnale Kützing ex Gomont 1892, have widely diverse morphotypes that dominate in Antarctic aquatic microbial mats, seepages, and wet soils. Currently little is known about the dispersion of cyanobacteria in Antarctica and of their population history. We tested the hypothesis that cyanobacteria survived Antarctic glaciations directly on site after the Gondwana breakup by using the relaxed and strict molecular clock in the analysis of the 16S rRNA gene. We estimated that the biogeographic history of Antarctic cyanobacteria belonging to P. autumnale lineages has ancient origins. The oldest go further back in time than the breakup of Gondwana and originated somewhere on the supercontinent between 442 and 297 Ma. Enhanced speciation rate was found around the time of the opening of the Drake Passage (c. 31-45 Ma) with beginning of glaciations (c. 43 Ma). Our results, based primarily on the strains collected in maritime Antarctica, mostly around James Ross Island, support the hypothesis that long-term survival took place in glacial refuges. The high morphological diversification of P. autumnale suggested the coevolution of lineages and formation of complex associations with different morphologies, resulting in a specific endemic Antarctic cyanobacterial flora.

  16. Algal and fungal diversity in Antarctic lichens.

    Science.gov (United States)

    Park, Chae Haeng; Kim, Kyung Mo; Elvebakk, Arve; Kim, Ok-Sun; Jeong, Gajin; Hong, Soon Gyu

    2015-01-01

    The composition of lichen ecosystems except mycobiont and photobiont has not been evaluated intensively. In addition, recent studies to identify algal genotypes have raised questions about the specific relationship between mycobiont and photobiont. In the current study, we analyzed algal and fungal community structures in lichen species from King George Island, Antarctica, by pyrosequencing of eukaryotic large subunit (LSU) and algal internal transcribed spacer (ITS) domains of the nuclear rRNA gene. The sequencing results of LSU and ITS regions indicated that each lichen thallus contained diverse algal species. The major algal operational taxonomic unit (OTU) defined at a 99% similarity cutoff of LSU sequences accounted for 78.7-100% of the total algal community in each sample. In several cases, the major OTUs defined by LSU sequences were represented by two closely related OTUs defined by 98% sequence similarity of ITS domain. The results of LSU sequences indicated that lichen-associated fungi belonged to the Arthoniomycetes, Eurotiomycetes, Lecanoromycetes, Leotiomycetes, and Sordariomycetes of the Ascomycota, and Tremellomycetes and Cystobasidiomycetes of the Basidiomycota. The composition of major photobiont species and lichen-associated fungal community were mostly related to the mycobiont species. The contribution of growth forms or substrates on composition of photobiont and lichen-associated fungi was not evident.

  17. St. George at Prague Castle and Perseus: an Impossible Encounter?

    OpenAIRE

    Bažant, J. (Jan)

    2015-01-01

    St. George and Perseus crossed their paths for the first time in the 11th century when the myth of Greek hero inspired the legend of a Christian saint. In the 14th century, the pictorial types of St. George, Perseus and Bellerphon fighting the dragon started converging. The famous bronze statue of St. George at the Prague Castle, which was creted in 1373, represents an advanced stage opf the process.

  18. Open-ocean barriers to dispersal: a test case with the Antarctic Polar Front and the ribbon worm Parborlasia corrugatus (Nemertea: Lineidae).

    Science.gov (United States)

    Thornhill, Daniel J; Mahon, Andrew R; Norenburg, Jon L; Halanych, Kenneth M

    2008-12-01

    Open-ocean environments provide few obvious barriers to the dispersal of marine organisms. Major currents and/or environmental gradients potentially impede gene flow. One system hypothesized to form an open-ocean dispersal barrier is the Antarctic Polar Front, an area characterized by marked temperature change, deep water, and the high-flow Antarctic Circumpolar current. Despite these potential isolating factors, several invertebrate species occur in both regions, including the broadcast-spawning nemertean worm Parborlasia corrugatus. To empirically test for the presence of an open-ocean dispersal barrier, we sampled P. corrugatus and other nemerteans from southern South America, Antarctica, and the sub-Antarctic islands. Diversity was assessed by analyzing mitochondrial 16S rRNA and cytochrome c oxidase subunit I sequence data with Bayesian inference and tcs haplotype network analysis. Appropriate neutrality tests were also employed. Although our results indicate a single well-mixed lineage in Antarctica and the sub-Antarctic, no evidence for recent gene flow was detected between this population and South American P. corrugatus. Thus, even though P. corrugatus can disperse over large geographical distances, physical oceanographic barriers (i.e. Antarctic Polar Front and Antarctic Circumpolar Current) between continents have likely restricted dispersal over evolutionary time. Genetic distances and haplotype network analysis between South American and Antarctic/sub-Antarctic P. corrugatus suggest that these two populations are possibly two cryptic species.

  19. Chemical studies of differentiated meteorites. I - Labile trace elements in Antarctic and non-Antarctic eucrites

    Science.gov (United States)

    Paul, Rick L.; Lipschutz, Michael E.

    1990-01-01

    Element contents of Ag, Au, Bi, Cd, Co, Cs, Ga, In, Rb, Sb, Se, Te, Tl, U, and Zn were analyzed, using RNAA, in 25 Antarctic and nine non-Antarctic eucrites to determine whether these two populations differ significantly in thermal history and derive from the same or different eucrite parent body. Data for these 15 elements indicate that basaltic Antarctic and non-Antarctic eucrite populations reflect the same genetic processes and, hence, come from the same parent asteroid.

  20. TECHNIQUE AND STYLE OF GEORGE BALANCHINE SCHOOL

    Directory of Open Access Journals (Sweden)

    Petr A. Silkin

    2016-02-01

    Full Text Available Creativity of any outstanding master in any art has always attracted and attracts keen interest. One of the most influential figures in the 20th century, who created the classical Ballet in America, was George Balanchine. His greatest merit was that he, by taking the steps of classical dance of St. Petersburg as a base, managed to give it a totally different context. By his comparative methodological approach the author confirms that Balanchine founded his school on the basis of the Russian school of classical dance of pre-Vaganova period, modifying it by taking into account the characteristics of the American national character, as well as the psychological and physical structure of the performers. Thus Balanchine developed neoclassicism, a form that combines the essence of the Russian ballet with modern and dynamic sensuality of American audience. The author's main goal is to show the technique and style of George Balanchine. He takes into consideration the basic dance steps showing how these steps are performing according to Balanchine's interpretation and differentiated from Soviet, Vaganova Ballet School. The author discusses fundamental skills on which classical technique is based: battement tendu, battement fondu, battement développé, enveloppé, general details of adagio, and pointe work. The paper has its implication in promoting pedagogical approach that insists in mastering basic movements in students in order to develop skills and speed necessary for superb dancers.

  1. Concept design of HAYATE : Small satellite for supporting Antarctic geophysical observation

    OpenAIRE

    Yoshihara, Keisuke; Sugiura, Yoshiki; Sekiguchi,Masato; Ui, Kyoichi; Tsurumi,Singo; Nakaya, Koji; Mori, Makoto; Matsunaga, Saburo; Ohkami, Yoshiaki

    1999-01-01

    This paper presents the results of conceptual design of a small communication satellite (HAYATE) for supporting research in Antarctica and remote islands. The HAY ATE satellite collects environmental data from unmanned probes located on the Antarctic ice plate and also transmits data from Syowa Station in Antarctica to Japan and the United States. Through the satellite mission analyses, we confirmed that the HAYATE satellite would be able to gather data for GPS baseline analysis and to observ...

  2. Comparative mesocosm study of biostimulation efficiency in two different oil-amended sub-antarctic soils

    OpenAIRE

    Delille, Daniel; Coulon, Frederic

    2008-01-01

    Biological treatment has become increasingly popular as a remediation method for soils and groundwater contaminated with petroleum hydrocarbon, chlorinated solvents, and pesticides. Bioremediation has been considered for application in cold regions such as Arctic and sub-Arctic climates and Antarctica. Studies to date suggest that indigenous microbes suitable for bioremediation exist in soils in these regions. This paper reports on two case studies at the sub-Antarctic Kerguelen Island, in wh...

  3. Leaf and floral heating in cold climates: do sub-Antarctic megaherbs resemble tropical alpine giants?

    OpenAIRE

    Little, Lorna; Eidesen, Pernille Bronken; Müller, Eike; Katharine J M Dickinson; Janice M. Lord

    2016-01-01

    High latitude and altitude floras are characterized by low-statured, small, wind-pollinated plants, which mainly reproduce by self-pollination or asexual reproduction. However, at odds with this are some sub-Antarctic islands that have plant species with giant growth forms and large, brightly coloured flowers which require insect visitation for pollination. The size, colour and shape of the inflorescences and leaves of these megaherbs suggest thermal benefits similar to giant tropical alpine ...

  4. A new mini box corer for sampling muddy bottoms in antarctic shallow waters

    Directory of Open Access Journals (Sweden)

    Carlos Alejandro Echeverría

    2009-06-01

    Full Text Available A new Mini Box Corer (MBC-GEAMB was developed for bottom sampling in Antarctic shallow waters down to 100 m depth from a small vessel. It consists of a detachable stainless steel box with a total sampling area of 0.0625 m², and a closing arm with a detachable blade without an external frame. MBC allowed stratified bottom sampling and good quality samples comparable to those obtained through diving. A comparison between the MBC-GEAMB and a 0.056 m²van Veen grab (VV was undertaken for the benthic macrofaunal composition in Admiralty Bay, King George Island (Antarctica. MBC and VV samples were taken from three depths (20, 30 and 60m in two sites. Total densities sampled with the MBC were up to 10 times higher than those obtained with van Veen grab. VV samples might lead to faunistic abundance underestimation compared to the MBC samples. Besides, MBC showed a higher performance on discriminating different sites as regards total macrofaunal density. It is suggested that MBC could be employed as an efficient remote sampling device for shallow-waters where direct sampling by SCUBA was not advisable.Um novo Mini Box Corer (MBC-GEAMB foi desenvolvido para amostragens de fundo em águas rasas antárticas até 100 metros de profundidade, a partir de embarcações pequenas. Consiste em uma caixa de aço inox destacável com uma área total de amostragem de 0,0625 m², e um braço de fechamento com uma lâmina destacável, sem um suporte externo. MBC permite a amostragem estratificada do sedimento de fundo com amostras de qualidade comparáveis àquelas obtidas através de mergulho autônomo. Uma comparação entre o MBC-GEAMB e um van Veen de área 0,056 m²(VV foi realizada utilizando a composição da macrofauna bentônica na Baía do Almirantado, (Ilha Rei George, Antarctica. Amostragens com MBC e VV foram realizadas em três profundidades (20, 30 e 60m em dois locais. As densidades totais obtidas com o MBC foram até 10 vezes maiores que as obtidas

  5. Multibranch Antarctic Seismic Data Library facilitates research

    Science.gov (United States)

    Cooper, Alan K.

    In 1991, investigators from 11 nations involved in Antarctic multichannel seismic (MCS) reflection research sought a way to keep the Antarctic Treaty's promise of open access to data, and in the process to encourage Earth-science research using seismic data. The Antarctic Seismic Data Library System for Cooperative Research (SDLS) was the solution, and is now a recommendation of the Antarctic Treaty Consultative Parties (ATCP). Today—at 12 branches spanning the world—researchers can access over 68,000 km of marine MCS data to use for cooperative research.More than 150,000 km of MCS data have been accumulated since 1976 by 13 countries on nearly 70 cruises. The majority of data now in the library cover the Ross Sea, Wilkes Land, and Prydz Bay sectors of the Antarctic margin, with smaller amounts from the Weddell Sea and the Antarctic Peninsula.

  6. Development of a multi-parameter system for Antarctic researching

    Science.gov (United States)

    Garcia, Alicia; Peci, Luis Miguel; Berrocoso, Manuel; Fernandez-Ros, Alberto; Marrero, Jose Manuel; Ortiz, Ramon

    2014-05-01

    This work describes the development of a multi-parameter system for antarctic researching. The system permits the remote access and the connection of several modules in a network. An embedded ARM processor has been used, allowing a great flexibility in hardware configuration.The advantage of the system presented in this work is that it allows the rapid development of a monitoring network that uses the latest technologies of embedded systems. These embedded systems offer the possibility of developing the software necessary for managing the sensors and instruments available. Data can be transmitted in near real time or on demand to a Data Reception Center (DRC). The local storage allows retrieving data when the transmission fails and uses only short transmission periods rather than continuous transmission. The price of both hardware and software is very low. The use of a complete Linux solution (Debian) as Operating System permits a quick, easy application development to control sensors and communications. This provides all the capabilities required and great stability with relatively low energy consumption. The cost of the components and applications development is low since they are widely used in different fields. Sensors and commercial modules have been combined with other self-developed modules. The Modular System described has been deployed at Deception Island (Antarctica), within the Spanish Antarctic Program, and has proved successful for monitoring and researching the geodinamical activity, with proven reliability and efficient operation under extreme conditions. Deception Islan is an active volcano with some geothermal areas, this fact has allowed to develop a power system using Peltier cells. In another context, i.e., the recent volcanic activity on El Hierro Island (Canary Islands) in 2011, this technology has been used for the seismic equipment and GPS systems deployed, thus showing its efficiency in the monitoring of a volcanic crisis.

  7. Molecular Cytogenetic Analysis of Deschampsia antarctica Desv. (Poaceae), Maritime Antarctic.

    Science.gov (United States)

    Amosova, Alexandra V; Bolsheva, Nadezhda L; Samatadze, Tatiana E; Twardovska, Maryana O; Zoshchuk, Svyatoslav A; Andreev, Igor O; Badaeva, Ekaterina D; Kunakh, Viktor A; Muravenko, Olga V

    2015-01-01

    Deschampsia antarctica Desv. (Poaceae) (2n = 26) is one of the two vascular plants adapted to the harshest environment of the Antarctic. Although the species is a valuable model for study of environmental stress tolerance in plants, its karyotype is still poorly investigated. We firstly conducted a comprehensive molecular cytogenetic analysis of D. antarctica collected on four islands of the Maritime Antarctic. D. antarctica karyotypes were studied by Giemsa C- and DAPI/C-banding, Ag-NOR staining, multicolour fluorescence in situ hybridization with repeated DNA probes (pTa71, pTa794, telomere repeats, pSc119.2, pAs1) and the GAA simple sequence repeat probe. We also performed sequential rapid in situ hybridization with genomic DNA of D. caespitosa. Two chromosome pairs bearing transcriptionally active 45S rDNA loci and five pairs with 5S rDNA sites were detected. A weak intercalary site of telomere repeats was revealed on the largest chromosome in addition to telomere hybridization signals at terminal positions. This fact confirms indirectly the hypothesis that chromosome fusion might have been the cause of the unusual for cereals chromosome number in this species. Based on patterns of distribution of the examined molecular cytogenetic markers, all chromosomes in karyotypes were identified, and chromosome idiograms of D. antarctica were constructed. B chromosomes were found in most karyotypes of plants from Darboux Island. A mixoploid plant with mainly triploid cells bearing a Robertsonian rearrangement was detected among typical diploid specimens from Great Jalour Island. The karyotype variability found in D. antarctica is probably an expression of genome instability induced by environmental stress factors. The differences in C-banding patterns and in chromosome distribution of rDNA loci as well as homologous highly repeated DNA sequences detected between genomes of D. antarctica and its related species D. caespitosa indicate that genome reorganization involving

  8. Assessing environmental conditions of Antarctic footpaths to support management decisions.

    Science.gov (United States)

    Tejedo, Pablo; Benayas, Javier; Cajiao, Daniela; Albertos, Belén; Lara, Francisco; Pertierra, Luis R; Andrés-Abellán, Manuela; Wic, Consuelo; Luciáñez, Maria José; Enríquez, Natalia; Justel, Ana; Reck, Günther K

    2016-07-15

    Thousands of tourists visit certain Antarctic sites each year, generating a wide variety of environmental impacts. Scientific knowledge of human activities and their impacts can help in the effective design of management measures and impact mitigation. We present a case study from Barrientos Island in which a management measure was originally put in place with the goal of minimizing environmental impacts but resulted in new undesired impacts. Two alternative footpaths used by tourist groups were compared. Both affected extensive moss carpets that cover the middle part of the island and that are very vulnerable to trampling. The first path has been used by tourists and scientists since over a decade and is a marked route that is clearly visible. The second one was created more recently. Several physical and biological indicators were measured in order to assess the environmental conditions for both paths. Some physical variables related to human impact were lower for the first path (e.g. soil penetration resistance and secondary treads), while other biochemical and microbiological variables were higher for the second path (e.g. β-glucosidase and phosphatase activities, soil respiration). Moss communities located along the new path were also more diverse and sensitive to trampling. Soil biota (Collembola) was also more abundant and richer. These data indicate that the decision to adopt the second path did not lead to the reduction of environmental impacts as this path runs over a more vulnerable area with more outstanding biological features (e.g. microbiota activity, flora and soil fauna diversity). In addition, the adoption of a new route effectively doubles the human footprint on the island. We propose using only the original path that is less vulnerable to the impacts of trampling. Finally from this process, we identify several key issues that may be taken into account when carrying out impact assessment and environmental management decision-making in the

  9. Faroe Islands

    DEFF Research Database (Denmark)

    Christoffersen, Lisbet

    2015-01-01

    An update introduction including recent legislative changes on the Folkchurch of the Faroe Islands......An update introduction including recent legislative changes on the Folkchurch of the Faroe Islands...

  10. Snow on Antarctic sea ice

    Science.gov (United States)

    Massom, Robert A.; Eicken, Hajo; Hass, Christian; Jeffries, Martin O.; Drinkwater, Mark R.; Sturm, Matthew; Worby, Anthony P.; Wu, Xingren; Lytle, Victoria I.; Ushio, Shuki; Morris, Kim; Reid, Phillip A.; Warren, Stephen G.; Allison, Ian

    2001-08-01

    Snow on Antarctic sea ice plays a complex and highly variable role in air-sea-ice interaction processes and the Earth's climate system. Using data collected mostly during the past 10 years, this paper reviews the following topics: snow thickness and snow type and their geographical and seasonal variations; snow grain size, density, and salinity; frequency of occurrence of slush; thermal conductivity, snow surface temperature, and temperature gradients within snow; and the effect of snow thickness on albedo. Major findings include large regional and seasonal differences in snow properties and thicknesses; the consequences of thicker snow and thinner ice in the Antarctic relative to the Arctic (e.g., the importance of flooding and snow-ice formation); the potential impact of increasing snowfall resulting from global climate change; lower observed values of snow thermal conductivity than those typically used in models; periodic large-scale melt in winter; and the contrast in summer melt processes between the Arctic and the Antarctic. Both climate modeling and remote sensing would benefit by taking account of the differences between the two polar regions.

  11. Direct gravimetric measurements of the mass of the antarctic aerosol collected by high volume sampler: PM10 summer seasonal variation at Terra Nova Bay.

    Science.gov (United States)

    Truzzi, Cristina; Lambertucci, Luca; Illuminati, Silvia; Annibaldi, Anna; Scarponi, Giuseppe

    2005-01-01

    An on-site procedure was set up for direct gravimetric measurement of the mass of aerosol collected using high volume impactors (aerodynamic size cut point of 10 microm, PM10); this knowledge has hitherto been unavailable. Using a computerized microbalance in a clean chemistry laboratory, under controlled temperature (+/-0.5 degrees C) and relative humidity (+/-1%), continuous, long time filter mass measurements (hours) were carried out before and after exposure, after a 48 h minimun equilibration at the laboratory conditions. The effect of the electrostatic charge was exhausted in 30-60 min, after which stable measurements were obtained. Measurements of filters exposed for 7-11 days (1.13 m3 min(-1)) in a coastal site near Terra Nova Bay (December 2000 - February 2001), gave results for aerosol mass in the order of 10-20 mg (SD approximately 2 mg), corresponding to atmospheric concentrations of 0.52-1.27 microg m(-3). Data show a seasonal behaviour in the PM10 content with an increase during December - early January, followed by a net decrease. The above results compare well with estimates obtained from proxy data for the Antarctic Peninsula (0.30 microg m(-3)), the Ronne Ice Shelf (1.49 microg m(-3)), and the South Pole (0.18 microg m(-3), summer 1974-1975, and 0.37 microg m(-3), average summer seasons 1975-1976 and 1977-1978), and from direct gravimetric measurements recently obtained from medium volume samplers at McMurdo station (downwind 3.39 microg m(-3), upwind 4.15 microg m(-3)) and at King George Island (2.5 microg m(-3), summer, particle diameter <20 microm). This finding opens the way to the direct measurement of the chemical composition of the Antarctic aerosol and, in turn, to a better knowledge of the snow/air relationships as required for the reconstruction of the chemical composition of past atmospheres from deep ice core data.

  12. Evaluation of single-band snow-patch mapping using high-resolution microwave remote sensing: an application in the maritime Antarctic

    Science.gov (United States)

    Mora, Carla; Jiménez, Juan Javier; Pina, Pedro; Catalão, João; Vieira, Gonçalo

    2017-01-01

    The mountainous and ice-free terrains of the maritime Antarctic generate complex mosaics of snow patches, ranging from tens to hundreds of metres. These can only be accurately mapped using high-resolution remote sensing. In this paper we evaluate the application of radar scenes from TerraSAR-X in High Resolution SpotLight mode for mapping snow patches at a test area on Fildes Peninsula (King George Island, South Shetlands). Snow-patch mapping and characterization of snow stratigraphy were conducted at the time of image acquisition on 12 and 13 January 2012. Snow was wet in all studied snow patches, with coarse-grain and rounded crystals showing advanced melting and with frequent ice layers in the snow pack. Two TerraSAR-X scenes in HH and VV polarization modes were analysed, with the former showing the best results when discriminating between wet snow, lake water and bare soil. However, significant overlap in the backscattering signal was found. Average wet-snow backscattering was -18.0 dB in HH mode, with water showing -21.1 dB and bare soil showing -11.9 dB. Single-band pixel-based and object-oriented image classification methods were used to assess the classification potential of TerraSAR-X SpotLight imagery. The best results were obtained with an object-oriented approach using a watershed segmentation with a support vector machine (SVM) classifier, with an overall accuracy of 92 % and Kappa of 0.88. The main limitation was the west to north-west facing snow patches, which showed significant error, an issue related to artefacts from the geometry of satellite imagery acquisition. The results show that TerraSAR-X in SpotLight mode provides high-quality imagery for mapping wet snow and snowmelt in the maritime Antarctic. The classification procedure that we propose is a simple method and a first step to an implementation in operational mode if a good digital elevation model is available.

  13. Hans-Georg Gadamer, Language, and Intercultural Communication.

    Science.gov (United States)

    Roy, Abhik; Starosta, William J.

    2001-01-01

    Shows how Hans-Georg Gadamer's critical hermeneutics can be applied to intercultural communication. Suggests that by incorporating the philosophies of Hans-Georg Gadamer, intercultural communication scholars will be able to bring a fresh perspective to guide their theory, research, and practice. (Author/VWL)

  14. Our Western Heritage: An Interview with Robert George

    Science.gov (United States)

    Iannone, Carol

    2012-01-01

    This article presents an interview with Robert George, who holds Princeton's celebrated McCormick Chair in Jurisprudence and is the founding director of the James Madison Program. George has served on the President's Council on Bioethics and as a presidential appointee to the United States Commission on Civil Rights. He is also a member of the…

  15. George C.Lee Honored by White House

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ On November 16,2007,George C.Lee,the editor-in-chief of our journal-Earthquake Engineering and Engineering Vibration (EEEV),was among 11 people to receive a 2006 Presidential Award for Excellence in Science,Mathematics and Engineering Mentoring (PAESMEM) from President George W.Bush in a ceremony at the White House.

  16. Gilbert ja George lasevad oma kunstiteose alla laadida

    Index Scriptorium Estoniae

    2007-01-01

    9.05.2007 öösel on kõigil soovijail võimalik tasuta interneti vahendusel omandada Londonis tegutseva kunstnikepaari Gilbert & George (Gilbert Proesch ja George Passmore) teos "Planed". Aadressid: www.bbc.co.uk/imagine ja www.guardian.co.uk/art

  17. An Analysis of George Eliot's Positive Attitude towards Feminism

    Institute of Scientific and Technical Information of China (English)

    马寒

    2011-01-01

    As a woman writer in Victorian England,George Eliot,who comes to us almost uncontested as one of the greatest English writers in the nineteenth century,has aroused great enthusiasm in the literary world to study her from a feminist perspective.This thesis attempts to explore George Eliot's positive attitude towards feminism presented through herself and her novels.

  18. "The George Lopez Show": The Same Old Hispano?

    Science.gov (United States)

    Markert, John

    2007-01-01

    "The George Lopez Show" is the first successful television show with a Latino in a leading role that features Hispanic material since Freddie Prinze's thirty-year-old sitcom, "Chico and the Man." This study seeks to assess how Latinos are presented on "The George Lopez Show." A content analysis reveals that the show perpetuates some of the…

  19. Gilbert ja George lasevad oma kunstiteose alla laadida

    Index Scriptorium Estoniae

    2007-01-01

    9.05.2007 öösel on kõigil soovijail võimalik tasuta interneti vahendusel omandada Londonis tegutseva kunstnikepaari Gilbert & George (Gilbert Proesch ja George Passmore) teos "Planed". Aadressid: www.bbc.co.uk/imagine ja www.guardian.co.uk/art

  20. Hans-Georg Gadamer, Language, and Intercultural Communication.

    Science.gov (United States)

    Roy, Abhik; Starosta, William J.

    2001-01-01

    Shows how Hans-Georg Gadamer's critical hermeneutics can be applied to intercultural communication. Suggests that by incorporating the philosophies of Hans-Georg Gadamer, intercultural communication scholars will be able to bring a fresh perspective to guide their theory, research, and practice. (Author/VWL)

  1. George Engel's Epistemology of Clinical Practice.

    Science.gov (United States)

    Saraga, Michael; Fuks, Abraham; Boudreau, J Donald

    2014-01-01

    George Engel's (1913-1999) biopsychosocial model, one of the most significant proposals for the renewal of medicine in the latter half of the 20th century, has been understood primarily as a multi-factorial approach to the etiology of disease and as a call to re-humanize clinical practice. This common reading of Engel's model misses the central aspect of his proposal, that the biopsychosocial model is an epistemology for clinical work. By stating the simple fact that the clinician is not dealing directly with a body, but first, and inevitably, with a person, Engel challenged the epistemology implicit in the classical clinical method-a method predicated on the possibility of direct access to the body. Framed in epistemological terms, the issue at stake is not the need to complement medical science with humane virtues, but rather to acknowledge that the object of clinical practice is not the body but the patient.

  2. George Orwell and 1984: a personal view

    Directory of Open Access Journals (Sweden)

    ALFREDO SANDOVAL GÓMEZ

    2013-11-01

    Full Text Available George Orwell´s 1984 is considered a great negative utopia, in the sense it depicts the nightmare of what life might become in an oligarchic collectivism pursued to its logical conclusion. Under a social setup which is nothing but totalitarian barbarism, eternal warfare is the price one pays for an elusive peace. The Party with capital P keeps a total control over all of man´s actions as well as thoughts . The novel is a great satire and it attempts to diagnose man´s alienation in all its aspects, but with special emphasis on the social organization recommended by Marx and practiced by Stalin.  

  3. The Georg Jensen and Alessi Design

    DEFF Research Database (Denmark)

    Tanderup, Sisse

    2009-01-01

    as an independent identity category in design research. This article deals with the use of the memory theme in design examples from the two companies Georg Jensen and Alessi. Italian design practice is characterized by a tradition of involving memory categories from Italian history, philosophy, art and tradition...... in the design process. Alessi's motivation for involving the concept of memory is that it adds a cultural dimension to the design objects, enabling the objects to make an identity-forming impact. Compared to this, Danish and Scandinavian design practice has traditionally focused on form and function...... with frequent references to the forms of nature. This does not necessarily mean that the memory theme does not form a part of Danish design. Whereas memory is used deliberately in Italian design, it is perhaps manifested more intuitively as a non-culturally generated memory in Danish design, a memory, which...

  4. George Howard Herbig, 1920-2013

    CERN Document Server

    Soderblom, David R

    2014-01-01

    A great astronomer, George Herbig, passed away in Honolulu on October 12, 2013, at the age of 93. His life and career were long and productive, and consistently dedicated to the careful, thorough research that earned him his reputation. Herbig spent most of his career at Lick Observatory, first as a graduate student, and then from 1949 to 1987 as a staff member, rising through the ranks to Astronomer and becoming Professor as well when the observatory moved to the University of California at Santa Cruz in the late 1960s. Herbig retired from UCSC in 1987 and spent the remainder of his life in Honolulu at the Institute for Astronomy of the University of Hawai`i.

  5. Georges Sagnac: A life for optics

    Science.gov (United States)

    Darrigol, Olivier

    2014-12-01

    Georges Sagnac is mostly known for the optical effect in rotating frames that he demonstrated in 1913. His scientific interests were quite diverse: they included photography, optical illusions, X-ray physics, radioactivity, the blue of the sky, anomalous wave propagation, interferometry, strioscopy, and acoustics. An optical theme nonetheless pervaded his entire œuvre. Within optics, an original theory of the propagation of light motivated most of his investigations, from an ingenious explanation of the Fresnel drag, through the discovery of the Sagnac effect, to his quixotic defense of an alternative to relativity theory. Optical analogies efficiently guided his work in other domains. Optics indeed was his true passion. He saw himself as carrying the torch of the two great masters of French optics, Augustin Fresnel and Hippolyte Fizeau. In this mission he overcame his poor health and labored against the modernist tide, with much success originally and bitter isolation in the end. xml:lang="fr"

  6. Palynofacial approach across the Cretaceous - Paleogene boundary in Marambio (Seymour Island, Antarctic Peninsula Enfoque palinofacial a través del límite Cretácico - Paleógeno en la Isla Marambio (Seymour, Península Antártica

    Directory of Open Access Journals (Sweden)

    R. Rodríguez Brizuela

    2007-06-01

    Full Text Available This study analyzes the palynological organic matter behavior throughout the Cretaceous- Paleogene boundary in Marambio (Seymour Island, Antarctic Peninsula. The boundary is located in the upper part of the López de Bertodano Formation, coinciding with a widespread glauconitic level. Fifteen samples were analyzed and associated with four palynofacies. Defined palynofacies indicate an inner shelf marine environment of sedimentation. The palynofacial assemblages permitted discriminating the studied section into three minor stratigraphical intervals related to three sea-level stages. The integration of these stages results in a hypothetical sea-level curve, which reflects a minor transgressive - regressive pulse into a general regressive trend. The maximun water depth is about 1 m below the postulated K/P boundary. Palinofacial recognition of this pulse supports the earlier idea of a slow transgressive-regressive event with minor internal transgressive-regressive cycles. Palynofacial data indicates preservation of the organic matter across the K-P boundary, and therefore do not suggest any local effect of the hypothetical global catastrophic K/P event. Considering the monotonous lithology of the López de Bertodano Formation that makes the recognition of unconformities difficult, this work opens the possibility of applying a sequence stratigraphic approach based on the recognition of maximum flooding surfaces for future investigations.El presente estudio analiza el comportamiento de la materia orgánica palinológica a través del límite Cretácico-Paleógeno de la Isla Marambio (Seymour. El límite estudiado se encuentra en la sección superior de la Formación López de Bertodano y coincide con un horizonte glauconítico. Se analizaron quince muestras las cuales fueron agrupadas en cuatro palinofacies de acuerdo a la composición porcentual de la materia orgánica. La caracterización palinofacial es indicativa de un ambiente de depositaci

  7. Carbon dioxide emissions of Antarctic tourism

    NARCIS (Netherlands)

    Farreny, R.; Oliver-Solà, J.; Lamers, M.A.J.; Amelung, B.; Gabarrell, X.; Rieradevall, J.; Boada, M.; Benayas, J.

    2011-01-01

    The increase of tourism to the Antarctic continent may entail not only local but also global environmental impacts. These latter impacts, which are mainly caused by transport, have been generally ignored. As a result, there is a lack of data on the global impacts of Antarctic tourism in terms of

  8. South African antarctic biological research programme

    CSIR Research Space (South Africa)

    SASCAR

    1981-07-01

    Full Text Available This document provides a description of the past, current and planned South African biological research activities in the sub-Antarctic and Antarctic regions. Future activities will fall under one of the five components of the research programme...

  9. JCADM, new directions in Antarctic data management

    Science.gov (United States)

    Campbell, H.; de Bruin, T. F.

    2008-12-01

    The Joint Committee on Antarctic Data Management (JCADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP), to assist in the fulfilment of the data management obligations imposed by the Antarctic Treaty (section III.1.c): "Scientific observations and results from Antarctica shall be exchanged and made freely available." JCADM comprises representatives of the National Antarctic Data Centres or national points of contact. Currently 31 nations around the world are represented in JCADM. So far, JCADM has been focussing on the coordination of the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. Currently, JCADM is in a transition phase, moving forward to provide data access. Existing systems and web services technology will be used as much as possible, to increase efficiency and prevent 're-inventing the wheel' This poster will give an overview of this process, the current status and the expected results.

  10. Impact of climate change on Antarctic krill

    NARCIS (Netherlands)

    Florentino De Souza Silva, A.P.; Atkinson, A.; Kawaguchi, S.; Bravo Rebolledo, E.; Franeker, van J.A.

    2012-01-01

    Antarctic krill Euphausia superba (hereafter ‘krill’) occur in regions undergoing rapid environmental change, particularly loss of winter sea ice. During recent years, harvesting of krill has increased, possibly enhancing stress on krill and Antarctic ecosystems. Here we review the overall impact of

  11. Impact of climate change on Antarctic krill

    NARCIS (Netherlands)

    Florentino De Souza Silva, A.P.; Atkinson, A.; Kawaguchi, S.; Bravo Rebolledo, E.; Franeker, van J.A.

    2012-01-01

    Antarctic krill Euphausia superba (hereafter ‘krill’) occur in regions undergoing rapid environmental change, particularly loss of winter sea ice. During recent years, harvesting of krill has increased, possibly enhancing stress on krill and Antarctic ecosystems. Here we review the overall impact of

  12. Past Penguin Colony Linkages to Climate Change and Catastrophic Volcanism on the Northern Antarctic Peninsula

    Science.gov (United States)

    Roberts, S. J.; Monien, P.; Foster, L. C.; Loftfield, J.; Schnetger, B.; Pearson, E. J.; Hocking, E. P.; Fretwell, P.; Ireland, L.; Ochyra, R.; Haworth, A.; Allen, C. S.; Brumsack, H. J.; Bentley, M.; Hodgson, D.

    2016-12-01

    Recent warming and reductions in sea-ice in some parts of Antarctica are thought to be having a negative impact on populations of `ice-dependent' penguin species (e.g., Emperor, Adélie) that feed at the sea-ice edge because populations of `ice-avoiding'/more `adaptable' species (e.g., Gentoo, Chinstrap) have remained stable or increased, and some Adélie colonies located in areas of sea-ice expansion have increased. This hypothesis is based on short observational records and limited subfossil evidence, but has not been tested over longer, mid-late Holocene, timescales on the Antarctic Peninsula. Between 1950-1997, the northern Antarctic Peninsula was one of the most rapidly warming regions in the Southern Hemisphere and, over the last 30 years, the largest breeding population of Gentoo penguins in Antarctica on Ardley Island, north-western Antarctic Peninsula, has increased. We tracked past changes in the Ardley Island penguin colony size by comparing detailed biogeochemical analysis of an 8,500-year Ardley Lake sediment profile with past records of penguin presence, climate and sea-ice extent across the Antarctic Peninsula and found that the colony also responded positively during some local-regionally warmer parts of the late Holocene. However, at least three large volcanic eruptions from nearby Deception Island had a devastating impact on the colony between 7000-2000 years ago, with colony recovery taking up to 800 years following the most disruptive period of volcanic activity c. 5500-5000 years ago.

  13. The oldest elasmosaurs (Sauropterygia, Plesiosauria from Antarctica, Santa Marta Formation (upper Coniacian? Santonian–upper Campanian and Snow Hill Island Formation (upper Campanian–lower Maastrichtian, James Ross Island

    Directory of Open Access Journals (Sweden)

    José P. O'Gorman

    2012-10-01

    Full Text Available Elasmosaurs are recorded for the first time in the Lachman Crags Member (Beta Member of the Santa Marta Formation (lower Campanian and in the Herbert Sound Member of the Snow Hill Island Formation (upper Campanian. These are the first elasmosaurids from James Ross Island, Antarctic Peninsula. These records greatly improve our knowledge of the taxonomic diversity of plesiosaurs of the Santa Marta Formation and Herbert Sound Member of the Snow Hill Island Formation, and extend the lower limit of the record of Elasmosauridae in Antarctica to the lower Campanian, making this the oldest record of an Antarctic elasmosaur.

  14. Galapagos Islands

    Science.gov (United States)

    2002-01-01

    This true-color image of the Galapagos Islands was acquired on March 12, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra satellite. The Galapagos Islands, which are part of Ecuador, sit in the Pacific Ocean about 1000 km (620 miles) west of South America. As the three craters on the largest island (Isabela Island) suggest, the archipelago was created by volcanic eruptions, which took place millions of years ago. Unlike most remote islands in the Pacific, the Galapagos have gone relatively untouched by humans over the past few millennia. As a result, many unique species have continued to thrive on the islands. Over 95 percent of the islands' reptile species and nearly three quarters of its land bird species cannot be found anywhere else in the world. Two of the more well known are the Galapagos giant tortoise and marine iguanas. The unhindered evolutionary development of the islands' species inspired Charles Darwin to begin The Origin of Species eight years after his visit there. To preserve the unique wildlife on the islands, the Ecuadorian government made the entire archipelago a national park in 1959. Each year roughly 60,000 tourists visit these islands to experience what Darwin did over a century and a half ago. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

  15. Anti-inflammatory activity in selected Antarctic benthic organisms

    Directory of Open Access Journals (Sweden)

    Juan eMoles

    2014-07-01

    Full Text Available Antarctic benthos was prospected in search for anti-inflammatory activity in polar benthic invertebrates, in two different geographical areas: deep-bottoms of the Eastern Weddell Sea and shallow-waters of the South Shetland Islands. A total of 36 benthic algae and invertebrate species were selected to perform solubility tests in order to test them for anti-inflammatory activity. From these, ethanol extracts of ten species from five different phyla resulted suitable to be studied in cell macrophage cultures (RAW 264.7. Cytotoxicity (MTT method and production of inflammatory mediators (prostaglandin E2, leukotriene B4, interleukin-1 were determined at three extract concentrations (50, 125, 250 g/mL. Bioassays resulted in four different species showing anti-inflammatory activity corresponding to three sponges: Mycale (Oxymycale acerata, Isodictya erinacea, and I. toxophila; and one hemichordate: Cephalodiscus sp. These results show that Antarctic sessile invertebrates may have great value as a source of lead compounds with potential pharmaceutical applications.

  16. Influence of Ross Sea Bottom Water changes on the warming and freshening of the Antarctic Bottom Water in the Australian-Antarctic Basin

    Directory of Open Access Journals (Sweden)

    K. Shimada

    2012-07-01

    Full Text Available Changes to the properties of Antarctic Bottom Water in the Australian-Antarctic Basin (AA-AABW between the 1990s and 2000s are documented using data from the WOCE Hydrographic Program (WHP and repeated hydrographic surveys. Strong cooling and freshening are observed on isopycnal layers denser than γn = 28.30 kg m−3. Changes in the average salinity and potential temperature below this isopycnal correspond to a basin-wide warming of 1300 ± 200 GW and freshening of 24 ± 3 Gt year−1. Recent changes to dense shelf water in the source regions in the Ross Sea and George V Land can explain the freshening of AA-AABW but not its extensive warming. An alternative mechanism for this warming is a decrease in the supply of AABW from the Ross Sea (RSBW. Hydrographic profiles between the western Ross Sea and George V Land (171–158° E were analyzed with a simple advective-diffusive model to assess the causes of the observed changes. The model suggests that the warming of RSBW observed between the 1970s and 2000s can be explained by a 21 ± 23% reduction in RSBW transport and the enhancement of the vertical diffusion of heat resulting from a 30 ± 7% weakening of the abyssal stratification. The documented freshening of Ross Sea dense shelf water leads to a reduction in both salinity and density stratification. Therefore the direct freshening of RSBW at its source also produces an indirect warming of the RSBW. A simple box model suggests that the changes in RSBW properties and volume transport (a decrease of 6.7% is assumed between the year 1995 and 2005 can explain 51 ± 6% of the warming and 84 ± 10% of the freshening observed in AA-AABW.

  17. On the distribution of decapod crustaceans from the Magellan Biogeographic Province and the Antarctic region

    Directory of Open Access Journals (Sweden)

    Enrique E. Boschi

    2005-12-01

    Full Text Available The distribution of decapod crustaceans in the southernmost areas of South America and the Antarctic is assessed considering the Magellan Biogeographic Province instead of the antiboreal region. Possible associations between decapod crustaceans from the Magellan Biogeographic Province and those from the Antarctic region are analysed. Species records were assigned to seven geographic regions that were clustered using multivariate analyses based on species presence/absence and Bray-Curtis similarity. The results showed two well-established clusters, one of which included the Pacific and Atlantic areas of the Magellan Province, the southern tip of South America and the Kerguelen Arc islands, with the highest similarity between the southern tip and the Atlantic area. Another cluster was well separated and included the Antarctic and South Georgia with the highest similarity index. Earlier studies and results obtained here suggest that the faunas of southern Chile and southern Argentina are biogeographically related. There is a low level of association among decapod species from the circum-Antarctic region and the Magellan Province.

  18. George Smoot talks to the Bulletin

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Antimatter, dark matter, dark energy, the nature of space and time… The Nobel Laureate George Smoot answers Paola Catapano’s questions about his career and the many issues about the Universe that are still open.   You started your scientific career as a particle physicist, but soon you moved to astrophysics and in particular the Big Bang theory and cosmology. What motivated your interest in the Big Bang theory? After I graduated from MIT, I went to Berkeley to work with particle physicist Luis Alvarez. He knew I was interested in many areas and said, “tell me what you would like to do and we’ll try and work on that”. I saw astrophysics as a new field, with a lot of new and exciting opportunities. I started doing experiments looking for antimatter, which eventually led to the idea of ASTROMAG and later to AMS. Studying antimatter, we found that it was in less than one part in 10,000. I thought: “There’s no antimatter around us ...

  19. George A. Miller (1920-2012).

    Science.gov (United States)

    Pinker, Steven

    2013-09-01

    Presents an obituary for George A. Miller (1920-2012). Miller ranks among the most important psychologists of the 20th century. In addition to writing one of the best known papers in the history of psychology ("The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information," published in Psychological Review in 1956), Miller also fomented the cognitive revolution, invented psycholinguistics and cognitive psychology, imported powerful ideas from the theories of information, communication, grammar, semantics, and artificial intelligence, and left us a sparkling oeuvre that proves that a rigorous scientist needn't write in soggy prose. Honors rained down on Miller. APA gave him the Award for Distinguished Scientific Contributions (1963), the American Psychological Foundation Gold Medal Award for Life Achievement in Psychological Science (1990), the William James Book Award (1992, for The Science of Words), and the Award for Lifetime Contributions to Psychology (2003), and named a prize after him, as did the Cognitive Neuroscience Society. Miller was also honored by the Association for Psychological Science and the American Speech and Hearing Association. In 2000, he won the John P. McGovern Award in the Behavioral Sciences from the American Association for the Advancement of Science, and in 1991, the National Medal of Science, the country's highest scientific honor.

  20. George Gamow: Scientific Amateur and Polymath

    Science.gov (United States)

    Harper, Eamon

    George Gamow (1904-1968) was among the first of the many brilliant scientists who forsook Europe for the United States in the early 1930s. Although most were fleeing the fascist imperium of Hitler and Mussolini, Gamow was one of a few who managed to escape the burgeoning despotism of Stalin in the Soviet Union. His early application of quantum mechanics to the atomic nucleus and his subsequent insight into the role played by the physics of the atom and its nucleus in stars, galaxies, and the universe identifies him as a scientist of unusual genius. Gamow displayed a boisterous, infectious - almost Rutherfordian - interest in all aspects of pure science. His interests were broad and his industry prodigious. His scientific output covered areas as diverse as nuclear physics, astrophysics, cosmology, biological genetics, and the fascinating question of the relationship of the large-scale structure and development of the universe to the properties of elementary particles and fields. He also was an immensely imaginative and prolific author of popular expositions on scientific subjects. One who is as well-known for his authorship of the Mr. Tompkins series of science popularizations as for his contributions to the development of the physical consequences of the big-bang theory of the expanding universe and the prediction of the cosmic background radiation must be unique in the scientific pantheon.

  1. Hydrocarbon degradation by antarctic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Cavanagh, J.A.E.; Nichols, P.D.; McMeekin, T.A.; Franzmann, P.D. [Univ. of Tasmania (Australia)] [and others

    1996-12-31

    Bacterial cultures obtained from sediment samples collected during a trial oil spill experiment conducted at Airport beach, Eastern Antarctica were selectively enriched for n-alkane-degrading and phenanthrenedegrading bacteria. Samples were collected from a control site and sites treated with different hydrocarbon mixtures - Special Antarctic blend (SAB), BP-Visco and orange roughy oils. One set of replicate sites was also treated with water from Organic Lake which had previously been shown to contain hydrocarbon-degrading bacteria. No viable bacteria were obtained from samples collected from sites treated with orange roughy oil. Extensive degradation of n-alkanes by enrichment cultures obtained from sites treated with SAB and BP-Visco occurred at both 25{degrees}C and 10{degrees}C. Extensive degradation of phenanthrene also occurred in enrichment cultures from these sites grown at 25{degrees}C. Concurrent increases of polar lipid in these cultures were also observed. The presence of 1,4-naphthaquinone and 1-naphthol during the growth of the cultures on phenanthrene is unusual and warrants further investigation of the mechanism of phenanthrene-degradation by these Antarctic bacteria.

  2. Underwater Optics in Sub-Antarctic and Antarctic Coastal Ecosystems.

    Science.gov (United States)

    Huovinen, Pirjo; Ramírez, Jaime; Gómez, Iván

    2016-01-01

    Understanding underwater optics in natural waters is essential in evaluating aquatic primary production and risk of UV exposure in aquatic habitats. Changing environmental conditions related with global climate change, which imply potential contrasting changes in underwater light climate further emphasize the need to gain insights into patterns related with underwater optics for more accurate future predictions. The present study evaluated penetration of solar radiation in six sub-Antarctic estuaries and fjords in Chilean North Patagonian region (39-44°S) and in an Antarctic bay (62°S). Based on vertical diffuse attenuation coefficients (Kd), derived from measurements with a submersible multichannel radiometer, average summer UV penetration depth (z1%) in these water bodies ranged 2-11 m for UV-B (313 nm), 4-27 m for UV-A (395 nm), and 7-30 m for PAR (euphotic zone). UV attenuation was strongest in the shallow Quempillén estuary, while Fildes Bay (Antarctica) exhibited the highest transparency. Optically non-homogeneous water layers and seasonal variation in transparency (lower in winter) characterized Comau Fjord and Puyuhuapi Channel. In general, multivariate analysis based on Kd values of UV and PAR wavelengths discriminated strongly Quempillén estuary and Puyuhuapi Channel from other study sites. Spatial (horizontal) variation within the estuary of Valdivia river reflected stronger attenuation in zones receiving river impact, while within Fildes Bay a lower spatial variation in water transparency could in general be related to closeness of glaciers, likely due to increased turbidity through ice-driven processes. Higher transparency and deeper UV-B penetration in proportion to UV-A/visible wavelengths observed in Fildes Bay suggests a higher risk for Antarctic ecosystems reflected by e.g. altered UV-B damage vs. photorepair under UV-A/PAR. Considering that damage repair processes often slow down under cool temperatures, adverse UV impact could be further

  3. Pinnularia sofia Van de Vijver & Le Cohu spec. nov., a new spine-bearing, chain-forming Pinnularia species from the sub-Antarctic region

    NARCIS (Netherlands)

    VandeVijver, B.; Gremmen, N.J.M.; Beyens, L.; Le Cohu, T.

    2004-01-01

    The spine-bearing diatom Pinnularia sofia Van de Vijver & Le Cohn spec. nov. is described from the sub-Antarctic Heard Island. The morphology of this species was examined using the scanning electron microscopy (SEM). The most striking feature of the new taxon is the presence of three groups of wart-

  4. DNA damage and photosynthesis in Antarctic and Arctic Sanionia uncinata (Hedw.) Loeske under ambient and enhanced levels of UV-B radiation

    NARCIS (Netherlands)

    Lud, D; Moerdijk, T.C W; van de Poll, W.H.; Buma, A.G.J.; Huiskes, A.H L

    2002-01-01

    The response of the bipolar moss Sanionia uncinata (Hedw.) Loeske to ambient and enhanced UV-B radiation was investigated at an Antarctic (Leonie Island, 67degrees35' S, 68degrees20' W) and an Arctic (Ny-Alesund, 78degrees55' N, 11degrees56' E) site, which differed in ambient UV-B radiation (UV-BR:

  5. George Orwell and the Theory of Totalitarianism: A 1984 Retrospective.

    Science.gov (United States)

    Enteen, George M.

    1984-01-01

    Discusses the use of George Orwell's "1984" in a college-level course on communism and totalitarianism. Draws from personal experiences during a year's graduate study in Moscow to examine Orwell's perceptions of the Soviet Union. (AYC)

  6. EAARL Topography--George Washington Birthplace National Monument 2008

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first surface/bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the George Washington Birthplace National Monument in Virginia was...

  7. CURRENT AND SEDIMENT TRANSPORT STUDIES ON GEORGES BANK

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A collection of time-series oceanographic data was obtained from locations on Georges Bank and adjacent continental shelf between 1975 and 1984. Measurements...

  8. EAARL Topography--George Washington Birthplace National Monument 2008

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first surface/bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the George Washington Birthplace National Monument in Virginia was...

  9. Magnus Georg von Paucker (1787-1855) / Eckhard Spring

    Index Scriptorium Estoniae

    Spring, Eckhard

    2013-01-01

    Eestis sündinud ja Tartu Ülikoolis õppinud silmapaistvast baltisaksa teadlasest ja tema lapselapsest Alexandrine Pauckerist. 23. novembril 2012 Jelgavas/Mitaus toimunud Magnus Georg von Pauckerile pühendatud teaduskonverentsist

  10. CURRENT AND SEDIMENT TRANSPORT STUDIES ON GEORGES BANK

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A collection of time-series oceanographic data was obtained from locations on Georges Bank and adjacent continental shelf between 1975 and 1984. Measurements...

  11. Marine Ecosystem Response to Rapid Climate Warming on the West Antarctic Peninsula (Invited)

    Science.gov (United States)

    Ducklow, H.; Baker, K. S.; Doney, S. C.; Fraser, B.; Martinson, D. G.; Meredith, M. P.; Montes-Hugo, M. A.; Sailley, S.; Schofield, O.; Sherrell, R. M.; Stammerjohn, S. E.; Steinberg, D. K.

    2010-12-01

    The Palmer, Antarctica LTER builds on meteorological, ocean color and seabird observations since the late 1970s. It occupies annually in summer a regional-scale grid extending 700 km northward from Charcot Island to Anvers Island, and 200 km cross-shelf from the coast to the shelfbreak. In addition to routine CTD profiles and zooplankton tows throughout the grid, the observing system also includes Slocum Glider surveys and thermistor moorings. Geophysical changes include +6C atmospheric warming in winter since 1950, a 20% increase in heat content over the continental shelf since 1990, a surface ocean warming of +1C since 1950, an 83-day reduction in sea ice duration (advance 48 days later, retreat 35 days earlier) over the greater southern Bellingshausen Sea region from 1979-2007, intensification of westerly winds and differential changes in cloudiness. In response to these large changes in the regional climate, the marine ecosystem of the western Peninsula is changing at all trophic levels from diatoms to penguins. Ocean color indicates differential changes in phytoplankton stocks in response to regional decreases in sea ice cover. Surface chlorophyll has declined 89% in the north and increased 67% in the south. Antarctic krill and salps have declined and increased in our study area, respectively. Penguin diet sampling suggests changes in populations or distributions of the Antarctic Silverfish in the Anvers Island vicinity, possibly in response to ocean warming. Adélie penguins have declined 75% from 15000 to penguin breeding populations in the Anvers Island vicinity of the West Antarctic Peninsula

  12. George Eliot’s Humanistic View and Feminist View

    Institute of Scientific and Technical Information of China (English)

    TANG Jing-chun

    2013-01-01

    George Eliot is a great authoress in the Victorian age. She has made great contribution in many fields such as:philoso-phy, literature and humanism. However she is a controversial novelist as well not only because her life experience which revolts against the traditional way of life at that time but also her unique humanistic and feminist view. The purpose of the study is to get the panoramic view of George Eliot.

  13. The St. George's Respiratory Questionnaire in Lymphangioleiomyomatosis

    Institute of Scientific and Technical Information of China (English)

    Kai-feng Xu; Lan Wang; Xin-lun Tian; Yao-song Gui; Min Peng; Bai-qiang Cai; Yuan-jue Zhu

    2010-01-01

    Objective To examine the correlation between the health-related quality of life measured by the St. George's Respiratory Questionnaire (SGRQ) and the commonly used physiological measures in lymphangi-oleiomyomatosis (LAM).Methods This study retrospectively analyzed the SGRQ scores and other measures (the Borg scale of breathlessness at rest, 6-minute walking distance, blood oxygen levels, and pulmonary function) of patients diagnosed and confirmed with LAM. Altogether 38 patients between June 2007 and November 2009 were included.Results The mean values of the SGRQ three components (symptoms, activity, and impacts) and total scores in the LAM patients were 46.95±28.90, 58.47±25.41,47.89±29.66, and 51. 11±26.35, respec-tively. The SGRQ total or component scores were correlated well with the Borg scale of breathlessness, 6-minute walking distance, partial pressure of oxygen in arterial blood, spirometry and diffusion capacity of lung. There were poor correlations between SGRQ score and residual volume or total lung capacity. In our preliminary observation, sirolimus improved the SGRQ total and three component scores and the Borg scale of breathlessness significantly after 101-200 days of treatment (n=6).Conclusions The SGRQ score in LAM is correlated well with physiological measures (Borg scale of breathlessness, 6-minute walking distance, blood oxygen levels, and pulmonary function tests). The SGRQ could therefore be recommended in baseline and follow-up evaluation of patients with LAM. Treatment with sirolimus, an inhibitor of mammalian target of rapamycin, may improve the quality of life and patient's per-ception of breathlessness in LAM.

  14. Georges Canguilhem: sobre vida e conhecimento da vida [Georges Canguilhem: on life and knowledge of life

    Directory of Open Access Journals (Sweden)

    Filicio Mulinari

    2016-06-01

    Full Text Available Tendo como fundamento as obras de Georges Canguilhem, sobretudo a obra O normal e o patológico e os escritos "O pensamento e o vivente" e "O conceito e a vida", este artigo busca analisar o modo como Georges Canguilhem entende as noções de vida e conhecimento de vida, relacionando ambos os conceitos e indicando, nas linhas teóricas do filósofo francês, como é possível conhecimento o sobre a vida e o vivente. O artigo, inicialmente passando pelos conceitos de normal e patológico, buscará situar e fundamentar o conceito de vida enquanto "atividade normativa". Após isso, na segunda parte, buscará expor o tratamento dado por Canguilhem aos problemas relativos ao conhecimento da vida, analisando as questões histórico-filosóficas relacionadas ao problema e, por fim, as descobertas da biologia contemporânea que permitiram a Canguilhem lançar novos caminhos ao tema tratado.

  15. 75 FR 44727 - Proposed Revocation and Establishment of Class E Airspace; St. George, UT

    Science.gov (United States)

    2010-07-29

    ... Airspace; St. George, UT AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed..., St. George, UT, as the airport will be closing, eliminating the need for controlled airspace. This... Instrument Approach Procedures (SIAPs) at the new St. George Municipal Airport, St. George, UT. The FAA...

  16. 78 FR 63380 - Amendment of Class E Airspace; St. George, UT

    Science.gov (United States)

    2013-10-24

    ... Federal Aviation Administration 14 CFR Part 71 Amendment of Class E Airspace; St. George, UT AGENCY... airspace at St. George Municipal Airport, St. George, UT, by removing the operating hours established by a... Federal Register a notice of proposed rulemaking (NPRM) to amend controlled airspace at St. George, UT...

  17. 78 FR 45473 - Proposed Amendment of Class E Airspace; St. George, UT

    Science.gov (United States)

    2013-07-29

    ... Proposed Amendment of Class E Airspace; St. George, UT AGENCY: Federal Aviation Administration (FAA), DOT... St. George Municipal Airport, St. George, UT, by removing the operating hours established by a Notice... Airport, St. George, UT. DATES: Comments must be received on or before September 12, 2013. ADDRESSES:...

  18. A snapshot at the microbial ecology of petroleum contaminated sub-Antarctic soils

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, B.; Vandorst, J. [New South Wales Univ., Randwick, NSW (Australia). School of Biotechnology and Biomolecular Sciences; Snape, I.; Ferguson, S. [Australian Antarctic Div., Kingston, Tasmania (Australia)

    2010-07-01

    This study investigated the microbial diversity of the viable soil bacterial community in sub-Antarctic soils contaminated with hydrocarbons. The aim of the study was to develop a remediation strategy for petroleum contamination at a research station located on Macquarie Island. A soil substrate membrane system (SSMS) was used along with flow cytometry and molecular analysis techniques to characterize bacterial diversity following contamination with special Antarctic blend diesel. Independent analyses of both aerobic and anaerobic fractions within the soil were conducted. The study showed that the aerobic fraction of the community was more susceptible to hydrocarbon contamination, with a significant decline in total bacterial numbers. The addition of petroleum significantly altered the dominance of microbial families within the community. Results supported previous reports that the SSMS is capable of providing a more accurate snapshot of environmental diversity than traditional culturing techniques.

  19. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  20. South African Antarctic earth science research programme

    CSIR Research Space (South Africa)

    SASCAR

    1984-02-01

    Full Text Available This document describes the past, current and planned future South African earth science research programme in the Antarctic, Southern Ocean and subantarctic regions. The scientific programme comprises five components into which present and future...

  1. Unveiling the Antarctic subglacial landscape.

    Science.gov (United States)

    Warner, Roland; Roberts, Jason

    2010-05-01

    Better knowledge of the subglacial landscape of Antarctica is vital to reducing uncertainties regarding prediction of the evolution of the ice sheet. These uncertainties are associated with bedrock geometry for ice sheet dynamics, including possible marine ice sheet instabilities and subglacial hydrological pathways (e.g. Wright et al., 2008). Major collaborative aerogeophysics surveys motivated by the International Polar Year (e.g. ICECAP and AGAP), and continuing large scale radar echo sounding campaigns (ICECAP and NASA Ice Bridge) are significantly improving the coverage. However, the vast size of Antarctica and logistic difficulties mean that data gaps persist, and ice thickness data remains spatially inhomogeneous. The physics governing large scale ice sheet flow enables ice thickness, and hence bedrock topography, to be inferred from knowledge of ice sheet surface topography and considerations of ice sheet mass balance, even in areas with sparse ice thickness measurements (Warner and Budd, 2000). We have developed a robust physically motivated interpolation scheme, based on these methods, and used it to generate a comprehensive map of Antarctic bedrock topography, using along-track ice thickness data assembled for the BEDMAP project (Lythe et al., 2001). This approach reduces ice thickness biases, compared to traditional inverse distance interpolation schemes which ignore the information available from considerations of ice sheet flow. In addition, the use of improved balance fluxes, calculated using a Lagrangian scheme, eliminates the grid orientation biases in ice fluxes associated with finite difference methods (Budd and Warner, 1996, Le Brocq et al., 2006). The present map was generated using a recent surface DEM (Bamber et al., 2009, Griggs and Bamber, 2009) and accumulation distribution (van de Berg et al., 2006). Comparing our results with recent high resolution regional surveys gives confidence that all major subglacial topographic features are

  2. George Soros : sõda terroriga on kohutav viga / George Soros ; interv. Külli-Riin Tigasson

    Index Scriptorium Estoniae

    Soros, George, 1930-

    2006-01-01

    Ilmunud ka: Infopress 15. dets. nr. 50 lk. 149. Miljardär ja filantroop George Soros vastab küsimustele, mis puudutavad tema raamatus "Ekslikkuse ajastu. Sõda terroriga ja selle tagajärjed" esitatud seisukohti. Ta leiab, et sõjakuulutamine terrorismile oli vale reaktsioon 11. septembri rünnakutele. George W. Bushi kursi muutumine Iraagiga seoses on tulnud liiga hilja. USA peab naasma oma traditsioonilise rolli juurde maailmas ja tegelema inimkonna suurimate probleemidega

  3. George Soros : sõda terroriga on kohutav viga / George Soros ; interv. Külli-Riin Tigasson

    Index Scriptorium Estoniae

    Soros, George, 1930-

    2006-01-01

    Ilmunud ka: Infopress 15. dets. nr. 50 lk. 149. Miljardär ja filantroop George Soros vastab küsimustele, mis puudutavad tema raamatus "Ekslikkuse ajastu. Sõda terroriga ja selle tagajärjed" esitatud seisukohti. Ta leiab, et sõjakuulutamine terrorismile oli vale reaktsioon 11. septembri rünnakutele. George W. Bushi kursi muutumine Iraagiga seoses on tulnud liiga hilja. USA peab naasma oma traditsioonilise rolli juurde maailmas ja tegelema inimkonna suurimate probleemidega

  4. COMMENT ON AEROSOL EFFECT ON ANTARCTIC OZONE

    OpenAIRE

    イワサカ, ヤスノブ; Yasunobu, IWASAKA; Guang-Yu, SHI

    1987-01-01

    The structure of the aerosol layer disturbed by a cold air was suggested from the lidar measurements at Syowa Station (69°00′S, 39°35′E). The particle layer containing sublayers of spherical or nonspherical aerosols was frequently observed in Antarctic spring. It is a point one sholud not ignore when he discusses aerosol effects on "Antarctic ozone depletion" through radiative processes and heterogeneous chemical reactions.

  5. Ross Ice Shelf, Antarctic Ice and Clouds

    Science.gov (United States)

    1991-01-01

    In this view of Antarctic ice and clouds, (56.5S, 152.0W), the Ross Ice Shelf of Antarctica is almost totally clear, showing stress cracks in the ice surface caused by wind and tidal drift. Clouds on the eastern edge of the picture are associated with an Antarctic cyclone. Winds stirred up these storms have been known to reach hurricane force.

  6. Leaf and floral heating in cold climates: do sub-Antarctic megaherbs resemble tropical alpine giants?

    Directory of Open Access Journals (Sweden)

    Lorna Little

    2016-08-01

    Full Text Available High latitude and altitude floras are characterized by low-statured, small, wind-pollinated plants, which mainly reproduce by self-pollination or asexual reproduction. However, at odds with this are some sub-Antarctic islands that have plant species with giant growth forms and large, brightly coloured flowers which require insect visitation for pollination. The size, colour and shape of the inflorescences and leaves of these megaherbs suggest thermal benefits similar to giant tropical alpine plants of equatorial Africa, South America and Hawaii. We evaluated whether heating occurs in sub-Antarctic megaherbs, and to what extent it is related to environmental variables. We measured leaf and inflorescence temperature in six sub-Antarctic megaherb species on Campbell Island, latitude 52.3°S, New Zealand Biological Region. Using thermal imaging techniques, in combination with measurement of solar radiation, ambient air temperature, wind speed, wind chill and humidity, we assessed environmental influences on leaf and floral heating. We found that leaf and inflorescence temperatures of all megaherbs were higher than simultaneously measured ambient temperatures. Greatest heating was seen in Pleurophyllum speciosum, with observed leaves 9°C higher, and inflorescences nearly 11°C higher, than ambient temperature. Heating was highly correlated with brief, unpredictable periods of solar radiation, and occurred most rapidly in species with hairy, corrugated leaves and darkly pigmented, densely packed inflorescences. This is the first evidence that floral and leaf heating occurs in sub-Antarctic megaherbs, and suggests that leaf hairiness, flower colour and shape could provide thermal benefits like those seen in tropical alpine megaherbs.

  7. Simultaneous solution for mass trends on the West Antarctic Ice Sheet

    Directory of Open Access Journals (Sweden)

    N. Schön

    2014-06-01

    Full Text Available The Antarctic Ice Sheet is the largest potential source of future sea-level rise. Mass loss has been increasing over the last two decades in the West Antarctic Ice Sheet (WAIS, but with significant discrepancies between estimates, especially for the Antarctic Peninsula. Most of these estimates utilise geophysical models to explicitly correct the observations for (unobserved processes. Systematic errors in these models introduce biases in the results which are difficult to quantify. In this study, we provide a statistically rigorous, error-bounded trend estimate of ice mass loss over the WAIS from 2003–2009 which is almost entirely data-driven. Using altimetry, gravimetry, and GPS data in a hierarchical Bayesian framework, we derive spatial fields for ice mass change, surface mass balance, and glacial isostatic adjustment (GIA without relying explicitly on forward models. The approach we use separates mass and height change contributions from different processes, reproducing spatial features found in, for example, regional climate and GIA forward models, and provides an independent estimate, which can be used to validate and test the models. In addition, full spatial error estimates are derived for each field. The mass loss estimates we obtain are smaller than some recent results, with a time-averaged mean rate of −76 ± 15 GT yr−1 for the WAIS and Antarctic Peninsula (AP, including the major Antarctic Islands. The GIA estimate compares very well with results obtained from recent forward models (IJ05-R2 and inversion methods (AGE-1. Due to its computational efficiency, the method is sufficiently scalable to include the whole of Antarctica, can be adapted for other ice sheets and can easily be adapted to assimilate data from other sources such as ice cores, accumulation radar data and other measurements that contain information about any of the processes that are solved for.

  8. Simultaneous solution for mass trends on the West Antarctic Ice Sheet

    Science.gov (United States)

    Schoen, N.; Zammit-Mangion, A.; Rougier, J. C.; Flament, T.; Rémy, F.; Luthcke, S.; Bamber, J. L.

    2015-04-01

    The Antarctic Ice Sheet is the largest potential source of future sea-level rise. Mass loss has been increasing over the last 2 decades for the West Antarctic Ice Sheet (WAIS) but with significant discrepancies between estimates, especially for the Antarctic Peninsula. Most of these estimates utilise geophysical models to explicitly correct the observations for (unobserved) processes. Systematic errors in these models introduce biases in the results which are difficult to quantify. In this study, we provide a statistically rigorous error-bounded trend estimate of ice mass loss over the WAIS from 2003 to 2009 which is almost entirely data driven. Using altimetry, gravimetry, and GPS data in a hierarchical Bayesian framework, we derive spatial fields for ice mass change, surface mass balance, and glacial isostatic adjustment (GIA) without relying explicitly on forward models. The approach we use separates mass and height change contributions from different processes, reproducing spatial features found in, for example, regional climate and GIA forward models, and provides an independent estimate which can be used to validate and test the models. In addition, spatial error estimates are derived for each field. The mass loss estimates we obtain are smaller than some recent results, with a time-averaged mean rate of -76 ± 15 Gt yr-1 for the WAIS and Antarctic Peninsula, including the major Antarctic islands. The GIA estimate compares well with results obtained from recent forward models (IJ05-R2) and inverse methods (AGE-1). The Bayesian framework is sufficiently flexible that it can, eventually, be used for the whole of Antarctica, be adapted for other ice sheets and utilise data from other sources such as ice cores, accumulation radar data, and other measurements that contain information about any of the processes that are solved for.

  9. Antarctic Ice-Sheet Mass Balance from Satellite Altimetry 1992 to 2001

    Science.gov (United States)

    Zwally, H. Jay; Brenner, Anita C.; Cornejo, Helen; Giovinetto, Mario; Saba, Jack L.; Yi, Donghui

    2003-01-01

    A major uncertainty in understanding the causes of the current rate of sea level rise is the potential contributions from mass imbalances of the Greenland and Antarctic ice sheets. Estimates of the current mass balance of the Antarctic ice sheet are derived from surface- elevation changes obtained from 9 years of ERS - 1 & 2 radar altimeter data. Elevation time-series are created from altimeter crossovers among 90-day data periods on a 50 km grid to 81.5 S. The time series are fit with a multivariate linear/sinusoidal function to give the average rate of elevation change (dH/dt). On the major Rome-Filchner, Ross, and Amery ice shelves, the W d t are small or near zero. In contrast, the ice shelves of the Antarctic Peninsula and along the West Antarctic coast appear to be thinning significantly, with a 23 +/- 3 cm per year surface elevation decrease on the Larsen ice shelf and a 65 +/- 4 cm per year decrease on the Dotson ice shelf. On the grounded ice, significant elevation decreases are obtained over most of the drainage basins of the Pine Island and Thwaites glaciers in West Antarctica and inland of Law Dome in East Antarctica. Significant elevation increases are observed within about 200 km of the coast around much of the rest of the ice sheet. Farther inland, the changes are a mixed pattern of increases and decreases with increases of a few centimeters per year at the highest elevations of the East Antarctic plateau. The derived elevation changes are combined with estimates of the bedrock uplift from several models to provide maps of ice thickness change. The ice thickness changes enable estimates of the ice mass balances for the major drainage basins, the overall mass balance, and the current contribution of the ice sheet to global sea level change.

  10. Floating Cities, Islands and States

    CERN Document Server

    Bolonkin, Alexander

    2008-01-01

    Many small countries are in need of additional territory. They build landfills and expensive artificial islands. The ocean covers 71 per cent of the Earth surface. Those countries (or persons of wealth) starting the early colonization of the ocean may obtain advantages through additional territory or creating their own independent state. An old idea is building a big ship. The best solution to this problem, however, is the provision of floating cities, islands, and states. The author idea is to use for floating cities, islands, and states a cheap floating platform created from a natural ice field taken from the Arctic or Antarctic oceans. These cheap platforms protected by air-film (bottom and sides) and a conventional insulating cover (top) and having a cooling system can exist for an unlimited time. They can be increased in number or size at any time, float in warm oceans, travel to different continents and countries, serve as artificial airports, harbors and other marine improvements, as well as floating c...

  11. Analysis of chemical compositions of individual atmospheric aerosol collected in Arctic and Antarctic area%南北极大气气溶胶单颗粒成分特点研究

    Institute of Scientific and Technical Information of China (English)

    耿红; 李屹; 张志敏; 卢铁彦

    2012-01-01

    A quantitative single particle analytical technique, low-Z particle electron probe X-ray microanalysis (EPMA) was used to characterize 2821 individual particles in 16 sets of aerosol samples collected on July 25-31, 2007 at Ny-Alesund, Svalbard (78*551^1, 11?6'E) and 1460 individual particles in 5 sets of aerosol samples collected on March 12-16, 2009 at King George Island (62'13'S, 5%癢). There was great difference in chemical compositions between the atmospheric particles of the two sites. For the Arctic samples, aged sea salt, fresh (or genuine) sea salt, and mineral dust particles accounted for 44%, 9%, and 27%, respectively, in the examined particles (their aerodynamic diameters were in the range of 0.5~8um). Whereas for the Antarctic samples, fresh sea salt particles accounted for 74% and aged sea salt particles containing sulfate accounted for 19% in the examined particles (their aerodynamic diameters were in the range of 1-1 Oum). The majority of aged sea salt particles at Ny-Alesund contained nitrate, indicating that the atmosphere was disturbed by anthropogenic air pollutants. On the contrary, all of the aged sea salt particles contained sulfate in the samples at King George Island, none of them containing nitrate. It was likely that the oxidation of dimethylsulfide (DMS) emitted from phytoplanktons in the ocean rather than anthropogenic sulfur emission was responsible for the formation of sulfate-containing aged sea salt particles, implying that the air in the Antarctic area was relatively clean, without being polluted by anthropogenic pollutants.%运用定量电子探针微区分析技术(EPMA)分别测定了采自北极新奥尔松地区(78+55'N、11*56'E)和南极乔治王岛(62*3'S、58*47'W)极昼天气下PM10大气颗粒物样品.结果表明,北极和南极大气颗粒物化学成分存在很大差异,表现出各自不同的特点.北极的颗粒类型中,“反应的海盐”和“矿物尘”分别占颗粒总数的44%和27%,“新鲜

  12. The SCAR Standing Committee on Antarctic Data Management - new directions in access to Antarctic research data

    Science.gov (United States)

    de Bruin, T.

    2009-04-01

    The SCAR Standing Committee on Antarctic Data Management (SC-ADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP), to assist in the fulfillment of the data management obligations imposed by the Antarctic Treaty (section III.1.c): "Scientific observations and results from Antarctica shall be exchanged and made freely available." SC-ADM comprises representatives of the National Antarctic Data Centres or national points of contact. Currently 31 nations around the world are represented in SC-ADM. So far, SC-ADM has been focussing on the coordination of the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. Currently, SC-ADM is in a transition phase, moving forward to provide data access. Existing systems and web services technology will be used as much as possible, to increase efficiency and prevent 're-inventing the wheel' This poster will give an overview of this process, the current status and the expected results.

  13. Georg(e) Placzek: a bibliometric study of his scientific production and its impact

    CERN Document Server

    Cardona, M; Cardona, Manuel; Marx, Werner

    2006-01-01

    The availability of a number of databases, in particular the Science Citation Index (SCI), have encouraged the development and use of bibliometric techniques to analyze and evaluate the production and impact of scientists. To avoid pitfalls and their sometimes serious consequences, however, considerable experience with the method is needed. The case of George Placzek appears as an excellent one to illustrate the procedure and its problems. Placzeks work covered a broad range of topics, including optical and neutron spectroscopy, neutron diffusion, nuclear reactions, and nuclear energy. He worked in a large number of places with some of the most outstanding collaborators and also as sole author during his short professional life. His publications appeared in regular, so-called source journals, in books, lecture notes and also internal reports which were classified till several years after the end of the war. In this article we analyze Placzeks work and its impact with the aim of illustrating the power and virt...

  14. Island Armor

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new law has been enacted to protect China’s islands from destruction After three rounds of deliberations that began in June 2009, the National People’s Congress (NPC) Standing Committee endorsed the Law of Sea

  15. MATERIALISM AND DIALETIC IN GEORGES BATAILLE MATERIALISMO E DIALÉTICA EM GEORGES BATAILLE

    Directory of Open Access Journals (Sweden)

    João Emiliano Fortaleza de Aquino

    2011-03-01

    Full Text Available Like other thinkers of the 1920s and 1930s, Georges Bataille seeks to identify a unifying theoretical-philosophical principle of dialectical materialism, accomplishing this through affirmation of a radical materialism, whose characteristics are the recovery of ”base matter” and the critique of all sublimated elevation to what is “higher.” In this effort, in a distinctive juxtaposition to both Marxism and psychoanalysis, he considers the relations of materialism with the Hegelian dialectic and Nietzschean genealogy, valuing the presence of “base matter” in these philosophical projects and critiquing, in the same manner, the fact that, in them, “base matter” is sublimated in the “higher.”Como outros pensadores dos anos 1920-1930, Georges Bataille busca pensar o estatuto teórico-filosófico do então chamado materialismo dialético, fazendo-o, porém, com a afirmação de um materialismo radical, cujas características são a reivindicação do “baixo” e a crítica de toda elevação sublimadora ao “alto”. Para tanto, em uma peculiar aproximação entre marxismo e psicanálise, considera as relações do materialismo com a dialética hegeliana e a genealogia nietzschiana, relações nas quais valoriza a presença do “baixo” nesses projetos filosóficos e critica, do mesmo modo, o fato de que neles o “baixo” é sublimado no “alto”.

  16. The uncinated crisis of George Gershwin As crises uncinadas de George Gershwin

    Directory of Open Access Journals (Sweden)

    Hélio A.G. Teive

    2002-06-01

    Full Text Available George Gershwin, renowned composer and pianist, well known for his popular works, died on the 11th July 1937 due to a brain tumor. His neurological symptoms first appeared on that same year, in February, with a simple olfactory partial seizure, characterized by an unpleasant smell of burnt rubber (uncinated seizure. He later had a quick clinical descend, with severe headache that occurred in bouts, dizziness, coordination compromise and olfactory seizures, eventually lapsing into a coma on the 9th July 1937. It was then that a gliomatosus cyst was diagnosed, which on microscopic examination proved to be a "glioblastoma multiforme". Despite the surgical intervention, Gershwin died soon after the procedure without recovering his consciousness. We make a brief review of Gershwin's neurologic disease, with emphasis on the initial symptoms, namely the uncinated seizures.O célebre pianista e compositor George Gershwin, renomado pelas suas composições harmônicas e de apelo popular, faleceu em 11 de Julho de 1937 como consequência de um tumor cerebral. Seus sintomas neurológicos tiveram início em fevereiro daquele ano com uma crise epiléptica de tipo uncinado. Posteriormente houve rápida deterioração do quadro com cefaléia intensa, acompanhada por tonturas, até que em 9 de Julho de 1937 Gershwin foi internado em coma, tendo então o diagnóstico de tumor cerebral. Foi realizada a remoção cirúrgica parcial de tumor cístico, cujo exame anátomo-patológico revelou tratar-se de um glioblastoma. Gershwin faleceu logo após a neurocirurgia, sem ter ao menos recobrado a consciência. Fazemos uma breve revisão sobre a enfermidade neurológica de Gershwin, com ênfase aos sintomas iniciais da doença, as crises uncinadas.

  17. Past penguin colony responses to explosive volcanism on the Antarctic Peninsula

    Science.gov (United States)

    Roberts, Stephen J.; Monien, Patrick; Foster, Louise C.; Loftfield, Julia; Hocking, Emma P.; Schnetger, Bernhard; Pearson, Emma J.; Juggins, Steve; Fretwell, Peter; Ireland, Louise; Ochyra, Ryszard; Haworth, Anna R.; Allen, Claire S.; Moreton, Steven G.; Davies, Sarah J.; Brumsack, Hans-Jürgen; Bentley, Michael J.; Hodgson, Dominic A.

    2017-04-01

    Changes in penguin populations on the Antarctic Peninsula have been linked to several environmental factors, but the potentially devastating impact of volcanic activity has not been considered. Here we use detailed biogeochemical analyses to track past penguin colony change over the last 8,500 years on Ardley Island, home to one of the Antarctic Peninsula's largest breeding populations of gentoo penguins. The first sustained penguin colony was established on Ardley Island c. 6,700 years ago, pre-dating sub-fossil evidence of Peninsula-wide occupation by c. 1,000 years. The colony experienced five population maxima during the Holocene. Overall, we find no consistent relationships with local-regional atmospheric and ocean temperatures or sea-ice conditions, although the colony population maximum, c. 4,000-3,000 years ago, corresponds with regionally elevated temperatures. Instead, at least three of the five phases of penguin colony expansion were abruptly ended by large eruptions from the Deception Island volcano, resulting in near-complete local extinction of the colony, with, on average, 400-800 years required for sustainable recovery.

  18. Radioactive concentrations of the Livingston Island soils (Antarctica). Dosimetry considerations

    Energy Technology Data Exchange (ETDEWEB)

    Baeza, A.; Rio, M. del; Paniagua, J.M. (Facultad de Veterinaria, Ctra. de Trujillo, Caceres (Spain)); Navarro, E.; Rodriguez, M.J.; Sanchez, F. (Centro Mixto Univ. de Valencia (Spain). Inst. de Fisica Corpuscular)

    1994-06-01

    The radioactive concentrations of natural and man-made ([sup 90]Sr and [sup 137]Cs) emitters were studied in soil samples collected from an area of 2.3 km[sup 2] around the Spanish Antarctic Base on Livingston Island in the South Shetlands. The levels of radiation detected, for natural radioisotopes, as well as consequently the measured levels of effective dose equivalent rate, are of the order of half the values commonly assigned as world averages for these magnitudes. (Author).

  19. George Mikenberg honoured by the Sharing Knowledge Foundation

    CERN Multimedia

    CERN Bulletin

    2016-01-01

    The Sharing Knowledge Foundation Prize was presented to the ATLAS physicist at a ceremony on 18 March.   ATLAS physicist George Mikenberg receives the Sharing Knowledge Foundation Prize. From left to right: Peter Jenni, former ATLAS Spokesperson, Rolf Heuer, former CERN Director-General, Frédérick Bordry, CERN Director for Accelerators and Technology, George Mikenberg, Patrick Fassnacht, CERN International Relations sector, Eliane Jacot-Des-Combes Mikenberg, Herwig Schopper, former CERN Director-General, Constantin Lanaras, treasurer of the Sharing Knowledge Foundation, Robert Klapisch, President of the Sharing Knowledge Foundation, Federico Saldana, logistical support, Catherine Cesarsky, Vice-President of the CERN Council, Eliezer Rabinovici, Vice-President of the CERN Council and of SESAME. (Image: Sophia Bennett/CERN) The Sharing Knowledge Foundation awarded its 2016 prize to George Mikenberg, a member of the LHC's ATLAS experiment who has been...

  20. Penguin response to the Eocene climate and ecosystem change in the northern Antarctic Peninsula region

    Science.gov (United States)

    Jadwiszczak, Piotr

    2010-08-01

    Eocene Antarctic penguins are known solely from the La Meseta Formation (Seymour Island, James Ross Basin). They are most numerous and taxonomically diverse (at least ten species present) within strata formed at the end of this epoch, which is concomitant with a significant cooling trend and biotic turnover prior to the onset of glaciation. Moreover, all newly appeared taxa were small-bodied, and most probably evolved in situ. Interestingly, some chemical proxies suggest enhanced nutrient upwelling events that coincided with obvious changes in the record of La Meseta penguins.

  1. Recent dramatic thinning of largest West Antarctic ice stream triggered by oceans

    Science.gov (United States)

    Payne, Antony J.; Vieli, Andreas; Shepherd, Andrew P.; Wingham, Duncan J.; Rignot, Eric

    2004-12-01

    A growing body of observational data suggests that Pine Island Glacier (PIG) is changing on decadal or shorter timescales. These changes may have far-reaching consequences for the future of the West Antarctic ice sheet (WAIS) and global sea levels because of PIG's role as the ice sheet's primary drainage portal. We test the hypothesis that these changes are triggered by the adjoining ocean. Specifically, we employ an advanced numerical ice-flow model to simulate the effects of perturbations at the grounding line on PIG's dynamics. The speed at which these changes are propagated upstream implies a tight coupling between ice-sheet interior and surrounding ocean.

  2. Diet and feeding ecology of the Antarctic skua in New Island, Falkland Islands

    OpenAIRE

    Alves, Tatiana de Mendonça

    2015-01-01

    Tese de mestrado, Ecologia Marinha, Universidade de Lisboa, Faculdade de Ciências, 2015 Os moleiros são aves marinhas filogeneticamente relacionadas com as gaivotas (ordem: Charadriiformes), pertencentes à família Stercorariidae. Estas aves passam a maior parte do tempo no oceano, vindo a terra apenas com o intuito de se reproduzirem. Apresentam dimorfismo sexual invertido, sendo as fêmeas geralmente maiores que os machos. Estes animais são predadores generalistas, alimentando-se oportunis...

  3. Antarctic teleost immunoglobulins: more extreme, more interesting.

    Science.gov (United States)

    Coscia, Maria Rosaria; Varriale, Sonia; Giacomelli, Stefano; Oreste, Umberto

    2011-11-01

    We have investigated the immunoglobulin molecule and the genes encoding it in teleosts living in the Antarctic seas at the constant temperature of -1.86 °C. The majority of Antarctic teleosts belong to the suborder Notothenioidei (Perciformes), which includes only a few non-Antarctic species. Twenty-one Antarctic and two non-Antarctic Notothenioid species were included in our studies. We sequenced immunoglobulin light chains in two species and μ heavy chains, partially or totally, in twenty species. In the case of heavy chain, genomic DNA and the cDNA encoding the secreted and the membrane form were analyzed. From one species, Trematomus bernacchii, a spleen cDNA library was constructed to evaluate the diversity of VH gene segments. T. bernacchii IgM, purified from the serum and bile, was characterized. Homology Modelling and Molecular Dynamics were used to determine the molecular structure of T. bernacchii and Chionodraco hamatus immunoglobulin domains. This paper sums up the previous results and broadens them with the addition of unpublished data.

  4. George Romeros „Land of the Dead“

    OpenAIRE

    Kozlowski, Timo

    2009-01-01

    Einige der blutigsten Splatterfilme gehen auf George Alvar Romeros Konto. Sein „Night of the living dead“ gilt als Geburtsstunde des Zombiefilms, wie man ihn heute kennt, und ohne den auch Capcoms Action-Adventure-Serie „Resident Evil“ nicht entstanden wäre. In seinen Zombiefilmen hatte George Romero nicht nur die Grenze des Zeigbaren im Gruselkino neu ausgelotet und den Jugendschützern neue Dimensionen des Schneidbaren aufgezeigt – Romeros Filme waren immer auch mit einem zynischen Gesellsch...

  5. Antarctic station life: The first 15 years of mixed expeditions to the Antarctic

    Science.gov (United States)

    Sarris, Aspa

    2017-02-01

    This study examined the experiences of women who lived and worked on remote and isolated Antarctic stations for up to 15 months at a time. The study employed purposeful sampling and a longitudinal - processual approach to study women's experiences over the first 15 years of mixed gender Antarctic expeditions. The retrospective analysis was based on a semi-structured interview administered to 14 women upon their return to Australia. The results showed that women referred to the natural physical Antarctic environment as one of the best aspects of their experience and the reason they would recommend the Antarctic to their friends as a good place to work. In describing the worst aspect of their experience, women referred to aspects of Antarctic station life, including: (i) the male dominated nature of station culture; (ii) the impact of interpersonal conflict, including gender based conflict and friction between scientists and trades workers; and (iii) the lack of anonymity associated with living and working with the same group of individuals, mainly men, for up to 12 months or more. The results are discussed within the context of the evolution of Antarctic station culture and recommendations are made in terms of the demography of expeditions, expeditioner selection and recruitment and the ongoing monitoring of Antarctic station culture. The study presents a framework that can be applied to groups and teams living and working in analogous isolated, confined and extreme work environments, including outer space missions.

  6. 76 FR 9849 - Comprehensive Environmental Evaluations for Antarctic Activities

    Science.gov (United States)

    2011-02-22

    .... SUPPLEMENTARY INFORMATION: Article 3 of Annex I to the Protocol on Environmental Protection to the Antarctic Treaty requires the preparation of a CEE for any proposed Antarctic activity likely to have more than a... Comprehensive Environmental Evaluations for Antarctic Activities SUMMARY: The Department of State gives...

  7. Dredging in the Spratly Islands: Gaining Land but Losing Reefs.

    Science.gov (United States)

    Mora, Camilo; Caldwell, Iain R; Birkeland, Charles; McManus, John W

    2016-03-01

    Coral reefs on remote islands and atolls are less exposed to direct human stressors but are becoming increasingly vulnerable because of their development for geopolitical and military purposes. Here we document dredging and filling activities by countries in the South China Sea, where building new islands and channels on atolls is leading to considerable losses of, and perhaps irreversible damages to, unique coral reef ecosystems. Preventing similar damage across other reefs in the region necessitates the urgent development of cooperative management of disputed territories in the South China Sea. We suggest using the Antarctic Treaty as a positive precedent for such international cooperation.

  8. Dredging in the Spratly Islands: Gaining Land but Losing Reefs.

    Directory of Open Access Journals (Sweden)

    Camilo Mora

    2016-03-01

    Full Text Available Coral reefs on remote islands and atolls are less exposed to direct human stressors but are becoming increasingly vulnerable because of their development for geopolitical and military purposes. Here we document dredging and filling activities by countries in the South China Sea, where building new islands and channels on atolls is leading to considerable losses of, and perhaps irreversible damages to, unique coral reef ecosystems. Preventing similar damage across other reefs in the region necessitates the urgent development of cooperative management of disputed territories in the South China Sea. We suggest using the Antarctic Treaty as a positive precedent for such international cooperation.

  9. Dredging in the Spratly Islands: Gaining Land but Losing Reefs

    Science.gov (United States)

    Mora, Camilo; Caldwell, Iain R.; Birkeland, Charles; McManus, John W.

    2016-01-01

    Coral reefs on remote islands and atolls are less exposed to direct human stressors but are becoming increasingly vulnerable because of their development for geopolitical and military purposes. Here we document dredging and filling activities by countries in the South China Sea, where building new islands and channels on atolls is leading to considerable losses of, and perhaps irreversible damages to, unique coral reef ecosystems. Preventing similar damage across other reefs in the region necessitates the urgent development of cooperative management of disputed territories in the South China Sea. We suggest using the Antarctic Treaty as a positive precedent for such international cooperation. PMID:27031949

  10. Venom on ice: first insights into Antarctic octopus venoms.

    Science.gov (United States)

    Undheim, E A B; Georgieva, D N; Thoen, H H; Norman, J A; Mork, J; Betzel, C; Fry, B G

    2010-11-01

    The venom of Antarctic octopus remains completely unstudied. Here, a preliminary investigation was conducted into the properties of posterior salivary gland (PSG) extracts from four Antarctica eledonine (Incirrata; Octopodidae) species (Adelieledone polymorpha, Megaleledone setebos, Pareledone aequipapillae, and Pareledone turqueti) collected from the coast off George V's Land, Antarctica. Specimens were assayed for alkaline phosphatase (ALP), acetylcholinesterase (AChE), proteolytic, phospholipase A(2) (PLA(2)), and haemolytic activities. For comparison, stomach tissue from Cirroctopus sp. (Cirrata; Cirroctopodidae) was also assayed for ALP, AChE, proteolytic and haemolytic activities. Dietary and morphological data were collected from the literature to explore the ecological importance of venom, taking an adaptive evolutionary approach. Of the incirrate species, three showed activities in all assays, while P. turqueti did not exhibit any haemolytic activity. There was evidence for cold-adaptation of ALP in all incirrates, while proteolytic activity in all except P. turqueti. Cirroctopus sp. stomach tissue extract showed ALP, AChE and some proteolytic activity. It was concluded that the AChE activity seen in the PSG extracts was possibly due to a release of household proteins, and not one of the secreted salivary toxins. Although venom undoubtedly plays an important part in prey capture and processing by Antarctica eledonines, no obvious adaptations to differences in diet or morphology were apparent from the enzymatic and haemolytic assays. However, several morphological features including enlarged PSG, small buccal mass, and small beak suggest such adaptations are present. Future studies should be conducted on several levels: Venomic, providing more detailed information on the venom compositions as well as the venom components themselves; ecological, for example application of serological or genetic methods in identifying stomach contents; and behavioural

  11. Gender Metaphor for Colonialism in John Bull's Other Island

    Institute of Scientific and Technical Information of China (English)

    曹笑丽

    2015-01-01

    John Bull's Other Island is the only play of George Bernard Shaw dealing with the Irish problem.He manages to define and ridicule colonialism in it and satires English colonialist’s intention and nature.This paper studies colonialism in this play through sexual metaphor,to decipher how it works simultaneously as an intimation of the British colonial attitudes and a satire of economicexploitation.

  12. Antarctic “quiet” site stirs debate

    Science.gov (United States)

    Simarski, Lynn Teo

    Geophysicists from the United States and New Zealand plan to meet in the coming months to assess the electromagnetic pollution of an Antarctic site especially designated for research. U.S. scientists charge that a satellite Earth station erected apparently inside the preserve by New Zealand's Telecom company could interfere with experiments on the ionosphere and magnetosphere (Eos, April 28, 1992). The Site of Special Scientific Interest at Arrival Heights, the only Antarctic preserve specifically for physical science, is located near the U.S. McMurdo and New Zealand Scott bases.Debate over the Telecom facility inter-twines diplomatic and scientific issues. One question is whether the station violates the Antarctic treaty. Secondly, does it actually impair research at the site—or could it harm future experiments? To deepen the imbroglio, those involved from both nations say that transmissions from sources off-site also interfere with research—raising doubts about how pristine the site really is.

  13. NSF's role in Antarctic environment scrutinized

    Science.gov (United States)

    Bush, Susan

    In the last few years, the National Science Foundation has come under criticism by environmental groups for inadequate stewardship in the U.S. Antarctic Program's environmental issues. Since 1978, NSF was given full responsibility, by Executive Order, for budgeting and managing the entire U.S. national program in Antarctica, including logistics support. NSF has also been responsible for the compliance of the U.S. Antarctic Program with environmental protection measures agreed to by the Antarctic Treaty nations. Specifically under fire by environmentalists have been NSF's maintenance of a land-fill, open-air burning of solid waste, and the removal of toxic substances. According to Peter E. Wilkniss, director of the Division of Polar Programs at NSF, open burning is no longer taking place and will not be allowed in the future.

  14. Climatically sensitive transfer of iron to maritime Antarctic ecosystems by surface runoff

    Science.gov (United States)

    Hodson, Andy; Nowak, Aga; Sabacka, Marie; Jungblut, Anne; Navarro, Francisco; Pearce, David; Ávila-Jiménez, María Luisa; Convey, Peter; Vieira, Gonçalo

    2017-01-01

    Iron supplied by glacial weathering results in pronounced hotspots of biological production in an otherwise iron-limited Southern Ocean Ecosystem. However, glacial iron inputs are thought to be dominated by icebergs. Here we show that surface runoff from three island groups of the maritime Antarctic exports more filterable (iron (6–81 kg km−2 a−1) than icebergs (0.0–1.2 kg km−2 a−1). Glacier-fed streams also export more acid-soluble iron (27.0–18,500 kg km−2 a−1) associated with suspended sediment than icebergs (0–241 kg km−2 a−1). Significant fluxes of filterable and sediment-derived iron (1–10 Gg a−1 and 100–1,000 Gg a−1, respectively) are therefore likely to be delivered by runoff from the Antarctic continent. Although estuarine removal processes will greatly reduce their availability to coastal ecosystems, our results clearly indicate that riverine iron fluxes need to be accounted for as the volume of Antarctic melt increases in response to 21st century climate change. PMID:28198359

  15. Contrasting patterns in lichen diversity in the continental and maritime Antarctic

    Science.gov (United States)

    Singh, Shiv Mohan; Olech, Maria; Cannone, Nicoletta; Convey, Peter

    2015-09-01

    Systematic surveys of the lichen floras of Schirmacher Oasis (Queen Maud Land, continental Antarctic), Victoria Land (Ross Sector, continental Antarctic) and Admiralty Bay (South Shetland Islands, maritime Antarctic) were compared to help infer the major factors influencing patterns of diversity and biogeography in the three areas. Biogeographic patterns were determined using a variety of multivariate statistical tools. A total of 54 lichen species were documented from Schirmacher Oasis (SO), 48 from Victoria Land (VL) and 244 from Admiralty Bay (AB). Of these, 21 species were common to all areas. Most lichens from the SO and VL areas were microlichens, the dominant genus being Buellia. In AB, in contrast, many macrolichens were also present and the dominant genus was Caloplaca. In SO and VL large areas lacked any visible lichen cover, even where the ground was snow-free in summer. Small-scale diversity patterns were present in AB, where the number of species and genera was greater close to the coast. Most species recorded were rare in the study areas in which they were present and endemic to Antarctica.

  16. Microbes influence the biogeochemical and optical properties of maritime Antarctic snow

    Science.gov (United States)

    Hodson, A. J.; Nowak, A.; Cook, J.; Sabacka, M.; Wharfe, E. S.; Pearce, D. A.; Convey, P.; Vieira, G.

    2017-06-01

    Snowmelt in the Antarctic Peninsula region has increased significantly in recent decades, leading to greater liquid water availability across a more expansive area. As a consequence, changes in the biological activity within wet Antarctic snow require consideration if we are to better understand terrestrial carbon cycling on Earth's coldest continent. This paper therefore examines the relationship between microbial communities and the chemical and physical environment of wet snow habitats on Livingston Island of the maritime Antarctic. In so doing, we reveal a strong reduction in bacterial diversity and autotrophic biomass within a short (rock debris and marine fauna, develop obvious, pigmented snow algal communities that control the absorption of visible light to a far greater extent than with the inland glacial snowpacks. Absorption by carotenoid pigments is most influential at the surface, while chlorophyll is most influential beneath it. The coastal snowpacks also indicate higher concentrations of dissolved inorganic carbon and CO2 in interstitial air, as well as a close relationship between chlorophyll and dissolved organic carbon (DOC). As a consequence, the DOC resource available in coastal snow can support a more diverse bacterial community that includes microorganisms from a range of nearby terrestrial and marine habitats. Therefore, since further expansion of the melt zone will influence glacial snowpacks more than coastal ones, care must be taken when considering the types of communities that may be expected to evolve there.

  17. Mysterious iodine-overabundance in Antarctic meteorites

    Science.gov (United States)

    Dreibus, G.; Waenke, H.; Schultz, L.

    1986-01-01

    Halogen as well as other trace element concentrations in meteorite finds can be influenced by alteration processes on the Earth's surface. The discovery of Antarctic meteorites offered the opportunity to study meteorites which were kept in one of the most sterile environment of the Earth. Halogen determination in Antartic meteorites was compared with non-Antarctic meteorites. No correlation was found between iodine concentration and the weathering index, or terrestrial age. The halogen measurements indicate a contaminating phase rich in iodine and also containing chlorine. Possible sources for this contamination are discussed.

  18. Videoconference with Georges Charpak for his 85th Birthday

    CERN Multimedia

    CERN Audiovisual Service

    2009-01-01

    On 9 March CERN’s Main Auditorium was the venue for a fascinating and moving celebration marking the 85th birthday of Georges Charpak, who was awarded the Nobel Prize for Physics in 1992 for his invention of the multi-wire proportional chamber.

  19. SShA nuzhna silnaja Jevropa / Georg Schwarte

    Index Scriptorium Estoniae

    Schwarte, Georg

    2005-01-01

    USA president George W. Bush kohtus Euroopa Komisjoni presidendi Jose Manuel Barroso, EL-i eesistuja Luksemburgi peaministri Jean-Claude Junckeri ja EL-i välispoliitika juhi Javier Solanaga. G. Bush kinnitas kohtumisel, et USA toetab tugevat Euroopa Liitu

  20. Georges et les trésors du cosmos

    CERN Document Server

    Hawking, Lucy; Parsons, Gary

    2011-01-01

    Les voisins excentriques de Georges, Annie et Eric, ont déménagé en Floride à l'agence Spatiale Globale. Là-bas, Eric s'occupe de son nouveau robot, Homer, qui doit détécter les signes de vie sur Mars. Mais bientôt, Georges reçoit un e-mail : Annie lui demande de la rejoindre au plus vite pour une " mission cosmique " secrète. La jeune fille est persuadée qu'il se passe de drôles de choses sur Mars, car Homer vient de recevoir un message extraterrestre ! Georges et Anne (avec l'aide d'Emmett, un petit garçon bizarre) décident de réparer Cosmos, leur super-ordinateur, et d'aller voir par eux-mêmes... Emmaillotés dans des combinaisons spéciales, ils se lancent alors dans une fabuleuse chasse aux trésors sur Mars, sur les lunes de Saturne, puis sur Titan, avant de se perdre en orbite autour d'Alpha Centauri B... Mais avant de pouvoir élucider le mystère du message extraterrestre, Georges et Annie devront se livrer à une bataille spatiale acharnée qui mettra leur vie en danger, ainsi que ce...

  1. Bottom Sediments of Georges Bank (WIGLEY61 shapefile)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data were collected as part of a survey of the bottom sediments of Georges Bank. The purpose of the survey was to provide basic data for use in studying the...

  2. Robert E. Lee, George Peabody, and Sectional Reunion.

    Science.gov (United States)

    Parker, Franklin

    1994-01-01

    Discusses an 1869 meeting between George Peabody, educational philanthropist, and Robert E. Lee. The meeting focused public attention on the Peabody Education Fund and the South's educational plight. Significant measures of educational efforts in the South are directly attributable to several informal meetings centered around Peabody and Lee…

  3. Tuning the Self : George Herbert's poetry as cognitive behaviour

    NARCIS (Netherlands)

    van Es, Eelco

    2013-01-01

    This book provides a cognitive analysis of the poetry of George Herbert (1593- 1633). From Herbert’s own thinking, recorded in his prose treatises, can be deduced that his poems should serve a specific function: teaching self-knowledge to his readers. Self-knowledge is a necessary skill, to be

  4. Reputation, Canon-Formation, Pedagogy: George Orwell in the Classroom.

    Science.gov (United States)

    Rodden, John

    1991-01-01

    Investigates the process by which books become canonized in British and U.S. schools and universities. Uses the case of George Orwell to examine the institutional and historical factors which condition the inclusion and exclusion of writer's work in Anglo-American classrooms. (SR)

  5. Georges Paillard 1932-2004 - French version only

    CERN Multimedia

    2004-01-01

    J'ai eu le plaisir de rencontrer Georges en juillet 1959 au groupe Magnet de la division PS au moment où le centième et dernier aimant venait d'être installé dans l'anneau. Le groupe commençait déjà à s'orienter vers de nouveaux projets et mon premier travail avec Georges consista dans des essais de tubes flash de puissance pour la future chambre à bulles. Ensuite, bien que travaillant dans des domaines différents, mais toujours dans les mêmes divisions, nous ne nous sommes jamais perdus de vue. J'ai rencontré Georges en janvier 1961 au laboratoire d'électronique de la division NPA. Georges avait déjà six ans de CERN : c'était un ancien. Au début, il y eut la chambre à « boules ». Le chef de la division NPA, M. Colin Ramm, australien, éprouvait une certaine difficulté à prononcer le « u » français et une machine classique de la physique nucléaire est devenue l'unique chambre à « boules » jamais construite. Chambre qui connut son heure de gloire puisqu'elle enreg...

  6. Sorose suured soovid / George Soros ; interv. Neeme Raud

    Index Scriptorium Estoniae

    Soros, George, 1930-

    2006-01-01

    Miljardär ja filantroop George Soros vastab küsimustele, mis puudutavad tema raamatut "Ekslikkuse ajastu", kriitika USA kui maailma korratuse ühe põhjustaja suhtes, terroriohu vähendamist maailmas, avatud ühiskonnast

  7. William Butler Yeats, George Antheil, Ezra Pound Friends and Music

    Directory of Open Access Journals (Sweden)

    Ann Saddlemyer

    2013-03-01

    Full Text Available William Butler Yeats was throughout his life determined to relate his words to music, and involved many writers and musicians in his search for the key. While in Rapallo staying near Ezra Pound, he met the young composer George Antheil, who became one of his converts. Others followed, with Yeats continuing to expound and clarify his ambition.

  8. The St George's Respiratory Questionnaire revisited : a psychometric evaluation

    NARCIS (Netherlands)

    Paap, Muirne C S; Brouwer, Danny; Glas, Cees A W; Monninkhof, Evelyn M.; Forstreuter, Benjamin; Pieterse, Marcel E.; van der Palen, Job

    2015-01-01

    PURPOSE: The St George's Respiratory Questionnaire (SGRQ) has clearly acquired the status of legacy questionnaire for measuring health-related quality of life in patients with chronic obstructive pulmonary disease (COPD). The main aim of this study was to assess the underlying dimensionality of the

  9. George Pierce Baker's "Principles of Argumentation": "Completely Logical"?

    Science.gov (United States)

    Bordelon, Suzanne

    2006-01-01

    The article contends that previous scholars have misread George Pierce Baker's efforts by focusing primarily on "The Principles of Argumentation" and the role of logic. Baker's view of logic was more complex than scholars have claimed. He challenged traditional concepts of formal logic, highlighting only those aspects that would help students…

  10. George Herbert Mead's Contribution to the Philosophy of American Education.

    Science.gov (United States)

    Renger, Paul, III

    1980-01-01

    George Herbert Mead's general philsophy showed that he regarded the development of distinctively human behavior as essentially the result of an individual's meaningful participation in the social process of the community to which he belongs. Mead believed that education was a social process involving the meaningful interaction and communication…

  11. George Herbert Mead, Um, osoba i društvo

    OpenAIRE

    Bačeković, Alica

    2004-01-01

    Prikaz knjige George Herbert Mead, Um, osoba i društvo sa stajališta socijalnog biheviorista, priredio i uvod napisao Charles W. Morris, s engleskoga preveo Srđan Dvornik, Naklada Jesenski i Turk, Hrvatsko sociološko društvo, Zagreb 2003, xxx + 392 str

  12. Becoming a Voice: A Conversation with George Littlechild, Illustrator.

    Science.gov (United States)

    Mendoza, Jean

    2001-01-01

    Presents an interview with George Littlechild, a Canadian Plains Cree artist, writer and illustrator who has created nearly 500 paintings that have been exhibited on several continents. Discusses his autobiographical "This Land is My Land" which is illustrated with his paintings and which won the Jane Addams Picture Book Award. (SG)

  13. On George Orwell ’ s Politics and the English Language

    Institute of Scientific and Technical Information of China (English)

    卢云川; 岳春梅

    2014-01-01

    George Orwell is an important essayist in the 20th century and of great influence for his critical essays. Politics and the English Language is an essay with an aim to criticize the misused English at the historical setting when World War II was about to break out. The following article is to explore the es-say’ s language style and its theme.

  14. Georg Schmorl on trophoblasts in the maternal circulation

    NARCIS (Netherlands)

    Lapaire, O.; Holzgreve, W.; Oosterwijk, J. C.; Brinkhaus, R.; Bianchi, D. W.

    Trafficking of cells between the fetus and its mother provides indirect clues to the underlying pathophysiology of pregnancy. Georg Schmorl first documented the presence of fetal cells in the maternal body and emphasized the importance of the placenta in eclampsia. Although his classic paper,

  15. Energy acceptance of the St. George recoil separator

    Science.gov (United States)

    Meisel, Z.; Moran, M. T.; Gilardy, G.; Schmitt, J.; Seymour, C.; Couder, M.

    2017-04-01

    Radiative alpha-capture, (α , γ) , reactions play a critical role in nucleosynthesis and nuclear energy generation in a variety of astrophysical environments. The St. George recoil separator at the University of Notre Dame's Nuclear Science Laboratory was developed to measure (α , γ) reactions in inverse kinematics via recoil detection in order to obtain nuclear reaction cross sections at the low energies of astrophysical interest, while avoiding the γ-background that plagues traditional measurement techniques. Due to the γ ray produced by the nuclear reaction at the target location, recoil nuclei are produced with a variety of energies and angles, all of which must be accepted by St. George in order to accurately determine the reaction cross section. We demonstrate the energy acceptance of the St. George recoil separator using primary beams of helium, hydrogen, neon, and oxygen, spanning the magnetic and electric rigidity phase space populated by recoils of anticipated (α , γ) reaction measurements. We find the performance of St. George meets the design specifications, demonstrating its suitability for (α , γ) reaction measurements of astrophysical interest.

  16. Becoming a Voice: A Conversation with George Littlechild, Illustrator.

    Science.gov (United States)

    Mendoza, Jean

    2001-01-01

    Presents an interview with George Littlechild, a Canadian Plains Cree artist, writer and illustrator who has created nearly 500 paintings that have been exhibited on several continents. Discusses his autobiographical "This Land is My Land" which is illustrated with his paintings and which won the Jane Addams Picture Book Award. (SG)

  17. Sorose suured soovid / George Soros ; interv. Neeme Raud

    Index Scriptorium Estoniae

    Soros, George, 1930-

    2006-01-01

    Miljardär ja filantroop George Soros vastab küsimustele, mis puudutavad tema raamatut "Ekslikkuse ajastu", kriitika USA kui maailma korratuse ühe põhjustaja suhtes, terroriohu vähendamist maailmas, avatud ühiskonnast

  18. Matvere mängib filmis Georg Otsa

    Index Scriptorium Estoniae

    2006-01-01

    Eurovisiooni uudiseid vahendav www.oikotimes.com teatab režissöör Peeter Simmi mängufilmist "Georg", mis on Eesti, Venemaa ja Soome ühisprojekt lauljast (stsenaristid Mati Põldre, Aleksandr Borodjanski). Filmi operaator on Igor Koshevnikov, kunstnik Kalju Kivi, võtted algavad augustis

  19. Legendaarse Georg Otsa elust valmib film / Tuuli Koch, Priit Rajalo

    Index Scriptorium Estoniae

    Koch, Tuuli

    2006-01-01

    Eesti Filmi Sihtasutus eraldas eile tootmistoetuse režissöör Peeter Simmi mängufilmile "Georg". Eesti, Venemaa ja Soome ühisprojekt on eluloofilm lauljast (stsenaristid Mati Põldre, Aleksandr Borodjanski), nähtuna tema teise naise Asta Otsa silme läbi

  20. Tuning the Self : George Herbert's poetry as cognitive behaviour

    NARCIS (Netherlands)

    van Es, Eelco

    2013-01-01

    This book provides a cognitive analysis of the poetry of George Herbert (1593- 1633). From Herbert’s own thinking, recorded in his prose treatises, can be deduced that his poems should serve a specific function: teaching self-knowledge to his readers. Self-knowledge is a necessary skill, to be appli

  1. Prince George's Community College Marketing Plan, 1981-1982.

    Science.gov (United States)

    Engleberg, Isa N., Ed.; Leach, Ernest R., Ed.

    Developed by the Marketing Task Force at Prince George's Community College (PGCC) in 1981, this report presents a plan which identifies educational service needs, recommends strategies for responding to those needs, and suggests a marketing approach. The report begins by providing background on the four-stage marketing process implemented during…

  2. Festschrift Charpak (Georges) on his 65th birthday

    CERN Document Server

    Lehmann, Pierre; Rubbia, Carlo; Saudinos, Jean; CERN. Geneva

    1989-01-01

    On the occasion of the 65th birthday of Georges Charpak and of his retirement, the Director-General and the EP Division invite you to a symposium in his h. Chairman : P. Lehmann. - Opening address : C. Rubbia. - Message from V. Weisskopf. - L. Lederman : Superstrings needs sealing wax. - J. Saudinos : Quelques applications des detecteurs gazeux a la medecine et a la biologie.

  3. Bottom Sediments of Georges Bank (WIGLEY61 shapefile)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data were collected as part of a survey of the bottom sediments of Georges Bank. The purpose of the survey was to provide basic data for use in studying the...

  4. Tourism Changes on a Mediterranean Island: Experiences from Mallorca

    Directory of Open Access Journals (Sweden)

    Stephen A. Royle

    2009-11-01

    Full Text Available Mediterranean islands exemplify well the interactions between tourism, heritage and culture on islands. After an introduction that considers their heritage and the pressures which might be applied by tourism because of insular characteristics such as scale, the paper considers the Spanish island of Mallorca as a case study. First its history and consequent heritage is identified and then various stages in its tourism development, which might be recognized in Butler’s model, are treated with particular reference to two very different foreigner commentators on the island, George Sand and Robert Trimnell. The mass market tourism exemplified by Trimnell has brought a reaction and in recent decades Mallorca has given much more consideration to its environment and heritage, illustrated here through the example of the district of Calvià and its Local Agenda 21 policies. This has seen a considerable impact on the island’s tourism and marketing initiatives, as well as upon its natural environment.

  5. Spatially Extensive Standardized Surveys Reveal Widespread, Multi-Decadal Increase in East Antarctic Adélie Penguin Populations

    National Research Council Canada - National Science Library

    Southwell, Colin; Emmerson, Louise; McKinlay, John; Newbery, Kym; Takahashi, Akinori; Kato, Akiko; Barbraud, Christophe; DeLord, Karine; Weimerskirch, Henri

    2015-01-01

    .... Recent studies of penguin populations, the most commonly abundant Antarctic seabirds in the west Antarctic Peninsula and western Ross Sea, have demonstrated that physical changes in Antarctic marine...

  6. The Moscow Times kajastab Peeter Simmi filmi "Georg" valmimist / Ave Randviir

    Index Scriptorium Estoniae

    Randviir, Ave, 1981-

    2006-01-01

    Seoses sellega, et Peeter Simmi mängufilmi "Georg" võtted toimusid ka Moskvas, kirjutas ajakirjanik Aleksander Braterski pikemalt ka Georg Otsast ning P. Simm räägib samas ka oma filmi kontseptsioonist

  7. Modeling of ground temperatures in South Shetlands (Antarctic Peninsula): Forcing a land surface model with the reanalysis ERA-Interim

    Science.gov (United States)

    João Rocha, Maria; Dutra, Emanuel; Vieira, Gonçalo; Miranda, Pedro; Ramos, Miguel

    2010-05-01

    This study focus on Livingston Island (South Shetlands Antarctic Peninsula), one of the Earth's regions where warming has been more significant in the last 50 years. Our work is integrated in a project focusing on studying the influence of climate change on permafrost temperatures, which includes systematic and long-term terrain monitoring and also modeling using land surface models. A contribution will be the evaluation of the possibilities for using land surface modeling approaches to areas of the Antarctic Peninsula with lack of data on observational meteorological forcing data, as well as on permafrost temperatures. The climate variability of the Antarctic Peninsula region was studied using the new reanalysis product from European Centre for Medium-Range Weather Forecasts (ECMWF) Era-Interim and observational data from boreholes run by our group. Monthly and annual cycles of near surface climate variables are compared. The modeling approach includes the HTESSEL (Hydrology Tiled ECMWF Scheme for Surface Exchanges over Land) forced with ERA-Interim for modeling ground temperatures in the study region. The simulation results of run of HTESSEL are compared against soil temperature observations. The results show a favorable match between simulated and observed soil temperatures. The use of different forcing parameters is compared and the model vs. observation results from different results is analyzed. The main variable needing further improvement in the modeling is snow cover. The developed methodology provides a good tool for the analysis of the influence of climate variability on permafrost of the Maritime Antarctic.

  8. Deformational evolution of a Cretaceous subduction complex: Elephant Island, South Shetland Islands, Antarctica

    Science.gov (United States)

    Trouw, Rudolph A. J.; Passchier, Cees W.; Valeriano, Claudio M.; Simões, Luiz Sérgio A.; Paciullo, Fabio V. P.; Ribeiro, André

    2000-03-01

    New structural data from Elephant Island and adjacent islands are presented with the objective to improve the understanding of subduction kinematics in the area northeast of the Antarctic Peninsula. On the island, a first deformation phase, D 1, produced a strong SL fabric with steep stretching and mineral lineations, partly defined by relatively high pressure minerals, such as crossite and glaucophane. D 1 is interpreted to record southward subduction along an E-W trench with respect to the present position of the island. A second phase, D 2, led to intense folding with steep E-W-trending axial surfaces. The local presence of sinistral C'-type shear bands related to this phase and the oblique inclination of the L 2 stretching lineations are the main arguments to interpret this phase as representing oblique sinistral transpressive shear along steep, approximately E-W-trending shear zones, with the northern (Pacific) block going down with respect to the southern (Antarctic Peninsula) block. The sinistral strike-slip component may represent a trench-linked strike-slip movement as a consequence of oblique subduction. Lithostatic pressure decreased and temperature increased to peak values during D 2, interpreted to represent the collision of thickened oceanic crust with the active continental margin. The last deformation phase, D 3, is characterised by post-metamorphic kink bands, partially forming conjugate sets consistent with E-W shortening and N-S extension. The rock units that underlie the island probably rotated during D 3, in Cenozoic times, together with the trench, from an NE-SW to the present ENE-WSW position, during the progressive opening of the Scotia Sea. The similarity between the strain orientation of D 3 and that of the sinistral NE-SW Shackleton Fracture Zone is consistent with this interpretation.

  9. Antarctic Data Management as Part of the IPY Legacy

    Science.gov (United States)

    de Bruin, T.

    2006-12-01

    The Antarctic Treaty states that "scientific observations and results from Antarctica shall be exchanged and made freely available". Antarctica includes the Southern Ocean. In support of this, National Antarctic Data Centres (NADC) are being established to catalogue data sets and to provide information on data sets to scientists and others with interest in Antarctic science. The Joint Committee on Antarctic Data Management (JCADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP). JCADM comprises representatives of the National Antarctic Data Centres. Currently 30 nations around the world are represented in JCADM. JCADM is responsible for the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. JCADM is the Antarctic component of the IPY Data Infrastructure, which is presently being developed. This presentation will give an overview of the organization of Antarctic and Southern Ocean data management with sections on the organizational structure of JCADM, contents of the Antarctic Master Directory, relationships to the SCAR Scientific Research Programmes (SRP) and IPY, international embedding and connections with discipline-based peer organizations like the International Oceanographic Data and Information Exchange Committee (IODE). It will focus primarily on the role that an existing infrastructure as JCADM, may play in the development of the IPY Data Infrastructure and will provide considerations for IPY data management, based on the experiences in Antarctic and oceanographic data management.

  10. 75 FR 62461 - Revocation and Establishment of Class E Airspace; St. George, UT

    Science.gov (United States)

    2010-10-12

    .... George, UT AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action will remove Class E airspace at St. George, UT, as the airport will be closing, eliminating the need... Municipal Airport, St. George, UT (75 FR 44727). Interested parties were invited to participate in...

  11. Contrasts between Antarctic and Arctic ozone depletion.

    Science.gov (United States)

    Solomon, Susan; Portmann, Robert W; Thompson, David W J

    2007-01-09

    This work surveys the depth and character of ozone depletion in the Antarctic and Arctic using available long balloon-borne and ground-based records that cover multiple decades from ground-based sites. Such data reveal changes in the range of ozone values including the extremes observed as polar air passes over the stations. Antarctic ozone observations reveal widespread and massive local depletion in the heart of the ozone "hole" region near 18 km, frequently exceeding 90%. Although some ozone losses are apparent in the Arctic during particular years, the depth of the ozone losses in the Arctic are considerably smaller, and their occurrence is far less frequent. Many Antarctic total integrated column ozone observations in spring since approximately the 1980s show values considerably below those ever observed in earlier decades. For the Arctic, there is evidence of some spring season depletion of total ozone at particular stations, but the changes are much less pronounced compared with the range of past data. Thus, the observations demonstrate that the widespread and deep ozone depletion that characterizes the Antarctic ozone hole is a unique feature on the planet.

  12. Global dynamics of the Antarctic ice sheet

    NARCIS (Netherlands)

    Oerlemans, J.

    2002-01-01

    The total mass budget of the Antarctic ice sheet is studied with a simple axi-symmetrical model. The ice-sheet has a parabolic profile resting on a bed that slopes linearly downwards from the centre of the ice sheet into the ocean. The mean ice velocity at the grounding line is assumed to be proport

  13. Ultrastructural observations on five pioneer soil algae from ice denuded areas (King George Island, West Antarctica)

    OpenAIRE

    MASSALSKI, ANDRZEJ; Mrozinska ,Teresa; Olech, Maria

    2001-01-01

    Morphological observations were made using transmission electron microscopy on five species of green soil algae, including Chlorosarcinopsis cf. gelatinosa Chantanachat & Bold, Muriella decolor visher, Tetracystis aeria Brown & Bold, Tetracystis pampae Brown & bold, and Stichococcus bacillaris Nageli. With an exception of the latter species, they are all new records in Antarctica. These species were the important pioneers in the colonization process of the areas recently denuded of ice. Colle...

  14. {sup 137}Cs in marine sediments of Admiralty Bay, King George Island, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Paulo Alves de Lima [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil); Ribeiro, Andreza Portella, E-mail: andrezpr@usp.br [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil); Mestrado de Gestão Ambiental e Sustentabilidade, Universidade Nove de Julho (UNINOVE), Avenida Francisco Matarazzo, 612, prédio C, andar térreo, Água Branca, São Paulo, SP, 05001 100 (Brazil); Nascimento, Mylene Giseli do; Martins, Cesar de Castro [Centro de Estudos do Mar, Universidade Federal do Paraná (CEM-UFPR), Av. Beira-mar, no number, Balneário Pontal do Sul, Pontal do Paraná, PR, 83255 971 (Brazil); Mahiques, Michel Michaelovitch de; Montone, Rosalinda Carmelo; Figueira, Rubens Cesar Lopes [Instituto Oceanográfico, Universidade de São Paulo (IO-USP), Pça. do Oceanográfico, 191, Butantã, SP, 05508 900 (Brazil)

    2013-01-15

    The radionuclide cesium-137 ({sup 137}Cs) is produced exclusively by anthropogenic processes and primarily by nuclear explosions. This study determined the reference inventory that is {sup 137}Cs associated with the element's original input, and utilized the levels of activity of this radionuclide previously measured in five sediment profiles collected from Admiralty Bay, Antarctica, to investigate the mobility of this element in the environment. {sup 137}Cs has a half-life of 30 years. Because of this, it is environmentally persistent and has been shown to accumulate in marine organisms. The mean reference inventory of this radionuclide in Admiralty Bay sediments, determined using high resolution gamma ray spectrometry, was 20.23 ± 8.94 Bq m{sup −2}, and within the ambient {sup 137}Cs activity range. A model of {sup 137}Cs diffusion–convection was applied to data collected from 1 cm intervals in sediment cores with the aim of providing insights with respect to this element's behavior in sediments. Model results showed a significant correlation between measured and modeled values using the concentrations of {sup 137}Cs, and estimated input into the system from the global fallout of past nuclear tests and expected values based on local sedimentation rates. Results highlight the importance of accounting for the vertical diffusion of {sup 137}Cs in marine sediments when used as a tracer for environmental processes and for assessing potential bioavailability. - Highlights: ► Cesium-137 ({sup 137}Cs) is produced exclusively by anthropogenic processes. ► A model of diffusion–convection simulated {sup 137}Cs environmental behavior. ► This is important for assessing the bioavailability of this toxic element. ► In Antarctica ice cover influenced the input to the sediments.

  15. An initial attempt at least auklet productivity sampling at St. George Island, Alaska in 2007

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A large proportion of the world's population of least auklets (Aethia pusilla) breeds on the Alaska Maritime National Wildlife Refuge (AMNWR; Sowls et al. 1978)....

  16. Determination of element composition of three lichens and their distribution in King George Island, Antarctica

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Cross-section slices of Usnea antarctica Du Rietz, Usnea aurantiaco-atra (Jacq.) Bory. and Cladonia sp. at upper, middle and basal positions were prepared, respectively. The element composition and relative content were determined by SEM and EDS at the surface, intermediate and inner layers in each slice, respectively. The result indicated that the composition of element is mostly same in these lichens. The relative content of Al, Si, K and Ca elements is high, and P is close at each position. The result is of benefit to study the structure and physiological characteristics of lichens, and to analyze geological environment in Antarctica.

  17. Spectroscopic characterization of Antarctic marine aerosol

    Science.gov (United States)

    Paglione, Marco; Zanca, Nicola; Rinaldi, Matteo; Dall'osto, Manuel; Simo, Rafel; Facchini, Maria Cristina; Decesari, Stefano

    2017-04-01

    Marine aerosol constitutes an important and not thoroughly investigated natural aerosol system. In particular, the poor knowledge of the physical-chemical properties of primary (sea-spray) and secondary particles, especially over biologically active seawaters, affects the current capability of modeling the effect of marine aerosol on climate (O'Dowd et al., 2004). In polar regions, surface seawater composition and its exchanges with the atmosphere is complicated also by the presence of sea-ice and of the variety of micro-organisms (viruses, prokaryotes and microalgae) living within it (Levasseur,2013). In the framework of the Spanish project PEGASO (Plankton-derived Emission of Gases and Aerosols in the Southern Ocean) submicron aerosol samples were collected during a 6 weeks long oceanographic cruise (2nd January 2015 - 11th February 2015) conducted in the regions of Antarctic Peninsula, South Orkney and South Georgia Islands, an area of the Southern Ocean characterized every summer by both large patches of productive waters (phytoplankton blooms) and sea-ice cover. The collected samples were analyzed by means of proton-Nuclear Magnetic Resonance (H-NMR) spectroscopy with aim of organic compounds characterization in terms of functional groups and specific molecular tracers identification (Decesari et al., 2011). H-NMR spectral features resulted quite variable among the different samples both in terms of relative abundance of main functional groups and in terms of presence of specific compounds. In all the samples were found biogenic markers, like low-molecular-weight alkyl-amines and methanesulphonate (MSA), of secondary origin (formed by the condensation of vapors onto particles). Resonance signals of other aliphatic compounds of possible primary origin, like lipids, aminoacids (e.g. alanine) and sugars (e.g. sucrose) are present in variable concentrations in the samples. A hierarchical cluster analysis applied on the NMR spectra allowed to identify similarities

  18. Neogene kinematic history of Nazca-Antarctic-Phoenix slab windows beneath Patagonia and the Antarctic Peninsula

    Science.gov (United States)

    Breitsprecher, Katrin; Thorkelson, Derek J.

    2009-01-01

    The Patagonian slab window is a subsurface tectonic feature resulting from subduction of the Nazca-Antarctic spreading-ridge system (Chile Rise) beneath southern South America. The geometry of the slab window had not been rigorously defined, in part because of the complex nature of the history of ridge subduction in the southeast Pacific region, which includes four interrelated spreading-ridge systems since 20 Ma: first, the Nazca-Phoenix ridge beneath South America, then simultaneous subduction of the Nazca-Antarctic and the northern Phoenix-Antarctic spreading-ridge systems beneath South America, and the southern Phoenix-Antarctic spreading-ridge system beneath Antarctica. Spreading-ridge paleo-geographies and rotation poles for all relevant plate pairs (Nazca, Phoenix, Antarctic, South America) are available from 20 Ma onward, and form the mathematical basis of our kinematic reconstruction of the geometry of the Patagonia and Antarctic slab windows through Neogene time. At approximately 18 Ma, the Nazca-Phoenix-Antarctic oceanic (ridge-ridge-ridge) triple junction enters the South American trench; we recognize this condition as an unstable quadruple junction. Heat flow at this junction and for some distance beneath the forearc would be considerably higher than is generally recognized in cases of ridge subduction. From 16 Ma onward, the geometry of the Patagonia slab window developed from the subduction of the trailing arms of the former oceanic triple junction. The majority of the slab window's areal extent and geometry is controlled by the highly oblique (near-parallel) subduction angle of the Nazca-Antarctic ridge system, and by the high contrast in relative convergence rates between these two plates relative to South America. The very slow convergence rate of the Antarctic slab is manifested by the shallow levels achieved by the slab edge (< 45 km); thus no point on the Antarctic slab is sufficiently deep to generate "normal" mantle-derived arc-type magmas

  19. Relationships between the Arctic and the Antarctic cyanobacteria; three Phormidium-like strains evaluated by a polyphasic approach.

    Science.gov (United States)

    Comte, Katia; Sabacká, Marie; Carré-Mlouka, Alyssa; Elster, Josef; Komárek, Jirí

    2007-02-01

    Selected strains of filamentous Phormidium-like cyanobacteria isolated from two Arctic regions (Ellesmere Island, High Canadian Arctic and Svalbard) and from Antarctica (Antarctic peninsula, South Shetland Islands and South Orkney Islands) were studied. The polyphasic approach used included phenotypic observations of morphological features and genotypic analyses (restriction fragment length polymorphism of 16S rRNA gene, internal transcribed space, 16S rRNA gene sequence analysis). Although genotypes generally correspond to observed morphotypes, the genetic analyses revealed a high degree of biodiversity that could not be unveiled using solely morphological evaluations. According to the phylogenetic analysis, the three clones were divided into two major clades, indicating that the phylogenetic distance between Arct-Ph5/Ant-Ph68 and Ant-Ph58 was so large they belonged to different genera. The polyphyletic position of strains of the genus Phormidium was confirmed by this study, attesting the need to entirely revise classification in this taxon in the future.

  20. Georges Didi-Huberman, Images malgré tout

    OpenAIRE

    Shafto, Sally

    2008-01-01

    « Pour savoir, il faut s’imaginer. »Georges Didi-Huberman Avec son dernier livre, Images malgré tout, l’historien de l’art et philosophe Georges Didi-Huberman nous livre un texte élégamment écrit et divisé en trois mouvements. Il y a d’abord une réimpression de son article, paru auparavant dans le catalogue, Mémoires des camps. Photographies des camps de concentration et d’extermination nazis 1933-1999. Il s’agit d’une lecture phénoménologique de quatre photographies, prises à Auschwitz en ao...