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Sample records for arctic sediments svalbard

  1. Large ancient organic matter contributions to Arctic marine sediments (Svalbard)

    NARCIS (Netherlands)

    Kim, J.-H.; Peterse, F.; Willmott, V.; Klitgaard Kristensen, D.; Baas, M.; Schouten, S.; Sinninghe Damsté, J.S.

    2011-01-01

    Soils, fine-grained ice-rafted detritus (IRD), coals, and marine surface sediments in the Arctic realm (Svalbard) were collected in 2007 and 2008 to characterize organic matter (OM) sources in Arctic marine sediments. Bulk geochemical (C : N ratio and stable carbon isotopic composition) parameters s

  2. Large ancient organic matter contributions to Arctic marine sediments (Svalbard)

    NARCIS (Netherlands)

    Kim, J.-H.; Peterse, F.; Willmott, V.; Klitgaard Kristensen, D.; Baas, M.; Schouten, S.; Sinninghe Damsté, J.S.

    2011-01-01

    Soils, fine-grained ice-rafted detritus (IRD), coals, and marine surface sediments in the Arctic realm (Svalbard)were collected in 2007 and 2008 to characterize organic matter (OM) sources in Arctic marine sediments. Bulkgeochemical (C : N ratio and stable carbon isotopic composition) parameters sug

  3. Molecular organic geochemistry of ornithogenic sediment from Svalbard, Arctic

    Institute of Scientific and Technical Information of China (English)

    Wang Jianjun; Sun Liguang

    2009-01-01

    The molecular biomarker compositions of the ornithogenic sediments (YN), from Svalbard, Arctic were investigated. The results showed that n-alkanes had a bimodal pattern and their odd-even preference was not obvious. The alkanes contained unresolved complex mixtures (UCM) and relatively high levels of pristine and retene, indicating pollution from the nearby coal mines. The n-alkanols in the sediments had even-to-odd preference, and they might originate mainly from modern biota. Sistosterol, the main sterol in herbivores feces, was the dominant sterol, indicating that sitosterol might be a good biomarker of input from the birds feces in the sediments. The fatty acids of the sediments showed acid. The α-hydroxyl acids and ω-hydroxyl fatty acids were also detected in the sediments. In summary, the organic matters in the YN sediments were from the adjacent coal mines, bird feces, and plants.

  4. Isolation and Physiological Characterization of Psychrophilic Denitrifying Bacteria from Permanently Cold Arctic Fjord Sediments (Svalbard, Norway)

    Science.gov (United States)

    Canion, Andy; Prakash, Om; Green, Stefan J.; Jahnke, Linda; Kuypers, Marcel M. M.; Kostka, Joel E.

    2013-01-01

    A large proportion of reactive nitrogen loss from polar sediments is mediated by denitrification, but microorganisms mediating denitrification in polar environments remain poorly characterized. A combined approach of most-probable-number (MPN) enumeration, cultivation and physiological characterization was used to describe psychrophilic denitrifying bacterial communities in sediments of three Arctic fjords in Svalbard (Norway). A MPN assay showed the presence of 10(sup 3)-10(sup 6) cells of psychrophilic nitrate-respiring bacteria g(sup -1) of sediment. Fifteen strains within the Proteobacteria were isolated using a systematic enrichment approach with organic acids as electron donors and nitrate as an electron acceptor. Isolates belonged to five genera, including Shewanella, Pseudomonas, Psychromonas (Gammaproteobacteria), Arcobacter (Epsilonproteobacteria) and Herminiimonas (Betaproteobacteria). All isolates were denitrifiers, except Shewanella, which exhibited the capacity for dissimilatory nitrate reduction to ammonium (DNRA). Growth from 0 to 40 degC demonstrated that all genera except Shewanella were psychrophiles with optimal growth below 15 degC, and adaptation to low temperature was demonstrated as a shift from primarily C16:0 saturated fatty acids to C16:1 monounsaturated fatty acids at lower temperatures. This study provides the first targeted enrichment and characterization of psychrophilic denitrifying bacteria from polar sediments, and two genera, Arcobacter and Herminiimonas, are isolated for the first time from permanently cold marine sediments.

  5. Persistent toxic substances in remote lake and coastal sediments from Svalbard, Norwegian Arctic: levels, sources and fluxes.

    Science.gov (United States)

    Jiao, Liping; Zheng, Gene J; Minh, Tu Binh; Richardson, Bruce; Chen, Liqi; Zhang, Yuanhui; Yeung, Leo W; Lam, James C W; Yang, Xulin; Lam, Paul K S; Wong, Ming H

    2009-04-01

    Surface sediments from remote lakes and coastal areas from Ny-Alesund, Svalbard, Norwegian Arctic were analyzed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Relatively high levels of PAHs were encountered from several lakes from Ny-Alesund, which were within the range of levels reported for European high mountain lakes and some urban/industrialized areas in the world, pointing to the role of remote Arctic lakes as potential reservoir of semi-volatile organic compounds. Specific patterns of PBDEs were observed, showing higher concentrations of lower brominated compounds such as BDE-7, 17 and 28. Estimated surface sediment fluxes of PAHs in Ny-Alesund remote lakes were similar to those observed for some European high mountain lakes. The current PAH levels in sediments from three lakes exceeded Canadian sediment quality guidelines, suggesting the presence of possible risks for aquatic organisms and the need for further studies.

  6. Volatile fatty acids as substrates for iron and sulfate reduction in Arctic marine sediments, Svalbard

    Science.gov (United States)

    Finke, N.; Vandieken, V.; Jorgensen, B. B.

    2006-12-01

    Anaerobic degradation of complex organic material in aquatic systems is a multi-step process. The metabolic products of fermentative bacteria serve as electron donors for the terminal oxidizing bacteria. In marine sediments, iron reduction and sulfate reduction are generally the most important terminal oxidation processes in the upper anoxic zone [1]. Microorganisms that reduce iron and sulfate may use a broad range of electron donors, yet the list of potential substrates provides little information about the substrates used in situ by these organisms. Investigations on the electron donors for sulfate reducers in marine sediments have shown that volatile fatty acids (VFA), and in particular acetate, together with hydrogen are the major substrates (e.g. [2-4]). Similar investigations for iron reduction or simultaneous iron and sulfate reduction are lacking for marine sediments. Furthermore, most of these studies were made in temperate sediments and little is known about the substrates for sulfate reducers in permanently cold sediments, which account for >90% of the ocean floor [5]. We investigated the relative contributions of iron reduction and sulfate reduction to the terminal oxidation of organic carbon and the importance of acetate, lactate, propionate, and isobutyrate as electron donors for iron and sulfate reduction in permanently cold, Arctic sediments from Svalbard. In the surface layer (0-2 cm) sulfate reduction accounted for 2/3 of the organic carbon oxidation (determined as DIC production), the remaining 1/3 were attributed to iron reduction. In the 5-9 cm layer sulfate reduction was the sole important terminal oxidation step. The contribution of acetate to terminal oxidation was determined by radiotracer incubation as well as from the accumulation after the inhibition of sulfate reduction by selenate. The rates determined with the two methods varied by less than 20%. Acetate turnover, determined with the tracer incubations, accounted for 10 and 40% of

  7. Persistent toxic substances in remote lake and coastal sediments from Svalbard, Norwegian Arctic: Levels, sources and fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Jiao Liping [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Key Laboratory of Global Change and Marine-Atmospheric Chemistry, State Oceanic Administration, 178 Daxue Road, Xiamen, Fijian (China); Third Institute of Oceanography, State Oceanic Administration, 178 Daxue Road, Xiamen, Fujian (China); Zheng, Gene J. [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong (China); Minh, Tu Binh; Richardson, Bruce [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Chen Liqi; Zhang Yuanhui [Key Laboratory of Global Change and Marine-Atmospheric Chemistry, State Oceanic Administration, 178 Daxue Road, Xiamen, Fijian (China); Third Institute of Oceanography, State Oceanic Administration, 178 Daxue Road, Xiamen, Fujian (China); Yeung, Leo W.; Lam, James C.W. [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Yan, Xulin [Key Laboratory of Global Change and Marine-Atmospheric Chemistry, State Oceanic Administration, 178 Daxue Road, Xiamen, Fijian (China); Third Institute of Oceanography, State Oceanic Administration, 178 Daxue Road, Xiamen, Fujian (China); Lam, Paul K.S. [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China)], E-mail: bhpksl@cityu.edu.hk; Wong, Ming H. [Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong (China)], E-mail: mhwong@hkbu.edu.hk

    2009-04-15

    Surface sediments from remote lakes and coastal areas from Ny-Alesund, Svalbard, Norwegian Arctic were analyzed for polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Relatively high levels of PAHs were encountered from several lakes from Ny-Alesund, which were within the range of levels reported for European high mountain lakes and some urban/industrialized areas in the world, pointing to the role of remote Arctic lakes as potential reservoir of semi-volatile organic compounds. Specific patterns of PBDEs were observed, showing higher concentrations of lower brominated compounds such as BDE-7, 17 and 28. Estimated surface sediment fluxes of PAHs in Ny-Alesund remote lakes were similar to those observed for some European high mountain lakes. The current PAH levels in sediments from three lakes exceeded Canadian sediment quality guidelines, suggesting the presence of possible risks for aquatic organisms and the need for further studies. - High levels of PAHs and specific patterns of PBDEs were found in sediments from the remote Norwegian Arctic lakes.

  8. Biomarker responses and PAH uptake in Mya truncata following exposure to oil-contaminated sediment in an Arctic fjord (Svalbard)

    Energy Technology Data Exchange (ETDEWEB)

    Camus, L. [Akvamiljoe as, Mekjarvik 12, N-4070 Randaberg (Norway); Birkely, S.R.; Loenne, O.J. [The University Courses on Svalbard, PB 156, N-9170 Longyearbyen (Norway); Jones, M.B.; Depledge, M.H. [School of Biological Sciences, Plymouth Environmental Research Centre, University of Plymouth, Plymouth, Devon, PL4 8AA (United Kingdom); Boerseth, J.F.; Groesvik, B.E. [RF-Rogaland Research, P.O. Box 2503, Ullandhaug, N-4004 Stavanger (Norway); Gulliksen, B. [Norwegian College of Fishery Sciences, University of Tromsoe, N-9037 Tromsoe (Norway); Regoli, F. [Institute of Biology and Genetic, University of Ancona, Via Ranieri, Monte d' Ago, I-60100 Ancona (Italy)

    2003-06-01

    Expanding industrial activity (notably oil and gas exploration) in the Arctic requires assessment of the potential impact of chemicals on marine organisms living in seawater at low temperature. The bivalve Mya truncata is common in Svalbard fjord (Norway) where it experiences low temperature throughout the year. To measure the impact of polycyclic aromatic hydrocarbons (PAH) on M. truncata, the responses of three biomarkers [total oxyradical scavenging capacity-assay (TOSC), plasma membrane stability of haemocytes and respiration rates] were investigated from bivalves exposed to sediment contaminated with a PAH mixture (crude oil). After two weeks of exposure to the contaminated sediment, TOSC showed no change. The high TOSC value (4010{+-}1339 unit mg{sup -1} protein) of Mya truncata (control group) is thought to protect biomolecules with a low turnover rate efficiently in a low food availability environment. In the exposed bivalves, the haemocyte cellular membranes were significantly destabilised compared with controls (P<0.05). Respiration rate of control and PAH-exposed individuals (0.055{+-}0.020 mg O{sub 2} dw{sup -1} h{sup -1}) was similar and relatively low as is typical for polar bivalves, reflecting a strategy to minimise energy expenditure to cope with 9 months of starvation. Bioaccumulation of PAH by M. truncata was also low, due probably to a combination of low metabolic rate and reduced solubility of the oil compounds at low temperature. Data indicated an uptake of mainly low molecular weight compounds (two and three ring molecules). A good correlation of logBAF{sub lipid} (bioaccumulation factor) and logK{sub ow} (octanol/water partitioning coefficient) was shown (r{sup 2}=0.87). Tissue sensitivity and/or functional differences (digestive gland vs. haemocytes), PAH uptake route (dietary vs. gills), the low metabolic rate of M. truncata and the low environmental temperature (reducing the bioavailability of PAH) are factors that help explain these

  9. Desulfuromonas svalbardensis sp nov and Desulfuromusa ferrireducens sp nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard

    DEFF Research Database (Denmark)

    Vandieken, V.; Mussmann, M.; Niemann, Hans Henrik

    2006-01-01

    Two psychrophilic, Gram-negative, rod-shaped, motile bacteria (strains 112(T) and 102(T)) that conserved energy from dissimilatory Fe(III) reduction concomitant with acetate oxidation were isolated from permanently cold Arctic marine sediments. Both strains grew at temperatures down to -2 degrees C...

  10. Desulfuromonas svalbardensis sp. nov. and Desulfuromusa ferrireducens sp. nov., psychrophilic, Fe(III)-reducing bacteria isolated from Arctic sediments, Svalbard

    DEFF Research Database (Denmark)

    Vandieken, Verona; Mussmann, Marc; Niemann, Helge

    2006-01-01

    Two psychrophilic, Gram-negative, rod-shaped, motile bacteria (strains 112T and 102T) that conserved energy from dissimilatory Fe(III) reduction concomitant with acetate oxidation were isolated from permanently cold Arctic marine sediments. Both strains grew at temperatures down to -2 degrees C...

  11. Arctic West and North of Svalbard

    Energy Technology Data Exchange (ETDEWEB)

    Sundvor, E.; Austegard, A. (Bergen Univ. (Norway)) Myhre, A.M.; Eldholm, O. (Oslo Univ., (Norway) Dept. of Geology)

    1982-01-01

    Recent multichannel seismic data have revealed that the Svalbard passive margin has undergone a complex geological history which largely reflects the plate tectonic evolution of the Greenland Sea and the Arctic Ocean. On the western margin the continent-ocean boundary is located at or close to the Hornsund Fault Zone. In the late Paleocene/Early Eocene, the region between Svalbard and Northeast Greenland was subjected to regional shear movements associated with a transform system between the young Lofoten-Greenland Basin and the Arctic Ocean. Approximately 50My ago the spreading axis migrated northeastwards forming the passive margin between Bear Island and 76.5degN. At the time of the main reorganization of the plate motion the northern margin evolved and a continental fragment was possibly cut off from the Svalbard margin, appearing, today, as the submarine ridge associated with the Hovgaard Fracture Zone. The northern Svalbard margin is of a rifted type, though the seismic results indicate two structurally different regions: The Yermak Plateau and the Hinlopen Margin. A major problem in understanding the geology and evolution of the Yermak Plateau is the nature of the opaque acoustic basement. 12 drawings.

  12. Acetate, lactate, propionate, and isobutyrate as electron donors for iron and sulfate reduction in Arctic marine sediments, Svalbard

    DEFF Research Database (Denmark)

    Finke, Niko; Vandieken, Verona; Jørgensen, Bo Barker

    2007-01-01

    the oxidized (0-2 cm) and the reduced (5-9 cm) zone. In the 0-2 cm layer, 2/3 of the mineralization could be attributed to sulfate reduction and 1/3 to iron reduction. In the 5-9 cm layer, sulfate reduction was the sole mineralization process. Acetate and lactate turnover rates were measured by radiotracer......The contribution of volatile fatty acids (VFA) as e--donors for anaerobic terminal oxidation of organic carbon through iron and sulfate reduction was studied in Arctic fjord sediment. Dissolved inorganic carbon, Fe2+, VFA concentrations, and sulfate reduction were monitored in slurries from....... Inhibition of sulfate reduction with selenate resulted in the accumulation of acetate, propionate, and isobutyrate. The acetate turnover rates determined by radiotracer and accumulation after inhibition were similar. VFA turnover accounted for 21% and 52% of the mineralization through sulfate reduction...

  13. Pathways of carbon oxidation in an Arctic fjord sediment (Svalbard) and isolation of psychrophilic and psychrotolerant Fe(III)-reducing bacteria

    DEFF Research Database (Denmark)

    Vandieken, Verona; Finke, Niko; Jørgensen, Bo Barker

    2006-01-01

    , Desulfuromusa, Shewanella and Desulfovibrio were isolated from enrichment cultures of 2 fjord sediments from Svalbard. Strains related to Desulfovibrio reduced Fe(III) without energy generation for growth. All isolates were psychrophilic or psychrotolerant and grew at –2°C, the freezing point of sea water...

  14. Pathways of carbon oxidation in an Arctic fjord sediment (Svalbard) and isolation of psychrophilic and psychrotolerant Fe(III)-reducing bacteria

    DEFF Research Database (Denmark)

    Vandieken, Verona; Finke, Niko; Jørgensen, Bo Barker

    2006-01-01

    Desulfuromonas, Desulfuromusa, Shewanella and Desulfovibrio were isolated from enrichment cultures of 2 fjord sediments from Svalbard. Strains related to Desulfovibrio reduced Fe(III) without energy generation for growth. All isolates were psychrophilic or psychro-tolerant and grew at -2 degrees C, the freezing...

  15. Rabies in the arctic fox population, Svalbard, Norway.

    Science.gov (United States)

    Mørk, Torill; Bohlin, Jon; Fuglei, Eva; Åsbakk, Kjetil; Tryland, Morten

    2011-10-01

    Arctic foxes, 620 that were trapped and 22 found dead on Svalbard, Norway (1996-2004), as well as 10 foxes trapped in Nenets, North-West Russia (1999), were tested for rabies virus antigen in brain tissue by standard direct fluorescent antibody test. Rabies antigen was found in two foxes from Svalbard and in three from Russia. Blood samples from 515 of the fox carcasses were screened for rabies antibodies with negative result. Our results, together with a previous screening (1980-1989, n=817) indicate that the prevalence of rabies in Svalbard has remained low or that the virus has not been enzootic in the arctic fox population since the first reported outbreak in 1980. Brain tissues from four arctic foxes (one from Svalbard, three from Russia) in which rabies virus antigen was detected were further analyzed by reverse-transcriptase polymerase chain reaction direct amplicon sequencing and phylogenetic analysis. Sequences were compared to corresponding sequences from rabies virus isolates from other arctic regions. The Svalbard isolate and two of the Russian isolates were identical (310 nucleotides), whereas the third Russian isolate differed in six nucleotide positions. However, when translated into amino acid sequences, none of these substitutions produced changes in the amino acid sequence. These findings suggest that the spread of rabies virus to Svalbard was likely due to migration of arctic foxes over sea ice from Russia to Svalbard. Furthermore, when compared to other Arctic rabies virus isolates, a high degree of homology was found, suggesting a high contact rate between arctic fox populations from different arctic regions. The high degree of homology also indicates that other, and more variable, regions of the genome than this part of the nucleoprotein gene should be used to distinguish Arctic rabies virus isolates for epidemiologic purposes.

  16. The potential of high arctic colluvial fan development and process regeneration as palaeoclimate proxies; Colluvial source area and sediment mapping within the CRYOSLOPE Svalbard framework.

    Science.gov (United States)

    Rubensdotter, L.; Stalsberg, K.; Christiansen, H.; Neumann, U.; Eckerstorfer, M.; Humlum, O.

    2009-04-01

    Within the CRYOSLOPE Svalbard project we have conducted detailed geomorphological mapping and analysis of colluvial deposits in some valleys in central Spitsbergen. The scope of the project is to provide links between arctic slope processes and climate through the work with 1) meteorological monitoring 2) geomorphological mapping and present process monitoring and 3) future projections of slope activity. The lack of vegetation on arctic Svalbard together with intensive frost weathering and resulting high colluvial activity creates a potential for achieving palaeoclimate information by analysing slope deposit development through time and comparing this to present day process observations. We present results from a genetic classification of colluvium and colluvial fan development and process regeneration in the Todalen Valley, east of Longyearbyen. The north-south running U-shaped valley is eroded by repeated glaciations, and today modern glaciers occupy two of its tributary valleys. The fractured sedimentary bedrock in the region is exposed to intensive frost weathering and both valley sides are covered by different types of colluvium. The presently active slope processes are primarily rock falls, dry- and wet snow avalanches, debris flows and slush flows. 2008 field observations compared with 1990 aerial photographs show that highly erosive debris-flow activity has had a significant morphological imprint on the landscape in the last decades. Multi-genetic colluvial fan areas are widespread in both east- and west facing valley sides. Most fans have a main body of snow-avalanche and rock fall material with a younger imprint of wetter processes, such as debris-flows, superimposed on the surface. The debris-flows have remobilized the fan deposits and brought them further out on the valley floor, resulting in a lower surface angle than in the convex snow-avalanche fans. Two fans, however, show a more regenerative succession of development which can be separated into

  17. Filamentous sulfur bacteria, Beggiatoa spp., in arctic marine sediments (Svalbard, 79°N)

    DEFF Research Database (Denmark)

    Jørgensen, Bo Barker; Dunker, Rita; Grünke, Stefanie;

    2010-01-01

    is closely associated with other large, marine, nitrate-storing Beggiatoa. The Beggiatoa mostly occurred in the upper 2-5 cm of oxidized surface sediment between oxygen and the deeper sulfidic zone. In spite of a very low or an undetectable sulfide concentration, sulfate reduction provided abundant H2S...

  18. Origin of bentonites and clastic sediments of the Paleocene Basilika Formation, Svalbard

    Science.gov (United States)

    Elling, Felix; Spiegel, Cornelia; Estrada, Solveig; Davis, Donald; Reinhardt, Lutz; Henjes-Kunst, Friedhelm; Allroggen, Niklas; Dohrmann, Reiner; Piepjohn, Karsten; Lisker, Frank

    2016-07-01

    The Paleocene was a time of transition for the Arctic, with magmatic activity of the High Arctic Large Igneous Province giving way to magmatism of the North Atlantic Large Igneous Province in connection to plate tectonic changes in the Arctic and North Atlantic. In this study we investigate the Paleocene magmatic record and sediment pathways of the Basilika Formation exposed in the Central Tertiary Basin of Svalbard. By means of geochemistry, Sm-Nd isotopic signatures and zircon U-Pb geochronology we investigate the characteristics of several bentonite layers contained in the Basilika Formation, as well as the provenance of the intercalated clastic sediments. Our data show that the volcanic ash layers of the Basilika Formation, which were diagenetically altered to bentonites, originate from alkaline continental-rift magmatism such as the last, explosive stages of the High Arctic Large Igneous Province in North Greenland and the Canadian Arctic. The volcanic ash layers were deposited on Svalbard in a flat shelf environment with dominant sediment supply from the east. Dating of detrital zircons suggests that the detritus was derived from Siberian sources, primarily from the Verkhoyansk Fold-and-Thrust Belt, which would require transport over ~3000 km across the Arctic.

  19. The Svalbard REU Program: Undergraduates Pursuing Arctic Climate Change Research on Svalbard, Norway

    Science.gov (United States)

    Roof, S.; Werner, A.

    2007-12-01

    The Svalbard Research Experiences for Undergraduates (REU) program sponsored by the Arctic Natural Sciences Program of the National Science Foundation has been successfully providing international field research experiences since 2004. Each year, 7-9 undergraduate students have participated in 4-5 weeks of glacial geology and climate change fieldwork on Spitsbergen in the Svalbard archipelago in the North Atlantic (76- 80° N lat.). While we continue to learn new and better ways to run our program, we have learned specific management and pedagogical strategies that allow us to streamline our logistics and to provide genuine, meaningful research opportunities to undergraduate students. We select student participants after extensive nationwide advertising and recruiting. Even before applying to the program, students understand that they will be doing meaningful climate change science, will take charge of their own project, and will be expected to continue their research at their home institution. We look for a strong commitment of support from a student's advisor at their home institution before accepting students into our program. We present clear information, including participant responsibilities, potential risks and hazards, application procedures, equipment needed, etc on our program website. The website also provides relevant research papers and data and results from previous years, so potential participants can see how their efforts will contribute to growing body of knowledge. New participants meet with the previous years' participants at a professional meeting (our "REUnion") before they start their field experience. During fieldwork, students are expected to develop research questions and test their own hypotheses while providing and responding to peer feedback. Professional assessment by an independent expert provides us with feedback that helps us improve logistical procedures and shape our educational strategies. The assessment also shows us how

  20. Bacterial Diversity of Ny-Ålesund, Arctic Archipelago Svalbard

    Directory of Open Access Journals (Sweden)

    Battsetseg Choidash

    2012-12-01

    Full Text Available The bacterial diversity of the water sample, collected from Ny-Ålesund, Arctic Archipelago Svalbard was analyzed by a phenotypic as well as a genotypic approach. Pure colonies of the culturable bacteria were established and grown at a range of temperatures: 4ºC, 15ºC, 22ºC and 37ºC. Optimum growth was found at 15ºC, and around 28 colonies were obtained. The library was dominated by 16S rDNAs of Gram-negative bacteria ( γ -Proteobacteria. Twenty two isolates exhibited sequences were similar to that of known bacterial isolates (>97% sequence similarity, represented by the species of the genera Psychrobacter , Pseudomonas , and Acinetobacter . Six isolates exhibited sequences showed less affi liation with known taxa (<97% sequence similarity, and may represent novel taxa.

  1. Modern Process Studies in Kongsfjord, Svalbard: Arctic Geoscience Research Experience for U.S. Undergraduates (Svalbard REU)

    Science.gov (United States)

    Powell, R. D.; Brigham-Grette, J.

    2011-12-01

    The Svalbard REU (Research Experience for Undergraduates) program focuses on understanding how high latitude glaciers, meltwater streams, and sedimentation in lakes and fjords respond to changing climate. Since summer of 2004, six under-graduate students have been selected to participate in the summer field program. Students work on individual projects and in close conjunction with faculty advisors and other student researchers. They formulate their own research questions, develop their project, and complete their field research during a five-week program on Svalbard, Norway. Following the summer program, students complete their projects at their home institution during the following academic year as a senior thesis. A spring symposium brings all participants back together again with their final results. The most recent field season was completed in Kongsfjord (79N) showing that the contemporary studies of tidewater glacier margins provide an unparalleled opportunity for introducing motivated third year undergraduate students to the challenges and rewards of polar geoscientific field research. Rates of rapid change in this high-latitude Arctic environment emphasize the complexity of the Earth System at the interface of the ocean, atmosphere and cryosphere. Given background information in glacial and marine geology, glaciology, hydrology, climatology and fjord oceanography not routinely offered in undergraduate curricula, students develop the science questions to be addressed and establish a field plan for instrumentation and sampling. Working together in small boats in one of the most challenging natural environments, the students expand their leadership skills, learn the value of teamwork and collaborative data sharing while maintaining a strong sense of ownership over their individual science projects. The rigors of studying an actively calving tidewater glacier also builds on their outdoor skills, especially when it is necessary to improvise and become

  2. Towards a process-based understanding of Holocene polar climate change. Using glacier-fed lake sediments from Arctic Svalbard and Antarctic South Georgia

    OpenAIRE

    2016-01-01

    Earth`s polar regions are undergoing dramatic changes due to ongoing climate change as demonstrated by increasing temperatures, collapsing ice shelves, Arctic sea ice loss and rapid glacier retreat. Driving an accelerating rise in global sea level, this amplified regional response may have devastating global socio-economic consequences in the foreseeable future. Yet the causes and range of polar climate variability remain poorly understood as observational records are short and fragmentary, w...

  3. Differential methane oxidation activity and microbial community composition at cold seeps in the Arctic off western Svalbard

    Science.gov (United States)

    Gründger, Friederike; Svenning, Mette M.; Niemann, Helge; Silyakova, Anna; Serov, Pavel; Li Hong, Wei; Wegener, Gunter; Panieri, Giuliana; Carroll, JoLynn

    2016-04-01

    Most models considering climate change related bottom water warming suggest that gas hydrates may become destabilized, leading to the mobilization of methane into seabed and water column ecosystems, and, eventually, into the atmosphere. However, the capacity of methanotrophic microbes retaining methane in sediments and the hydrosphere is not well constrained. Here, we investigate the microbial utilization of methane in sediments and the water column, focusing on cold seeps discovered at the arctic continental margin of western Svalbard. We measured ex situ rates of methane oxidation and sulfate reduction in two active gas flare sites with different geological settings at the Vestnesa Ridge (1204 m water depth) and within a pingolike feature area southwest off Svalbard (PLF; 380 m water depth). Our results show contrarily situations at our two sampling sites: At Vestnesa Ridge we find high methane oxidation rates with values up to 2055 nmol cm-3 d-1 at the sediment surface where the sediments are oversaturated with methane. Whereas, methane concentration and oxidation rates are low in the overlying water column (2 pmol cm-3 d-1). In contrast, at the sediment surface at PLF methane concentration and oxidation rates are considerably lower (up to 1.8 nmol cm-3 d-1). While the overlying bottom water contains high concentration of methane and shows oxidation rates with values of up to 3.8 nmol cm-3 d-1. The data on methane oxidation and sulfate reduction activity are compared to the sediment geochemistry and to data from metagenomic analysis identifying the methanotrophic community composition. These results provide unique insight into the dynamic responses of the seabed biological filter at cold seeps in the Arctic off western Svalbard. This study is part of the Centre for Arctic Gas Hydrate, Environment and Climate and was supported by the Research Council of Norway through its Centres of Excellence funding scheme grant No. 223259.

  4. Bioaccumulation of polycyclic aromatic hydrocarbons, polychlorinated biphenyls and hexachlorobenzene by three Arctic benthic species from Kongsfjorden (Svalbard, Norway).

    Science.gov (United States)

    Szczybelski, Ariadna S; van den Heuvel-Greve, Martine J; Kampen, Tineke; Wang, Chenwen; van den Brink, Nico W; Koelmans, Albert A

    2016-11-15

    The predicted expansion of oil and gas (O&G) activities in the Arctic urges for a better understanding of impacts of these activities in this region. Here we investigated the influence of location, feeding strategy and animal size on the bioaccumulation of Polycyclic Aromatic Hydrocarbons (PAHs), Polychlorinated Biphenyls (PCBs) and Hexachlorobenzene (HCB) by three Arctic benthic species in Kongsfjorden (Svalbard, Norway). No toxicity was expected based on biota PAH critical body residues. Biota PCB levels were mainly below limit of detection, whereas samples were moderately polluted by HCB. PAH concentrations in biota and Biota Sediment Accumulation Factors (BSAFs) were generally higher in Blomstrandhalvøya than in Ny-Ålesund, which was explained by a higher abundance of black carbon in Ny-Ålesund harbour. BSAFs differed significantly among species and stations. We conclude that contaminant body residues are a less variable and more straightforward monitoring parameter than sediment concentrations or BSAFs in Arctic benthos.

  5. Carbon mineralization in Arctic sediments northeast of Svalbard: Mn(IV) and Fe(III) reduction as principal anaerobic respiratory pathways

    DEFF Research Database (Denmark)

    Vandieken, Verona; Nickel, Maren; Jørgensen, Bo Barker

    2006-01-01

    Carbon oxidation rates and pathways were determined in 3 sediments at latitude 79 degrees to 81 degrees N in the Barents Sea, where the ice cover restricts primary production to a few months of the year. Oxygen uptake (1.5 to 3.5 imnol m(-2) d(-1)) and sulfate reduction (= 60 mu mol cm(-3)) and F...

  6. Glacier inputs influence organic matter composition and prokaryotic distribution in a high Arctic fjord (Kongsfjorden, Svalbard)

    Science.gov (United States)

    Bourgeois, Solveig; Kerhervé, Philippe; Calleja, Maria Ll.; Many, Gaël; Morata, Nathalie

    2016-12-01

    With climate change, the strong seasonality and tight pelagic-benthic coupling in the Arctic is expected to change in the next few decades. It is currently unclear how the benthos will be affected by changes of environmental conditions such as supplies of organic matter (OM) from the water column. In the last decade, Kongsfjorden (79°N), a high Arctic fjord in Svalbard influenced by several glaciers and Atlantic water inflow, has been a site of great interest owing to its high sensitivity to climate change, evidenced by a reduction in ice cover and an increase in melting freshwater. To investigate how spatial and seasonal changes in vertical fluxes can impact the benthic compartment of Kongsfjorden, we studied the organic matter characteristics (in terms of quantity and quality) and prokaryotic distribution in sediments from 3 stations along a transect extending from the glacier into the outer fjord in 4 different seasons (spring, summer, autumn and winter) in 2012-2013. The biochemical parameters used to describe the sedimentary organic matter were organic carbon (OC), total nitrogen, bulk stable isotope ratios, pigments (chorophyll-a and phaeopigments) and biopolymeric carbon (BPC), which is the sum of the main macromolecules, i.e. lipids, proteins and carbohydrates. Prokaryotic abundance and distribution were estimated by 4‧,6-diamidino-2-phenylindole (DAPI) staining. This study identifies a well-marked quantitative gradient of biogenic compounds throughout all seasons and also highlights a discrepancy between the quantity and quality of sedimentary organic matter within the fjord. The sediments near the glacier were organic-poor (< 0.3%OC), however the high primary productivity in the water column displayed during spring was reflected in summer sediments, and exhibited higher freshness of material at the inner station compared to the outer basin (means C-chlorophyll-a/OC 5 and 1.5%, respectively). However, sediments at the glacier front were depleted in BPC

  7. Desulfovibrio frigidus sp. nov. and Desulfovibrio ferrireducens sp. nov., psychrotolerant bacteria isolated from Arctic fjord sediments (Svalbard) with the ability to reduce Fe(III)

    DEFF Research Database (Denmark)

    Vandieken, Verona; Knoblauch, Christian; Jørgensen, Bo Barker

    2006-01-01

    fermentation products such as hydrogen, formate and lactate with sulfate as the electron acceptor. Sulfate could be replaced by sulfite, thiosulfate or elemental sulfur. Poorly crystalline and soluble Fe(III) compounds were reduced in sulfate-free medium, but no growth occurred under these conditions......Strains 18T, 61T and 77 were isolated from two permanently cold fjord sediments on the west coast of Svalbard. The three psychrotolerant strains, with temperature optima at 20-23 degrees C, were able to grow at the freezing point of sea water, -2 degrees C. The strains oxidized important...

  8. Holocene record of glacier variability from lake sediments reveals tripartite climate history for Svalbard

    Science.gov (United States)

    van der Bilt, Willem; Bakke, Jostein; Vasskog, Kristian; D`Andrea, William; Bradley, Raymond; Olafsdottir, Sædis

    2016-04-01

    The Arctic is responding sensitively to ongoing global climate change, warming and moistening faster than any other region on the planet. Holocene proxy paleoclimate time series are increasingly used to put this amplified response in perspective by understanding Arctic climate processes beyond the instrumental period. Glaciers rapidly respond to climate shifts as demonstrated by their current demise around the world. This response has a composite climate signature, marked by shifts in hydroclimate (winter precipitation) as well as (summer) temperature. Attendant changes in glacier size are recorded by variations in glacigenic rock flour that may be deposited in downstream lakes. Here, we present a Holocene reconstruction of glacier activity, based on sediments from Hajeren, a glacier-fed lake on northwest Spitsbergen in the High Arctic Svalbard archipelago. Owing to undisturbed sediments and robust age control, we could resolve variability on a sub-centennial scale. To ensure the accurate detection of glacier activity, we applied a toolbox of physical, magnetic and geochemical proxies in conjunction with multivariate statistics. Our findings indicate a three-stage Holocene climate history for Svalbard, driving by melt water pulses, episodic Atlantic cooling and a decline in orbitally driven summer insolation. Correspondence between inferred advances, including a Holocene glacier maximum around 9.5 ka BP, suggests forcing by the melting LIS during the Early Holocene. Following a late Holocene Thermal Maximum around 7.4 ka BP, glaciers disappeared from the catchment. Glaciers reformed around 4.2 ka BP during the regional onset of the Neoglacial, supporting previous findings. This transition did, however, not mark the onset of persistent glacier activity in the catchment, but a series of centennial-scale cycles of growth and decay, including events around 3.3 and 1.1 ka BP. As orbitally driven insolation declined towards the present, the glaciation threshold

  9. Mechanism of Varve Formation and Paleoenvironmental Research at Lake Bolterskardet, Svalbard, the Arctic

    Institute of Scientific and Technical Information of China (English)

    CHU Guoqiang; LIU Jiaqi; GAO Denyi; SUN Qing

    2006-01-01

    On the basis of observation of thin sections and 137Cs data, laminations in sediment are interpreted to be varves in Bolterskardet Lake (78°06' N, 16°01' E), Svalbard, the Arctic. Varves appear under a petrologic microscope as couplets of dark-silt and light-clay layers. The mechanism of varve formation is surmized as follows: each silt layer is the production of sediment inflow interpreted as mainly derived from snowmelt during summer; each clay layer was deposited in a stillwater environment during an ice-cover period. A light -clay layer provides an important index bed to identify the annual interface. The high accumulation rates, long period of ice cover, and topographically closed basin are probably all critical factors in forming and preserving varves. Varve thickness is known to be controlled mainly by summer temperature. The variation of varve thickness in Lake Bolterskardet can then be used to reconstruct summer temperature. The varve series show that there has been distinct decade-scale variability of summer temperature over the past 150 years. Warm periods occurred in the 1860s, around 1900, the 1930s, 1950s, and 1970s, and in the last 20 years. The varved sediments of Lake Bolterskarde preserve an ideal record for high-resolution paleoclimatic and paleoenvironmental research in this data-sparse area.

  10. High Arctic Paraglacial Coastal Evolution in Northern Billefjorden, Svalbard

    Science.gov (United States)

    Strzelecki, Matt; Long, Antony; Lloyd, Jerry

    2013-04-01

    Most sediment budget studies in paraglacial, High Arctic, environments have focussed attention on quantifying sediment fluxes in glacial and fluvial catchments. In contrast, little attention has been paid to the functioning of the paraglacial coastal zone with existing models of coastal change based on relict systems developed in mid latitude settings. The pristine coasts of Spitsbergen provided a superb opportunity to quantify how High Arctic coasts are respondingto rapid climate warming and associated paraglacial landscape transformation. In this paper we reconstruct the development of the paraglacial coasts in Petuniabukta and Adolfbukta, the northernmost bays of Billefjorden, central Spitsbergen. The study area is characterized by a sheltered location, a semi-arid, sub-polar climate, limited wave fetch and tidal range, and rapid retreat of all surrounding glaciers. Using a combination of geomorphological, sedimentological, remote sensing and dating methods, we study the processes controlling the coastal zone development over annual, century and millennial timescales. Interannual changes observed between 2008-2010 show that gravel barriers in the study area are resilient to the impacts of local storms and the operation of sea-ice processes. In general, the processes controlling the short-term barrier development often operate in the opposite direction to the landforming patterns visible in the longer-term evolution. Over multi-decadal timescales, since the end of the Little Ice Age. we observe drammatic changes in sediment flux and coastal response under an interval characterised by a warming climate, retreating local ice masses, a shortened winter sea-ice season and melting permafrost. A new approach of dating juvenile mollusc found in uplifted marine barriers led to the better understating of the Late Holocene evolution of a Petuniabukta coastal zone and its reaction to deglaciation, glacioisostatic uplift and sea-level fluctuations. We propose a new

  11. Catching up: the state and potential of historical catch data from Svalbard in the European Arctic

    NARCIS (Netherlands)

    Kruse, Frigga

    2016-01-01

    Svalbard in the European Arctic has a well-documented history of natural-resource exploitation. Since its discovery in 1596, the archipelago has witnessed phases of commercial whaling, sealing, fur-hunting, and fishing. Scientific expeditions, mass tourism, and mining have also added to the depletio

  12. Influence of Large Igneous Provinces on Svalbard tectonics and sedimentation from the Late Mesozoic through Cenozoic: Insight from (U-Th)/He zircon and apatite thermochronology

    Science.gov (United States)

    Barnes, Christopher; Schneider, David; Majka, Jaroslaw

    2016-04-01

    Svalbard, the northwestern sub-aerial exposure of the Barents Shelf, offers significant insight into the geodynamics of the High Arctic. The tectonics and sedimentation on Svalbard from the Late Mesozoic through Cenozoic can be attributed to two Large Igneous Provinces: the High Arctic Large Igneous Province (HALIP; 130-90 Ma) and the North Atlantic Large Igneous Province (NAIP; 62-55 Ma). The relationship between the HALIP and the tectonics of the High Arctic remains somewhat unclear, whereas the NAIP is directly linked to opening of the North Atlantic Ocean. This study attempts to establish links between the HALIP and geodynamics of the High Arctic, and reveals the far-field tectonic consequences of the NAIP on Svalbard and the High Arctic. We focus on the Southwestern Caledonian Basement Terrane of Svalbard, characterized by the West Spitsbergen Fold and Thrust Belt, formed during the Eurekan Orogeny (c. 55-33 Ma). Crystalline basement was sampled from four regions (Prins Karls Forland, Oscar II Land, Wedel Jarlsberg Land, and Sørkapp Land) for the purpose of zircon and apatite (U-Th)/He thermochronometry which allows for resolution of thermal events below 200°C. We forward model our datasets using HeFTy software to produce temperature-time histories for each of these regions, and compare these thermal models with Svalbard stratigraphy to resolve the geodynamics of Svalbard from the Late Mesozoic through Cenozoic. The Cretaceous stratigraphy of Svalbard is characterized by a short-lived Mid-Cretaceous sub-aerial unconformity (c. 129 Ma) and a significant Late Cretaceous unconformity (c. 105-65 Ma). Our thermal models reveal a Mid-Cretaceous heating event, suggesting an increasing geothermal gradient coeval with development of the first unconformity. This may indicate that short-lived domal-uplift, related to the arrival of the HALIP plume, was a primary control on Svalbard tectonics and sedimentary deposition throughout the Mid-Cretaceous. Late Cretaceous

  13. Glacier inputs influence organic matter composition and prokaryotic distribution in a high Arctic fjord (Kongsfjorden, Svalbard)

    KAUST Repository

    Bourgeois, Solveig

    2016-08-23

    With climate change, the strong seasonality and tight pelagic-benthic coupling in the Arctic is expected to change in the next few decades. It is currently unclear how the benthos will be affected by changes of environmental conditions such as supplies of organic matter (OM) from the water column. In the last decade, Kongsfjorden (79°N), a high Arctic fjord in Svalbard influenced by several glaciers and Atlantic water inflow, has been a site of great interest owing to its high sensitivity to climate change, evidenced by a reduction in ice cover and an increase in melting freshwater. To investigate how spatial and seasonal changes in vertical fluxes can impact the benthic compartment of Kongsfjorden, we studied the organic matter characteristics (in terms of quantity and quality) and prokaryotic distribution in sediments from 3 stations along a transect extending from the glacier into the outer fjord in 4 different seasons (spring, summer, autumn and winter) in 2012–2013. The biochemical parameters used to describe the sedimentary organic matter were organic carbon (OC), total nitrogen, bulk stable isotope ratios, pigments (chorophyll-a and phaeopigments) and biopolymeric carbon (BPC), which is the sum of the main macromolecules, i.e. lipids, proteins and carbohydrates. Prokaryotic abundance and distribution were estimated by 4′,6-diamidino-2-phenylindole (DAPI) staining. This study identifies a well-marked quantitative gradient of biogenic compounds throughout all seasons and also highlights a discrepancy between the quantity and quality of sedimentary organic matter within the fjord. The sediments near the glacier were organic-poor (< 0.3%OC), however the high primary productivity in the water column displayed during spring was reflected in summer sediments, and exhibited higher freshness of material at the inner station compared to the outer basin (means C-chlorophyll-a/OC ~ 5 and 1.5%, respectively). However, sediments at the glacier front were depleted

  14. Reconstruction of Holocene patterns of change in a High Arctic coastal landscape, Southern Sassenfjorden, Svalbard

    Science.gov (United States)

    Sessford, Evangeline G.; Strzelecki, Mateusz C.; Hormes, Anne

    2015-04-01

    Abrupt shifts in sediment supply, relative sea level, permafrost regime, glacier state, snow cover and sea ice conditions associated with Holocene climate changes control processes operating on High Arctic coasts and make reconstructions of their past evolution a significant research challenge. This study attempts to describe the development of the coastal zone in southern Sassenfjorden, Svalbard, throughout the Holocene focusing on the styles of adjustment to major landscape changes. Five marine terraces (MT1-5) are identified and assessed. Spatial and chronological analysis suggests that the highest terrace, MT5, is pre-LGM (Last Glacial Maximum) and that MT4-3 underwent rapid uplift (151 and 11.4 mm/year, respectively) shortly prior to 11 061 ± 174 cal. yr BP and became fully terrestrial by 9100 years ago (as indicated by emergence rates) during the Holocene Thermal Maximum (HTM). Uplift rates for MT2-1 slowed to 5 and 2 mm/year, respectively, with suggested emergence between 7200 and 6800 cal. yr BP. A final 2 m uplift of the relict alluvial plain probably happened during the Medieval Warm Period (1200-950 cal. yr BP). Most recent coastal development (AD 1912-2012) is characterised by episodes of coastal erosion on the cliff and progradation of the Nøiselva delta. Interactions between sea ice, snow cover, permafrost, wind and wave regimes are assessed to understand their implications on future coastal development in a warming climate.

  15. The Globalization of the Arctic: Negotiating Sovereignty and Building Communities in Svalbard, Norway

    Directory of Open Access Journals (Sweden)

    Adam Grydehøj

    2012-05-01

    Full Text Available The Arctic archipelago of Svalbard has been under Norwegian sovereignty since 1920 yet remains subject to international law. Until recently, the islands’ only major economic activities were unprofitable Russian – and Norwegian – funded mining operations aimed at maintaining continuous settlement. Now, however, Norway’s top-down governance of the territory has been complicated by the emergence of economic diversity, multinationalism, and local democracy in the town of Longyearbyen. Simultaneously, China and other states are promoting their Arctic interests by exploiting the preoccupation with Russia that characterizes Norway’s Svalbard policy. By interpreting Svalbard’s local communities through the prism of international relations, this article highlights the practical challenges to creating genuinely international territories.

  16. Arctic ice core records of vanillic acid from Siberia, Greenland, and Svalbard

    Science.gov (United States)

    Grieman, M. M.; Saltzman, E. S.; McConnell, J.; Fritzsche, D.; Opel, T.; Isaksson, E. D.; Schwikowski, M.

    2015-12-01

    Biomass burning is a major source for atmospheric gases and aerosols, and an important part of the global carbon cycle and radiation budget. The factors controlling centennial and millennial variability in regional to global biomass burning dynamics are not well understood because there are few well-dated proxy records only. We are exploring ice core records of organic compounds resulting from incomplete combustion of lignin as tracers for biomass burning. In this study we investigate the distribution of vanillic acid (VA) in Arctic ice cores. VA is a major product of conifer combustion, but may also be produced from angiosperms. VA was measured in ice core samples using ion chromatography with electrospray MS/MS detection. Here we present measurements of vanillic acid in three Arctic ice cores from Siberia (Akademii Nauk; 0-3 kyr bp), northern Greenland (Tunu; 0-1.75 kyr bp), and Svalbard (Lomonosovfonna; 0-0.75 kyr bp). The Siberian record exhibits 3 strong centennial scale maxima (1200-600 BC, AD 300-800, and AD 1450-1700). All three cores exhibit a smaller feature around 1250, with a subsequent decline in Greenland and Svalbard. VA levels in Greenland and Svalbard are generally smaller than those in Siberia. These results suggest strong regional input from Northern Eurasian sources (i.e. boreal forests) to the Siberian core, and lower Arctic-wide "background" levels at the other sites.

  17. Climate change impacts on wildlife in a High Arctic archipelago - Svalbard, Norway.

    Science.gov (United States)

    Descamps, Sébastien; Aars, Jon; Fuglei, Eva; Kovacs, Kit M; Lydersen, Christian; Pavlova, Olga; Pedersen, Åshild Ø; Ravolainen, Virve; Strøm, Hallvard

    2017-02-01

    The Arctic is warming more rapidly than other region on the planet, and the northern Barents Sea, including the Svalbard Archipelago, is experiencing the fastest temperature increases within the circumpolar Arctic, along with the highest rate of sea ice loss. These physical changes are affecting a broad array of resident Arctic organisms as well as some migrants that occupy the region seasonally. Herein, evidence of climate change impacts on terrestrial and marine wildlife in Svalbard is reviewed, with a focus on bird and mammal species. In the terrestrial ecosystem, increased winter air temperatures and concomitant increases in the frequency of 'rain-on-snow' events are one of the most important facets of climate change with respect to impacts on flora and fauna. Winter rain creates ice that blocks access to food for herbivores and synchronizes the population dynamics of the herbivore-predator guild. In the marine ecosystem, increases in sea temperature and reductions in sea ice are influencing the entire food web. These changes are affecting the foraging and breeding ecology of most marine birds and mammals and are associated with an increase in abundance of several temperate fish, seabird and marine mammal species. Our review indicates that even though a few species are benefiting from a warming climate, most Arctic endemic species in Svalbard are experiencing negative consequences induced by the warming environment. Our review emphasizes the tight relationships between the marine and terrestrial ecosystems in this High Arctic archipelago. Detecting changes in trophic relationships within and between these ecosystems requires long-term (multidecadal) demographic, population- and ecosystem-based monitoring, the results of which are necessary to set appropriate conservation priorities in relation to climate warming.

  18. Stable climate and surface mass balance in Svalbard over 1979–2013 despite the Arctic warming

    Directory of Open Access Journals (Sweden)

    C. Lang

    2015-01-01

    (Model for Interdisciplinary Research on Climate global model (MARMIROC5 from the CMIP5 (Coupled Model Intercomparison Project database, we have modelled the climate and surface mass balance of Svalbard at a 10 km resolution over 1979–2013. The integrated total surface mass balance (SMB over Svalbard modelled by MARERA is negative (−1.6 Gt yr−1 with a large interannual variability (7.1 Gt but, unlike over Greenland, there has been no acceleration of the surface melt over the past 35 years because of the recent change in atmospheric circulation bringing northwesterly flows in summer over Svalbard, contrasting the recent observed Arctic warming. However, in 2013, the atmospheric circulation changed to a south–southwesterly flow over Svalbard causing record melt, SMB (−20.4 Gt yr−1 and summer temperature. MIROC5 is significantly colder than ERA-Interim over 1980–2005 but MARMIROC5 is able to improve the near-surface MIROC5 results by simulating not significant SMB differences with MARERA over 1980–2005. On the other hand, MIROC5 does not represent the recent atmospheric circulation shift in summer and induces in MARMIROC5 a significant trend of decreasing SMB (−0.6 Gt yr−2 over 1980–2005.

  19. Stable climate and surface mass balance in Svalbard over 1979–2013 despite the Arctic warming

    Directory of Open Access Journals (Sweden)

    C. Lang

    2014-08-01

    Full Text Available With the help of the regional climate model MAR forced by the ERA-Interim reanalysis (MARERA and the MIROC5 global model (MARMIROC5 from the CMIP5 database, we have modelled the climate and surface mass balance of Svalbard at a 10 km resolution over 1979–2013. The integrated total SMB over Svalbard modelled by MARERA is negative (−1.6 Gt yr−1 with a large interannual variability (7.1 Gt but, unlike over Greenland, there has been no acceleration of the surface melt over the past 35 years because of the recent change in atmospheric circulation bringing northerly flows in summer over Svalbard, contrasting the recent observed Arctic warming. However, in 2013, the atmospheric circulation changed to a southwesterly flow over Svalbard causing a record of melt, SMB (−20.4 Gt yr−1 and summer temperature. MIROC5 is significantly colder than ERA-Interim over 1980–2005 but MARMIROC5 is able to improve the near-surface MIROC5 results by simulating not significant SMB differences with MARERA over 1980–2005. On the other hand, MIROC5 does not represent the recent atmospheric circulation shift in summer and induces in MARMIROC5 a significant trend of decreasing SMB (−0.6 Gt yr−2 over 1980–2005.

  20. Seasonal patterns in Arctic planktonic metabolism (Fram Strait – Svalbard region

    Directory of Open Access Journals (Sweden)

    R. Vaquer-Sunyer

    2012-06-01

    Full Text Available The metabolism of the Arctic Ocean is marked by extreme pronounced seasonality and spatial heterogeneity associated with light conditions, ice cover, water masses and nutrient availability. Here we report the marine planktonic metabolic rates (Net Community Production, Gross Primary Production and Community Respiration along three different seasons of the year for a total of eight cruises along the western sector of the European Arctic (Fram Strait – Svalbard region in the Arctic Ocean margin: one at the end of 2006 (fall/winter, two in 2007 (early spring and summer, two in 2008 (early spring and summer, one in 2009 (late spring–early summer and one in 2010 (spring. The results show that metabolisms of the western sector of the European Arctic varies throughout the year, depending mostly on the stage of bloom, which is mainly determined by availability of light and nutrients. Here we report metabolic rates for the different periods, including the spring bloom, summer and the dark period, increasing considerably the empirical basis on metabolic rates in the Artic Ocean, and especially in the European Arctic corridor. We also report a rough annual metabolic balance for this area of the Arctic Ocean, resulting in a Net Community Production of 108 g C m−2 yr−1.

  1. Triassic Sequence Geological Development of the Arctic with focus on Svalbard and the Barents Shelf

    Energy Technology Data Exchange (ETDEWEB)

    Moerk, Atle

    1998-12-31

    Triassic rocks are of great interest for exploration in Arctic areas as they have proved to include both good hydrocarbon source rocks and potential hydrogen reservoir rocks. In this thesis, the stratigraphy and sedimentology of the Arctic Triassic successions are studied within a sequence stratigraphical framework. Inter-regional comparisons throughout the Arctic are based on comparisons of transgressive-regressive sequences. Improved dating of the studied sequences, and the recognition and correlation of sequence boundaries of second and third order, facilitate interpretation of facies distribution and the geological development both within and between the studied areas. Main emphasis is given to the Triassic succession of Svalbard and the Barents Shelf, which through this study is integrated within a circum-Arctic sequence stratigraphical framework. Good correspondence of the Triassic sequence boundaries between the different Arctic areas indicate that they are mainly controlled by eustacy, while decreasing correspondence of the sequence boundaries in the Jurassic and Cretaceous periods indicate that local and large scale tectonism becomes progressively more dominant in the circum-Arctic Realm through the Mesozoic Era. These hypotheses are further discussed. 701 refs., 110 figs., 12 tabs.

  2. Variation in bird's originating nitrogen availability limits High Arctic tundra development over last 2000 year (Hornsund, Svalbard)

    Science.gov (United States)

    Skrzypek, Grzegorz; Wojtuń, Bronisław; Hua, Quan; Richter, Dorota; Jakubas, Dariusz; Wojczulanis-Jakubas, Katarzyna; Samecka-Cymerman, Aleksandra

    2016-04-01

    Arctic and subarctic regions play important roles in the global carbon balance. However, nitrogen (N) deficiency is a major constraint for organic carbon sequestration in the High Arctic. Hence, the identification of the relative contributions from different N-sources is critical for understanding the constraints that limit tundra growth. The stable nitrogen composition of the three main N-sources and numerous plants were analyzed in ten tundra types (including those influenced by seabirds) in the Fuglebekken catchment (Hornsund, Svalbard, 77°N 15°E). The percentage of the total tundra N-pool provided by seabirds' feces (from planktivorous colonially breeding little auks Alle alle), ranged from 0-21% in Patterned-ground tundra to 100% in Ornithocoprophilous tundra. The total N-pool utilized by tundra plants in the studied catchment originated from birds (36%), atmospheric deposition (38%), and N2-fixation (26%). The results clearly show that N-pool in the tundra is significantly supplemented by nesting seabirds. Thus, if they experienced climate change induced substantial negative environmental pressure, it would adversely influence the tundra N-budget (Skrzypek et al. 2015). The growth rates and the sediment thickness (PLoS ONE 10(9): e0136536.

  3. The role of cornice fall avalanche sedimentation in the valley Longyeardalen, Central Svalbard

    Directory of Open Access Journals (Sweden)

    M. Eckerstorfer

    2012-12-01

    Full Text Available In arctic and alpine high relief landscapes snow avalanches are traditionally ranked behind rockfall in terms of their significance for mass wasting processes of rock slopes. Cornice fall avalanches are at present the most dominant snow avalanche type at two slope systems, called Nybyen and Larsbreen, in the valley Longyeardalen in Central Svalbard. Both slope systems are situated on NW-facing lee slopes underneath large summit plateau, where cornices form annually, and high frequency and magnitude cornice fall avalanching is observed by daily automatic time-lapse photography. In addition, rock debris sedimentation by these cornice fall avalanches was measured directly in either permanent sediment traps or by snow inventories. The results from a maximum of 7 yr of measurements in a total of 13 catchments show maximum avalanche sedimentation rates ranging from 8.2 to 38.7 kg m−2 at Nybyen and from 0.8 to 55.4 kg m−2 at Larsbreen. Correspondingly, the avalanche fan-surfaces accreted annually in a~maximum range from 3.7 to 13 mm yr−1 at Nybyen and from 0.3 to 21.4 mm yr−1 at Larsbreen. This comparably efficient rock slope mass wasting is due to collapsing cornices producing cornice fall avalanche with high rock debris content throughout the entire winter. The rock debris of different origin stems from the plateau crests, the adjacent free rock face and the transport pathway, accumulating distinct avalanche fans at both slope systems and contributing to the development of a rock glacier at the Larsbreen slope system.

  4. The impact of a seasonally ice free Arctic Ocean on the temperature, precipitation and surface mass balance of Svalbard

    Directory of Open Access Journals (Sweden)

    J. J. Day

    2012-01-01

    Full Text Available The observed decline in summer sea ice extent since the 1970s is predicted to continue until the Arctic Ocean is seasonally ice free during the 21st Century. This will lead to a much perturbed Arctic climate with large changes in ocean surface energy flux. Svalbard, located on the present day sea ice edge, contains many low lying ice caps and glaciers and is expected to experience rapid warming over the 21st Century. The total sea level rise if all the land ice on Svalbard were to melt completely is 0.02 m.

    The purpose of this study is to quantify the impact of climate change on Svalbard's surface mass balance (SMB and to determine, in particular, what proportion of the projected changes in precipitation and SMB are a result of changes to the Arctic sea ice cover. To investigate this a regional climate model was forced with monthly mean climatologies of sea surface temperature (SST and sea ice concentration for the periods 1961–1990 and 2061–2090 under two emission scenarios. In a novel forcing experiment, 20th Century SSTs and 21st Century sea ice were used to force one simulation to investigate the role of sea ice forcing. This experiment results in a 3.5 m water equivalent increase in Svalbard's SMB compared to the present day. This is because over 50 % of the projected increase in winter precipitation over Svalbard under the A1B emissions scenario is due to an increase in lower atmosphere moisture content associated with evaporation from the ice free ocean. These results indicate that increases in precipitation due to sea ice decline may act to moderate mass loss from Svalbard's glaciers due to future Arctic warming.

  5. Single-particle characterization of summertime arctic aerosols collected at Ny-Alesund, Svalbard.

    Science.gov (United States)

    Geng, Hong; Ryu, Jiyeon; Jung, Hae-Jin; Chung, Hyeok; Ahn, Kang-Ho; Ro, Chul-Un

    2010-04-01

    Single-particle characterization of summertime Arctic aerosols is useful to understand the impact of air pollutants on the polar atmosphere. In the present study, a quantitative single particle analytical technique, low-Z particle electron probe X-ray microanalysis, was used to characterize 8100 individual particles overall in 16 sets of aerosol samples collected at Ny-Alesund, Svalbard, Norway on 25-31 July, 2007. Based on their X-ray spectral and secondary electron image data of individual particles, 13 particle types were identified, in which particles of marine origin were the most abundant, followed by carbonaceous and mineral dust particles. A number of aged (reacted) sea salt (and mixture) particles produced by the atmospheric reaction of genuine sea-salts, especially with NO(x) or HNO(3), were significantly encountered in almost all the aerosol samples. They greatly outnumbered genuine sea salt particles, implying that the summertime Arctic atmosphere, generally regarded as a clean background environment, is disturbed by anthropogenic air pollutants. The main sources of airborne NO(x) (or HNO(3)) are probably ship emissions around the Arctic Ocean, industry emission from northern Europe and northwestern Siberia, and renoxification of NO(3)(-) within or on the melting snow/ice surface.

  6. Concentrations and patterns of hydroxylated polybrominated diphenyl ethers and polychlorinated biphenyls in arctic foxes (Vulpes lagopus) from Svalbard.

    Science.gov (United States)

    Routti, Heli; Andersen, Martin S; Fuglei, Eva; Polder, Anuschka; Yoccoz, Nigel G

    2016-09-01

    Concentrations and patterns of hydroxylated (OH) polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) were investigated in liver from arctic foxes (Vulpes lagopus) sampled from Svalbard 1997-2011 (n = 100). The most important OH-PBDE in the arctic foxes was 6-OH-BDE47 detected in 24% of the samples. Relationships between 6-OH-BDE47, δ(13)C and BDE47 suggest that 6-OH-BDE47 residues in arctic foxes are related to marine dietary input, while the relative importance of the metabolic/natural origin of this compound remains unclear. 4-OH-CB187 and 4-OH-CB146 were the main OH-PCBs among the analyzed compounds. The OH-PCB pattern in the present arctic foxes indicates that arctic foxes have a capacity to biotransform a wide range of PCBs of different structures. Formation and retention of OH-PCBs was tightly related to PCB exposure. Furthermore, ΣOH-PCB concentrations were four times higher in the leanest compared to the fattest foxes. Concentrations of 4-OH-CB187 and 4-OH-CB146 among the highest contaminated arctic foxes were similar to the previously reported concentrations for polar bears. Given the high endocrine disruptive potential of OH-PCBs, we suggest that endocrine system may be affected by the relatively high OH-PCB residues in the Svalbard arctic fox population.

  7. Svalbard Integrated Arctic Earth Observing System (sios): Facilitating Easy Access to Multidisciplinary Arctic Data Through the Brokering Approach.

    Science.gov (United States)

    Bye, B. L.; Godøy, Ø.

    2014-12-01

    Environmental and climate changes are important elements of our global challenges. They are observed at a global scale and in particular in the Arctic. In order to give better estimates of the future changes, the Arctic has to be monitored and analyzed by a multi-disciplinary observation system that will improve Earth System Models. The best chance to achieve significant results within a relatively short time frame is found in regions with a large natural climate gradient, and where processes sensitive to the expected changes are particularly important. Svalbard and the surrounding ocean areas fulfil all these criteria. The vision for SIOS is to be a regional observational system for long term acquisition and proliferation of fundamental knowledge on global environmental change within an Earth System Science perspective in and around Svalbard. SIOS will systematically develop and implement methods for how observational networks are to be construed. The distributed SIOS data management system (SDMS) will be implemented through a combination of technologies tailored to the multi-disciplinary nature of the Arctic data. One of these technologies is The Brokering approach or "Framework". The Brokering approach provides a series of services such as discovery, access, transformation and semantics support to enable translation from one discipline/culture to another. This is exactly the challenges the SDMS will have to handle and thus the Brokering approach is integrated in the design of the system. A description of the design strategy for the SDMS that includes The Brokering approach will be presented. The design and implementation plans for the SDMS are based on research done in the EU funded ESFRI project SIOS and examples of solutions for interoperable systems producing Arctic datasets and products coordinated through SIOS will be showcased. The reported experience from SIOS brokering approach will feed into the process of developing a sustainable brokering governance

  8. Norwegian Arctic climate. Climate influencing emissions, scenarios and mitigation options at Svalbard

    Energy Technology Data Exchange (ETDEWEB)

    Vestreng, Vigdis; Kallenborn, Roland; Oekstad, Elin

    2010-07-01

    The goal of this study was to establish an emission inventory and emission scenarios for climate influencing compounds at Svalbard, as a basis to develop strategies for emission reduction measures and policies. Emissions for the years 2000-2007 have been estimated for the Svalbard Zone. This area, covering about 173 000 km{sub 2}, ranges from 10 E to 35 E longitude and 74 N to 81 N latitude (Figure 1). In addition, air and ship transport between Tromsoe at the Norwegian mainland and Svalbard has been included. Pollutants considered in our inventory are carbon dioxide (CO{sub 2}), methane (CH{sub 4}), Sulphur dioxide (SO{sub 2}), Nitrogen oxides (NO{sub x} as NO{sub 2}), and for the first time also estimates of black carbon (BC, soot) and organic carbon (OC) have been included. Our results show that emissions of all pollutants have increased over the time span 2000-2007 (Figure 2), and are expected to increase also in the future if additional measures are not implemented (Figure 12). The emissions from Svalbard are minuscule compared to emission released from the Norwegian mainland and waters (1% in the case of CO{sub 2}). Even so, local releases of climate influencing compounds in the vulnerable Arctic may turn out to make a difference both with respect to adverse environmental effects and to climate change. Emissions have been estimated for all activities of any significance taking place at and around Svalbard. Combustion sources as well as fugitive emissions of methane are included. The main sectors are coal mining, energy production and transportation. Pollution from 28 sub sectors related to these activities has been estimated. The scope of this work differs from that covered by national inventories since emission estimates are based on the fuel consumed and include emissions from international shipping and aviation. Fuel consumption data were collected from local authorities, institutions and industry. Emission factors have been selected from relevant

  9. Demographic population structure and fungal associations of plants colonizing High Arctic glacier forelands, Petuniabukta, Svalbard

    Directory of Open Access Journals (Sweden)

    Jakub Těšitel

    2014-04-01

    Full Text Available The development of vegetation in Arctic glacier forelands has been described as unidirectional, non-replacement succession characterized by the gradual establishment of species typical for mature tundra with no species turnover. Our study focused on two early colonizers of High Arctic glacier forelands: Saxifraga oppositifolia (Saxifragaceae and Braya purpurascens (Brassicaceae. While the first species is a common generalist also found in mature old growth tundra communities, the second specializes on disturbed substrate. The demographic population structures of the two study species were investigated along four glacier forelands in Petuniabukta, north Billefjorden, in central Spitsbergen, Svalbard. Young plants of both species occurred exclusively on young substrate, implying that soil conditions are favourable for establishment only before soil crusts develop. We show that while S. oppositifolia persists from pioneer successional stages and is characterized by increased size and flowering, B. purpurascens specializes on disturbed young substrate and does not follow the typical unidirectional, non-replacement succession pattern. Plants at two of the forelands were examined for the presence of root-associated fungi. Fungal genus Olpidium (Fungus incertae sedis was found along a whole successional gradient in one of the forelands.

  10. Severe aromatic hydrocarbon pollution in the Arctic town of Longyearbyen (Svalbard) caused by snowmobile emissions.

    Science.gov (United States)

    Reimann, Stefan; Kallenborn, Roland; Schmidbauer, Norbert

    2009-07-01

    The aromatic hydrocarbons benzene, toluene and C2-benzenes (ethyl benzene and m,p,o-xylene) (BTEX) were measured during a 2-month monitoring campaign in 2007 in the Arctic town of Longyearbyen (Spitsbergen, Svalbard). Reflecting the remoteness of the location, very low mixing ratios were observed during night and in windy conditions. In late spring (April-May), however, the high frequency of guided snowmobile tours resulted in "rush-hour" maximum values of more than 10 ppb of BTEX. These concentration levels are comparable to those in European towns and are caused predominately by the outdated 2-stroke engines, which are still used by approximately 30% of the snowmobiles in Longyearbyen. During summer, peak events were about a factor of 100 lower compared to those during the snowmobile season. Emissions in summer were mainly caused by diesel-fueled heavy duty vehicles (HDVs), permanently used for coal transport from the adjacent coal mines. The documented high BTEX mixing ratios from snowmobiles in the Arctic provide an obvious incentive to change the regulation practice to a cleaner engine technology.

  11. The impact of a seasonally ice free Arctic Ocean on the climate and surface mass balance of Svalbard

    Directory of Open Access Journals (Sweden)

    J. J. Day

    2011-07-01

    Full Text Available General circulation models (GCMs predict a rapid decrease in Arctic sea ice extent in the 21st century. The decline of September sea ice is expected to continue until the Arctic Ocean is seasonally ice free, leading to a much perturbed Arctic climate with large changes in surface energy flux. Svalbard, located on the present day sea ice edge, contains many low lying ice caps and glaciers which are extremely sensitive to changes in climate. Records of past accumulation indicate that the surface mass balance (SMB of Svalbard is also sensitive to changes in the position of the sea ice edge.

    To investigate the impact of 21st Century sea ice decline on the climate and surface mass balance of Svalbard a high resolution (25 km regional climate model (RCM was forced with a repeating cycle of sea surface temperatures (SSTs and sea ice conditions for the periods 1961–1990 and 2061–2090. By prescribing 20th Century SSTs and 21st Century sea ice for one simulation, the impact of sea ice decline is isolated. This study shows that the coupled impact of sea ice decline and SST increase results in a decrease in SMB, whereas the impact of sea ice decline alone causes an increase in SMB of similar magnitude.

  12. Organic matter pools, C turnover and meiofaunal biodiversity in the sediments of the western Spitsbergen deep continental margin, Svalbard Archipelago

    Science.gov (United States)

    Pusceddu, A.; Carugati, L.; Gambi, C.; Mienert, J.; Petani, B.; Sanchez-Vidal, A.; Canals, M.; Heussner, S.; Danovaro, R.

    2016-01-01

    We investigated organic matter (OM) quantity, nutritional quality and degradation rates, as well as abundance and biodiversity of meiofauna and nematodes along the deep continental margin off Spitsbergen, in the Svalbard Archipelago. Sediment samples were collected in July 2010 and 2011 along a bathymetric gradient between 600 m and 2000 m depth, and total mass flux measured at the same depths from July 2010 to July 2011. In both sampling periods sedimentary OM contents and C degradation rates increased significantly with water depth, whereas OM nutritional quality was generally higher at shallower depths, with the unique exception at 600 m depth in 2010. Meiofaunal abundance and biomass (largely dominated by nematodes) showed the highest values at intermediate depths (ca 1500 m) in both sampling periods. The richness of meiofaunal higher taxa and nematode species richness did not vary significantly with water depth in both sampling periods. We suggest here that patterns in OM quantity, C degradation rates, and meiofauna community composition in 2011 were likely influenced by the intensification of the warm West Spitsbergen Current (WSC). We hypothesize that the intensity of the WSC inflow to the Arctic Ocean could have an important role on benthic biodiversity and functioning of deep-sea Arctic ecosystems.

  13. The Svalbard REU Program: A High-Latitude Undergraduate Research Program in Glacial, Fluvial and Marine Processes Relevant to Arctic Climate Change

    Science.gov (United States)

    Powell, R.; Brigham-Grette, J.; Cumpston, R.; Trusel, L.; Werner, A.; Roof, S.; Retelle, M.

    2005-12-01

    A pilot-study field season was conducted this past summer from the most northerly permanent settlement in the world as part of our ongoing Svalbard REU program funded by the National Science Foundation (award OPP-0244097). Ny Alesund, on the island of Spitsbergen, Svalbard, is an international research center operated by Norway, and during summers, hosts about 100 scientists from over 15 nations. With NSF support, the US now participates in a new marine laboratory that opened this year, and we made that our operations center. The success of our field program is enhanced by tight logistics and research objectives integrated with UNIS (the University Centre on Svalbard), the Norwegian Polar Institute and Kings Bay AS. Our program provides genuine research experiences in Arctic Quaternary science for undergraduates. Research focuses on modern glacial sedimentation processes relevant to understanding records of past climate changes preserved in marine and lacustrine basins. Students in this marine portion of the program had a total immersion experience, being surrounded by scientists from different nations and from disciplines differing widely from theirs. They interacted with these scientists formally and informally, discussing their science plans, attending weekly science talks, and enjoying conversations at meal times. First, we introduced the students to arctic glacial and marine systems, and then through discussion and demonstration they developed their own research plans and made decisions on modifying sampling schemes through the field season. Studies focused on sediment transport and deposition in Kongsfjorden by polythermal tidewater glaciers, icebergs, meltwater streams and marine currents. Students sampled glaciers and icebergs for debris concentrations, collected seawater samples for suspended sediment concentrations, performed CTD casts to define water column structure, conducted bathymetric profiling using GPS control, and collected fjord sediment samples

  14. Norwegian Arctic climate. Climate influencing emissions, scenarios and mitigation options at Svalbard

    Energy Technology Data Exchange (ETDEWEB)

    Vestreng, Vigdis; Kallenborn, Roland; Oekstad, Elin

    2010-07-01

    The goal of this study was to establish an emission inventory and emission scenarios for climate influencing compounds at Svalbard, as a basis to develop strategies for emission reduction measures and policies. Emissions for the years 2000-2007 have been estimated for the Svalbard Zone. This area, covering about 173 000 km{sub 2}, ranges from 10 E to 35 E longitude and 74 N to 81 N latitude (Figure 1). In addition, air and ship transport between Tromsoe at the Norwegian mainland and Svalbard has been included. Pollutants considered in our inventory are carbon dioxide (CO{sub 2}), methane (CH{sub 4}), Sulphur dioxide (SO{sub 2}), Nitrogen oxides (NO{sub x} as NO{sub 2}), and for the first time also estimates of black carbon (BC, soot) and organic carbon (OC) have been included. Our results show that emissions of all pollutants have increased over the time span 2000-2007 (Figure 2), and are expected to increase also in the future if additional measures are not implemented (Figure 12). The emissions from Svalbard are minuscule compared to emission released from the Norwegian mainland and waters (1% in the case of CO{sub 2}). Even so, local releases of climate influencing compounds in the vulnerable Arctic may turn out to make a difference both with respect to adverse environmental effects and to climate change. Emissions have been estimated for all activities of any significance taking place at and around Svalbard. Combustion sources as well as fugitive emissions of methane are included. The main sectors are coal mining, energy production and transportation. Pollution from 28 sub sectors related to these activities has been estimated. The scope of this work differs from that covered by national inventories since emission estimates are based on the fuel consumed and include emissions from international shipping and aviation. Fuel consumption data were collected from local authorities, institutions and industry. Emission factors have been selected from relevant

  15. How quickly do High Arctic coastal environments respond to rapid deglaciation and the paraglacial transformation of proglacial areas? - Answers from Spitsbergen, Svalbard Archipelago

    Science.gov (United States)

    Strzelecki, Matt; Long, Antony; Lloyd, Jerry; Zagórski, Piotr

    2014-05-01

    The coastal zone is one of the most important storage systems for sediments that are eroded and transported by rivers, wind and slope processes from deglacierised valleys and proglacial areas before reaching their final sediment sink (fjords or the open sea. The Svalbard archipelago provides an excellent location to quantify how High Arctic coasts are responding to climate warming and the associated paraglacial landscape transformations. In this paper we summarize the results of several coastal surveys carried out by our research teams along the paraglacial coasts of Spitsbergen during the last decade. We reconstruct the post-Little Ice Age development of selected coastlines in Spitsbergen to illustrate the variable coastal response to paraglacial and periglacial processes activated following the recent retreat of glaciers. Our surveys use aerial photogrammetric and GIS analyses, sedimentological classification of coastal deposits and field-based geomorphological mapping in Kongsfjorden, Billefjorden, Bellsund, Hornsund and Sørkappland. Our results document dramatic changes in sediment flux and coastal response under intervals characterized by a warming climate, retreating local ice masses, a shortened winter sea-ice season and thawing permafrost. The study highlights the need for a greater understanding of the controls on High Arctic coastal geomorphology, especially given the potential for future accelerated warming and sea-level rise.

  16. The alien terrestrial invertebrate fauna of the High Arctic archipelago of Svalbard: potential implications for the native flora and fauna

    Directory of Open Access Journals (Sweden)

    Stephen J. Coulson

    2015-09-01

    Full Text Available Experience from the Antarctic indicates that the establishment of alien species may have significant negative effects on native flora and fauna in polar regions and is considered to be amongst the greatest threats to biodiversity. But, there have been few similar studies from the Arctic. Although the terrestrial invertebrate inventory of the Svalbard Archipelago is amongst the most complete for any region of the Arctic, no consideration has yet been made of alien terrestrial invertebrate species, their invasiveness tendencies, threat to the native biology or their route of entry. Such baseline information is critical for appropriate management strategies. Fifteen alien invertebrate species have established in the Svalbard environment, many of which have been introduced via imported soils. Biosecurity legislation now prohibits such activities. None of the recorded established aliens yet show invasive tendencies but some may have locally negative effects. Ten species are considered to be vagrants and a further seven are classified as observations. Vagrants and the observations are not believed to be able to establish in the current tundra environment. The high connectivity of Svalbard has facilitated natural dispersal processes and may explain why few alien species are recorded compared to isolated islands in the maritime Antarctic. The vagrant species observed are conspicuous Lepidoptera, implying that less evident vagrant species are also arriving regularly. Projected climate change may enable vagrant species to establish, with results that are difficult to foresee.

  17. Turbulence and heat flux observations in the Arctic north of Svalbard

    Science.gov (United States)

    Meyer, Amelie; Sundfjord, Arild; Fer, Ilker; Smedsrud, Lars Henrik

    2016-04-01

    Heat fluxes and mixing between the ocean and the sea ice in the Arctic is fundamental to understanding the new first year sea ice regime and consequences for regional and global ocean circulation. Here we present observations collected between January and June 2015 during the Norwegian Young sea Ice (N-ICE2015) campaign in the Arctic Ocean north of Svalbard. In January 2015, the Norwegian research vessel Lance was frozen into the ice at 83o.3N 21.5oE. Oceanographic, atmospheric, sea ice, snow and biological data were collected above, on, and below the ice using R/V Lance as the base for the ice camp that was drifting south towards the Fram Strait. Over the following six months, four different drifts took place in the same area, from the Nansen Basin, through the Marginal Ice Zone, to the open ocean. Throughout the drifts, the oceanography team collected turbulence measurements to estimate mixing, heat, salt, and momentum fluxes in the ice-ocean boundary layer and between the sub-surface warm Atlantic Water layer and the ice-ocean boundary layer close to freezing point. Water tracer data was collected to map water mass properties, and the distribution of the Atlantic Water inflow. Here we present 600 under-ice microstructure profiles spanning five months, from the deep Nansen Basin to the Yermak Plateau. During this period, several large atmospheric storms took place, forcing a fast drift of the ice camp. Tides were weak in the Nansen Basin and strong on the Yermak Plateau. We investigate vertical heat fluxes between the Atlantic Water layer and the surface mixed layer. Variations in mixing and heat fluxes are interpreted in terms of atmospheric forcing and regional topography.

  18. Tracing Atlantic Water Signature in the Arctic Sea Ice Cover East of Svalbard

    Directory of Open Access Journals (Sweden)

    Vladimir V. Ivanov

    2012-01-01

    Full Text Available We focus on the Arctic Ocean between Svalbard and Franz Joseph Land in order to elucidate the possible role of Atlantic water (AW inflow in shaping ice conditions. Ice conditions substantially affect the temperature regime of the Spitsbergen archipelago, particularly in winter. We test the hypothesis that intensive vertical mixing at the upper AW boundary releases substantial heat upwards that eventually reaches the under-ice water layer, thinning the ice cover. We examine spatial and temporal variation of ice concentration against time series of wind, air temperature, and AW temperature. Analysis of 1979–2011 ice properties revealed a general tendency of decreasing ice concentration that commenced after the mid-1990s. AW temperature time series in Fram Strait feature a monotonic increase after the mid-1990s, consistent with shrinking ice cover. Ice thins due to increased sensible heat flux from AW; ice erosion from below allows wind and local currents to more effectively break ice. The winter spatial pattern of sea ice concentration is collocated with patterns of surface heat flux anomalies. Winter minimum sea ice thickness occurs in the ice pack interior above the AW path, clearly indicating AW influence on ice thickness. Our study indicates that in the AW inflow region heat flux from the ocean reduces the ice thickness.

  19. The effect of misleading surface temperature estimations on the sensible heat fluxes at a high Arctic site – the Arctic turbulence experiment 2006 on Svalbard (ARCTEX-2006

    Directory of Open Access Journals (Sweden)

    J. Bareiss

    2009-08-01

    Full Text Available The observed rapid climate warming in the Arctic requires improvements in permafrost and carbon cycle monitoring, accomplished by setting up long-term observation sites with high-quality in-situ measurements of turbulent heat, water and carbon fluxes as well as soil physical parameters in an Arctic landscape. But accurate quantification and well adapted parameterizations of turbulent fluxes in polar environments presents fundamental problems in soil-snow-ice-vegetation-atmosphere interaction studies. One of these problems is the accurate estimation of the surface or aerodynamic temperature T(0 required to force most of the bulk aerodynamic formula currently used. Results from the Arctic-Turbulence-Experiment (ARCTEX-2006 performed on Svalbard during the winter/spring transition 2006 helped to better understand the physical exchange and transport processes of energy. The existence of an untypical temperature profile close to the surface in the Arctic spring at Svalbard could be proven to be one of the major issues hindering estimation of the appropriate surface temperature. Thus, it is essential to adjust the set-up of measurement systems carefully when applying flux-gradient methods that are commonly used to force atmosphere-ocean/land-ice models. The results of a comparison of different sensible heat-flux parameterizations with direct measurements indicate that only the use of a hydrodynamic three-layer temperature-profile model achieves enough accuracy for heat flux calculations as it reliably reproduces the temporal variability of the surface temperature.

  20. The effect of misleading surface temperature estimations on the sensible heat fluxes at a high Arctic site – the Arctic Turbulence Experiment 2006 on Svalbard (ARCTEX-2006

    Directory of Open Access Journals (Sweden)

    J. Lüers

    2010-01-01

    Full Text Available The observed rapid climate warming in the Arctic requires improvements in permafrost and carbon cycle monitoring, accomplished by setting up long-term observation sites with high-quality in-situ measurements of turbulent heat, water and carbon fluxes as well as soil physical parameters in Arctic landscapes. But accurate quantification and well adapted parameterizations of turbulent fluxes in polar environments presents fundamental problems in soil-snow-ice-vegetation-atmosphere interaction studies. One of these problems is the accurate estimation of the surface or aerodynamic temperature T(0 required to force most of the bulk aerodynamic formulae currently used. Results from the Arctic-Turbulence-Experiment (ARCTEX-2006 performed on Svalbard during the winter/spring transition 2006 helped to better understand the physical exchange and transport processes of energy. The existence of an atypical temperature profile close to the surface in the Arctic spring at Svalbard could be proven to be one of the major issues hindering estimation of the appropriate surface temperature. Thus, it is essential to adjust the set-up of measurement systems carefully when applying flux-gradient methods that are commonly used to force atmosphere-ocean/land-ice models. The results of a comparison of different sensible heat-flux parameterizations with direct measurements indicate that the use of a hydrodynamic three-layer temperature-profile model achieves the best fit and reproduces the temporal variability of the surface temperature better than other approaches.

  1. Controls on microalgal community structures in cryoconite holes upon high Arctic glaciers, Svalbard

    Directory of Open Access Journals (Sweden)

    T. R. Vonnahme

    2015-07-01

    Full Text Available Glaciers are known to harbor surprisingly complex ecosystems. On their surface, distinct cylindrical holes filled with meltwater and sediments are considered as hot spots for microbial life. The present paper addresses possible biological interactions within the community of prokaryotic cyanobacteria and eukaryotic microalgae (microalgae and relations to their potential grazers, additional to their environmental controls. Svalbard glaciers with substantial allochthonous input of material from local sources reveal high microalgal densities. Small valley glaciers with high sediment coverages and high impact of birds show high biomasses and support a high biological diversity. Invertebrate grazer densities do not show any significant negative correlation with microalgal abundances, but a positive correlation with eukaryotic microalgae. Most microalgae found in this study form large colonies ( 25 μm, which may protect them against invertebrate grazing. This finding rather indicates grazing as a positive control on eukaryotic microalgae by nutrient recycling. Density differences between the eukaryotic microalgae and prokaryotic cyanobacteria and their high distinction in RDA and PCA analyses indicate that these two groups are in strong contrast. Eukaryotic microalgae occurred mainly in unstable cryoconite holes with high sediment loads, high N : P ratios, and a high impact of bird guano, as a proxy for nutrients. In these environments autochthonous nitrogen fixation appears to be negligible. Selective wind transport of Oscillatoriales via soil and dust particles is proposed to explain their dominance in cryoconites further away from the glacier margins. We propose that, for the studied glaciers, nutrient levels related to recycling of limiting nutrients is the main factor driving variation in the community structure of microalgae and grazers.

  2. Controls on microalgal community structures in cryoconite holes upon high Arctic glaciers, Svalbard

    Science.gov (United States)

    Vonnahme, T. R.; Devetter, M.; Žárský, J. D.; Šabacká, M.; Elster, J.

    2015-07-01

    Glaciers are known to harbor surprisingly complex ecosystems. On their surface, distinct cylindrical holes filled with meltwater and sediments are considered as hot spots for microbial life. The present paper addresses possible biological interactions within the community of prokaryotic cyanobacteria and eukaryotic microalgae (microalgae) and relations to their potential grazers, additional to their environmental controls. Svalbard glaciers with substantial allochthonous input of material from local sources reveal high microalgal densities. Small valley glaciers with high sediment coverages and high impact of birds show high biomasses and support a high biological diversity. Invertebrate grazer densities do not show any significant negative correlation with microalgal abundances, but a positive correlation with eukaryotic microalgae. Most microalgae found in this study form large colonies (cells, or > 25 μm), which may protect them against invertebrate grazing. This finding rather indicates grazing as a positive control on eukaryotic microalgae by nutrient recycling. Density differences between the eukaryotic microalgae and prokaryotic cyanobacteria and their high distinction in RDA and PCA analyses indicate that these two groups are in strong contrast. Eukaryotic microalgae occurred mainly in unstable cryoconite holes with high sediment loads, high N : P ratios, and a high impact of bird guano, as a proxy for nutrients. In these environments autochthonous nitrogen fixation appears to be negligible. Selective wind transport of Oscillatoriales via soil and dust particles is proposed to explain their dominance in cryoconites further away from the glacier margins. We propose that, for the studied glaciers, nutrient levels related to recycling of limiting nutrients is the main factor driving variation in the community structure of microalgae and grazers.

  3. Controls on microalgal community structures in cryoconite holes upon high-Arctic glaciers, Svalbard

    Science.gov (United States)

    Vonnahme, T. R.; Devetter, M.; Žárský, J. D.; Šabacká, M.; Elster, J.

    2016-02-01

    Glaciers are known to harbor surprisingly complex ecosystems. On their surface, distinct cylindrical holes filled with meltwater and sediments are considered hot spots for microbial life. The present paper addresses possible biological interactions within the community of prokaryotic cyanobacteria and eukaryotic microalgae (microalgae) and relations to their potential grazers, such as tardigrades and rotifers, additional to their environmental controls. Svalbard glaciers with substantial allochthonous input of material from local sources reveal high microalgal densities. Small valley glaciers with high sediment coverages and high impact of birds show high biomasses and support a high biological diversity. Invertebrate grazer densities do not show any significant negative correlation with microalgal abundances but rather a positive correlation with eukaryotic microalgae. Shared environmental preferences and a positive effect of grazing are the proposed mechanisms to explain these correlations. Most microalgae found in this study form colonies (cells, or > 25 µm), which may protect them against invertebrate grazing. This finding rather indicates grazing as a positive control on eukaryotic microalgae by nutrient recycling. Density differences between the eukaryotic microalgae and prokaryotic cyanobacteria and their high distinction in redundancy (RDA) and principal component (PCA) analyses indicate that these two groups are in strong contrast. Eukaryotic microalgae occurred mainly in unstable cryoconite holes with high sediment loads, high N : P ratios, and a high impact of nutrient input by bird guano, as a proxy for nutrients. In these environments autochthonous nitrogen fixation appears to be negligible. Selective wind transport of Oscillatoriales via soil and dust particles is proposed to explain their dominance in cryoconites further away from the glacier margins. We propose that, for the studied glaciers, nutrient levels related to recycling of limiting

  4. The influence of cruise ship emissions on air pollution in Svalbard – a harbinger of a more polluted Arctic?

    Directory of Open Access Journals (Sweden)

    S. Eckhardt

    2013-08-01

    Full Text Available In this study we have analyzed whether tourist cruise ships have an influence on measured sulfur dioxide (SO2, ozone (O3, Aitken mode particle and equivalent black carbon (EBC concentrations at Ny Ålesund and Zeppelin Mountain on Svalbard in the Norwegian Arctic during summer. We separated the measurement data set into periods when ships were present and periods when ships were not present in the Kongsfjord area, according to a long-term record of the number of passengers visiting Ny Ålesund. We show that when ships with more than 50 passengers cruise in the Kongsfjord, measured daytime mean concentrations of 60 nm particles and EBC in summer show enhancements of 72 and 45%, respectively, relative to values when ships are not present. Even larger enhancements of 81 and 72% were found for stagnant conditions. In contrast, O3 concentrations were 5% lower on average and 7% lower under stagnant conditions, due to titration of O3 with the emitted nitric oxide (NO. The differences between the two data subsets are largest for the highest measured percentiles, while relatively small differences were found for the median concentrations, indicating that ship plumes are sampled relatively infrequently even when ships are present although they carry high pollutant concentrations. We estimate that the ships increased the total summer mean concentrations of SO2, 60 nm particles and EBC by 15, 18 and 11%, respectively. Our findings have two important implications. Firstly, even at such a remote Arctic observatory as Zeppelin, the measurements can be influenced by tourist ship emissions. Careful data screening is recommended before summertime Zeppelin data is used for data analysis or for comparison with global chemistry transport models. However, Zeppelin remains as one of the most valuable Arctic observatories, as most other Arctic observatories face even larger local pollution problems. Secondly, given landing statistics of tourist ships on Svalbard, it is

  5. The influence of cruise ship emissions on air pollution in Svalbard – a harbinger of a more polluted Arctic?

    Directory of Open Access Journals (Sweden)

    A. Baecklund

    2013-01-01

    Full Text Available In this study we have analyzed whether tourist cruise ships have an influence on measured sulfur dioxide (SO2, ozone (O3, Aitken mode particle and equivalent black carbon (EBC concentrations at Ny Ålesund and Zeppelin Mountain on Svalbard in the Norwegian Arctic, during summer. We separated the measurement data set into periods when ships were present and periods when no ships were present in the Kongsfjord area, according to a long-term record of the number of passengers visiting Ny Ålesund. We show that when ships with more than 50 passengers cruise in the Kongsfjord, measured daytime-mean concentrations of 60-nm particles and EBC in summer show enhancements of 72 and 45% relative to values when no ships are present. Even larger enhancements of 81 and 72% were found for stagnant conditions. In contrast, O3 concentrations were 5% lower on average and 7% lower under stagnant conditions, due to titration of O3 with the emitted nitric oxide (NO. The differences between the two data subsets are largest for the highest measured percentiles while relatively small differences were found for the median concentrations, indicating that ship plumes are sampled relatively infrequently even when ships are generally present but carry high concentrations. We estimate that the ships increased the total summer mean concentrations of SO2, 60-nm particles and EBC by 15, 18 and 11%, respectively. Our findings have two important implications: firstly, even at such a remote Arctic observatory as Zeppelin, the measurements can be influenced by tourist ship emissions. Careful data screening is recommended before summer-time Zeppelin data is used for data analysis or for comparison with global chemistry transport models. However, Zeppelin remains one of the most valuable Arctic observatories, as most other Arctic observatories face even larger local pollution problems. Secondly, given landing statistics of tourist ships on Svalbard, it is suspected that large parts

  6. The influence of cruise ship emissions on air pollution in Svalbard - a harbinger of a more polluted Arctic?

    Science.gov (United States)

    Eckhardt, S.; Hermansen, O.; Grythe, H.; Fiebig, M.; Stebel, K.; Cassiani, M.; Baecklund, A.; Stohl, A.

    2013-08-01

    In this study we have analyzed whether tourist cruise ships have an influence on measured sulfur dioxide (SO2), ozone (O3), Aitken mode particle and equivalent black carbon (EBC) concentrations at Ny Ålesund and Zeppelin Mountain on Svalbard in the Norwegian Arctic during summer. We separated the measurement data set into periods when ships were present and periods when ships were not present in the Kongsfjord area, according to a long-term record of the number of passengers visiting Ny Ålesund. We show that when ships with more than 50 passengers cruise in the Kongsfjord, measured daytime mean concentrations of 60 nm particles and EBC in summer show enhancements of 72 and 45%, respectively, relative to values when ships are not present. Even larger enhancements of 81 and 72% were found for stagnant conditions. In contrast, O3 concentrations were 5% lower on average and 7% lower under stagnant conditions, due to titration of O3 with the emitted nitric oxide (NO). The differences between the two data subsets are largest for the highest measured percentiles, while relatively small differences were found for the median concentrations, indicating that ship plumes are sampled relatively infrequently even when ships are present although they carry high pollutant concentrations. We estimate that the ships increased the total summer mean concentrations of SO2, 60 nm particles and EBC by 15, 18 and 11%, respectively. Our findings have two important implications. Firstly, even at such a remote Arctic observatory as Zeppelin, the measurements can be influenced by tourist ship emissions. Careful data screening is recommended before summertime Zeppelin data is used for data analysis or for comparison with global chemistry transport models. However, Zeppelin remains as one of the most valuable Arctic observatories, as most other Arctic observatories face even larger local pollution problems. Secondly, given landing statistics of tourist ships on Svalbard, it is suspected that

  7. Metagabbro associated with the shear zone on Prins Karls Forland (Svalbard, Arctic)

    Science.gov (United States)

    Maraszewska, Maria; Manecki, Maciej; Czerny, Jerzy; Schneider, David; Myhre, Per Inge; Faehnrich, Karol; Barnes, Christopher

    2016-04-01

    Prins Karls Forland (PKF) is a N-S elongated island situated west of Spitsbergen in the Svalbard archipelago, High Arctic. The northern part of the island is dominated by siliciclastic metasediments regionally metamorphosed to greenshist facies assemblages during one distinct stage of tectonism. Amphibolite facies garnet-mica schists, mica schists, quartzites and carbonate-silicate rocks exhibiting evidence of at least two distinct, strong deformation episodes (including mylonitization) locally outcrop on the east coast of PKF, termed the Pinkie Unit. A ~1 km wide shear zone containing ductile to brittle structures and distinct outcrops of greenstones (metagabbros and greenschists), associated with magnetite ore, separates these two contrasting tectonic units. Ten samples of greenstones were collected on the slopes of Lauratzonfjellet and Boureefjellet for petrologic and geochemical analyses. Despite intense localized shearing, the metagabbros are undeformed and preserve coarse crystalline, magmatic texture, which is locally poikilitic. The primary magmatic assemblage consists of brown hornblende, plagioclase, biotite and opaque minerals, with accessory apatite and titanite. No relicts of pyroxenes are preserved. Formation of secondary uralite, sericite and chlorite is observed. Metamorphic assemblage consists of actinolite pseudomorhs after hornblende, epidote, and second generation biotite. Blue amphibole is observed in one sample from Boureefjellet; greenschists from Boureefjellet also contain fibrous blue amphibole, as well as garnets, actinolite, epidote and biotite. Some rocks sampled on Boureefjellet are more strongly deformed and exhibit probably two stages of metamorphism: amphibolite facies metamorphism resulting in blue amphibole-garnet assemblage followed by greenschist facies metamorphism resulting in actinolite-epidote-biotite paragenesis. Parallel and overlapping patterns on chondrite-normalized REE diagrams and spider diagrams indicate that these

  8. Reconstructing Climate Change Since The Late Glacial At Amsterdamøya, NW Svalbard (80°N), Based On Lake Sediments From Lake Hakluytvatnet

    Science.gov (United States)

    Gjerde, Marthe; Bakke, Jostein; D'Andrea, William J.; Balascio, Nicholas L.; Hormes, Anne; Bradley, Raymond S.

    2015-04-01

    Records of past climatic changes are sparse and poorly resolved in the Arctic due to obvious reasons such as lack of dateable organic material and logistical challenges. Here, we present a new time series from the island of Amsterdamøya, NW Svalbard (80°N), based on lake sediments from Lake Hakluytvatnet. Located at the northernmost branch of the North Atlantic Current, this high-Arctic site is ideally placed to infer changes in past atmospheric and oceanic circulation patterns recorded as changes in precipitation and temperature. Our novel data set provides a climatic reconstruction based on multi-proxy analyses on lake sediments from a non-glacial lake. We have combined one long piston core with a shorter gravity core to capture the entire sediment infill from the bottom of the basin to the most recently accumulated sediments on top. A robust chronology has been established for the cores through 28 AMS radiocarbon (14C) ages in combination with one lead (210Pb) profile of the most recent sediments, and this gives an unprecedented age control for a lake at this latitude as well as a precise sediment accumulation rate. The Hakluytvatnet cores are analysed for physical sediment properties as well as newer scanning instruments (e.g. XRF scanning, Scanning Electron Microscope, SEM, analyses) in order to produce a high-resolution reconstruction of the climate development for the study site. A separate alkenone study will produce a high-resolution temperature curve for the area. Soil samples from the surrounding catchment have also been subject to geochemical analyses in order to distinguish between the relative influences of different sediment sources on sediment accumulation in the lake. Geomorphological mapping has been carried out to combine interpretation of the catchment development with the lake sediment record interpretation. Numerical analyses (e.g. Principal Component Analysis, PCA) are applied on the results from the lake sediment and catchment samples in

  9. Basal processes beneath an Arctic glacier and their geomorphic imprint after a surge, Elisebreen, Svalbard

    Science.gov (United States)

    Christoffersen, Poul; Piotrowski, Jan A.; Larsen, Nicolaj K.

    2005-09-01

    The foreground of Elisebreen, a retreating valley glacier in West Svalbard, exhibits a well-preserved assemblage of subglacial landforms including ice-flow parallel ridges (flutings), ice-flow oblique ridges (crevasse-fill features), and meandering ridges (infill of basal meltwater conduits). Other landforms are thrust-block moraine, hummocky terrain, and drumlinoid hills. We argue in agreement with geomorphological models that this landform assemblage was generated by ice-flow instability, possibly a surge, which took place in the past when the ice was thicker and the bed warmer. The surge likely occurred due to elevated pore-water pressure in a thin layer of thawed and water-saturated till that separated glacier ice from a frozen substratum. Termination may have been caused by a combination of water drainage and loss of lubricating sediment. Sedimentological investigations indicate that key landforms may be formed by weak till oozing into basal cavities and crevasses, opening in response to accelerated ice flow, and into water conduits abandoned during rearrangement of the basal water system. Today, Elisebreen may no longer have surge potential due to its diminished size. The ability to identify ice-flow instability from geomorphological criteria is important in deglaciated terrain as well as in regions where ice dynamics are adapting to climate change.

  10. 900-m high gas plumes rising from marine sediments containing structure II hydrates at Vestnesa Ridge, offshore W-Svalbard

    Science.gov (United States)

    Smith, Andrew J.; Mienert, Jürgen; Bünz, Stefan; Greinert, Jens; Rasmussen, Tine L.

    2013-04-01

    We study an arctic sediment drift in ~1200 m water depth at Vestnesa Ridge, offshore western Svalbard. The ridge is spotted with pockmarks that range in size from a few meters to hundreds of meters in diameter and centimeters to tens of meters in height (e.g. Vogt et al., 1994). There is a strong negative-polarity seismic reflection below the ridge that is interpreted to record a negative impedance contrast marking the boundary between gas hydrate and water above and free gas and water below: it is the bottom-simulating reflector (BSR). Seismically transparent zones, interpreted as gas chimneys, extend from pockmarks at the seafloor to depths below the BSR (180-220 meters below the seafloor) (Bünz et al., 2012). Gas flares, gas hydrate, and methane-seep-specific biological communities (pogonphora and begiatoa bacterial mats) have been observed adjacent to pockmarks at the ridge (Bünz et al., 2012). We present new single-beam echosounding data that were acquired during 2010 and 2012 cruises on the R/V Helmer Hanssen at Vestnesa Ridge using a Simrad EK60 system that operates at frequencies of 18 and 38 kHz. During both cruises which lasted 3-5 days, we detected continuous bubble release from 4 separate pockmarks in 2010 and 6 separate pockmarks in 2012. There were no noticeable, short-term (hourly or daily) variations in the bubble release from the pockmarks, indicating that the venting from the pockmarks does not undergo rapid changes. Plumes from the pockmarks rise between 875 to 925m above the seafloor to a final water depth of 325 to 275m, respectively. This depth is in excellent agreement with the top of the hydrate stability zone (275 meters below sea level) for the gas composition of hydrate sampled at the ridge (96.31% C1; 3.36% C2; 0.21% C3; 0.11% IC4; 0.01% NC4). This suggests that hydrate skins are forming around the gas bubbles, inhibiting the dissolution of gas, and allowing the bubbles to rise to such great heights in the water column. Our results

  11. Diversity and composition of bacterial community in soils and lake sediments from an Arctic lake area

    Directory of Open Access Journals (Sweden)

    Nengfei Wang

    2016-07-01

    Full Text Available This study assessed the diversity and composition of bacterial communities within soils and lake sediments from an Arctic lake area (London Island, Svalbard. A total of 2,987 operational taxonomic units (OTUs were identified by high throughput sequencing, targeting bacterial 16S rRNA. The samples from four sites (three samples in each site were significantly different in geochemical properties and bacterial community composition. Proteobacteria and Acidobacteria were abundant phyla in the nine soil samples, whereas Proteobacteria and Bacteroidetes were abundant phyla in the three sediment samples. Furthermore, Actinobacteria, Chlorobi, Chlorofiexi, Elusimicrobia, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Proteobacteria significantly varied in their abundance among the four sampling sites. Additionally, members of the dominant genera, such as Clostridium, Luteolibacter, Methylibium, Rhodococus, and Rhodoplanes, were significantly different in their abundance among the four sampling sites. Besides, distance-based redundancy analysis revealed that pH (p < 0.001, water content (p < 0.01, ammonium nitrogen (NH4--N, p < 0.01, silicate silicon (SiO42--Si, p < 0.01, nitrite nitrogen (NO2--N, p < 0.05, organic carbon (p < 0.05, and organic nitrogen (p < 0.05 were the most significant factors that correlated with the bacterial community composition. The results suggest soils and sediments from a lake area in the Arctic harbor a high diversity of bacterial communities, which are influenced by many geochemical factors of Arctic environments.

  12. Variability of the mixed phase in the Arctic with a focus on the Svalbard region: a study based on spaceborne active remote sensing

    Directory of Open Access Journals (Sweden)

    G. Mioche

    2014-09-01

    Full Text Available The Arctic region is known to be very sensitive to climate change. Clouds and in particular mixed phase clouds (MPC remain one of the greatest sources of uncertainties in the modeling of the Arctic response to climate change due to an inaccurate representation of their variability and their quantification. In this study, we present a characterization of the vertical, spatial and seasonal variability of Arctic clouds and MPC over the whole Arctic region based on satellite active remote sensing observations. MPC properties in the region of Svalbard archipelago (78° N, 15° E are also investigated. The occurrence frequency of clouds and MPC are determined from CALIPSO/CLOUDSAT measurements processed with the DARDAR retrieval algorithm which allows for a reliable cloud thermodynamic phase classification (warm liquid, supercooled liquid, ice, mixing of ice and supercooled liquid. Significant differences are observed between MPC variability over the whole Arctic region and over the Svalbard region. Results show that MPC are ubiquitous all along the year, with a minimum occurrence of 30% in winter and 50% during the rest of the year, in average over the whole Arctic. Over the Svalbard region, MPC occurrence is more constant with time with larger values (55% compared to the average observed in the Arctic. MPC are especially located at low altitudes, below 3000 m, where their frequency of occurrence reaches 90%, in particular during winter, spring and autumn. Moreover, results highlight that MPC statistically prevail over sea. The temporal and spatial distribution of MPC over the Svalbard region seems to be linked to the contribution of moister air and warmer water from the North Atlantic Ocean which contribute to the initiation of the liquid water phase. Over the whole Arctic, and particularly in western regions, the increase of MPC occurrence from spring to autumn could be connected to the sea ice melting. During this period, the open water transports

  13. Terrestrial atmospheric responses on Svalbard to the 20 March 2015 Arctic total solar eclipse under extreme conditions.

    Science.gov (United States)

    Pasachoff, J M; Peñaloza-Murillo, M A; Carter, A L; Roman, M T

    2016-09-28

    This article reports on the near-surface atmospheric response at the High Arctic site of Svalbard, latitude 78° N, as a result of abrupt changes in solar insolation during the 20 March 2015 equinox total solar eclipse and notifies the atmospheric science community of the availability of a rare dataset. Svalbard was central in the path of totality, and had completely clear skies. Measurements of shaded air temperature and atmospheric pressure show only weak, if any, responses to the reduced insolation. A minimum in the air temperature at 1.5 m above the ground occurred starting 2 min following the end of totality, though this drop was only slightly beyond the observed variability for the midday period. Eclipse-produced variations in surface pressure, if present, were less than 0.3 hPa.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  14. Aerosol optical properties over the Svalbard region of Arctic: ground-based measurements and satellite remote sensing

    Science.gov (United States)

    Gogoi, Mukunda M.; Babu, S. Suresh

    2016-05-01

    In view of the increasing anthropogenic presence and influence of aerosols in the northern polar regions, long-term continuous measurements of aerosol optical parameters have been investigated over the Svalbard region of Norwegian Arctic (Ny-Ålesund, 79°N, 12°E, 8 m ASL). This study has shown a consistent enhancement in the aerosol scattering and absorption coefficients during spring. The relative dominance of absorbing aerosols is more near the surface (lower single scattering albedo), compared to that at the higher altitude. This is indicative of the presence of local anthropogenic activities. In addition, long-range transported biomass burning aerosols (inferred from the spectral variation of absorption coefficient) also contribute significantly to the higher aerosol absorption in the Arctic spring. Aerosol optical depth (AOD) estimates from ground based Microtop sun-photometer measurements reveals that the columnar abundance of aerosols reaches the peak during spring season. Comparison of AODs between ground based and satellite remote sensing indicates that deep blue algorithm of Moderate Resolution Imaging Spectroradiometer (MODIS) retrievals over Arctic snow surfaces overestimate the columnar AOD.

  15. Physical properties of the arctic summer aerosol particles in relation to sources at Ny-Alesund, Svalbard

    Indian Academy of Sciences (India)

    C G Deshpande; A K Kamra

    2014-02-01

    Measurements of the number concentration and size distribution of aerosol particles in the size range of 0.5–20 m diameter were made with an aerodynamic particle sizer at an Arctic site at Ny-Alesund, Svalbard in August–September 2007 during the International Polar Year 2007–2008. Data are analyzed to study the aerosol number concentration–wind speed relationships. The sea-salt particles of marine origin generated within the Arctic circle are identified as the main source of the Arctic summer aerosols. Total number concentration of aerosol particles increases with increase in wind speed, the increase being more when winds from open leads over the oceanic sector are reaching the station as compared to when winds from pack ice in other directions are reaching the station. The larger increase with winds from the oceanic sector is attributed to the enhanced bubble-breaking activity and increased entrainment of dimethyl sulphide particles at the sea surface. Although, the increase in total aerosol number concentration associated with the winds from the oceanic sector is spread over the whole range of particle sizes, the increase in coarse mode particles is more prominent than that in the accumulation mode particles. The age of airmass over pack ice is also an important factor to determine the aerosol concentration over the Arctic region. The process of rainout/washout of the aerosol particles due to drizzle/snowfall is an effective sink mechanism in the Arctic environment. The aerosol particle concentration starts decreasing within a few minutes from the start of these events but requires a few hours to restore to the normal background aerosol level after the end of event.

  16. Levels and temporal trends of persistent organic pollutants (POPs) in arctic foxes (Vulpes lagopus) from Svalbard in relation to dietary habits and food availability

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, Martin S. [Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø (Norway); Department of Arctic and Marine Biology, UiT The Arctic University of Norway, NO-9037 Tromsø (Norway); Fuglei, Eva; König, Max [Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø (Norway); Lipasti, Inka [Department of Biology, University of Eastern Finland, FI-80101 Joensuu (Finland); Pedersen, Åshild Ø. [Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø (Norway); Polder, Anuschka [Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås (Norway); Yoccoz, Nigel G. [Department of Arctic and Marine Biology, UiT The Arctic University of Norway, NO-9037 Tromsø (Norway); Routti, Heli, E-mail: heli.routti@npolar.no [Norwegian Polar Institute, Fram Centre, NO-9296 Tromsø (Norway)

    2015-04-01

    Temporal trends of persistent organic pollutants (POPs) in arctic foxes (Vulpes lagopus) from Svalbard, Norway, were investigated in relation to feeding habits and seasonal food availability. Arctic foxes from Svalbard forage in both marine and terrestrial ecosystems and the availability of their food items are impacted by climatic variability. Concentrations of polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs) and brominated flame retardants (polybrominated diphenyl ethers [PBDEs] and hexabromocyclododecane [HBCDD]) were analyzed in the liver of 141 arctic foxes collected between 1997 and 2013. Stable carbon isotope values (δ{sup 13}C) were used as a proxy for feeding on marine versus terrestrial prey. The annual number of recovered reindeer carcasses and sea ice cover were used as proxies for climate influenced food availability (reindeers, seals). Linear models revealed that concentrations of PCBs, chlordanes, p,p′-DDE, mirex and PBDEs decreased 4–11% per year, while no trends were observed for hexachlorobenzene (HCB) or β-hexachlorocyclohexane (β-HCH). Positive relationships between POP concentrations and δ{sup 13}C indicate that concentrations of all compounds increase with increasing marine dietary input. Increasing reindeer mortality was related to lower HCB concentrations in the foxes based on the linear models. This suggests that concentrations of HCB in arctic foxes may be influenced by high mortality levels of Svalbard reindeer. Further, β-HCH concentrations showed a positive association with sea ice cover. These results in addition to the strong effect of δ{sup 13}C on all POP concentrations suggest that climate-related changes in arctic fox diet are likely to influence contaminant concentrations in arctic foxes from Svalbard. - Highlights: • POPs were analyzed in the arctic foxes' liver (n = 141) from Svalbard collected in 1997–2013. • PCBs, chlordanes, p,p′-DDE, mirex and PBDEs decreased 4–11% per year.

  17. Diversity and Distribution of Aquatic Fungal Communities in the Ny-Ålesund Region, Svalbard (High Arctic): Aquatic Fungi in the Arctic.

    Science.gov (United States)

    Zhang, Tao; Wang, Neng-Fei; Zhang, Yu-Qin; Liu, Hong-Yu; Yu, Li-Yan

    2016-04-01

    We assessed the diversity and distribution of fungi in 13 water samples collected from four aquatic environments (stream, pond, melting ice water, and estuary) in the Ny-Ålesund Region, Svalbard (High Arctic) using 454 pyrosequencing with fungi-specific primers targeting the internal transcribed spacer (ITS) region of the ribosomal rRNA gene. Aquatic fungal communities in this region showed high diversity, with a total of 43,061 reads belonging to 641 operational taxonomic units (OTUs) being found. Of these OTUs, 200 belonged to Ascomycota, 196 to Chytridiomycota, 120 to Basidiomycota, 13 to Glomeromycota, and 10 to early diverging fungal lineages (traditional Zygomycota), whereas 102 belonged to unknown fungi. The major orders were Helotiales, Eurotiales, and Pleosporales in Ascomycota; Chytridiales and Rhizophydiales in Chytridiomycota; and Leucosporidiales and Sporidiobolales in Basidiomycota. The common fungal genera Penicillium, Rhodotorula, Epicoccum, Glaciozyma, Holtermanniella, Betamyces, and Phoma were identified. Interestingly, the four aquatic environments in this region harbored different aquatic fungal communities. Salinity, conductivity, and temperature were important factors in determining the aquatic fungal diversity and community composition. The results suggest the presence of diverse fungal communities and a considerable number of potentially novel fungal species in Arctic aquatic environments, which can provide reliable data for studying the ecological and evolutionary responses of fungi to climate change in the Arctic ecosystem.

  18. Long term trends of CCN concentration in Arctic region at Zeppelin station, Ny-Ålesund, Svalbard

    Science.gov (United States)

    Jung, C. H.; Yoon, Y. J.; Kang, H. J.; Gim, Y. T.; Lee, B. Y.; Ström, J.; Krejci, R.; Tunved, P.

    2015-12-01

    The Arctic is a challenging region when assessing aerosol impacts due to their large variations in concentration, and varying chemical, physical and optical properties. In the climate effects of atmosphere aerosol indirect force, cloud condensation nuclei (CCN) play an important role because particles acting as they can grow to cloud droplets by condensation of water vapor, affecting cloud properties in various ways. For example, the increased CCN concentrations lead to the production of more numerous and smaller cloud drops, which can result in optically thicker clouds that tend to reflect more incoming solar radiation back to space (Twomey, 1977). Thus, investigating the physical process of the CCN aerosol that controls cloud droplet formation is important in understanding the radiative transfer and climate effect. In addition, there are still large variabilities in Arctic CCN number concentrations remaining. These variabilities are mainly due to the result of varying aerosol sources and chemical composition (Browse et al., 2012). Especially, the analysis on the long term trends as well as seasonality of CCN and relation with aerosols are very rare and need to be investigated. In this study, CCN concentration data collected at the Zeppelin observatory located on the top of Mt. Zeppelin, Svalbard (78° 54' N, 11° 53' E) are analyzed during 2007-2013. The seasonal and yearly trends of CCN in the Arctic region during the long periods are presented. The obtained results are compared with other instrumental data such as aerosol size distribution and total number concentration. ReferenceBrowse, J., Carslaw, K. S., Arnold, S. R., Pringle, K., and Boucher, O, 2012, The scavenging processes controlling the seasonal cycle in Arctic sulphate and black carbon aerosol, Atmos. Chem. Phys., 12, 6775-6798. Twomey, S., 1977: Atmospheric Aerosols. Elsevier.

  19. Temporal constraints on future accumulation-area loss of a major Arctic ice cap due to climate change (Vestfonna, Svalbard).

    Science.gov (United States)

    Möller, Marco; Schneider, Christoph

    2015-01-28

    Arctic glaciers and ice caps are major contributors to past, present and future sea-level fluctuations. Continued global warming may eventually lead to the equilibrium line altitudes of these ice masses rising above their highest points, triggering unstoppable downwasting. This may feed future sea-level rise considerably. We here present projections for the timing of equilibrium-line loss at the major Arctic ice cap Vestfonna, Svalbard. The projections are based on spatially distributed climatic mass balance modelling driven by the outputs of multiple climate models from the Coupled Model Intercomparison Project Phase 5 (CMIP5) forced by the Representative Concentration Pathways (RCPs) 2.6, 4.5, 6.0 and 8.5. Results indicate strongly decreasing climatic mass balances over the 21(st) century for all RCPs considered. Glacier-wide mass-balance rates will drop down to -4 m a(-1) w.e. (water equivalent) at a maximum. The date at which the equilibrium line rises above the summit of Vestfonna (630 m above sea level) is calculated to range between 2040 and 2150, depending on scenario.

  20. Cold season soil respiration in response to grazing and warming in the High Arctic Svalbard

    DEFF Research Database (Denmark)

    Strebel, Ditte; Elberling, Bo; Morgner, Elke;

    2010-01-01

    ) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Results reveal variations in soil carbon cycling, with significant seasonal trends controlled by temperature, water content and snow. Experimental warming (OTCs) increased near-surface temperatures in the growing season, resulting......The influence of goose grazing intensity and open-topped chambers (OTCs) on near-surface quantities and qualities of soil organic carbon (SOC) was evaluated in wet and mesic ecosystems in Svalbard. This study followed up a field experiment carried out in 2003-05 (part of the project Fragility...

  1. Phytochemical profiles and antioxidant potential of four Arctic vascular plants from Svalbard

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, P.; Singh, S.M.; De; Wahidullah, S.

    Environmental stress in the Arctic region leads to damage in plant membranes as a result of oxidation processes. To withstand these stress conditions, plants are expected to produce antioxidants that differ from phenolics. Here, we investigated...

  2. Community structure, cellular rRNA content, and activity of sulfate-reducing bacteria in marine Arctic sediments

    DEFF Research Database (Denmark)

    Ravenschlag, K.; Sahm, K.; Knoblauch, C.;

    2000-01-01

    The community structure of sulfate-reducing bacteria (SRB) of a marine Arctic sediment (Smeerenburg-fjorden, Svalbard) a-as characterized by both fluorescence in situ hybridization (FISH) and rRNA slot blot hybridization by using group- and genus-specific 16S rRNA-targeted oligonucleotide probes...... that FISH and rRNA slot blot hybridization gave comparable results. Furthermore, a combination of the two methods allowed us to calculate specific cellular rRNA contents with respect to localization in the sediment profile. The rRNA contents of Desulfosarcina-Desulfococcus cells were highest in the first 5...... mm of the sediment (0.9 and 1.4 fg, respectively) and decreased steeply with depth, indicating that maximal metabolic activity occurred close to the surface, Based on SRB cell numbers, cellular sulfate reduction rates were calculated. The rates were highest in the surface layer (0.14 fmol cell(-1...

  3. Relationship of cyanobacterial and algal assemblages with vegetation in the high Arctic tundra (West Spitsbergen, Svalbard Archipelago

    Directory of Open Access Journals (Sweden)

    Richter Dorota

    2015-09-01

    Full Text Available The paper presents the results of a study of cyanobacteria and green algae assemblages occurring in various tundra types determined on the basis of mosses and vascular plants and habitat conditions. The research was carried out during summer in the years 2009-2013 on the north sea-coast of Hornsund fjord (West Spitsbergen, Svalbard Archipelago. 58 sites were studied in various tundra types differing in composition of vascular plants, mosses and in trophy and humidity. 141 cyanobacteria and green algae were noted in the research area in total. Cyanobacteria and green algae flora is a significant element of many tundra types and sometimes even dominate there. Despite its importance, it has not been hitherto taken into account in the description and classification of tundra. The aim of the present study was to demonstrate the legitimacy of using phycoflora in supplementing the descriptions of hitherto described tundra and distinguishing new tundra types. Numeric hierarchical-accumulative classification (MVSP 3.1 software methods were used to analyze the cyanobacterial and algal assemblages and their co-relations with particular tundra types. The analysis determined dominant and distinctive species in the communities in concordance with ecologically diverse types of tundra. The results show the importance of these organisms in the composition of the vegetation of tundra types and their role in the ecosystems of this part of the Arctic.

  4. Current knowledge of the Tardigrada of Svalbard with the first records of water bears from Nordaustlandet (High Arctic

    Directory of Open Access Journals (Sweden)

    Krzysztof Zawierucha

    2013-11-01

    Full Text Available The first investigations of the tardigrades of Svalbard took place in the early 20th century and 30 papers on the subject have been published to date. In this article, we summarize available information on the distribution of tardigrades in this Arctic archipelago with remarks on the dubious species and records. Additionally, we examined 28 new moss, lichen and soil samples collected from the islands of Nordaustlandet, Edgeøya and Prins Karls Forland. These samples yielded 324 specimens, 15 exuvia and 132 free-laid eggs belonging to 16 limnoterrestrial species (Heterotardigrada and Eutardigrada. These include five first records of water bears from Nordaustlandet, eight new records for Edgeøya and four for Prince Karls Forland. The most dense population of tardigrades was found in a sample with 253 specimens/10 g of dry material and the least dense population in a sample with three specimens/10 g of dry material. The most frequently recorded species in samples collected in this study were Testechiniscus spitsbergensis Scourfield, 1897, Macrobiotus harmsworthi harmsworthi Murray, 1907, and M. islandicus islandicus Richters, 1904. This article also provides the first ever scanning electron microscope photomicrographs of Tenuibiotus voronkovi Tumanov, 2007.

  5. Deposition history of brominated flame retardant compounds in an ice core from Holtedahlfonna, Svalbard, Norway

    NARCIS (Netherlands)

    Hermanson, M.H.; Isaksson, E.; Forsström, S.; Teixeira, C.; Muir, D.C.G.; Pohjola, V.A.; van de Wal, R.S.W.

    2010-01-01

    Brominated flame retardants (BFRs) have been found in Arctic wildlife, lake sediment, and air. To identify the atmospheric BFR deposition history on Svalbard, Norway, we analyzed 19 BFRs, including hexabromocyclododecane (HBCD), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane

  6. Contaminants, benthic communities, and bioturbation: potential for PAH mobilisation in Arctic sediments

    Energy Technology Data Exchange (ETDEWEB)

    Konovalov, D.; Renaud, P.E.; Berge, J.; Voronkov, A.Y.; Cochrane, S.K.J. [Polar Environmental Center, Tromso (Norway)

    2010-07-01

    Marine benthic fauna and biological mixing were studied in relation to sediment organic enrichment and polyaromatic hydrocarbons (PAHs) in bottom sediments of Svalbard. We investigated how organic enrichment may affect the fate and chemical composition of deposited contaminants by impacting biological reworking by faunal communities. Samples were collected near active coal mines at Barentsburg and at the mouth of Groenfjord. PAH sources in both areas were coal particles and pyrolytic compounds from coal-driven power stations. The results from a bioturbation experiment were consistent with the hypothesis that fauna enhance the vertical transport of PAHs within the sediment. Faunal community composition was similar at the two sites, with polychaete worms comprising 85% of the fauna. Abundances and taxon richness were eight and ten times higher in the organically enriched sediments near Barentsburg, and total PAH concentrations were up to three times higher in Barentsburg. Unlike expectations derived from models developed for temperate regions, organic enrichment in oligotrophic areas, such as this Arctic site, enhanced the biomass and bioturbation potential of benthic communities. Hence, new insights into the relationships among enrichment, benthic communities and the fate of contaminants must be considered in management and regulatory efforts in these areas.

  7. Surface morphology of fans in the high-Arctic periglacial environment of Svalbard : Controls and processes

    NARCIS (Netherlands)

    De Haas, Tjalling; Kleinhans, Maarten G.; Carbonneau, Patrice E.; Rubensdotter, Lena; Hauber, Ernst

    2015-01-01

    Fan-shaped landforms occur in all climatic regions on Earth. They have been extensively studied in many of these regions, but there are few studies on fans in periglacial, Arctic and Antarctic regions. Fans in such regions are exposed to many site-specific environmental conditions in addition to the

  8. A new concept for glacial geological investigations of surges, based on High-Arctic examples (Svalbard)

    Science.gov (United States)

    Lønne, Ida

    2016-01-01

    Svalbard is a key area for the investigation of glacial surges, and almost two centuries worth of field observations exists from this region. Studies have shown that the course of a surge and the associated formation of landforms are strongly influenced by basinal factors, and that the broad range of variables involved can hamper interpretations and comparisons. Based on a review of surges in Svalbard, a new concept for glacial geological investigations has been developed that combines ice-flows, ice-front movements, and morphostratigraphy. The concept is comprised of the following four elements: 1) classification based on the configuration and characteristics of the receiving basin, 2) division of the surge cycle into six stages, 3) guidelines for morphological mapping, and 4) use of an allostratigraphic approach for interpreting ice-front movements. In this context, delineation of the active phase is critical, which include the history of terminus movements, and four main categories of receiving basins are recognized. These are (A) terrestrial basins with deformable substrates, (B) terrestrial basins with poorly deformable substrates, (C) shallow water basins, and (D) deep water basins. The ice-front movement history is reconstructed by coupling information from the proglacial moraines (syn-surge), the supraglacial moraines (post-surge), and the associated traces of meltwater to the surge stages (I-VI). This approach has revealed a critical relationship between the termination of the active phase and three morphological elements, namely, the maximum ice-front position, the maximum moraine extent and the youngest proglacial moraine, which are unique for each of the basins A-D. The concept is thus a novel and more precise approach for mapping the active phase and the active phase duration, as shown by the ∼12-year long surge of Fridtjovbreen, where stage I was 30 months (inception), stage II was 54 months (ice-front advance), stage III was 12 months (stillstand

  9. Teachers, Researchers, and Students Collaborating in Arctic Climate Change Research: The Partnership Between the Svalbard REU and ARCUS PolarTREC programs

    Science.gov (United States)

    Roof, S.; Warburton, J.; Oddo, B.; Kane, M.

    2007-12-01

    Since 2004, the Arctic Research Consortium of the U.S. (ARCUS) "TREC" program (Teachers and Researchers Exploring and Collaborating, now "PolarTREC") has sent four K-12 teachers to Svalbard, Norway to work alongside researchers and undergraduate students conducting climate change research as part of the Svalbard Research Experiences for Undergraduates (REU) Program. The benefits of this scientist/educator/student partnership are many. Researchers benefit from teacher participation as it increases their understanding of student learning and the roles and responsibilities of K-12 teachers. The TREC teacher contributes to the research by making observations, analyzing data, and carrying heavy loads of equipment. In collaborating with K- 12 teachers, undergraduate student participants discover the importance of teamwork in science and the need for effective communication of scientific results to a broad audience. The questions that K-12 teachers ask require the scientists and students in our program to explain their work in terms that non-specialists can understand and appreciate. The K-12 teacher provides a positive career role model and several Svalbard REU undergraduate students have pursued K-12 teaching careers after graduating. TREC teachers benefit from working alongside the researchers and by experiencing the adventures of real scientific research in a remote arctic environment. They return to their schools with a heightened status that allows them to share the excitement and importance of scientific research with their students. Together, all parties contribute to greatly enhance public outreach. With ARCUS logistical support, TREC teachers and researchers do live web conferences from the field, reaching hundreds of students and dozens of school administrators and even local politicians. Teachers maintain web journals, describing the daily activities and progress of the researcher team. Online readers from around the world write in to ask questions, which the

  10. The impact of temperature change on the activity and community composition of sulfate-reducing bacteria in arctic versus temperate marine sediments

    DEFF Research Database (Denmark)

    Robador, Alberto; Brüchert, Volker; Jørgensen, Bo Barker

    2009-01-01

    that was weaker after prolonged incubations, which could imply an acclimatization response rather than a selection process of the SRB community. The microbial community composition was analysed by targeting the 16S ribosomal RNA using catalysed reporter deposition fluorescence in situ hybridization (CARD...... composition of sulfate-reducing bacteria were studied in the permanently cold sediment of north-western Svalbard (Arctic Ocean) and compared with a temperate habitat with seasonally varying temperature (German Bight, North Sea). Short-term 35S-sulfate tracer incubations in a temperature-gradient block......-FISH). The results showed the decline of specific groups of SRB and confirmed a strong impact of increasing temperatures on the microbial community composition of arctic sediment. Conversely, in seasonally changing sediment sulfate reduction rates and sulfate-reducing bacterial abundance changed little in response...

  11. Submarine Landslides in Arctic Sedimentation: Canada Basin

    Science.gov (United States)

    Mosher, David C.; Shimeld, John; Hutchinson, Deborah R.; Lebedova-Ivanova, N; Chapman, C.

    2016-01-01

    Canada Basin of the Arctic Ocean is the least studied ocean basin in the World. Marine seismic field programs were conducted over the past 6 years using Canadian and American icebreakers. These expeditions acquired more than 14,000 line-km of multibeam bathymetric and multi-channel seismic reflection data over abyssal plain, continental rise and slope regions of Canada Basin; areas where little or no seismic reflection data existed previously. Canada Basin is a turbidite-filled basin with flat-lying reflections correlateable over 100s of km. For the upper half of the sedimentary succession, evidence of sedimentary processes other than turbidity current deposition is rare. The Canadian Archipelago and Beaufort Sea margins host stacked mass transport deposits from which many of these turbidites appear to derive. The stratigraphic succession of the MacKenzie River fan is dominated by mass transport deposits; one such complex is in excess of 132,000 km2 in area and underlies much of the southern abyssal plain. The modern seafloor is also scarred with escarpments and mass failure deposits; evidence that submarine landsliding is an ongoing process. In its latest phase of development, Canada Basin is geomorphologically confined with stable oceanographic structure, resulting in restricted depositional/reworking processes. The sedimentary record, therefore, underscores the significance of mass-transport processes in providing sediments to oceanic abyssal plains as few other basins are able to do.

  12. What influences heavy metals accumulation in arctic lichen Cetrariella delisei in Svalbard?

    Science.gov (United States)

    Węgrzyn, Michał; Wietrzyk, Paulina; Lisowska, Maja; Klimek, Beata; Nicia, Paweł

    2016-12-01

    The main aim of this study was to identify variations in heavy metal concentrations in Cetrariella delisei along a transect from a High Arctic glacier forehead to the shoreline as well as determine the main environmental factors influencing the deposition of heavy metals in arctic lichens. The macrolichen Cetrariella delisei appears to be an interesting alternative to those lichen species used in the past (e.g. Flavocetraria nivalis, Cladonia sp.) for heavy metal biomonitoring purposes in the Arctic: it is widely distributed, easy to identify and reluctantly grazed by reindeer. Fieldwork was conducted in the summer of 2012 in the Kaffiøyra Plain, Oskar II Land, NW Spitsbergen. C. delisei and soil samples were collected from 5 localities. Concentrations of Cr, Mn, Ni, Cu, Zn, Pb, and Cd were measured in each sample. A bioaccumulation factor (BAF) was calculated for all the analyzed elements. The BAFs for Cu, Mn, and Ni showed a relatively low accumulation level in lichen thalli. On the other hand, the BAFs for Cr, Pb, and Zn, revealed an increased accumulation level in C. delisei. The Cd content in lichen is almost equal to its level in the soil. The statistical analyses covered three environmental factors: soil pH, substrate type and distance from the shoreline. The data were examined using the Kruskal-Wallis test, canonical correspondence analysis and a permutation test. The results show that distance from the shoreline had the greatest influence on the majority of the heavy metal concentrations in the lichen thalli and the soil. However, the level of Mn accumulated in the soil is determined by its source in the glacier. Moreover, the soil pH had the greatest effect on the Cd accumulated in the soil and the Mn accumulated in the lichen thalli.

  13. Recent transformations in the high-Arctic glacier landsystems based on examples from Svalbard

    Science.gov (United States)

    Ewertowski, Marek; Tomczyk, Aleksandra

    2014-05-01

    Glacier recession and landform development in the foreland of several Svalbard's glaciers were quantified for different spatio-temporal scales. Time-series orthophotos and digital elevation models from 1961, 1990 and 2009 (with ground resolution varying from 0.4 m to 0.7 m) were used for quantification of decadal changes for the whole glacial catchments. Time-series geomorphological maps were constructed using a combination of DEM visualization and stereoscopic viewing of aerial photographs. Planar transformations of landforms were quantified based on orthophotomaps, whereas changes of the volume of ice and landforms were assessed by creation of digital elevation models of differences (i.e. elevation changes between sequential DEMs). Repetitive geomorphological and geodetic field surveys were applied to estimates seasonal and inter-seasonal transformations of various landforms assemblages and individual landforms. Research were carried out for several glaciers in the central part of the Spitsbergen Island, including: Nordenskiöldbreen, Ebbabreen, Raganrbreen, Hørbyebreen, Cambridgebreen, Balliolbreen, Svenbreen and Ferdinandbreen. In the period LIA-2013, glaciers' margins retreated seriously, moreover ice volume and glaciers' surface profiles changed enormously emphasizing the relative importance of glaciers' thinning over area loss. In terms of landscape alteration, the landforms response was much more varied between glaciers. Most important transformation included: (1) developing of a terminoglacial and/or supraglacial lakes, which acted as a sedimentary trap and at the same time probably accelerated glacier erosion, (2) developing the lateral moraines whose transformations were divided into creation, initial, mature, and senile phases, with various magnitudes of debris flow and backwasting activity that changed with time (3) developing of end moraine complexes, which are now the most stable components, alternated mainly by dead-ice downwasting and to a lesser

  14. Hydroacoustic quantification of free-gas venting offshore Svalbard, Arctic: Changes in space and time

    Science.gov (United States)

    Greinert, J.; Veloso, M.; De Batist, M. A.; Mienert, J.

    2013-12-01

    Hydroacoustic data from a seep site area offshore Spitsbergen have been collected since 2009 by RV Helmer Hanssen (U. Tromsoe) in order to monitor the dynamics of gas bubble seepage and evaluate the amount of CH4 released at the seafloor. A large number of acoustic flares have been detected during four years of data acquisition at an intensely seeping area close to the shelf edge in 240m water depth and further down-slope between 330 and 450m water depth covering the top of the gas hydrate stability zone. Water column data were collected with an EK60 split-beam echosounder system. Seep positions were determined by accounting for motion and using split-beam information to determine the ';flare spine' for seep location as accurately as possible. The inverse hydroacoustic method for flux estimation developed by Muyakshin et al. (2010) has been adapted to be used with the angle information derived from split-beam data and using gridding algorithms for generating acoustic maps for each of the four surveys. The method evaluates the flux using the backscattering volume strength (SV) above the seafloor produced by free gas release, a bubble size distribution (BSD) function obtained from video footage and models for bubble rising speed (BRS) taken from the literature. Methane flux calculations depending on these input parameters vary from 187 T/yr to 250 T/yr assuming a continuous discharge for the 240m deep shelf-edge site, when all data sets are merged. Compared to other fluxes e.g. from specific seep areas in the Black Sea (683 T/yr Greinert et al., 2010 JGR; 1376 T/yr Römer et al., 2012 MarGeo) or the Håkon Mosby mud volcano (181 T/yr Sauter et al., 2006 EPSL) the fluxes from offshore Svalbard are similar in range but on the lower end. However, studying the ';common area' which was insonified during all four years reveals a decreasing flux of about 20% although the actual seep positions have been very persistent. The reason for this is currently unknown. The

  15. Recent transformations in the high-Arctic glacier landsystem Hørbyebreen, Svalbard.

    Science.gov (United States)

    Ewertowski, Marek; Evans, David; Roberts, David; Tomczyk, Aleksandra

    2016-04-01

    representative landsystem model for terrestrial-terminating Svalbard glaciers. The research was founded by Polish National Science Centre (project granted by decision number DEC-2011/01/D/ST10/06494).

  16. Desulfotomaculum arcticum sp. nov., a novel spore-forming, moderately thermophilic, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard

    DEFF Research Database (Denmark)

    Vandieken, Verona; Knoblauch, Christian; Jørgensen, Bo Barker

    2006-01-01

    Strain 15T is a novel spore-forming, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard. Sulfate could be replaced by sulfite or thiosulfate. Hydrogen, formate, lactate, propionate, butyrate, hexanoate, methanol, ethanol, propanol, butanol, pyruvate, malate, su...

  17. Methane in shallow subsurface sediments at the landward limit of the gas hydrate stability zone offshore western Svalbard

    Science.gov (United States)

    Graves, Carolyn A.; James, Rachael H.; Sapart, Célia Julia; Stott, Andrew W.; Wright, Ian C.; Berndt, Christian; Westbrook, Graham K.; Connelly, Douglas P.

    2017-02-01

    Offshore western Svalbard plumes of gas bubbles rise from the seafloor at the landward limit of the gas hydrate stability zone (LLGHSZ; ∼400 m water depth). It is hypothesized that this methane may, in part, come from dissociation of gas hydrate in the underlying sediments in response to recent warming of ocean bottom waters. To evaluate the potential role of gas hydrate in the supply of methane to the shallow subsurface sediments, and the role of anaerobic oxidation in regulating methane fluxes across the sediment-seawater interface, we have characterised the chemical and isotopic compositions of the gases and sediment pore waters. The molecular and isotopic signatures of gas in the bubble plumes (C1/C2+ = 1 × 104; δ13C-CH4 = -55 to -51‰; δD-CH4 = -187 to -184‰) are similar to gas hydrate recovered from within sediments ∼30 km away from the LLGHSZ. Modelling of pore water sulphate profiles indicates that subsurface methane fluxes are largely at steady state in the vicinity of the LLGHSZ, providing no evidence for any recent change in methane supply due to gas hydrate dissociation. However, at greater water depths, within the GHSZ, there is some evidence that the supply of methane to the shallow sediments has recently increased, which is consistent with downslope retreat of the GHSZ due to bottom water warming although other explanations are possible. We estimate that the upward diffusive methane flux into shallow subsurface sediments close to the LLGHSZ is 30,550 mmol m-2 yr-1, but it is <20 mmol m-2 yr-1 in sediments further away from the seafloor bubble plumes. While anaerobic oxidation within the sediments prevents significant transport of dissolved methane into ocean bottom waters this amounts to less than 10% of the total methane flux (dissolved + gas) into the shallow subsurface sediments, most of which escapes AOM as it is transported in the gas phase.

  18. Spatial and Temporal Variability in the Onset of the Growing Season on Svalbard, Arctic Norway — Measured by MODIS-NDVI Satellite Data

    Directory of Open Access Journals (Sweden)

    Stein Rune Karlsen

    2014-08-01

    Full Text Available The Arctic is among the regions with the most rapid changes in climate and has the expected highest increase in temperature. Changes in the timing of phenological phases, such as onset of the growing season observed from remote sensing, are among the most sensitive bio-indicators of climate change. The study area here is the High Arctic archipelago of Svalbard, located between 76°30ʹ and 80°50ʹN. The goal of this study was to use MODIS Terra data (the MOD09Q1 and MOD09A1 surface reflectance products, both with 8-day temporal composites to map the onset of the growing season on Svalbard for the 2000–2013 period interpreted from field observations. Due to a short and intense period with greening-up and frequent cloud cover, all the cloud free data is needed, which requires reliable cloud masks. We used a combination of three cloud removing methods (State QA values, own algorithms, and manual removal. This worked well, but is time-consuming as it requires manual interpretation of cloud cover. The onset of the growing season was then mapped by a NDVI threshold method, which showed high correlation (r2 = 0.60, n = 25, p < 0.001 with field observations of flowering of Salix polaris (polar willow. However, large bias was found between NDVI-based mapped onset and field observations in bryophyte-dominated areas, which indicates that the results in these parts must be interpreted with care. On average for the 14-year period, the onset of the growing season occurs after July 1st in 68.4% of the vegetated areas of Svalbard. The mapping revealed large variability between years. The years 2000 and 2008 were extreme in terms of late onset of the growing season, and 2002 and 2013 had early onset. Overall, no clear trend in onset of the growing season for the 2000–2013 period was found.

  19. Controls on morphometry and morphology of alluvial and colluvial fans in the high-Arctic setting, Petuniabukta, Svalbard.

    Science.gov (United States)

    Tomczyk, Aleksandra; Ewertowski, Marek

    2016-04-01

    The Petuniabukta (78o42' N, 16o32') is a bay in the northern part of Billefjorden in the central part of Spitsbergen Island, Svalbard. The bay is surrounded by six major, partly glaciated valleys. A numerous alluvial and colluvial fans have developed within valleys as well as along the fiord margins. Distribution and characterization of morphometric parameters of fans were investigated using time-series of orthophotos and digital elevation models (generated based on 1961, 1990, 2009 aerial photographs) and high resolution satellite imagery from 2013. In addition, a very detailed DEM and orthophoto (5 cm resolution) have been produced from unmanned aerial vehicle (UAV) imagery from 2014 and 2015, covering three fans characterised by different types of surface morphology. A 1:40,000 map showing the distribution of almost 300 alluvial and colluvial fans (ranging in area from 325 km2 to 451 275 km2), together with time-series of 1:5,000 geomorphological maps of sample fans enabled an assessment of the spatial and temporal evolution of processes responsible for delivery and erosion of sediments from the fans. The relationship between terrain parameters (e.g. slope, exposition) as well as geology was also investigated. Many of the studied alluvial fans were at least partly coupled and sediments were transferred from the upstream zone to the downstream zone, either due to debris-flow or channelized stream flow. In other cases, coarse sediments were stored within fans, and fines were transported downstream by sheet flows or sub-surface flows. In most of smaller colluvial fans and debris cones, sediments were delivered by mass movement processes (mainly rockfalls and snowfalls) and did not reach lower margin of landforms. Analysis of historical aerial photographs indicated recent increase in the activity of debris-flow modification of surface morphology of fans. Fans located outside limits of the Little Ice Age (LIA) glaciation are dominated by the secondary processes

  20. Gas-hydrate occurrence on the W-Svalbard margin at the gateway to the Arctic Ocean

    Science.gov (United States)

    Bünz, Stefan; Mienert, Jürgen

    2010-05-01

    Gas hydrates contain more carbon than does any other global reservoir and are abundant on continental margins worldwide. These two facts make gas hydrates important as a possible future energy resource, in submarine landsliding and in global climate change. With the ongoing global warming, there is a need for a better understanding of the distribution of gas hydrates and their sensitivity to environmental changes. Gas hydrate systems in polar latitudes may be of particular importance due to the fact that environmental changes will be felt here first and most likely are more extreme than elsewhere. The gas-hydrate systems offshore western Svalbard are far more extensive (~4000km^2) than previously assumed and include the whole Vestnesa Ridge, an elongated sediment drift north of the Molloy Transform and just east of the Molloy Ridge, one of the shortest segments of the slow spreading North-Atlantic Ridge system. However, in this peculiar setting gas hydrates also occur within few km of a mid-oceanic ridge and transform fault, which makes this gas hydrate system unique on Earth. The close proximity to the spreading centre and its hydrothermal circulation system affects the dynamics of the gas hydrate system. A strong cross-cutting BSR is visible, especially in areas of dipping seafloor. Other places show a weak almost subtle BSR. The base of gas-hydrate stability varies with distance from the ridge system, suggesting a strong temperature-controlled subsurface depth as the underlying young oceanic crust cools off eastward. High amplitude reflections over a depth range of up to 150m underneath the BSR indicate the presence of a considerable amount of free gas. The free gas is focused laterally upwards by the less-permeable hydrated sediments as the only fluid-escape features occur at the crest of the Vestnesa Ridge. The fluid migration system and its active plumbing system at the crest provide an efficient mechanism for gas escape from the base of the hydrate stability

  1. Ocean currents shape the microbiome of Arctic marine sediments.

    Science.gov (United States)

    Hamdan, Leila J; Coffin, Richard B; Sikaroodi, Masoumeh; Greinert, Jens; Treude, Tina; Gillevet, Patrick M

    2013-04-01

    Prokaryote communities were investigated on the seasonally stratified Alaska Beaufort Shelf (ABS). Water and sediment directly underlying water with origin in the Arctic, Pacific or Atlantic oceans were analyzed by pyrosequencing and length heterogeneity-PCR in conjunction with physicochemical and geographic distance data to determine what features structure ABS microbiomes. Distinct bacterial communities were evident in all water masses. Alphaproteobacteria explained similarity in Arctic surface water and Pacific derived water. Deltaproteobacteria were abundant in Atlantic origin water and drove similarity among samples. Most archaeal sequences in water were related to unclassified marine Euryarchaeota. Sediment communities influenced by Pacific and Atlantic water were distinct from each other and pelagic communities. Firmicutes and Chloroflexi were abundant in sediment, although their distribution varied in Atlantic and Pacific influenced sites. Thermoprotei dominated archaea in Pacific influenced sediments and Methanomicrobia dominated in methane-containing Atlantic influenced sediments. Length heterogeneity-PCR data from this study were analyzed with data from methane-containing sediments in other regions. Pacific influenced ABS sediments clustered with Pacific sites from New Zealand and Chilean coastal margins. Atlantic influenced ABS sediments formed another distinct cluster. Density and salinity were significant structuring features on pelagic communities. Porosity co-varied with benthic community structure across sites and methane did not. This study indicates that the origin of water overlying sediments shapes benthic communities locally and globally and that hydrography exerts greater influence on microbial community structure than the availability of methane.

  2. Origin and character of gaseous hydrocarbons in the hydrate and non-hydrate charged sediments on the Norway - Svalbard margins

    Energy Technology Data Exchange (ETDEWEB)

    Vaular, Espen Nesheim

    2011-05-15

    Gas incubated in clathrate water-structures, stabilizes the hydrogen bonded substance termed gas hydrate. In the marine environment vast amount of carbon is stored as gas hydrates within the temperature and pressure zone these ice-like structures are stable. Natural gas hydrate mapping and characterization is important basic research that brings about critical knowledge concerning various topics. Natural gas hydrates is a vital part of the carbon cycle, it is a potential energy resource (and thereby a potential climate agent) and it is a potential geo-hazard. One of the goals the GANS initiative aimed at exploring, was the hydrate bearing sediment of the Norway -Svalbard margins, to investigate the character and expansion of natural gas hydrates. Part of the investigation was to define how the gas in the hydrated sediment was produced and where it came from. As a result this thesis addresses the matter of light hydrocarbon characterization and origin in two Norwegian hydrate deposits. On cruises to Vestnesa on the Svalbard margin and to Nyegga in the mid-Norwegian margin, samples of hydrate charged and non-hydrate charged sediments were obtained and analyzed. Through compositional and isotopic analyses the origin of the hydrate bound gas in the fluid escape feature G11 at Nyegga was determined. The hydrate incubated methane is microbial produced as well as parts of the hydrate bound ethane. The compositional analysis in both the Nyegga area and at the Vestnesa Ridge points at thermogenic contributions in the sediment interstitials and pore water. The two hydrate bearing margins show large differences in hydrocarbon content and microbial activity in the pockmarks investigated. The gravity cores from the penetrated pockmark at Vestnesa showed low hydrocarbon content and thus suggest ceased or periodic venting. The fluid flow escape features at Nyegga show large variety of flux rates based on ROV monitoring and headspace analysis of the sediment and pore water. The

  3. Glaciomarine sedimentation and bottom current activity on the north-western and northern continental margins of Svalbard during the late Quaternary

    Science.gov (United States)

    Chauhan, Teena; Noormets, Riko; Rasmussen, Tine L.

    2016-04-01

    Palaeo-bottom current strength of the West Spitsbergen Current (WSC) and the influence of the Svalbard-Barents Sea Ice Sheet (SBIS) on the depositional environment along the northern Svalbard margins are poorly known. Two gravity cores from the southern Yermak Plateau and the upper slope north of Nordaustlandet, covering marine isotope stage (MIS) 1 to MIS 5, are investigated. Five lithofacies, based on grain size distribution, silt/clay ratio, content and mean of sortable silt (SS), are distinguished to characterise the contourite-dominated sedimentary environments. In addition, depositional environments are described using total organic carbon (TOC), total sulphur (TS) and calcium carbonate (CaCO3) contents of sediments. Facies A, containing coarse SS, suggests strong bottom current activity and good bottom water ventilation conditions as inferred from low TOC content. This facies was deposited during the glacial periods MIS 4, MIS 2 and during the late Holocene. Facies B is dominated by fine SS indicating weak bottom current and poor ventilation (cf. high TOC content of 1.2-1.6%), and correlates with the MIS 4/3 and MIS 2/1 transition periods. With an equal amount of clay and sand, fine SS and high content of TOC, facies C indicates reduced bottom current strength for intervals with sediment supply from proximal sources such as icebergs, sea ice or meltwater discharge. This facies was deposited during the last glacial maximum. Facies D represents mass-flow deposits on the northern Svalbard margin attributed to the SBIS advance at or near the shelf edge. Facies E sediments indicating moderate bottom current strength were deposited during MIS 5 and MIS 3, and during parts of MIS 2. This first late Quaternary proxy record of the WSC flow and sedimentation history from the northern Svalbard margin suggests that the oceanographic conditions and ice sheet processes have exerted first-order control on sediment properties.

  4. Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and significance for geotectonic interpretation of the High-Arctic Large Igneous Province

    Directory of Open Access Journals (Sweden)

    Zoltán Pécskay

    2011-08-01

    Full Text Available The dolerites of Svalbard are mineralogically and geochemically homogeneous with geochemical features typical of continental within-plate tholeiites. Their geochemistry is similar to tholeiites belonging to a bimodal suite defined as the High-Arctic Large Igneous Province (HALIP. K–Ar dating of numerous dolerites sampled from many locations across Svalbard define a narrow time span of this magmatism from 125.5±3.6 to 78.3±2.6 Mya. Discrete peaks of intensive activity occurred at 115.3, 100.8, 91.3 and 78.5 Mya corresponding to (1 breakup of the continental crust and formation of an initial rift as a result of mantle plume activity, located in the southern part of the Alpha Ridge; (2 magmatic activity related to spreading along the Alpha Ridge that led to the development of the initial oceanic crust and (3 continuation of spreading along the Alpha Ridge and termination of magmatic activity related to HALIP (last two peaks at 91.3 and 78.5 Mya.

  5. Late Weichselian and Holocene paleoceanography of Storfjordrenna, southern Svalbard

    Directory of Open Access Journals (Sweden)

    M. Łącka

    2014-08-01

    Full Text Available Multiproxy analyses (incl. benthic and planktonic foraminifera, δ18O and δ13C records, grain-size distribution, ice-rafted debris, XRF geochemistry and magnetic susceptibility were performed on a 14C dated marine sediment core from Storfjordrenna, off southern Svalbard. The sediments in the core cover the termination of Bølling–Allerød, the Younger Dryas and the Holocene, and they reflect general changes in the hydrology/climate of the European Arctic after the last glaciation. Grounded ice of the last Svalbard- Barents Sea Ice Sheet retreated from the coring site ca. 13 850 cal yr BP. During the transition from the sub-glacial to glacimarine setting, Arctic Waters dominated the hydrography in Storfjordrenna. However, the waters were not uniformly cold and experienced several warmer spells. A progressive warming and marked change in the nature of hydrology occurred during the early Holocene. Relatively warm and saline Atlantic Water started to dominate the hydrography from approx. 9500 cal yr BP. Even though the climate in eastern Svalbard was milder at that time than at present (smaller glaciers, there were two slight coolings observed in the periods of 9000–8000 cal yr BP and 6000–5500 cal yr BP. A change of the Storfjordrenna hydrology occurred at the beginning of late Holocene synchronously with glacier growth on land and enhanced bottom current velocities. Although cooling was observed in the surface water, Atlantic Water remained present in the deeper part of water column of Storfjordrenna.

  6. Arctic aerosol life cycle: linking aerosol size distributions observed between 2000 and 2010 with air mass transport and precipitation at Zeppelin station, Ny-Ålesund, Svalbard

    Directory of Open Access Journals (Sweden)

    P. Tunved

    2012-11-01

    Full Text Available In this study we present a qualitative and quantitative assessment of more the 10 yr of aerosol number size distribution data observed in the Arctic environment (Mt Zeppelin (78°56' N, 11°53' E, 474 m a.s.l., Ny Ålesund, Svalbard. We provide statistics on both seasonal and diurnal characteristics of the aerosol observations and conclude that the Arctic aerosol number size distribution and auxiliary parameters such as integral mass and surface have a very pronounced seasonal variation. This seasonal variation seems to be controlled by both dominating source as well as meteorological conditions in general. In principle, three distinctly different periods can be identified during the Arctic year: the haze period characterized by a dominating accumulation mode aerosol (March–May followed by the sunlit summer period with low abundance of accumulation mode particles but high concentration of small particles which likely are recently and locally formed (June–August. The rest of the year is characterized by comparably low concentration of accumulation mode particles and negligible abundance of ultra fine particles (September–February. Minimum aerosol mass and number concentration is usually observed during September/October. We further show that the transition between the different regimes is fast, suggesting rapid change in conditions defining their appearance. A source climatology based on trajectory analysis is provided and it is shown that there is a strong seasonality of dominating source areas, with dominance of Eurasia during the autumn-winter period and dominance of North Atlantic air during the summer months. We also show that new particle formation events seem to be a rather common phenomenon during the Arctic summer, and this is the result of both photochemical production of nucleating/condensing species and low condensation sink. It is also suggested that wet removal play a key role in defining the Arctic aerosol year, and plays a

  7. Longyearbyen, Svalbard, Norway

    Science.gov (United States)

    2008-01-01

    Longyearbyen is the administrative center of Svalbard and is located on Spitsbergen, the largest island of the Svalbard archipelago, part of the Kingdom of Norway. It is the world's northernmost town with over 1000 people. The settlement was founded in 1906 by John Longyear, owner of the Arctic Coal Company. Until the early 1990s the coal mining industry was the major employer of Longyearbyen. Near Longyearbyen, the Global Crop Diversity Trust administers the Svalbard Global Seed Vault, an Arctic safe capable of storing millions of crop seeds as a safeguard against natural and human disasters. Last week, the first deposit of 250,000 different species of crop seeds was made into the repository. The perspective view was created by draping a simulated natural color image over an ASTER-derived digital elevation model. The image was acquired July 12, 2003, and is located at 78.2 degrees north latitude, 15.6 degrees east longitude. The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  8. Suspended sediment in a high-Arctic river

    DEFF Research Database (Denmark)

    Ladegaard-Pedersen, Pernille; Sigsgaard, Charlotte; Kroon, Aart;

    2016-01-01

    Quantifying fluxes of water, sediment and dissolved compounds through Arctic rivers is important for linking the glacial, terrestrial and marine ecosystems and to quantify the impact of a warming climate. The quantification of fluxes is not trivial. This study uses a 8-years data set (2005......-1 and 61,000±16,000ty-1. Extreme events with high discharges had a mean duration of 1day. The average suspended sediment flux during extreme events was 17,000±5000ty-1, which constitutes a year-to-year variation of 20-37% of the total annual flux. The most accurate sampling strategy was bi......-agreements and accuracies variations in the measured suspended sediment concentrations. The discharge weighted mean...

  9. Soil pH is a Key Determinant of Soil Fungal Community Composition in the Ny-Ålesund Region, Svalbard (High Arctic).

    Science.gov (United States)

    Zhang, Tao; Wang, Neng-Fei; Liu, Hong-Yu; Zhang, Yu-Qin; Yu, Li-Yan

    2016-01-01

    This study assessed the fungal community composition and its relationships with properties of surface soils in the Ny-Ålesund Region (Svalbard, High Arctic). A total of thirteen soil samples were collected and soil fungal community was analyzed by 454 pyrosequencing with fungi-specific primers targeting the rDNA internal transcribed spacer (ITS) region. The following eight soil properties were analyzed: pH, organic carbon (C), organic nitrogen (N), ammonium nitrogen (NH4 (+)-N), silicate silicon (SiO4 (2-)-Si), nitrite nitrogen (NO2 (-)-N), phosphate phosphorus (PO4 (3-)-P), and nitrate nitrogen (NO3 (-)-N). A total of 57,952 reads belonging to 541 operational taxonomic units (OTUs) were found. of these OTUs, 343 belonged to Ascomycota, 100 to Basidiomycota, 31 to Chytridiomycota, 22 to Glomeromycota, 11 to Zygomycota, 10 to Rozellomycota, whereas 24 belonged to unknown fungi. The dominant orders were Helotiales, Verrucariales, Agaricales, Lecanorales, Chaetothyriales, Lecideales, and Capnodiales. The common genera (>eight soil samples) were Tetracladium, Mortierella, Fusarium, Cortinarius, and Atla. Distance-based redundancy analysis (db-rda) and analysis of similarities (ANOSIM) revealed that soil pH (p = 0.001) was the most significant factor in determining the soil fungal community composition. Members of Verrucariales were found to predominate in soils of pH 8-9, whereas Sordariales predominated in soils of pH 7-8 and Coniochaetales predominated in soils of pH 6-7. The results suggest the presence and distribution of diverse soil fungal communities in the High Arctic, which can provide reliable data for studying the ecological responses of soil fungal communities to climate changes in the Arctic.

  10. Heterotopisk Svalbard-krim

    Directory of Open Access Journals (Sweden)

    Lisbeth Pettersen Wærp

    2015-04-01

    Full Text Available How is the Arctic represented in modern crime fiction written by a female glaciologist, meterologist and polar explorer? Monica Kristensen is the author of a new, critically acclaimed, series of crime novels set in Svalbard. The first four novels of the series are Hollendergraven (2007, The Dutchman's Grave, Kullunge (2008, Coal Baby, Operasjon Fritham (2009, Operation Fritham, Den døde i Barentsburg (2011, The Dead Man in Barentsburg and Ekspedisjonen (2014, The Expedition. According to the publisher, Forlaget Press, the series, when completed, will consist of altogether 12 books. The originality of the series is the use of Svalbard as setting. The setting is not only spectacular, it is significant: Knowledge of nature and climate is of greatest importance to the characters, the protagonist, police officer (sysselmannsbetjent Knut Fjeld, as well as his various antagonists. Svalbard is not only a place in the Arctic, but also a group of islands. Both aspects are effectively exploited in Kristensen's novels. The representation of the Arctic archipelago is to a great extent based on the differences from other places, e.g. mainland Norway. The arcticle argues that the arctic archipelago as represented in these novels comes close to what French philosopher Michel Foucault calls heterotopia: A place that is totally different from other places, a place that represents the other, the deviant, and like the utopia and dystopia reflects the world of which it is an extension. Heterotopia is Foucault’s neologism (1967, and unlike the utopia/dystopia, the heterotopia actually exists. Within this theoretical framework the article presents a reading of the first five novels with special emphasis on the exploitation of place.

  11. Contrasting retinoid and thyroid hormone status in differentially-contaminated northern fulmar colonies from the Canadian Arctic, Svalbard and the Faroe Islands.

    Science.gov (United States)

    Verreault, Jonathan; Helgason, Lisa B; Gabrielsen, Geir W; Dam, Maria; Braune, Birgit M

    2013-02-01

    The northern fulmar (Fulmarus glacialis) has previously been shown to accumulate a wide range, and occasionally high concentrations of organochlorines (OCs) (e.g., PCBs, chlorobenzenes, DDT- and chlordane-related compounds, dioxins and furans). The present study aimed to investigate, using a meta-analysis approach, the variations in cytochrome P450 (CYP) 1A-like enzyme induction based on ethoxyresorufin O-deethylase activity (EROD) and selected physiological variables (retinoids and thyroid hormones) in northern fulmar breeding in three differentially OC-exposed populations: Nunavut (Canadian Arctic), Svalbard (Norwegian Arctic) and the Faroe Islands. Substantially higher (roughly two-fold) OC levels were uncovered in the liver of this long-lived fulmarine petrel breeding in the Faroe Islands relative to Svalbard and Nunavut. Liver levels of PCDDs, PCDFs and non-ortho PCBs in Faroe Islands fulmars were amongst the highest reported thus far in any seabirds from the northern regions. Positive correlations were depicted in combined fulmars (all three populations) between hepatic EROD activity and concentrations of OCs, in which strongest associations were found for dioxin-like compound (PCDFs and PCDDs) and TEQ concentrations. Moreover, moderate to strong positive correlations were found between liver OC concentrations and plasma total thyroxin (TT(4)) levels and TT(4)/total triiodothyronine (TT(3)) level ratios, as well as strong negative correlations between the same suite of OCs and plasma TT(3) levels. Hepatic OC concentrations (PCBs, PCDDs, PCDFs, HCB, p,p'-DDE and oxychlordane) also were positively correlated with hepatic retinyl palmitate levels which, in turn, were associated with a significant decrease in plasma retinol levels and somewhat unchanged liver retinol levels. The present meta-analysis investigation on northern fulmar breeding in three geographically-distant sites illustrated that OC exposure (mainly PCBs and dioxins/furans) may be associated with

  12. Changes in greening in the high Arctic: insights from a 30 year AVHRR max NDVI dataset for Svalbard

    Science.gov (United States)

    Vickers, Hannah; Arild Høgda, Kjell; Solbø, Stian; Rune Karlsen, Stein; Tømmervik, Hans; Aanes, Ronny; Hansen, Brage B.

    2016-10-01

    Satellite-aided studies of vegetation cover, biomass and productivity are becoming increasingly important for monitoring the effects of a changing climate on the biosphere. With their large spatial coverage and good temporal resolution, space-borne instruments are ideal to observe remote areas over extended time periods. However, long time series datasets with global coverage have in many cases too low spatial resolution for sparsely vegetated high latitude areas. This study has made use of a newly developed 30 year 1 km spatial resolution dataset from 1986 to 2015, provided by the NOAA AVHRR series of satellites, in order to calculate the annual maximum NDVI over parts of Svalbard (78°N). This parameter is indicative of vegetation productivity and has therefore enabled us to study long-term changes in greening within the Inner Fjord Zone on Svalbard. In addition, local meteorological data are available to link maximum NDVI values to the temporal behavior of the mean growing season (summer) temperature for the study area. Over the 30 year period, we find positive trends in both maximum NDVI (average increase of 29%) and mean summer temperature (59%), which were significantly positively correlated with each other. This suggests a temporal greening trend mediated by summer warming. However, as also recently reported for lower latitudes, the strength of the year-to-year correlation between maximum NDVI and mean summer temperature decreased, suggesting that the response of vegetation to summer warming has not remained the same over the entire study period.

  13. Trace elements and cathodoluminescence of detrital quartz in Arctic marine sediments – a new ice-rafted debris provenance proxy

    Directory of Open Access Journals (Sweden)

    A. Müller

    2013-07-01

    Full Text Available The records of ice-rafted debris (IRD provenance in the North Atlantic – Barents Sea allow the reconstruction of the spatial and temporal changes of ice-flow drainage patterns during glacial and deglacial periods. In this study a new approach to characterisation of the provenance of detrital quartz grains in the fraction > 500 μm of marine sediments offshore of Spitsbergen is introduced, utilizing scanning electron microscope backscattered electron and cathodoluminescence (CL imaging, combined with laser ablation inductively-coupled plasma mass spectrometry. Based on their micro-inclusions, CL and trace element characteristics the investigated IRD grains can be classified into five distinct populations. Three of the populations are indicative of potential IRD provenance provinces in the Storfjord area including Barentsøya and Egdeøya. The results imply that under modern (interglacial conditions IRD deposition along the western Spitsbergen margin is mainly governed by the East Svalbard Current controlling the ice-drift pattern. The presence of detrital quartz from local provinces, however, indicates that variations in IRD supply from western Spitsbergen may be quantified as well. In this pilot study it is demonstrated that this new approach applied on Arctic continental margin sediments, bears a considerable potential for the definition of the sources of IRD and thus of spatial/temporal changes in ice-flow drainage patterns during glacial/interglacial cycles.

  14. Desulfotomaculum arcticum sp nov., a novel spore-formin, moderately thermophilic, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard

    DEFF Research Database (Denmark)

    Vandieken, V.; Knoblauch, C.; Jørgensen, BB

    2006-01-01

    Strain 15 T is a novel spore-forming, sulfate-reducing bacterium isolated from a permanently cold fjord sediment of Svalbard. Sulfate could be replaced by sulfite or thiosulfate. Hydrogen, formate, lactate, propionate, butyrate, hexanoate, methanol, ethanol, propanol, butanol, pyruvate, malate, s...... related to Desulfotomaculum thermosapovorans MLF(T) (93-5% 16S rRNA gene sequence similarity). Strain 15 T represents a novel species, for which the name Desulfotomaculurn arcticum sp. nov. is proposed. The type strain is strain 15 T (=DSM 17038(T)=jCM 12923(T))....

  15. Taxonomic characterization, adaptation strategies and biotechnological potential of cryophilic yeasts from ice cores of Midre Lovénbreen glacier, Svalbard, Arctic.

    Science.gov (United States)

    Singh, Purnima; Tsuji, Masaharu; Singh, Shiv Mohan; Roy, Utpal; Hoshino, Tamotsu

    2013-04-01

    Ten strains of cryophilic yeast were studied from glacier ice cores of Svalbard, Arctic. The ice melt samples contained about 3×10(3) - 1×10(4) colony forming unit (CFUs) per ml. Sequence analysis of the isolates, using D1/D2 domain identified five species of yeasts: Cryptococcus adeliensis (MLB-18 JX192655), Cryptococcus albidosimilis (MLB-19 JX192656), Cryptococcus saitoi (MLB-22 JX192659), Rhodosporidium lusitaniae (MLB-20 JX192657), and Rhodotorula mucilaginosa (MLB-27 JX192664). Effect of temperature on growth of these isolates was studied. The strains are able to grow at temperatures ranging between 1 and 20°C. Screening of the cultures for amylase, cellulase, protease, lipase, urease and catalase activity were carried out indicating varying amounts of enzyme production at different temperatures. Characterization of lipase in strain Cryptococcus sp. MLB-24 was performed. Fatty acid methyl ester (FAME) analysis of the cultures grown at four different temperatures (1, 4, 15, and 20°C) was also done. Decrease in temperature was reported to cause increase in concentration of unsaturated fatty acids. High amount of oleic acid accumulated with increase in temperature. These fatty acids possibly help the strains to survive in glacial ice core cold environment. The extracellular and intracellular filtrate of the cultures showed negative antifreeze protein (AFP) activity. The observations indicate that probably the isolates in the present undertaking adapt to low temperatures, by enzyme and PUFA secretion rather than by antifreeze protein secretion.

  16. Evolved Gas Analysis and X-Ray Diffraction of Carbonate Samples from the 2009 Arctic Mars Analog Svalbard Expedition: Implications for Mineralogical Inferences from the Mars Science Laboratory

    Science.gov (United States)

    McAdam, A. C.; Mahaffy, P. R.; Blake, D. F.; Ming, D. W.; Franz, H. B.; Eigenbrode, J. L.; Steele, A.

    2010-01-01

    The 2009 Arctic Mars Analog Svalbard Expedition (AMASE) investigated several geologic settings using methodologies and techniques being developed or considered for future Mars missions, such as the Mars Science Laboratory (MSL), ExoMars, and Mars Sample Return (MSR). AMASE-related research comprises both analyses conducted during the expedition and further analyses of collected samples using laboratory facilities at a variety of institutions. The Sample Analysis at Mars (SAM) instrument suite, which will be part of the Analytical Laboratory on MSL, consists of a quadrupole mass spectrometer (QMS), a gas chromatograph (GC), and a tunable laser spectrometer (TLS). An Evolved Gas Analysis Mass Spectrometer (EGA-MS) was used during AMASE to represent part of the capabilities of SAM. The other instrument included in the MSL Analytical Laboratory is CheMin, which uses X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) to perform quantitative mineralogical characterization of samples. Field-portable versions of CheMin were used during the AMASE 2009. Here, we discuss the preliminary interpretation of EGA and XRD analyses of selected AMASE carbonate samples and implications for mineralogical interpretations from MSL. Though CheMin will be the primary mineralogical tool on MSL, SAM EGA could be used to support XRD identifications or indicate the presence of volatile-bearing minerals which may be near or below XRD detection limits. Data collected with instruments in the field and in comparable laboratory setups (e.g., the SAM breadboard) will be discussed.

  17. An Inter-Comparison of Techniques for Determining Velocities of Maritime Arctic Glaciers, Svalbard, Using Radarsat-2 Wide Fine Mode Data

    Directory of Open Access Journals (Sweden)

    Thomas Schellenberger

    2016-09-01

    Full Text Available Glacier dynamics play an important role in the mass balance of many glaciers, ice caps and ice sheets. In this study we exploit Radarsat-2 (RS-2 Wide Fine (WF data to determine the surface speed of Svalbard glaciers in the winters of 2012/2013 and 2013/2014 using Synthetic Aperture RADAR (SAR offset and speckle tracking. The RS-2 WF mode combines the advantages of the large spatial coverage of the Wide mode (150 × 150 km and the high pixel resolution (9 m of the Fine mode and thus has a major potential for glacier velocity monitoring from space through offset and speckle tracking. Faster flowing glaciers (1.95 m·d−1–2.55 m·d−1 that are studied in detail are Nathorstbreen, Kronebreen, Kongsbreen and Monacobreen. Using our Radarsat-2 WF dataset, we compare the performance of two SAR tracking algorithms, namely the GAMMA Remote Sensing Software and a custom written MATLAB script (GRAY method that has primarily been used in the Canadian Arctic. Both algorithms provide comparable results, especially for the faster flowing glaciers and the termini of slower tidewater glaciers. A comparison of the WF data to RS-2 Ultrafine and Wide mode data reveals the superiority of RS-2 WF data over the Wide mode data.

  18. Organic carbon degradation in arctic marine sediments, Svalbard: A comparison of initial and terminal steps

    DEFF Research Database (Denmark)

    Arnosti, C.; Jørgensen, BB

    2006-01-01

    . Polysaccharide hydrolysis rates exhibited substrate-related and, to a lesser extent, depth-related differences (p fucoidan hydrolysis was least rapid. Although there was a high degree of variability in parallel cores...

  19. Characteristics of Arctic winds at CANDAC-PEARL (80 N, 86 W) and Svalbard (78 N, 16 E) for 2006-2009. Radar observations and comparisons with the model CMAM-DAS

    Energy Technology Data Exchange (ETDEWEB)

    Manson, A.H.; Meek, C.E.; Xu, X. [Saskatchewan Univ., Saskatoon (Canada). Inst. of Space and Atmospheric Studies; Aso, T.; Tsutsumi, M. [National Institute for Polar Research, Tokyo (Japan); Drummond, J.R. [Dalhousie Univ., Halifax (Canada). Physics and Atmospheric Science Dept.; Hall, C.M. [Tromsoe Univ. (Norway). Tromsoe Geophysical Observatory; Hocking, W.K. [Western Onatario Univ., London (Canada). Physics and Astronomy Dept.; Ward, W.E. [New Brunswick Univ., Fredericton (Canada). Physics and Astronomy Dept.

    2011-07-01

    Operation of a Meteor Wind Radar (MWR) at Eureka, Ellesmere Island (80 N, 86 W) began in February 2006; this is the location of the Polar Environmental and Atmospheric Research Laboratory (PEARL), operated by the ''Canadian Network for the Detection of Atmospheric Change'' (CANDAC). The first 36 months of wind data (82- 97 km) are here combined with contemporaneous winds from the Meteor Wind Radar at Adventdalen, Svalbard (78 N, 16 E), to provide the first evidence for substantial interannual variability (IAV) of longitudinally spaced observations of mean/background winds and waves at such High Arctic latitudes. The influences of ''Sudden Stratospheric Warmings'' (SSW) are also apparent. Monthly meridional (north-south, NS) 3-year means for each location/radar demonstrate that winds (82-97 km) differ significantly between Canada and Norway, with winterequinox values generally northward over Eureka and southward over Svalbard. Using January 2008 as case study, these oppositely directed meridional winds are related to mean positions of the Arctic mesospheric vortex. The vortex is from the Canadian Middle Atmosphere Model, with its Data Assimilation System (CMAM-DAS). The characteristics of ''Sudden stratospheric Warmings'' SSW in each of the three winters are noted, as well as their uniquely distinctive short-term mesospheric wind disturbances. Comparisons of the mean winds over 36 months at 78 and 80 N, with those within CMAM-DAS, are featured. E.g. for 2007, while both monthly mean EW and NS winds from CMAM/radar are quite similar over Eureka (82-88 km), the modeled autumn-winter NS winds over Svalbard (73-88 km) differ significantly from observations. The latter are southward, and the modeled winds over Svalbard are predominately northward. The mean positions of the winter polar vortex are related to these differences. (orig.)

  20. Diagenetic regimes in Arctic Ocean sediments: Implications for sediment geochemistry and core correlation

    Science.gov (United States)

    Meinhardt, A.-K.; März, C.; Schuth, S.; Lettmann, K. A.; Schnetger, B.; Wolff, J.-O.; Brumsack, H.-J.

    2016-09-01

    Dark brown sediment layers are a potential stratigraphic tool in Quaternary Arctic Ocean sediments. They are rich in Mn, Fe, and trace metals scavenged from the water column and were most likely deposited during interglacial intervals. In this study, we combine sediment and pore water data from sediment cores taken in different parts of the Arctic Ocean to investigate the influence of early diagenetic processes on sediment geochemistry. In most studied cores, Mn, Co, and Mo are released into the pore waters from Mn oxide dissolution in deeper (>1.5 m) sediment layers. The relationship between sedimentary Mn, Co, and Mo contents in excess of the lithogenic background (elementxs) shows that Coxs/Moxs values are a diagnostic tool to distinguish between layers with diagenetic metal addition from the pore waters (Coxs/Moxs 10), and unaffected layers (Coxs/Moxs from 1 to 10). Steady-state calculations based on current pore water profiles reveal that in the studied cores, the diagenetic addition of these metals from the pore water pool alone is not sufficient to produce the sedimentary metal enrichments. However, it seems evident that dissolution of Mn oxides in the Mn reduction zone can permanently alter the primary geochemical signature of the dark brown layers. Therefore, pore water data and Coxs/Moxs values should be considered before core correlation when this correlation is solely based on Mn contents and dark sediment color. In contrast to the mostly non-lithogenic origin of Mn in the dark brown layers, sedimentary Fe consists of a large lithogenic (80%) and a small non-lithogenic fraction (20%). Our pore water data show that diagenetic Fe remobilization is not currently occurring in the sediment. The dominant Fe sources are coastal erosion and river input. Budget calculations show that Fe seems to be trapped in the modern Arctic Ocean and accumulates in shelf and basin sediments. The Fe isotopic signal δ56Fe of the solid phase is positive (∼0.2-0.3‰) in

  1. Arctic soil development on a series of marine terraces on central Spitsbergen, Svalbard: a combined geochronology, fieldwork and modelling approach

    NARCIS (Netherlands)

    Meij, van der W.M.; Temme, A.J.A.M.; Kleijn, de Christian; Reimann, T.; Heuvelink, G.B.M.; Zwoliński, Zbigniew; Rachlewicz, Grzegorz; Rymer, Krzysztof; Sommer, Michael

    2016-01-01

    Soils in Arctic regions currently enjoy attention because of their sensitivity to climate change. It is therefore important to understand the natural processes and rates of development of these soils. Specifically, there is a need to quantify the rates and interactions between various landscape- and

  2. Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard

    DEFF Research Database (Denmark)

    Semenchuk, Philipp R.; Elberling, Bo; Cooper, Elisabeth J.

    2013-01-01

    frequent extreme winter warming events. Flower production of many Arctic plants is dependent on melt out timing, since season length determines resource availability for flower preformation. We erected snow fences to increase snow depth and shorten growing season, and counted flowers of six species over 5...

  3. Exploring the role of shelf sediments in the Arctic Ocean in determining the Arctic contamination potential of neutral organic contaminants.

    Science.gov (United States)

    Armitage, James M; Choi, Sung-Deuk; Meyer, Torsten; Brown, Trevor N; Wania, Frank

    2013-01-15

    The main objective of this study was to model the contribution of shelf sediments in the Arctic Ocean to the total mass of neutral organic contaminants accumulated in the Arctic environment using a standardized emission scenario for sets of hypothetical chemicals and realistic emission estimates (1930-2100) for polychlorinated biphenyl congener 153 (PCB-153). Shelf sediments in the Arctic Ocean are shown to be important reservoirs for neutral organic chemicals across a wide range of partitioning properties, increasing the total mass in the surface compartments of the Arctic environment by up to 3.5-fold compared to simulations excluding this compartment. The relative change in total mass for hydrophobic organic chemicals with log air-water partition coefficients ≥0 was greater than for chemicals with properties similar to typical POPs. The long-term simulation of PCB-153 generated modeled concentrations in shelf sediments in reasonable agreement with available monitoring data and illustrate that the relative importance of shelf sediments in the Arctic Ocean for influencing surface ocean concentrations (and therefore exposure via the pelagic food web) is most pronounced once primary emissions are exhausted and secondary sources dominate. Additional monitoring and modeling work to better characterize the role of shelf sediments for contaminant fate is recommended.

  4. Current status, between-year comparisons and maternal transfer of organohalogenated compounds (OHCs) in Arctic char (Salvelinus alpinus) from Bjørnøya, Svalbard (Norway)

    Energy Technology Data Exchange (ETDEWEB)

    Bytingsvik, J., E-mail: jenny.bytingsvik@akvaplan.niva.no [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Frantzen, M. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Götsch, A.; Heimstad, E.S. [NILU (Norwegian Institute for Air Research), The Fram Centre, N-9296 Tromsø Norway (Norway); Christensen, G. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Evenset, A. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); University of Tromsø, The Arctic University of Norway, Pb 6050 Langnes, N-9037 Tromsø (Norway)

    2015-07-15

    High levels of organohalogenated compounds (OHCs) have been found in Arctic char from Lake Ellasjøen at Bjørnøya (Svalbard, Norway) compared to char from other arctic lakes. The first aim of the study was to investigate the OHC status, contaminant profile, and partitioning of OHCs between muscle and ovary tissue in spawning female char from the high-polluted Lake Ellasjøen and the low-polluted Lake Laksvatn. The second aim was to investigate if OHC levels in muscle tissue have changed over time. Between-lake comparisons show that the muscle levels (lipid weight) of hexachlorobenzene (HCB), chlordanes (∑ CHLs), mirex, dichlorodiphenyltrichloroethanes (∑ DDTs) and polychlorinated biphenyls (∑ PCBs) were up to 36 times higher in char from Ellasjøen than in Laksvatn, and confirm that the char from Ellasjøen are still heavily exposed compared to char from neighboring lake. A higher proportion of persistent OHCs were found in Ellasjøen compared to Laksvatn, while the proportion of the less persistent OHCs was highest in Laksvatn. A between-year comparison of OHC levels (i.e., HCB, DDTs, PCBs) in female and male char shows higher levels of HCB in female char from Ellasjøen in 2009/2012 compared to in 1999/2001. No other between-year differences in OHC levels were found. Due to small study groups, findings associated with between-year differences in OHC levels should be interpreted with caution. OHCs accumulate in the lipid rich ovaries of spawning females, resulting in up to six times higher levels of OHCs in ovaries compared to in muscle (wet weight). The toxic equivalent (TEQ)-value for the dioxin-like PCBs (PCB-105 and -118) in ovaries of the Ellasjøen char exceeded levels associated with increased egg mortality in rainbow trout (Oncorhynchus mykiss). Hence, we suggest that future studies should focus on the reproductive health and performance abilities of the high-exposed population of char inhabiting Lake Ellasjøen. - Highlights: • Examine levels

  5. Landscape imprints of changing glacial regimes during ice sheet build-up and decay: A study from Svalbard, Norwegian Arctic

    Science.gov (United States)

    Landvik, J. Y.; Alexanderson, H.; Henriksen, M.; Ingolfsson, O.

    2013-12-01

    Ice sheet behavior and their geologic imprints in fjord regions are often multifaceted. Fjords, which were temporarily occupied by fast flowing outlet glaciers or ice streams during major glaciations, and inter-fjord areas, which were covered by less active ice, show different signatures of past glaciations. The land and marine records of glaciations over the western Svalbard fjord region have been extensively studied during the last few decades. We have re-examined ice flow records from stratigraphic and geomorphic settings, and propose a succession of ice flow styles that occurred repeatedly over the glacial cycles: the maximum, the transitional, and the local flow style. The different topographically constrained segments of the ice sheet switched behavior as glacial dynamics changed during each glacial cycle. These segments, as well as the different flow styles, are reflected differently in the offshore stratigraphic record. We propose that the glacial geomorphological signatures in the inter ice-stream areas mostly developed under warm-based conditions during a late phase of the glaciations, and that the overall glacial imprints in the landscape are strongly biased towards the youngest events.

  6. A comparison of annual and seasonal carbon dioxide effluxes between subarctic Sweden and high-arctic Svalbard

    DEFF Research Database (Denmark)

    Björkman, Mats P.; Morgner, Elke; Björk, Robert G.;

    2010-01-01

    effluxes between snow regimes or vegetation types, indicating that spatial variability in winter soil CO2 effluxes are not directly linked to snow cover thickness or soil temperatures. Total winter emissions (0.004– 0.248 kg CO2 m–2) were found to be in the lower range of those previously described......Recent climate change predictions suggest altered patterns of winter precipitation across the Arctic. It has been suggested that the presence, timing and quantity of snow all affect microbial activity, thus influencing CO2 production in soil. In this study annual and seasonal emissions of CO2 were...... in order to evaluate the effect of snow depth on winter CO2 effluxes. Total annual emissions of CO2 from the sub-Arctic site (0.662–1.487 kg CO2 m–2 yr–1) were found to be more than double the emissions from the High-Arctic site (0.369–0.591 kg CO2 m–2 yr–1). There were no significant differences in winter...

  7. Response of Methanogens in Arctic Sediments to Temperature and Methanogenic Substrate Availability.

    Science.gov (United States)

    Blake, Lynsay I; Tveit, Alexander; Øvreås, Lise; Head, Ian M; Gray, Neil D

    2015-01-01

    Although cold environments are major contributors to global biogeochemical cycles, comparatively little is known about their microbial community function, structure, and limits of activity. In this study a microcosm based approach was used to investigate the effects of temperature, and methanogenic substrate amendment, (acetate, methanol and H2/CO2) on methanogen activity and methanogen community structure in high Arctic wetlands (Solvatnet and Stuphallet, Svalbard). Methane production was not detected in Stuphallet sediment microcosms (over a 150 day period) and occurred within Solvatnet sediments microcosms (within 24 hours) at temperatures from 5 to 40°C, the maximum temperature being at far higher than in situ maximum temperatures (which range from air temperatures of -1.4 to 14.1°C during summer months). Distinct responses were observed in the Solvatnet methanogen community under different short term incubation conditions. Specifically, different communities were selected at higher and lower temperatures. At lower temperatures (5°C) addition of exogenous substrates (acetate, methanol or H2/CO2) had no stimulatory effect on the rate of methanogenesis or on methanogen community structure. The community in these incubations was dominated by members of the Methanoregulaceae/WCHA2-08 family-level group, which were most similar to the psychrotolerant hydrogenotrophic methanogen Methanosphaerula palustris strain E1-9c. In contrast, at higher temperatures, substrate amendment enhanced methane production in H2/CO2 amended microcosms, and played a clear role in structuring methanogen communities. Specifically, at 30°C members of the Methanoregulaceae/WCHA2-08 predominated following incubation with H2/CO2, and Methanosarcinaceaeand Methanosaetaceae were enriched in response to acetate addition. These results may indicate that in transiently cold environments, methanogen communities can rapidly respond to moderate short term increases in temperature, but not

  8. Response of Methanogens in Arctic Sediments to Temperature and Methanogenic Substrate Availability.

    Directory of Open Access Journals (Sweden)

    Lynsay I Blake

    Full Text Available Although cold environments are major contributors to global biogeochemical cycles, comparatively little is known about their microbial community function, structure, and limits of activity. In this study a microcosm based approach was used to investigate the effects of temperature, and methanogenic substrate amendment, (acetate, methanol and H2/CO2 on methanogen activity and methanogen community structure in high Arctic wetlands (Solvatnet and Stuphallet, Svalbard. Methane production was not detected in Stuphallet sediment microcosms (over a 150 day period and occurred within Solvatnet sediments microcosms (within 24 hours at temperatures from 5 to 40°C, the maximum temperature being at far higher than in situ maximum temperatures (which range from air temperatures of -1.4 to 14.1°C during summer months. Distinct responses were observed in the Solvatnet methanogen community under different short term incubation conditions. Specifically, different communities were selected at higher and lower temperatures. At lower temperatures (5°C addition of exogenous substrates (acetate, methanol or H2/CO2 had no stimulatory effect on the rate of methanogenesis or on methanogen community structure. The community in these incubations was dominated by members of the Methanoregulaceae/WCHA2-08 family-level group, which were most similar to the psychrotolerant hydrogenotrophic methanogen Methanosphaerula palustris strain E1-9c. In contrast, at higher temperatures, substrate amendment enhanced methane production in H2/CO2 amended microcosms, and played a clear role in structuring methanogen communities. Specifically, at 30°C members of the Methanoregulaceae/WCHA2-08 predominated following incubation with H2/CO2, and Methanosarcinaceaeand Methanosaetaceae were enriched in response to acetate addition. These results may indicate that in transiently cold environments, methanogen communities can rapidly respond to moderate short term increases in temperature, but

  9. Field Characterization of the Mineralogy and Organic Chemistry of Carbonates from the 2010 Arctic Mars Analog Svalbard Expedition by Evolved Gas Analysis

    Science.gov (United States)

    McAdam, A. C.; Ten Kate, I. L.; Stern, J. C.; Mahaffy, P. R.; Blake, D. F.; Morris, R. V.; Steele, A.; Amundson, H. E. F.

    2011-01-01

    The 2010 Arctic Mars Analog Svalbard Expedition (AMASE) investigated two geologic settings using methodologies and techniques being developed or considered for future Mars missions, such as the Mars Science Laboratory (MSL), ExoMars, and Mars Sample Return. The Sample Analysis at Mars (SAM) [1] instrument suite, which will be on MSL, consists of a quadrupole mass spectrometer (QMS), a gas chromatograph (GC), and a tunable laser mass spectrometer (TLS); all will be applied to analyze gases created by pyrolysis of samples. During AMASE, a Hiden Evolved Gas Analysis-Mass Spectrometer (EGA-MS) system represented the EGA-MS capability of SAM. Another MSL instrument, CheMin, will use x-ray diffraction (XRD) and x-ray fluorescence (XRF) to perform quantitative mineralogical characterization of samples [e.g., 2]. Field-portable versions of CheMin were used during AMASE. AMASE 2010 focused on two sites that represented biotic and abiotic analogs. The abiotic site was the basaltic Sigurdfjell vent complex, which contains Mars-analog carbonate cements including carbonate globules which are excellent analogs for the globules in the ALH84001 martian meteorite [e.g., 3, 4]. The biotic site was the Knorringfjell fossil methane seep, which featured carbonates precipitated in a methane-supported chemosynthetic community [5]. This contribution focuses on EGA-MS analyses of samples from each site, with mineralogy comparisons to CheMin team results. The results give insight into organic content and organic-mineral associations, as well as some constraints on the minerals present.

  10. Arctic soil development on a series of marine terraces on central Spitsbergen, Svalbard: a combined geochronology, fieldwork and modelling approach

    Science.gov (United States)

    van der Meij, W. Marijn; Temme, Arnaud J. A. M.; de Kleijn, Christian M. F. J. J.; Reimann, Tony; Heuvelink, Gerard B. M.; Zwoliński, Zbigniew; Rachlewicz, Grzegorz; Rymer, Krzysztof; Sommer, Michael

    2016-06-01

    Soils in Arctic regions currently enjoy attention because of their sensitivity to climate change. It is therefore important to understand the natural processes and rates of development of these soils. Specifically, there is a need to quantify the rates and interactions between various landscape- and soil-forming processes. Soil chronosequences are ideal natural experiments for this purpose. In this contribution, we combine field observations, luminescence dating and soil-landscape modelling to improve and test our understanding of Arctic soil formation. The field site is a Holocene chronosequence of gravelly raised marine terraces in central Spitsbergen. Field observations show that soil-landscape development is mainly driven by weathering, silt translocation, aeolian deposition and rill erosion. Spatial soil variation is mainly caused by soil age, morphological position within a terrace and depth under the surface. Luminescence dating confirmed existing radiocarbon dating of the terraces, which are between ˜ 1.5 and ˜ 13.3 ka old. The soil-landscape evolution model LORICA was used to test our hypothesis that the field-observed processes indeed dominate soil-landscape development. Model results additionally indicated the importance of aeolian deposition as a source of fine material in the subsoil for both sheltered and vegetated trough positions and barren ridge positions. Simulated overland erosion was negligible. Consequently, an un-simulated process must be responsible for creating the observed erosion rills. Dissolution and physical weathering both play a major role. However, using present-day soil observations, the relative contribution of physical and chemical weathering could not be disentangled. Discrepancies between field and model results indicate that soil formation is non-linear and driven by spatially and temporally varying boundary conditions which were not included in the model. To conclude, Arctic soil and landscape development appears to be more

  11. In-situ calibration and validation of Cryosat-2 observations over arctic sea ice north of Svalbard

    DEFF Research Database (Denmark)

    Gerland, Sebastian; Renner, Angelika H. H.; Spreen, Gunnar

    photography. Measurements from a Twin-Otter aircraft carrying a laser scanner and the CryoSat airborne simulator ASIRAS were obtained over one sea ice station. Here we discuss effects of snow properties on the penetration of the radar signal into the snow pack, along with in-situ, helicopter, and aircraft......CryoSat-2's radar altimeter allows to observe the panArctic sea ice thickness up to 88°N on a monthly basis. However, calibration and validation are crucial to assess limitations and accuracy of the altimeter, and to better quantify the uncertainties involved in converting sea ice freeboard...

  12. Lidar Observations of Arctic Aerosols and Clouds in the Free Troposphere for More than Fifteen Months over Svalbard

    Science.gov (United States)

    Shibata, T.; Shiraishi, K.; Iwasaki, S.; Shiobara, M.; Takano, T.

    2015-12-01

    The information on spatial distributions and microphysical properties of aerosols and clouds is crucial for the studies on their direct and indirect impacts on Arctic climate. Observations of tropospheric aerosols and clouds by Mie/depolarization lidar have been made for more than a year at Ny-Ålesund (79◌N, 12◌E) since March 2014 by using a pulsed Nd:YAG laser and its wavelengths of 1064 nm and 532 nm. The backscattering coefficients at these two wavelengths, and depolarization ratio at 532nm of aerosols and clouds are obtained by the lidar observations. Figures show the results of aerosols for more than a year. Fig. 1 shows the mean backscattering coefficient of aerosols (BSC) at 532 nm, and Fig. 2 shows mean particle depolarization ratio of aerosols (PDR) at 532 nm in 1 km intervals (0.4 km for the lowest height interval) to 5 km in altitude since March 2014 to May 2015. There is a maximum in backscattering coefficient at spring as indicated by previous studies on Arctic aerosols. In addition, there is another maximum at autumn in depolarization ratio and in color ratio, or the ratio of BSC at 1064 nm to BSC at 532 nm.

  13. Impacts of coal dust from an active mine on the spectral reflectance of Arctic surface snow in Svalbard, Norway

    Science.gov (United States)

    Khan, Alia L.; Dierssen, Heidi; Schwarz, Joshua P.; Schmitt, Carl; Chlus, Adam; Hermanson, Mark; Painter, Thomas H.; McKnight, Diane M.

    2017-02-01

    Light-absorbing particles (LAPs) in snow such as dust and black carbon influence the radiative forcing at the Earth's surface, which has major implications for global climate models. LAPs also significantly influence the melting of glaciers, sea ice, and seasonal snow. Here we present an in situ study of surface snow near an active coal mine in the Norwegian Arctic. We couple measurements of spectral hemispherical directional reflectance factor (HDRF) with measurements of LAPs characterized in two ways, as refractory black carbon using a Single Particle Soot Photometer and the total light absorption of LAPs measured with the Light Absorption Heating Method. The Snow Ice and Aerosol Radiation model was constrained by LAP measurements. Results were compared to observed spectral albedo measurements. Modeled and observed albedos were similar at the cleaner and more remote sites. However, the modeled spectral albedos do not fully account for the low spectral albedo measured next to the mine. LAP measurements also showed a large variation in particle sizes (tenths to tens of microns) related to transport distance of the particles from the mine. Here we find that LAPs from coal dust reduce the spectral HDRF by up to 84% next to the mine and 55% 0.5 km downwind of the mine. The coupling of extreme LAP observations (1 ng g-1 to 4863 ng g-1) with HDRF measurements from 350 to 2500 nm has facilitated the development of spectral band pairs, which could be used in the future to remotely assess LAPs in Arctic snow.

  14. Quantification of the ice-cored moraines' short-term dynamics in the high-Arctic glaciers Ebbabreen and Ragnarbreen, Petuniabukta, Svalbard

    Science.gov (United States)

    Ewertowski, Marek W.; Tomczyk, Aleksandra M.

    2015-04-01

    Extensive ice-cored moraine complexes are common elements, marking the last advance of many Svalbard glaciers. Sediment gravity flows are among the most dynamic processes, transforming these landforms. The short-term (yearly and weekly) dynamics of mass-wasting processes were studied in a cm-scale using repetitive topographic scanning. We monitored several active sites on the forelands of two glaciers, Ebbabreen and Ragnarbreen, both of which are located near Petuniabukta at the northern end of Billefjorden in Spitsbergen. The surveys indicate high dynamic rates of landforms' transformation. The mean annual volume loss of sediments and dead-ice for the most active parts of the moraines was up to 1.8 m a- 1. However, most of the transformation occurred during summer, with the short-term values of mean elevation changes as high as - 104 mm day- 1. In comparison, the dynamics of the other (i.e. non-active) parts of the ice-cored moraines were much lower, namely, the mean annual lowering (attributed mainly to dead-ice downwasting) was up to 0.3 m a-1, whereas lowering during summer was up to 8 mm day- 1. Our results indicate that in the case of the studied glaciers, backwasting was much more effective than downwasting in terms of landscape transformation in the glacier forelands. However, despite the high activity of localised mass movement processes, the overall short-term dynamics of ice-cored moraines for the studied glaciers were relatively low. We suggest that as long as debris cover is sufficiently thick (thicker than the permafrost's active layer depths), the mass movement activity would occur only under specific topographic conditions and/or due to occurrence of external meltwater sources and slope undercutting. In other areas, ice-cored moraines remain a stable landsystem component in a yearly to decadal time-scale.

  15. Tectonic Map of the Ellesmerian and Eurekan deformation belts on Svalbard, North Greenland and the Queen Elizabeth Islands (Canadian Arctic)

    Science.gov (United States)

    Piepjohn, Karsten; von Gosen, Werner; Tessensohn, Franz; Reinhardt, Lutz; McClelland, William C.; Dallmann, Winfried; Gaedicke, Christoph; Harrison, Christopher

    2016-04-01

    The tectonic map presented here shows the distribution of the major post-Ellesmerian and pre-Eurekan sedimentary basins, parts of the Caledonian Orogen, the Ellesmerian Fold-and-Thrust Belt, structures of the Cenozoic Eurekan deformation, and areas affected by the Eurekan overprint. The present continental margin of North America towards the Arctic Ocean between the Queen Elizabeth Islands and Northeast Greenland and the present west margin of the Barents Shelf are characterized by the Paleozoic Ellesmerian Fold-and-Thrust Belt, the Cenozoic Eurekan deformation, and, in parts, the Caledonian Orogen. In many areas, the structural trends of the Ellesmerian and Eurekan deformations are more or less parallel, and often, structures of the Ellesmerian Orogeny are affected or reactivated by the Eurekan deformation. While the Ellesmerian Fold-and-Thrust Belt is dominated by orthogonal compression and the formation of wide fold-and-thrust zones on Ellesmere Island, North Greenland and Spitsbergen, the Eurekan deformation is characterized by a complex network of regional fold-and-thrust belts (Spitsbergen, central Ellesmere Island), large distinct thrust zones (Ellesmere Island, North Greenland) and a great number of strike-slip faults (Spitsbergen, Ellesmere Island). The Ellesmerian Fold-and-Thrust Belt was most probably related to the approach and docking of the Pearya Terrane (northernmost part of Ellesmere Island) and Spitsbergen against the north margin of Laurasia (Ellesmere Island/North Greenland) in the earliest Carboniferous. The Eurekan deformation was related to plate tectonic movements during the final break-up of Laurasia and the opening of Labrador Sea/Baffin Bay west, the Eurasian Basin north, and the Norwegian/Greenland seas east of Greenland. The tectonic map presented here shows the German contribution to the Tectonic Map of the Arctic 1:5,000,000 (TeMAr) as part of the international project "Atlas of geological maps of Circumpolar Arctic at 1

  16. Patterns of extracellular enzyme activities and microbial metabolism in an Arctic fjord of Svalbard and in the northern Gulf of Mexico: contrasts in carbon processing by pelagic microbial communities.

    Science.gov (United States)

    Arnosti, Carol; Steen, Andrew D

    2013-01-01

    The microbial community composition of polar and temperate ocean waters differs substantially, but the potential functional consequences of these differences are largely unexplored. We measured bacterial production, glucose metabolism, and the abilities of microbial communities to hydrolyze a range of polysaccharides in an Arctic fjord of Svalbard (Smeerenburg Fjord), and thus to initiate remineralization of high-molecular weight organic matter. We compared these data with similar measurements previously carried out in the northern Gulf of Mexico in order to investigate whether differences in the spectrum of enzyme activities measurable in Arctic and temperate environments are reflected in "downstream" aspects of microbial metabolism (metabolism of monomers and biomass production). Only four of six polysaccharide substrates were hydrolyzed in Smeerenburg Fjord; all were hydrolyzed in the upper water column of the Gulf. These patterns are consistent on an interannual basis. Bacterial protein production was comparable at both locations, but the pathways of glucose utilization differed. Glucose incorporation rate constants were comparatively higher in Svalbard, but glucose respiration rate constants were higher in surface waters of the Gulf. As a result, at the time of sampling ca. 75% of the glucose was incorporated into biomass in Svalbard, but in the northern Gulf of Mexico most of the glucose was respired to CO2. A limited range of enzyme activities is therefore not a sign of a dormant community or one unable to further process substrates resulting from extracellular enzymatic hydrolysis. The ultimate fate of carbohydrates in marine waters, however, is strongly dependent upon the specific capabilities of heterotrophic microbial communities in these disparate environments.

  17. Patterns of extracellular enzyme activities and microbial metabolism in an Arctic fjord of Svalbard and in the northern Gulf of Mexico: contrasts in carbon processing by pelagic microbial communities

    Directory of Open Access Journals (Sweden)

    Carol eArnosti

    2013-10-01

    Full Text Available The microbial community composition of polar and temperate ocean waters differs substantially, but the potential functional consequences of these differences are largely unexplored. We measured bacterial production, glucose metabolism, and the abilities of microbial communities to hydrolyze a range of polysaccharides in an Arctic fjord of Svalbard (Smeerenburgfjord, and thus to initiate remineralization of high-molecular weight organic matter. We compared these data with similar measurements previously carried out in the northern Gulf of Mexico in order to investigate whether differences in the spectrum of enzyme activities measurable in Arctic and temperate environments are reflected in ‘downstream’ aspects of microbial metabolism (metabolism of monomers and biomass production. Only 4 of 6 polysaccharide substrates were hydrolyzed in Smeerenburgfjord; all were hydrolyzed in the upper water column of the Gulf. These patterns are consistent on an interannual basis. Bacterial protein production was comparable at both locations, but the pathways of glucose utilization differed. Glucose incorporation rate constants were comparatively higher in Svalbard, but glucose respiration rate constants were higher in surface waters of the Gulf. As a result, at the time of sampling ca. 75% of the glucose was incorporated into biomass in Svalbard, but in the northern Gulf of Mexico most of the glucose was respired to CO2. A limited range of enzyme activities is therefore not a sign of a dormant community or one unable to further process substrates resulting from extracellular enzymatic hydrolysis. The ultimate fate of carbohydrates in marine waters, however, is strongly dependent upon the specific capabilities of heterotrophic microbial communities in these disparate environments.

  18. Pleistocene iceberg dynamics on the west Svalbard margin: Evidence from bathymetric and sub-bottom profiler data

    Science.gov (United States)

    Zhao, Fang; Minshull, Timothy A.; Crocker, Anya J.; Dowdeswell, Julian A.; Wu, Shiguo; Soryal, Simon M.

    2017-04-01

    Large icebergs leave evidence of their drift via ploughing of the seabed, thereby providing a geological record of episodes of calving from thick ice sheets. We interpret large-scale curvilinear depressions on the western Svalbard margin as ploughmarks produced by the keels of icebergs that grounded on the seafloor as they drifted through this area. Iceberg ploughmarks were identified at modern water depths between 300 m and 1000 m and in two distinct stratigraphic units. Combining data from sediment cores with seismic stratigraphy from sub-bottom profiler data suggests that the ploughmarks developed in two phases: (1) during Marine Isotope Stage (MIS) 6; and (2) during MIS 2, indicating the presence of large drifting icebergs on the western Svalbard margin during both the Late Saalian and Late Weichselian glaciations. Sediment-core data along the western Svalbard margin indicate a sharp increase in mass-transported sediments dated at 23.7 ± 0.2 ka, consistent with the MIS 2 age of the younger iceberg-ploughed surface. The ploughmarks are oriented in two main directions: SW-NE and S-N. S-N oriented ploughmarks, which shallow to the north, indicate iceberg drift from the south with a SW-NE component marking the zone of splitting of the West Spitsbergen Current (WSC) into the Yermak Slope Current (YSC) and North Spitsbergen Current (NSC). Large MIS 6 and MIS 2 icebergs most likely had an Arctic Ocean source. We suggest that these icebergs probably left the Arctic Ocean southward through Fram Strait and circulated within the Norwegian-Greenland Sea before being transported northwards along the Svalbard margin by the WSC. An additional likely source of icebergs to the western Svalbard margin during MIS 2 was the ice-sheet terminating in the western Barents Sea, from which icebergs drifted northward.

  19. The potential transport of pollutants by Arctic sea ice

    OpenAIRE

    Pfirman, S. L.; Eicken, H.; Bauch, Dorothea; Weeks, W. F.

    1995-01-01

    Drifting sea ice in the Arctic may transport contaminants from coastal areas across the pole and release them during melting far from the source areas. Arctic sea ice often contains sediments entrained on the Siberian shelves and receives atmospheric deposition from Arctic haze. Elevated levels of some heavy metals (e.g. lead, iron, copper and cadmium) and organochlorines (e.g. PCBs and DDTs) have been observed in ice sampled in the Siberian seas, north of Svalbard, and in Baffin Bay. In orde...

  20. Snow cover and extreme winter warming events control flower abundance of some, but not all species in high arctic Svalbard.

    Science.gov (United States)

    Semenchuk, Philipp R; Elberling, Bo; Cooper, Elisabeth J

    2013-08-01

    The High Arctic winter is expected to be altered through ongoing and future climate change. Winter precipitation and snow depth are projected to increase and melt out dates change accordingly. Also, snow cover and depth will play an important role in protecting plant canopy from increasingly more frequent extreme winter warming events. Flower production of many Arctic plants is dependent on melt out timing, since season length determines resource availability for flower preformation. We erected snow fences to increase snow depth and shorten growing season, and counted flowers of six species over 5 years, during which we experienced two extreme winter warming events. Most species were resistant to snow cover increase, but two species reduced flower abundance due to shortened growing seasons. Cassiope tetragona responded strongly with fewer flowers in deep snow regimes during years without extreme events, while Stellaria crassipes responded partly. Snow pack thickness determined whether winter warming events had an effect on flower abundance of some species. Warming events clearly reduced flower abundance in shallow but not in deep snow regimes of Cassiope tetragona, but only marginally for Dryas octopetala. However, the affected species were resilient and individuals did not experience any long term effects. In the case of short or cold summers, a subset of species suffered reduced reproductive success, which may affect future plant composition through possible cascading competition effects. Extreme winter warming events were shown to expose the canopy to cold winter air. The following summer most of the overwintering flower buds could not produce flowers. Thus reproductive success is reduced if this occurs in subsequent years. We conclude that snow depth influences flower abundance by altering season length and by protecting or exposing flower buds to cold winter air, but most species studied are resistant to changes. Winter warming events, often occurring

  1. Characteristics of Arctic tides at CANDAC-PEARL (80 N, 86 W) and Svalbard (78 N, 16 E) for 2006-2009. Radar observations and comparisons with the model CMAM-DAS

    Energy Technology Data Exchange (ETDEWEB)

    Manson, A.H.; Meek, C.E.; Xu, X. [Saskatchewan Univ., Saskatoon (Canada). Inst. of Space and Atmospheric Studies; Aso, T.; Tsutsumi, M. [National Institute for Polar Research, Tokyo (Japan); Drummond, J.R. [Dalhousie Univ., Halifax (Canada). Physics and Atmospheric Science Dept.; Hall, C.M. [Tromsoe Univ. (Norway). Tromsoe Geophysical Observatory; Hocking, W.K. [Western Onatario Univ., London (Canada). Physics and Astronomy Dept.; Ward, W.E. [New Brunswick Univ., Fredericton (Canada). Physics and Astronomy Dept.

    2011-07-01

    Operation of a Meteor Radar (MWR) at Eureka, Ellesmere Island (80 N, 86 W) began in February 2006: this is the location of the Polar Environmental and Atmospheric Research Laboratory (PEARL), operated by the ''Canadian Network for the Detection of Atmospheric Change'' (CANDAC). The first 36 months of tidal wind data (82-97 km) are here combined with contemporaneous tides from the Meteor Radar (MWR) at Adventdalen, Svalbard (78 N, 16 E), to provide the first significant evidence for interannual variability (IAV) of the High Arctic's diurnal and semidiurnal migrating (MT) and non-migrating tides (NMT). The three-year monthly means for both diurnal (DT) and semi-diurnal (SDT) winds demonstrate significantly different amplitudes and phases at Eureka and Svalbard. Typically the summer-maximizing DT is much larger ({proportional_to}24ms{sup -1} at 97 km) at Eureka, while the Svalbard tide (5-24ms{sup -1} at 97 km) is almost linear (north-south) rather than circular. Interannual variations are smallest in the summer and autumn months. The High Arctic SDT has maxima centred on August/September, followed in size by the winter features; and is much larger at Svalbard (24ms{sup -1} at 97 km, versus 14-18ms{sup -1} in central Canada). Depending on the location, the IAV are largest in spring/winter (Eureka) and summer/autumn (Svalbard). Fitting of wave-numbers for the migrating and nonmigrating tides (MT, NMT) determines dominant tides for each month and height. Existence of NMT is consistent with nonlinear interactions between migrating tides and (quasi) stationary planetary wave (SPW) S =1 (SPW1). For the diurnal oscillation, NMT s = 0 for the east-west (EW) wind component dominates (largest tide) in the late autumn and winter (November-February); and s =+2 is frequently seen in the north-south (NS) wind component for the same months. The semi-diurnal oscillation's NMT s =+1 dominates from March to June/July. There are patches of s =+3 and +1, in

  2. Distribution of detrital minerals and sediment color in western Arctic Ocean and northern Bering Sea sediments: Changes in the provenance of western Arctic Ocean sediments since the last glacial period

    Science.gov (United States)

    Kobayashi, Daisuke; Yamamoto, Masanobu; Irino, Tomohisa; Nam, Seung-Il; Park, Yu-Hyeon; Harada, Naomi; Nagashima, Kana; Chikita, Kazuhisa; Saitoh, Sei-Ichi

    2016-12-01

    This paper describes the distribution of detrital minerals and sediment color in the surface sediments of the western Arctic Ocean and the northern Bering Sea and investigates the relationship between mineral composition and sediment provenance. This relationship was used to determine the provenance of western Arctic Ocean sediments deposited during the last glacial period. Sediment color is governed by water depth, diagenesis, and mineral composition. An a*-b* diagram was used to trace color change during diagenesis in the Arctic Ocean sediments. The mineral composition of surface sediments is governed by grain size and provenance. The feldspar/quartz ratio of the sediments studied was higher on the Siberian side than on the North American side of the western Arctic Ocean. The (chlorite + kaolinite)/illite and chlorite/illite ratios were high in the Bering Sea but decrease northwards in the Chukchi Sea. Thus, these ratios are useful for provenance studies in the Chukchi Sea area as indices of the Beaufort Gyre circulation and the Bering Strait inflow. The sediments deposited during the last glacial period have a lower feldspar/quartz ratio and a higher dolomite intensity than Holocene sediments on the Chukchi Plateau, suggesting a greater contribution of North American grains during the last glacial period.

  3. CHARACTERISTICS OF SURFACE MOVEMENT ON THE AUSTRE LOVÉNBREEN AND PEDERSENBREEN GLACIERS, SVALBARD, THE ARCTIC%北极 Svalbard 群岛 Austre Lov énbreen 和Pedersenbreen 冰川表面运动特征

    Institute of Scientific and Technical Information of China (English)

    李鹏; 闫明; 艾松涛; 徐跃通; 刘雷保; 孙维君

    2015-01-01

    以野外实测数据为基础,分析北极Svalbard群岛Austre Lovénbreen和Pedersenbreen 冰川表面运动特征。结果表明:(1) Austre Lovénbreen和Pedersenbreen冰川表面水平运动速度平均分别为2.14 m· a-1和6.28 m· a-1,变差系数平均分别为0.24和0.14,夏季水平运动速度略高于冬季,水平运动速度与其所处海拔高度具有多项式型关系,冰川主流线表面水平运动速度高于两侧,冰川两侧的表面水平运动速度不对称,Austre Lovénbreen冰川从源头至末端依次表现为运动的压缩区、拉伸区和压缩区;(2) Austre Lovénbreen和Pedersenbreen冰川表面垂直运动速度平均分别为0.76 m· a-1和0.90 m· a-1,两条冰川表面夏季垂直运动速度均大于冬季且夏季变差系数小,垂直运动速度与海拔高度具有一元线性相关性,表面物质平衡造成的高程变化对垂直运动速度的贡献率最大;(3) Austre Lovénbreen 和Pedersenbreen 冰川表面应变率分布表现为沿主流线方向逐渐减小然后负向增加,且其变差系数平均分别为0.19和0.15。%The glaciers Austre Lov énbreen and Pedersenbreen are located near Ny-Å lesund on the Svalbard archipelago in the Arctic.Surface movement characteristics were analyzed using field data collected from 2005 to 2011 on both glaciers.The average horizontal velocities of Austre Lov énbreen and Pedersenbreen were 2.14 m· a -1 and 6.28 m· a -1 , respectively, and their corresponding variation coefficients were 0.24 and 0.14.The average hori-zontal velocity of the two glaciers in summer was slightly higher than that in winter .There was a multinomial rela-tionship between the glacial horizontal velocity and elevation .The horizontal velocity was larger along the main-stream line of the glaciers than that on the sides , and the distribution was not symmetrical between the two sides of Austre Lovénbreen.Based on the glacial

  4. Mineralogical study of surface sediments in the western Arctic Ocean and their implications for material sources

    Institute of Scientific and Technical Information of China (English)

    DONG Linsen; SHI Xuefa; LIU Yanguang; FANG Xisheng; CHEN Zhihua; WANG Chunjuan; ZOU Jianjun; HUANG Yuanhui

    2014-01-01

    Mineralogical analysis was performed on bulk sediments of 79 surface samples using X-ray diffraction. The analytical results, combined with data on ocean currents and the regional geological background, were used to investigate the mineral sources. Mineral assemblages in sediments and their distribution in the study area indicate that the material sources are complex. (1) Feldspar is abundant in the sediments of the middle Chukchi Sea near the Bering Strait, originating from sediments in the Anadyr River carried by the Anadyr Current. Sediments deposited on the western side of the Chukchi Sea are rich in feldspar. Compared with other areas, sediments in this region are rich in hornblende transported from volcanic and sedimentary rocks in Siberia by the Anadyr Stream and the Siberian Coastal Current. Sediments in the eastern Chukchi Sea are rich in quartz sourced from sediments of the Yukon and Kuskokwim rivers carried by the Alaska Coastal Current. Sediments in the northern Chukchi Sea are rich in quartz and carbonates from the Mackenzie River sediments. (2) Sediments of the southern and central Canada Basin contain little calcite and dolomite, mainly due to the small impact of the Beaufort Gyre carrying carbonates from the Canadian Arctic Islands. Compared with other areas, the mica content in the region is high, implying that the Laptev Sea is the main sediment source for the southern and central Canada Basin. In the other deep sea areas, calcite and dolomite levels are high caused by the input of large amounts of sediment carried by the Beaufort Gyre from the Canadian Arctic Islands (Banks and Victoria). The Siberian Laptev Sea also provides small amounts of sediment for this region. Furthermore, the Atlantic mid-water contributes some fine-grained material to the entire deep western Arctic Ocean.

  5. Monitoring and modelling snow avalanches in Svalbard

    Science.gov (United States)

    Humlum, O.; Christiansen, H.; Neumann, U.; Eckerstorfer, M.; Sjöblom, A.; Stalsberg, K.; Rubensdotter, L.

    2009-04-01

    Monitoring and modelling snow avalanches in Svalbard Ole Humlum 1,3, Hanne H. Christiansen 1, Ulrich Neumann 1, Markus Eckerstorfer 1, Anna Sjöblom 1, Knut Stalsberg 2 and Lena Rubensdotter 2. 1: The University Centre in Svalbard (UNIS). 2: Geological Survey of Norway (NGU) 3: University of Oslo Ground based transportation in Svalbard landscape all takes place across mountainous terrain affected by different geomorphological slope processes. Traffic in and around the Svalbard settlements is increasing, and at the same time global climate models project substantial increases in temperature and precipitation in northern high latitudes for coming century. Therefore improved knowledge on the effect of climatic changes on slope processes in such high arctic landscapes is becoming increasingly important. Motivated by this, the CRYOSLOPE Svalbard research project since 2007 has carried out field observations on snow avalanche frequency and associated meteorological conditions. Snow avalanches are important geomorphic agents of erosion and deposition, and have long been a source of natural disasters in many mid-latitude mountain areas. Avalanches as a natural hazard has thereby been familiar to inhabitants of the Alps and Scandinavia for centuries, while it is a more recent experience in high arctic Svalbard. In addition, overall climate, topography and especially high winter wind speeds makes it difficult to apply snow avalanche models (numerical or empirical) developed for use at lower latitudes, e.g. in central Europe. In the presentation we examplify results from the ongoing (since winter 2006-07) monitoring of snow avalanches in Svalbard along a 70 km long observational route in the mountains. In addition, we present observations on the geomorphological impact of avalanches, with special reference to the formation of rock glaciers. Finally, we also present some initial results from numerical attempts of snow avalanche risk modelling within the study area.

  6. Deepened winter snow increases stem growth and alters stem δ13C and δ15N in evergreen dwarf shrub Cassiope tetragona in high-arctic Svalbard tundra

    DEFF Research Database (Denmark)

    Blok, Daan; Weijers, Stef; Welker, Jeffrey M

    2015-01-01

    of winter snow depth on shrub growth and ecophysiology by measuring stem length and stem hydrogen ( δ2H), carbon ( δ13C), nitrogen ( δ15N) and oxygen ( δ18O) isotopic composition of the circumarctic evergreen dwarf shrub Cassiope tetragona growing in high-arctic Svalbard, Norway. Measurements were carried...... out on C. tetragona individuals sampled from three tundra sites, each representing a distinct moisture regime (dry heath, meadow, moist meadow). Individuals were sampled along gradients of experimentally manipulated winter snow depths in a six-year old snow fence experiment: in ambient ( c . 20 cm......-snow individuals compared to individuals growing in ambient-snow plots during the course of the experiment, suggesting that soil N-availability was increased in deep-snow plots as a result of increased soil winter N mineralization. Although inter-annual growing season-precipitation δ 2 H and stem δ 2 H records...

  7. Late Quaternary stratigraphy and sedimentation patterns in the western Arctic Ocean

    Science.gov (United States)

    Polyak, L.; Bischof, J.; Ortiz, J.D.; Darby, D.A.; Channell, J.E.T.; Xuan, C.; Kaufman, D.S.; Lovlie, R.; Schneider, D.A.; Eberl, D.D.; Adler, R.E.; Council, E.A.

    2009-01-01

    Sediment cores from the western Arctic Ocean obtained on the 2005 HOTRAX and some earlier expeditions have been analyzed to develop a stratigraphic correlation from the Alaskan Chukchi margin to the Northwind and Mendeleev-Alpha ridges. The correlation was primarily based on terrigenous sediment composition that is not affected by diagenetic processes as strongly as the biogenic component, and paleomagnetic inclination records. Chronostratigraphic control was provided by 14C dating and amino-acid racemization ages, as well as correlation to earlier established Arctic Ocean stratigraphies. Distribution of sedimentary units across the western Arctic indicates that sedimentation rates decrease from tens of centimeters per kyr on the Alaskan margin to a few centimeters on the southern ends of Northwind and Mendeleev ridges and just a few millimeters on the ridges in the interior of the Amerasia basin. This sedimentation pattern suggests that Late Quaternary sediment transport and deposition, except for turbidites at the basin bottom, were generally controlled by ice concentration (and thus melt-out rate) and transportation distance from sources, with local variances related to subsurface currents. In the long term, most sediment was probably delivered to the core sites by icebergs during glacial periods, with a significant contribution from sea ice. During glacial maxima very fine-grained sediment was deposited with sedimentation rates greatly reduced away from the margins to a hiatus of several kyr duration as shown for the Last Glacial Maximum. This sedimentary environment was possibly related to a very solid ice cover and reduced melt-out over a large part of the western Arctic Ocean.

  8. Contamination of arctic Fjord sediments by Pb-Zn mining at Maarmorilik in central West Greenland

    DEFF Research Database (Denmark)

    Perner, Kerstin; Leipe, Thomas; Dellwig, O;

    2010-01-01

    This study focuses on heavy metal contamination of arctic sediments from a small Fjord system adjacent to the Pb-Zn "Black Angel" mine (West Greenland) to investigate the temporal and spatial development of contamination and to provide baseline levels before the mines re-opening in January 2009...... illustrate this transport and spatial distribution pattern of the contaminated material....

  9. Increased accumulation of sulfur in lake sediments of the high Arctic

    DEFF Research Database (Denmark)

    Drevnick, Paul E.; Muir, Derek C.G.; Lamborg, Carl H.;

    2010-01-01

    stimulates dissimilatory sulfate reduction. The sulfide produced is stored in sediment (as acid volatile sulfide), converted to other forms of sulfur, or reoxidized to sulfate and lost to the water column. An acceleration of the sulfur cycle in Arctic lakes could have profound effects on important...

  10. Deep water masses and sediments are main compartments for polychlorinated biphenyls in the Arctic Ocean.

    Science.gov (United States)

    Sobek, Anna; Gustafsson, Örjan

    2014-06-17

    There is a wealth of studies of polychlorinated biphenyls (PCB) in surface water and biota of the Arctic Ocean. Still, there are no observation-based assessments of PCB distribution and inventories in and between the major Arctic Ocean compartments. Here, the first water column distribution of PCBs in the central Arctic Ocean basins (Nansen, Amundsen, and Makarov) is presented, demonstrating nutrient-like vertical profiles with 5-10 times higher concentrations in the intermediate and deep water masses than in surface waters. The consistent vertical profiles in all three Arctic Ocean basins likely reflect buildup of PCBs transported from the shelf seas and from dissolution and/or mineralization of settling particles. Combined with measurement data on PCBs in other Arctic Ocean compartments collected over the past decade, the total Arctic Ocean inventory of ∑7PCB was estimated to 182 ± 40 t (±1 standard error of the mean), with sediments (144 ± 40 t), intermediate (5 ± 1 t) and deep water masses (30 ± 2 t) storing 98% of the PCBs in the Arctic Ocean. Further, we used hydrographic and carbon cycle parametrizations to assess the main pathways of PCBs into and out of the Arctic Ocean during the 20th century. River discharge appeared to be the major pathway for PCBs into the Arctic Ocean with 115 ± 11 t, followed by ocean currents (52 ± 17 t) and net atmospheric deposition (30 ± 28 t). Ocean currents provided the only important pathway out of the Arctic Ocean, with an estimated cumulative flux of 22 ± 10 t. The observation-based inventory of ∑7PCB of 182 ± 40 t is consistent with the contemporary inventory based on cumulative fluxes for ∑7PCB of 173 ± 36 t. Information on the concentration and distribution of PCBs in the deeper compartments of the Arctic Ocean improves our understanding of the large-scale fate of POPs in the Arctic and may also provide a means to test and improve models used to assess the fate of organic pollutants in the Arctic.

  11. Impacts of ocean acidification on sediment processes in shallow waters of the Arctic Ocean.

    Science.gov (United States)

    Gazeau, Frédéric; van Rijswijk, Pieter; Pozzato, Lara; Middelburg, Jack J

    2014-01-01

    Despite the important roles of shallow-water sediments in global biogeochemical cycling, the effects of ocean acidification on sedimentary processes have received relatively little attention. As high-latitude cold waters can absorb more CO2 and usually have a lower buffering capacity than warmer waters, acidification rates in these areas are faster than those in sub-tropical regions. The present study investigates the effects of ocean acidification on sediment composition, processes and sediment-water fluxes in an Arctic coastal system. Undisturbed sediment cores, exempt of large dwelling organisms, were collected, incubated for a period of 14 days, and subject to a gradient of pCO2 covering the range of values projected for the end of the century. On five occasions during the experimental period, the sediment cores were isolated for flux measurements (oxygen, alkalinity, dissolved inorganic carbon, ammonium, nitrate, nitrite, phosphate and silicate). At the end of the experimental period, denitrification rates were measured and sediment samples were taken at several depth intervals for solid-phase analyses. Most of the parameters and processes (i.e. mineralization, denitrification) investigated showed no relationship with the overlying seawater pH, suggesting that ocean acidification will have limited impacts on the microbial activity and associated sediment-water fluxes on Arctic shelves, in the absence of active bio-irrigating organisms. Only following a pH decrease of 1 pH unit, not foreseen in the coming 300 years, significant enhancements of calcium carbonate dissolution and anammox rates were observed. Longer-term experiments on different sediment types are still required to confirm the limited impact of ocean acidification on shallow Arctic sediment processes as observed in this study.

  12. Arctic deltaic lake sediments as recorders of fluvial organic matter deposition

    Science.gov (United States)

    Vonk, Jorien; Dickens, Angela; Giosan, Liviu; Zipper, Samuel; Galy, Valier; Holmes, Robert; Montlucon, Daniel; Kim, Bokyung; Hussain, Zainab; Eglinton, Timothy

    2016-08-01

    Arctic deltas are dynamic and vulnerable regions that play a key role in land-ocean interactions and the global carbon cycle. Delta lakes may provide valuable historical records of the quality and quantity of fluvial fluxes, parameters that are challenging to investigate in these remote regions. Here we study lakes from across the Mackenzie Delta, Arctic Canada, that receive fluvial sediments from the Mackenzie River when spring flood water levels rise above natural levees. We compare downcore lake sediments with suspended sediments collected during the spring flood, using bulk (% organic carbon, % total nitrogen, 13C, 14C) and molecular organic geochemistry (lignin, leaf waxes). High-resolution age models (137Cs, 210Pb) of downcore lake sediment records (n=11) along with lamina counting on high-resolution radiographs show sediment deposition frequencies ranging between annually to every 15 years. Down-core geochemical variability in a representative delta lake sediment core is consistent with historical variability in spring flood hydrology (variability in peak discharge, ice jamming, peak water levels). Comparison with earlier published Mackenzie River depth profiles shows that (i) lake sediments reflect the riverine surface suspended load, and (ii) hydrodynamic sorting patterns related to spring flood characteristics are reflected in the lake sediments. Bulk and molecular geochemistry of suspended particulate matter from the spring flood peak and lake sediments are relatively similar showing a mixture of modern higher-plant derived material, older terrestrial permafrost material, and old rock-derived material. This suggests that deltaic lake sedimentary records hold great promise as recorders of past (century-scale) riverine fluxes and may prove instrumental in shedding light on past behaviour of arctic rivers, as well as how they respond to a changing climate.

  13. Arctic deltaic lake sediments as recorders of fluvial organic matter deposition

    Directory of Open Access Journals (Sweden)

    Jorien E Vonk

    2016-08-01

    Full Text Available Arctic deltas are dynamic and vulnerable regions that play a key role in land-ocean interactions and the global carbon cycle. Delta lakes may provide valuable historical records of the quality and quantity of fluvial fluxes, parameters that are challenging to investigate in these remote regions. Here we study lakes from across the Mackenzie Delta, Arctic Canada, that receive fluvial sediments from the Mackenzie River when spring flood water levels rise above natural levees. We compare downcore lake sediments with suspended sediments collected during the spring flood, using bulk (% organic carbon, % total nitrogen, 13C, 14C and molecular organic geochemistry (lignin, leaf waxes. High-resolution age models (137Cs, 210Pb of downcore lake sediment records (n=11 along with lamina counting on high-resolution radiographs show sediment deposition frequencies ranging between annually to every 15 years. Down-core geochemical variability in a representative delta lake sediment core is consistent with historical variability in spring flood hydrology (variability in peak discharge, ice jamming, peak water levels. Comparison with earlier published Mackenzie River depth profiles shows that (i lake sediments reflect the riverine surface suspended load, and (ii hydrodynamic sorting patterns related to spring flood characteristics are reflected in the lake sediments. Bulk and molecular geochemistry of suspended particulate matter from the spring flood peak and lake sediments are relatively similar showing a mixture of modern higher-plant derived material, older terrestrial permafrost material, and old rock-derived material. This suggests that deltaic lake sedimentary records hold great promise as recorders of past (century-scale riverine fluxes and may prove instrumental in shedding light on past behaviour of arctic rivers, as well as how they respond to a changing climate.

  14. Bacterial and archaeal community structures in the Arctic deep-sea sediment

    Institute of Scientific and Technical Information of China (English)

    LI Yan; LIU Qun; LI Chaolun; DONG Yi; ZHANG Wenyan; ZHANG Wuchang; XIAO Tian

    2015-01-01

    Microbial community structures in the Arctic deep-sea sedimentary ecosystem are determined by organic matter input, energy availability, and other environmental factors. However, global warming and earlier ice-cover melting are affecting the microbial diversity. To characterize the Arctic deep-sea sediment microbial diversity and its rela-tionship with environmental factors, we applied Roche 454 sequencing of 16S rDNA amplicons from Arctic deep-sea sediment sample. Both bacterial and archaeal communities’ richness, compositions and structures as well as tax-onomic and phylogenetic affiliations of identified clades were characterized. Phylotypes relating to sulfur reduction and chemoorganotrophic lifestyle are major groups in the bacterial groups;while the archaeal community is domi-nated by phylotypes most closely related to the ammonia-oxidizing Thaumarchaeota (96.66%) and methanogenic Euryarchaeota (3.21%). This study describes the microbial diversity in the Arctic deep marine sediment (>3 500 m) near the North Pole and would lay foundation for future functional analysis on microbial metabolic processes and pathways predictions in similar environments.

  15. Community size and metabolic rates of psychrophilic sulfate-reducing bacteria in Arctic marine sediments

    DEFF Research Database (Denmark)

    Knoblauch, C.; Jørgensen, BB; Harder, J.

    1999-01-01

    The numbers of sulfate reducers in two Arctic sediments within situ temperatures of 2.6 and -1.7 degrees C were determined. Most-probable-number counts were higher at 10 degrees C than at 20 degrees C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates...... of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than...

  16. Community size and metabolic rates of psychrophilic sulfate-reducing bacteria in Arctic marine sediments

    Energy Technology Data Exchange (ETDEWEB)

    Knoblauch, C.; Joergensen, B.B.; Harder, J.

    1999-09-01

    The numbers of sulfate reducers in two Arctic sediments with in situ temperatures of 2.6 and {minus}1.7C were determined. Most-probable-number counts were higher at 10 C than at 20 C, indicating the predominance of a psychrophilic community. Mean specific sulfate reduction rates of 19 isolated psychrophiles were compared to corresponding rates of 9 marine, mesophilic sulfate-reducing bacteria. The results indicate that, as a physiological adaptation to the permanently cold Arctic environment, psychrophilic sulfate reducers have considerably higher specific metabolic rates than their mesophilic counterparts at similarly low temperatures.

  17. Shifts in identity and activity of methanotrophs in arctic lake sediments in response to temperature changes

    Science.gov (United States)

    He, Ruo; Wooller, Matthew J.; Pohlman, John W.; Quensen, John; Tiedje, James M.; Leigh, Mary Beth

    2012-01-01

    Methane (CH4) flux to the atmosphere is mitigated via microbial CH4 oxidation in sediments and water. As arctic temperaturesincrease, understanding the effects of temperature on the activity and identity of methanotrophs in arctic lake sediments is importantto predicting future CH4 emissions. We used DNA-based stable-isotope probing (SIP), quantitative PCR (Q-PCR), andpyrosequencing analyses to identify and characterize methanotrophic communities active at a range of temperatures (4°C, 10°C,and 21°C) in sediments (to a depth of 25 cm) sampled from Lake Qalluuraq on the North Slope of Alaska. CH4 oxidation activitywas measured in microcosm incubations containing sediments at all temperatures, with the highest CH4 oxidation potential of37.5 mol g1 day1 in the uppermost (depth, 0 to 1 cm) sediment at 21°C after 2 to 5 days of incubation. Q-PCR of pmoA and ofthe 16S rRNA genes of type I and type II methanotrophs, and pyrosequencing of 16S rRNA genes in 13C-labeled DNA obtained bySIP demonstrated that the type I methanotrophs Methylobacter, Methylomonas, and Methylosoma dominated carbon acquisitionfrom CH4 in the sediments. The identity and relative abundance of active methanotrophs differed with the incubation temperature.Methylotrophs were also abundant in the microbial community that derived carbon from CH4, especially in the deeper sediments(depth, 15 to 20 cm) at low temperatures (4°C and 10°C), and showed a good linear relationship (R0.82) with the relativeabundances of methanotrophs in pyrosequencing reads. This study describes for the first time how methanotrophiccommunities in arctic lake sediments respond to temperature variations.

  18. Fram-2014/2015: A 400 Day Investigation of the Arctic's Oldest Sediments over the Alpha Ridge with a Research Hovercraft

    Science.gov (United States)

    Hall, J. K.; Kristoffersen, Y.

    2014-12-01

    The thickest multi-year ice in the Arctic covers a secret. Four short cores raised from the Alpha Ridge in the 1970s and 1980s from drift stations T-3 and CESAR showed ages between 45 and 76 my. The reason for these old ages became clear when examination of legacy seismic data from T-3 showed that in some places up to 500 m of sediments had been removed within an area of some 200 by 600 km, presumably by an impact of asteroid fragments. To investigate the impact area, the authors conceived an innovative research platform in 2007. Named the R/H SABVABAA, this 12m by 6m hovercraft has been home-based in Svalbard since June 2008. During the following 6 years the craft and its evolving innovative light-weight equipment have made 18 trips to the summer ice pack, traveling some 4410 km over ice during some six months of scientific investigations. An opportunity to get a lift to this area, some 1500 km from Svalbard, came in a 2011 invitation to join AWI's icebreaker POLARSTERN in its ARK-XXVIII/4 expedition departing Tromsö August 5, 2014. The 400 day drift will be the first wintering over, ever, of a mobile research platform with geophysical, geological, and oceanographic capabilities. The Arctic ice pack continually moves due to winds and currents. While at the main camp, observations will consist of marine geophysics (seismic profiling with four element CHIRP, a 20 in³ airgun with single hydrophone, as well as 12 kHz bathymetry and 200 kHz sounding of the deep scattering layer), marine geology (coring with a hydrostatically-boosted 3 or 6 m corer; bottom photography; and two rock dredges), and oceanography. Deployed away from the camp, four sonobuoys will allow 3-D seismic acquisition. Access to the depths below the ice is via a hydraulic capstan winch, with 6500 m of Kevlar aramid fiber rope with 2.8 ton breaking strength. Ice thickness monitoring of the local 100 km² will be made with the craft's EM-31 probe when away from the camp, moving to choice locations for

  19. Orbital-Scale Cyclostratigraphy and Ice Volume Fluctuations from Arctic Ocean Sediments

    Science.gov (United States)

    Cronin, T. M.; Marzen, R.; DeNinno, L. H.

    2014-12-01

    Deep-sea foraminiferal oxygen isotope curves (δ18Of) are excellent paleoclimate records but are limited as proxies of global ice volume history during orbital glacial-interglacial cycles (GIC) due to the influence of deep-sea bottom water temperature, regional hydrography, ocean circulation and other factors affecting δ18Of. A more direct source of northern hemisphere [NH] ice history comes from central Arctic Ocean (CAO) submarine ridges (Northwind, Mendeleev, Lomonosov) where, at orbital timescales, sedimentation is controlled by the growth and decay of ice sheets, ice shelves, and sea ice. Calcareous microfossil density in CAO sediments is one of many proxies, such as manganese concentrations, grain size, bulk density, color, mineral content, organic geochemistry, and foraminiferal δ18O, that reveal GIC changes in ice cover, biological productivity, and primary and post-depositional sediment processes. In order to better understand NH ice history, we constructed 600-kyr-long stacked records of Arctic foraminiferal and ostracode density (AFD, AOD) from 19 CAO sediment cores following stacking and astronomical tuning procedures used for deep-sea δ18Of curves. Results show discrepancies between the Arctic AFD and AOD curves, the LR04 δ18Of stack (Lisiecki and Raymo 2005, Paleoceanography), the Red Sea and Mediterranean δ18Of sea level curves (Rohling et al. 2014 Nature), and modeled Antarctic Ice Sheet volume, suggesting asynchronous polar ice sheet behavior in the two hemispheres, notably during MIS 3, 5a, 5c, 7d, and 11.

  20. Short-lived high-amplitude cooling on Svalbard during the Dark Ages

    Science.gov (United States)

    van der Bilt, Willem; D`Andrea, William; Bakke, Jostein; Balascio, Nicholas; Werner, Johannes; Hoek, Wim

    2016-04-01

    As the paradigm of a stable Holocene climate has shifted, an increasing number of high-resolution proxy timeseries reveal dynamic conditions, characterized by high-amplitude climate shifts. Some of these events occurred during historical times and allow us to study the interaction between environmental and cultural change, providing valuable lessons for the near future. These include the Dark Ages Cold Period (DACP) between 300 and 800 AD, a period marked by political upheaval and climate instability that remains poorly investigated. Here, we present two temperature reconstructions from the High Arctic Svalbard Archipelago. To this end, we applied the established alkenone-based UK37 paleothermometer on sediments from two lakes on western Spitsbergen, Lake Hajeren and Lake Hakluyt. The Arctic is presently warming twice as fast as the global average and proxy data as well as model simulations suggest that this amplified response is characteristic for regional climate. The Arctic therefore provides a uniquely sensitive environment to study relatively modest climate shifts, like the DACP, that may not be adequately captured at lower-latitude sites. Owing to undisturbed sediments, a high sampling resolution and robust chronological control, the presented reconstructions resolve the attendant sub-centennial-scale climate shifts. Our findings suggest that the DACP marks a cold spell within the cool Neoglacial period, which started some 4 ka BP on Svalbard. Close investigation reveals a distinct temperature minimum around 500 AD that is reproduced in another alkenone-based temperature reconstruction from a nearby lake. At ± 1.75 °C, cooling underlines the sensitivity of Arctic climate as well as the magnitude of the DACP.

  1. 1st Science-Industry platform on expedition cruise tourism in Svalbard

    NARCIS (Netherlands)

    Lamers, M.A.J.; Olsen, J.; Hovelsrud, G.; Lang, I.; Jorgensen, F.

    2014-01-01

    The interest in Svalbard as a cruise tourism destination has increased gradually over the past decades, leading to a range of opportunities and challenges for marine and terrestrial ecosystems, communities, and regulatory systems on Svalbard and elsewhere in the Arctic (e.g. Greenland, Iceland, Russ

  2. Sources and cycling of mercury in the paleo Arctic Ocean from Hg stable isotope variations in Eocene and Quaternary sediments

    Science.gov (United States)

    Gleason, J. D.; Blum, J. D.; Moore, T. C.; Polyak, L.; Jakobsson, M.; Meyers, P. A.; Biswas, A.

    2017-01-01

    Mercury stable isotopic compositions were determined for marine sediments from eight locations in the Arctic Ocean Basin. Mass dependent fractionation (MDF) and mass independent fractionation (MIF) of Hg stable isotopes were recorded across a variety of depositional environments, water depths, and stratigraphic ages. δ202Hg (MDF) ranges from -2.34‰ to -0.78‰; Δ199Hg (MIF) from -0.18‰ to +0.12‰; and Δ201Hg (MIF) from -0.29‰ to +0.05‰ for the complete data set (n = 33). Holocene sediments from the Chukchi Sea and Morris Jesup Rise record the most negative Δ199Hg values, while Pleistocene sediments from the Central Arctic Ocean record the most positive Δ199Hg values. The most negative δ202Hg values are recorded in Pleistocene sediments. Eocene sediments (Lomonosov Ridge) show some overlap in their Hg isotopic compositions with Quaternary sediments, with a sample of the Arctic Ocean PETM (56 Ma) most closely matching the average Hg isotopic composition of Holocene Arctic marine sediments. Collectively, these data support a terrestrially-dominated Hg source input for Arctic Ocean sediment through time, although other sources, as well as influences of sea ice, atmospheric mercury depletion events (AMDEs), and anthropogenic Hg (in core top samples) on Hg isotopic signatures must also be considered.

  3. Anoxic carbon degradation in Arctic sediments: Microbial transformations of complex substrates

    Science.gov (United States)

    Arnosti, C.; Finke, N.; Larsen, O.; Ghobrial, S.

    2005-05-01

    Complex substrates are degraded in anoxic sediments by the concerted activities of diverse microbial communities. To explore the effects of substrate complexity on carbon transformations in permanently cold anoxic sediments, four substrates— Spirulina cells, Isochrysis cells, and soluble high molecular weight carbohydrate-rich extracts of these cells (Spir-Ex and Iso-Ex)—were added to sediments collected from Svalbard. The sediments were homogenized, incubated anaerobically in gas-tight bags at 0°C, and enzyme activities, fermentation, and terminal respiration were monitored over a 1134 h time course. All substrate additions yielded a fraction (8%-13%) of carbon that was metabolized to CO 2 over the first 384 h of incubation. The timecourse of VFA (volatile fatty acid) production and consumption, as well as the suite of VFAs produced, was similar for all substrates. After this phase, pathways of carbon degradation diverged, with an additional 43%, 32%, 33%, and 8% of Isochrysis, Iso-Ex, Spirulina, and Spir-Ex carbon respired to CO 2 over the next 750 h of incubation. Somewhat surprisingly, the soluble, carbohydrate-rich extracts did not prove to be more labile substrates than the whole cells from which they were derived. Although Spirulina and Iso-Ex differed in physical and chemical characteristics (solid/soluble, C/N ratio, lipid and carbohydrate content), nearly identical quantities of carbon were respired to CO 2. In contrast, only 15% of Spir-Ex carbon was respired, despite the initial burst of activity that it fueled, its soluble nature, and its relatively high (50%) carbohydrate content. The microbial community in these cold anoxic sediments clearly has the capacity to react rapidly to carbon input; extent and timecourse of remineralization of added carbon is similar to observations made at much higher temperatures in temperate sediments. The extent of carbon remineralization from these specific substrates, however, would not likely have been predicted

  4. Thermophilic anaerobes in arctic marine sediments induced to mineralize complex organic matter at high temperature

    DEFF Research Database (Denmark)

    Hubert, Casey; Arnosti, Carol; Brüchert, Volker

    2010-01-01

    , as well as with the addition of freeze-dried Spirulina or individual high-molecular-weight polysaccharides. During 50°C incubation experiments, Arctic thermophiles catalysed extensive mineralization of the organic matter via extracellular enzymatic hydrolysis, fermentation and sulfate reduction. This high...... reactivity determined the extent of the thermophilic response. Fjord sediments with higher in situ SRR also supported higher SRR at 50°C. Amendment with Spirulina significantly increased volatile fatty acids production and SRR relative to unamended sediment in 50°C incubations. Spirulina amendment also...

  5. Svalbard surging glacier landsystems

    Science.gov (United States)

    Lovell, Harold; Benn, Douglas; Lukas, Sven; Flink, Anne

    2014-05-01

    The percentage of Svalbard glaciers thought to be of surge-type is somewhere between 13-90% according to different sources variously based on statistical analysis and observations of diagnostic glaciological and geomorphological features, e.g. looped moraines. Developing a better understanding of which of these figures, if either, is most realistic is important in the context of glacier dynamics and related contributions of small glaciers and ice caps to sea level change in the immediate future. We present detailed geomorphological assessments of the margins of several known surge-type glaciers in Svalbard in order to update and improve the existing framework by which they are identified, and to provide a foundation for future reassessments of the surge-type glacier population based on distinct landform-sediment assemblages. Three landsystems are proposed: (1) Surges of small valley glaciers produce a prominent ice-cored latero-frontal moraine at their surge maximum and are characterised by an inner zone of ice stagnation terrain (hummocky topography, kettle lakes, debris flows) with no or only very few poorly-defined bedforms (crevasse squeeze ridges, eskers and flutes) and no recessional moraines. Many of these glaciers may have surged in the past but show no signs that they have the capability to do so again in the future. (2) Larger land-terminating glaciers, often with several tributaries, typically produce a push moraine complex which contains evidence for multiple advances, as identified from ridge-meltwater channel relationships. The inner zone often contains a large lagoon, partly dammed by the push moraine complex, and widespread ice stagnation terrain. Crevasse squeeze ridges, eskers and flutes are well-defined but small and limited in number and distribution. (3) Surges of large tidewater glaciers produce distinctive, often multi-generational, landform assemblages both in submarine and lateral terrestrial positions. The well-preserved submarine record

  6. Production of fluorescent dissolved organic matter in Arctic Ocean sediments

    Science.gov (United States)

    Chen, Meilian; Kim, Ji-Hoon; Nam, Seung-Il; Niessen, Frank; Hong, Wei-Li; Kang, Moo-Hee; Hur, Jin

    2016-12-01

    Little is known about the production of fluorescent dissolved organic matter (FDOM) in the anoxic oceanic sediments. In this study, sediment pore waters were sampled from four different sites in the Chukchi-East Siberian Seas area to examine the bulk dissolved organic carbon (DOC) and their optical properties. The production of FDOM, coupled with the increase of nutrients, was observed above the sulfate-methane-transition-zone (SMTZ). The presence of FDOM was concurrent with sulfate reduction and increased alkalinity (R2 > 0.96, p  0.95, p oceans.

  7. Norwegian fisheries in the Svalbard zone since 1980. Regulations, profitability and warming waters affect landings

    OpenAIRE

    Misund, Ole Arve; Heggland, Kristin; Skogseth, Ragnheid; Falck, Eva; Gjøsæter, Harald; Sundet, Jan Henry; Watne, Jens; Lønne, Ole Jørgen

    2016-01-01

    The Svalbard archipelago in the High Arctic is influenced by cold Arctic water masses from the north-east and the warm West Spitsbergen Current flowing northwards along its western coast. The eastern waters and the fjords are normally frozen during the winter months, while the coastal waters west of the archipelago remain open. Norwegian fishers have been harvesting from Svalbard waters for decades and detailed records of catches exists from 1980 onwards. We analyze the catch records from the...

  8. Distribution of branched GDGTs in surface sediments from the Colville River, Alaska: Implications for the MBT'/CBT paleothermometer in Arctic marine sediments

    Science.gov (United States)

    Hanna, Andrea J. M.; Shanahan, Timothy M.; Allison, Mead A.

    2016-07-01

    Significant climate fluctuations in the Arctic over the recent past, and additional predicted future temperature changes, highlight the need for high-resolution Arctic paleoclimate records. Arctic coastal environments supplied with terrigenous sediment from Arctic rivers have the potential to provide annual to subdecadal resolution records of climate variability over the last few millennia. A potential tool for paleotemperature reconstructions in these marine sediments is the revised methylation index of branched tetraethers (MBT')/cyclization ratio of branched tetraethers (CBT) proxy based on branched glycerol dialkyl glycerol tetraethers (brGDGTs). In this study, we examine the source of brGDGTs in the Colville River, Alaska, and the adjacent Simpson Lagoon and reconstruct temperatures from Simpson Lagoon sediments to evaluate the applicability of this proxy in Arctic estuarine environments. The Colville catchment soils, fluvial sediments, and estuarine sediments contain statistically similar brGDGT distributions, indicating that the brGDGTs throughout the system are soil derived with little alteration from in situ brGDGT production in the river or coastal waters. Temperatures reconstructed from the MBT'/CBT indices for surface samples show good agreement with regional summer (June through September) temperatures, suggesting a seasonal bias in Arctic temperature reconstructions from the Colville system. In addition, we reconstruct paleotemperatures from an estuarine sediment core that spans the last 75 years, revealing an overall warming trend in the twentieth century that is consistent with trends observed in regional instrumental records. These results support the application of this brGDGT-based paleotemperature proxy for subdecadal-scale summer temperature reconstructions in Arctic estuaries containing organic material derived from sediment-laden, episodic rivers.

  9. Distribution of benthic foraminifers (>125 um) in the surface sediments of the Arctic Ocean

    Science.gov (United States)

    Osterman, Lisa E.; Poore, Richard Z.; Foley, Kevin M.

    1999-01-01

    Census data on benthic foraminifers (>125 ?m) in surface sediment samples from 49 box cores are used to define four depth-controlled biofacies, which will aid in the paleoceanographic reconstruction of the Arctic Ocean. The shelf biofacies contains a mix of shallow-water calcareous and agglutinated species from the continental shelves of the Beaufort and Chukchi Seas and reflects the variable sedimentologic and oceanic conditions of the Arctic shelves. The intermediate-depth calcareous biofacies, found between 500 and 1,100 meters water depth (mwd), contains abundant Cassidulina teretis , presumably indicating the influence of Atlantic-derived water at this depth. In water depths between 1,100 and 3,500 m, a deepwater calcareous biofacies contains abundant Oridorsalis umbonatus . Below 3,500 mwd, the deepwater mixed calcareous/agglutinated biofacies of the Canada, Makarov, and Eurasian Basins reflects a combination of low productivity, dissolution, and sediment transport. Two other benthic foraminiferal species show specific environmental preferences. Fontbotia wuellerstorfi has a depth distribution between 900 and 3,500 mwd, but maximum abundance occurs in the region of the Mendeleyev Ridge. The elevated abundance of F. wuellerstorfi may be related to increased food supply carried by a branch of Atlantic water that crosses the Lomonosov Ridge near the Russian Continental Shelf. Triloculina frigida is recognized to be a species preferring lower slope sediments commonly disturbed by turbidites and bottom currents. INTRODUCTION At present, our understanding of the Arctic Ocean lags behind our understanding of other oceans, and fundamental questions still exist about its role in and response to global climate change. The Arctic Ocean is particularly sensitive to climatic fluctuations because small changes in the amounts of sea-ice cover can alter global albedo and thermohaline circulation (Aagaard and Carmack, 1994). Numerous questions still exist regarding the nature

  10. Depositional environment, ichnological features and oxygenation of Permian to earliest Triassic marine sediments in central Spitsbergen, Svalbard

    Directory of Open Access Journals (Sweden)

    Alfred Uchman

    2016-05-01

    Full Text Available Late Early Permian–lowermost Triassic carbonate, siliceous (spiculites and clastic marine sediments in the Marmierfjellet area (Isfjorden, central Spitsbergen contain a relatively diverse and abundant trace fossil assemblage providing important information about the depositional processes. The Vøringen Member (Late Artinskian–Kungurian of the Kapp Starostin Formation (Late Artinskian–? Changhsingian contains trace fossils (Nereites, Phycosiphon, Zoophycos and Arenicolites—common in tempestites typical of the proximal–archetypal Cruziana ichnofacies, which indicates lower shoreface. Nereites, Phycosiphon and Zoophycos, accompanied by other rare trace fossils, characterize the Svenskegga and Hovtinden members of the Kapp Starostin Formation. They are interpreted as the distal Cruziana ichnofacies, possibly transitional to the Zoophycos ichnofacies typical of the lower offshore zone. However, the sporadic occurrences of Arenicolites and Macaronichnus can point to episodic shallowing to upper offshore–lower shoreface. The lowest part of the Triassic Vikinghøgda Formation (Induan–Olenekian contains a very low-diverse ichnoassemblage composed of a few simple and branched forms ascribed to the impoverished Cruziana ichnofacies (lower to upper offshore environment, which is attributed to the early recovery stage after the Permian–Triassic extinction. The trace fossils and loss of primary sedimentary structures caused by intense bioturbation throughout most of the section point to generally oxygenated pore waters on the sea floor. However, some horizons, especially laminated black shales, display reduced or no bioturbational activity. These horizons also show high V/(V+Ni ratios, which indicate oxygen-depleted sediments with periods of anoxic conditions. A remarkable black shale unit deposited under anoxic and sulphidic conditions occurs at the Permian–Triassic transition.

  11. Temperature induced decoupling of enzymatic hydrolysis and carbon remineralization in long-term incubations of Arctic and temperate sediments

    DEFF Research Database (Denmark)

    Robador, Alberto; Brüchert, Volker; Steen, Andrew;

    2010-01-01

    , and 20 ºC. The short-term temperature response of the active microbial community was tested in temperature gradient block incubations. The temperature optimum of extracellular enzymatic hydrolysis, as measured with a polysaccharide (chondroitin sulfate), differed between Arctic and temperate habitats...... by about 8–13 C in fresh sediments and in sediments incubated for 24 months. In both Arctic and temperate sediments, the temperature response of chondroitin sulfate hydrolysis was initially similar to that of sulfate reduction. After 24 months, however, hydrolysis outpaced sulfate reduction rates...

  12. Annual CO2 budget and seasonal CO2 exchange signals at a high Arctic permafrost site on Spitsbergen, Svalbard archipelago

    DEFF Research Database (Denmark)

    Luërs, J.; Westermann, Signe; Piel, K.;

    2014-01-01

    The annual variability of CO2 exchange in most ecosystems is primarily driven by the activities of plants and soil microorganisms. However, little is known about the carbon balance and its controlling factors outside the growing season in Arctic regions dominated by soil freeze/thaw processes, lo...

  13. A new methodology for quantifying bubble flow rates in deep water using splitbeam echosounders: Examples from the Arctic offshore NW-Svalbard

    NARCIS (Netherlands)

    Veloso, M.; Greinert, J.; Mienert, J.; De Batist, M.

    2015-01-01

    Quantifying marine methane fluxes of free gas (bubbles) from the seafloor into the water column is of importance for climate related studies, for example, in the Arctic, reliable methodologies are also of interest for studying man-made gas and oil leakage systems at hydrocarbon production sites. Hyd

  14. Chemometric Analysis for Pollution Source Assessment of Harbour Sediments in Arctic Locations

    DEFF Research Database (Denmark)

    Pedersen, Kristine B.; Lejon, Tore; Jensen, Pernille Erland

    2015-01-01

    Pollution levels, pollutant distribution and potential source assessments based on multivariate analysis (chemometrics) were made for harbour sediments from two Arctic locations; Hammerfest in Norway and Sisimiut in Greenland. High levels of heavy metals were detected in addition to organic...... pollutants. Preliminary assessments based on principal component analysis (PCA) revealed different sources and pollutant distribution in the sediments of the two harbours. Tributyltin (TBT) was, however, found to originate from point source(s), and the highest concentrations of TBT in both harbours were...... indicated relation primarily to German, Russian and American mixtures in Hammerfest; and American, Russian and Japanese mixtures in Sisimiut. PCA was shown to be an important tool for identifying pollutant sources and differences in pollutant composition in relation to sediment characteristics....

  15. Sedimentary processes in High Arctic lakes (Cape Bounty, Melville Island, Canada): What do sediments really record?

    Science.gov (United States)

    Normandeau, Alexandre; Lamoureux, Scott; Lajeunesse, Patrick; Francus, Pierre

    2016-04-01

    Lacustrine sedimentary sequences can hold a substantial amount of information regarding paleoenvironments, hydroclimate variability and extreme events, providing critical insights into past climate change. The study of lacustrine sediments is often limited to the analysis of sediment cores from which past changes are inferred. However, studies have provided evidence that the accumulation of sediments in lacustrine basins and their distribution can be affected by a wide range of internal and external forcing mechanisms. It is therefore crucial to have a good knowledge of the factors controlling the transport and distribution of sediments in lakes prior to investigating paleoenvironmental archives. To address this knowledge gap, the Cape Bounty Arctic Watershed Observatory (CBAWO), located on southern Melville Island in the Canadian High Arctic, was initiated in 2003 as a long term monitoring site with the aim of understanding the controls over sediment transport within similar paired watersheds and lakes. The East and West lakes have been monitored each year since 2003 to document the role of hydro-climate variability on water column processes and sediment deposition. Moorings recording water electrical conductivity, temperature, density, dissolved oxygen and turbidity, as well as sediment traps were deployed during the active hydrological period (generally May-July). These data were analyzed in combination with hydrological and climatic data from the watersheds. Additionally, a high-resolution bathymetric and sub-bottom survey was completed in 2015 and allowed imaging the lake floor and sub-surface in great detail. This combination of process and lake morphological data are unique in the Arctic. The morphostratigraphic analysis reveals two highly disturbed lake floors, being widely affected by subaqueous mass movements that were triggered during the last 2000 years. Backscatter intensity maps and the presence of bedforms on each delta foresets indicate that

  16. Tapped lakes as sediment traps in an Arctic delta

    Science.gov (United States)

    Walker, J.; McGraw, M.

    2015-03-01

    Lakes within the Colville River delta in northern Alaska, USA, vary in size from small ponds created by ice-wedge growth to thaw lakes that are as much as three kilometres long and ten metres deep. As the river migrates, lake edges are breached and the lakes are drained. Such lake tapping is aided by permafrost thaw and ice wedge melt and, in the case of the larger lakes, by wave action within them. Once a lake is tapped, it drains rapidly creating a deep scour hole at its entrance and from then on it is subject to the varying stages and discharge of the river. During flooding, when the river is transporting its largest amount of sediment, the tapped lakes become settling basins and rapidly fill. The Colville River delta has lakes in all stages from freshly breached to those that are now being destroyed by channel migration.

  17. Provenance analysis of central Arctic Ocean sediments: Implications for circum-Arctic ice sheet dynamics and ocean circulation during Late Pleistocene

    Science.gov (United States)

    Kaparulina, Ekaterina; Strand, Kari; Lunkka, Juha Pekka

    2016-09-01

    Mineralogical and geochemical data generated from the well referred shallow core 96/12-1pc on the Lomonosov Ridge, central Arctic Ocean was used to evaluate ice transport from the circum-Arctic sources and variability in sediment drainage and provenance changes. In this study heavy minerals in central Arctic sediments were used to determine those most prominent provenance areas and their changes related to the Late Pleistocene history of glaciations in the Arctic. Provenance changes were then used to infer variations in the paleoceanographic environment of the central Arctic Ocean, such as variations in the distribution of sea ice, icebergs controlled by the Arctic Ocean circulation. Four critical end-members including Victoria and Banks Islands, the Putorana Plateau, the Anabar Shield, and the Verkhoyansk Fold Belt were identified from the Amerasian and Eurasian source areas, and their proportional contributions were estimated in relation to Late Pleistocene ice sheet dynamics and ocean circulation. The results show changes in transport pathways and source areas within two examined transitions MIS6-5 and MIS4-3. The main source for material during MIS6-5 transition was Amerasian margin due to the high dolomite content in the studied section of sediments inferring strong Beaufort Gyre (BG) and Transpolar Drift (TPD) transport for this material. IRD material during late the MIS6 to 5 deglacial event was from terrigenous input through from the MacKenzie route Banks/Victoria Islands then transported as far as the Lomonosov Ridge area. The transition, MIS4-3 in comparison with MIS6-5, shows a clear shift in source areas, reflected in a different mineralogical composition of sediments, supplied from the Eurasian margin, such as the Anabar Shield, the Putorana Plateau and the Verkhoyansk Fold Belt during active decay of the Barents-Kara Ice Sheet presumable associated with an ice-dammed lake outburst then triggered by a strong TPD over the central Arctic. These two

  18. Hydrological response of a High-Arctic catchment to changing climate over the past 35 years: a case study of Bayelva watershed, Svalbard

    Directory of Open Access Journals (Sweden)

    Aga Nowak

    2013-08-01

    Full Text Available Our study considers climate change and its influence upon the hydrology and water balance of the glacierized Bayelva watershed in Svalbard. We find that changes are most noticeable within the last 10 years, when winters have become warmer and wetter. The change is most significant during the shoulder months, especially September, when the transition from summer ablation to winter accumulation is taking place. Winter rainfalls, when extreme, produce ground icings and runoff outside the summer period. Dependent upon summer air temperatures, these icings may either melt and produce additional runoff or persist until the following hydrological year. These processes have a direct influence upon the water budget. They represent sources of error for water-balance calculations that either ignore winter runoff events and/or assume water storage is negligible. We show that even when the watershed is underlain by permafrost and accommodates cold-based glaciers, storage can no longer be ignored. Furthermore, we find that the use of a precipitation gradient correction of 19% per 100 m, a gauge catch correction and glacier mass-balance data (for snow accumulation and icemelt runoff should be used for accurate water-balance calculations. We also find that despite sustained glacier retreat, annual runoff volume showed no trend during 1989–2010. Discharge is more variable and longer during the last decade due to the winter rainfalls. Finally, flow recession analyses reveal increasingly efficient evacuation of meltwater from the catchment and the increasing occurrence of a delayed flowpath through the glaciers’ forefield.

  19. Organophosphate Ester Flame Retardants and Plasticizers in Ocean Sediments from the North Pacific to the Arctic Ocean.

    Science.gov (United States)

    Ma, Yuxin; Xie, Zhiyong; Lohmann, Rainer; Mi, Wenying; Gao, Guoping

    2017-04-04

    The presence of organophosphate ester (OPE) flame retardants and plasticizers in surface sediment from the North Pacific to Arctic Ocean was observed for the first time during the fourth National Arctic Research Expedition of China in the summer of 2010. The samples were analyzed for three halogenated OPEs [tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), and tris(dichloroisopropyl) phosphate], three alkylated OPEs [triisobutyl phosphate (TiBP), tri-n-butyl phosphate, and tripentyl phosphate], and triphenyl phosphate. Σ7OPEs (total concentration of the observed OPEs) was in the range of 159-4658 pg/g of dry weight. Halogenated OPEs were generally more abundant than the nonhalogenated OPEs; TCEP and TiBP dominated the overall concentrations. Except for that of the Bering Sea, Σ7OPEs values increased with increasing latitudes from Bering Strait to the Central Arctic Ocean, while the contributions of halogenated OPEs (typically TCEP and TCPP) to the total OPE profile also increased from the Bering Strait to the Central Arctic Ocean, indicating they are more likely to be transported to the remote Arctic. The median budget of 52 (range of 17-292) tons for Σ7OPEs in sediment from the Central Arctic Ocean represents only a very small amount of their total production volume, yet the amount of OPEs in Arctic Ocean sediment was significantly larger than the sum of polybrominated diphenyl ethers (PBDEs) in the sediment, indicating they are equally prone to long-range transport away from source regions. Given the increasing level of production and usage of OPEs as substitutes of PBDEs, OPEs will continue to accumulate in the remote Arctic.

  20. Controls on stable sulfur isotope fractionation during bacterial sulfate reduction in Arctic sediments

    DEFF Research Database (Denmark)

    Bruchert, V.; Knoblauch, C.; Jørgensen, BB

    2001-01-01

    Sulfur isotope fractionation experiments during bacterial sulfate reduction were performed with recently isolated strains of cold-adapted sulfate-reducing bacteria from Arctic marine sediments with year-round temperatures below 2 degreesC. The bacteria represent quantitatively important members...... parts per thousand and 8 parts per thousand above 25 degreesC, respectively. In absence of significant differences in sulfate reduction rates in the high and low temperature range, respectively, we infer that different genera of sulfate-reducing bacteria dominate the sulfate-reducing bacterial community...

  1. Effects of sample mass and macrofossil type on radiocarbon dating of arctic and boreal lake sediments

    Energy Technology Data Exchange (ETDEWEB)

    Oswald, W W; Anderson, P M; Brown, T A; Brubaker, L B; Hu, F S; Lozhkin, A V; Tinner, W; Kaltenrieder, P

    2006-05-29

    Dating lake sediments by accelerator mass spectrometry (AMS) {sup 14}C analysis of plant macrofossils overcomes one of the main problems associated with dating bulk sediment samples, the presence of old organic matter. Even so, many AMS dates from arctic and boreal sites appear to misrepresent the age of the sediment. To understand the nature of these apparent dating anomalies better, we conducted a series of {sup 14}C dating experiments using samples from Alaskan and Siberian lake-sediment cores. First, to test whether our analytical procedures introduced a sample-mass bias, we obtained {sup 14}C dates for different-sized pieces of single woody macrofossils. In these sample-mass experiments, sized statistically equivalent ages were found for samples as small as 0.05 mg C. Second, to assess whether macrofossil type influenced dating results, we conducted sample-type experiments in which {sup 14}C dates were obtained for different macrofossil types sieved from the same depth in the sediment. We dated materials from multiple levels in sediment cores from Upper Capsule Lake (North Slope, northern Alaska) and Grizzly Lake (Copper River Basin, southern Alaska), and from single depths in other records from northern Alaska. In several of the experiments there were significant discrepancies between dates for different plant tissues, and in most cases wood and charcoal were older than other macrofossil types, usually by several hundred years. This pattern suggests that {sup 14}C dates for woody macrofossils may misrepresent the age of the sediment by centuries, perhaps due to their longer terrestrial residence time and the potential in-built age of long-lived plants. This study identifies why some {sup 14}C dates appear to be inconsistent with the overall age-depth trend of a lake-sediment record, and it may guide the selection of {sup 14}C samples in future studies.

  2. Distribution and sources of organic matter in surface marine sediments across the North American Arctic margin

    Science.gov (United States)

    Goñi, Miguel A.; O'Connor, Alison E.; Kuzyk, Zou Zou; Yunker, Mark B.; Gobeil, Charles; Macdonald, Robie W.

    2013-09-01

    As part of the International Polar Year research program, we conducted a survey of surface marine sediments from box cores along a section extending from the Bering Sea to Davis Strait via the Canadian Archipelago. We used bulk elemental and isotopic compositions, together with biomarkers and principal components analysis, to elucidate the distribution of marine and terrestrial organic matter in different regions of the North American Arctic margin. Marked regional contrasts were observed in organic carbon loadings, with the highest values (≥1 mg C m-2 sediment) found in sites along Barrow Canyon and the Chukchi and Bering shelves, all of which were characterized by sediments with low oxygen exposure, as inferred from thin layers (cutin acids) all indicate marked regional differences in the proportions of marine and terrigenous organic matter present in surface sediments. Regions such as Barrow Canyon and the Mackenzie River shelf were characterized by the highest contributions of land-derived organic matter, with compositional characteristics that suggested distinct sources and provenance. In contrast, sediments from the Canadian Archipelago and Davis Strait had the smallest contributions of terrigenous organic matter and the lowest organic carbon loadings indicative of a high degree of post-depositional oxidation.

  3. Geomorphologic mapping in the Ny Ålesund area (Svalbard Island, Norway) for the analysis of geomorphologic effects on rock slopes induced by glacier retreat in climate sensitive High Arctic regions

    Science.gov (United States)

    Miccadei, Enrico; Piacentini, Tommaso; Casacchia, Ruggero; Sparapani, Roberto

    2014-05-01

    The geomorphological effects of glacial retreat, rapidly changing Arctic environments and consequent local temporary permafrost melting are several types of glacial and periglacial landforms (pingos, solifluction, drumlins, etc.) but also debris and rock falls, alluvial fan and glacial outwash development and scarp/slopes retreat and evolution. In this work we have realized a geomorphologic map of rockfalls, landslides, alluvial fans and the slopes and scarps of steep mountainsides in the Ny Ålesund area (Svalbard Island, Norway) focused on the analysis of rock falls as geomorphological effects of glacier retreat, permafrost degradation and higher temperatures on slope processes. The investigation is based on geological and geomorphological field survey, and remote sensing and aerial photo interpretation, The Ny Ålesund area landscape is characterized by rugged non-vegetated mountains only partially covered by glaciers, with steep flanks and rock scarps; the scarps are formed by different types of rocks (intrusive and effusive igneous rocks, marine sedimentary rocks); this landscape is highly affected by debris and rock falls (from scarps and slopes) forming wide talus slopes and by alluvial fan and fluvial outwash (from glaciers), which make the surface sedimentary cover of the island together with rock glaciers and moraine deposits and locally fluvial deposits. The work is focused on the comprehension of the role of different factors in inducing rock falls, alluvial fans, slope/scarps evolution in high geomorphological sensitivity environments (i.e. glacial, periglacial or mountain) including: orography, lithology, rock fracturation, morphostructural setting, meteorological context. The conclusions focus on the possible geomorphological hazards affecting the Ny Ålesund area.

  4. Suspended sediment in a high-Arctic river: An appraisal of flux estimation methods.

    Science.gov (United States)

    Ladegaard-Pedersen, Pernille; Sigsgaard, Charlotte; Kroon, Aart; Abermann, Jakob; Skov, Kirstine; Elberling, Bo

    2017-02-15

    Quantifying fluxes of water, sediment and dissolved compounds through Arctic rivers is important for linking the glacial, terrestrial and marine ecosystems and to quantify the impact of a warming climate. The quantification of fluxes is not trivial. This study uses a 8-years data set (2005-2012) of daily measurements from the high-Artic Zackenberg River in Northeast Greenland to estimate annual suspended sediment fluxes based on four commonly used methods: M1) is the discharge weighted mean and uses direct measurements, while M2-M4) are one uncorrected and two bias corrected rating curves extrapolating a continuous concentration trace from measured values. All methods are tested on complete and reduced datasets. The average annual runoff in the period 2005-2012 was 190±25mio·m(3)y(-1). The different estimation methods gave a range of average annual suspended sediment fluxes between 43,000±10,000ty(-1) and 61,000±16,000ty(-1). Extreme events with high discharges had a mean duration of 1day. The average suspended sediment flux during extreme events was 17,000±5000ty(-1), which constitutes a year-to-year variation of 20-37% of the total annual flux. The most accurate sampling strategy was bi-daily sampling together with a sampling frequency of 2h during extreme events. The most consistent estimation method was an uncorrected rating curve of bi-daily measurements (M2), combined with a linear interpolation of extreme event fluxes. Sampling can be reduced to every fourth day, with both method-agreements and accuracies agreements were Arctic Zackenberg River, unless sampling was done bi-daily, every day and events sampled high-frequently.

  5. Environmental behaviour of short-chain chlorinated paraffins in aquatic and terrestrial ecosystems of Ny-Ålesund and London Island, Svalbard, in the Arctic.

    Science.gov (United States)

    Li, Huijuan; Fu, Jianjie; Pan, Wenxiao; Wang, Pu; Li, Yingming; Zhang, Qinghua; Wang, Yawei; Zhang, Aiqian; Liang, Yong; Jiang, Guibin

    2017-07-15

    The environmental behaviour of short-chain chlorinated paraffins (SCCPs) was investigated in both aquatic and terrestrial ecosystems in the Arctic. The mean concentrations of SCCPs in the aquatic and terrestrial samples were 178.9ng/g dry weight (dw) and 157.2ng/g dw, respectively. Short carbon chain (C10) and less-chlorinated (Cl6) congener groups were predominant in the Arctic samples, accounting for 48.6% and 34.8% of the total SCCPs, respectively. The enrichment of lighter SCCP congener groups (i.e., fewer chlorine atoms with shorter carbon chain lengths) indicated that the fractionation process occurred during long-range transport. The biomagnification factor (BMF) was 0.46 from gammarid to cod, which indicated that the SCCPs did not biomagnify between these two species. The soil-vegetation bioaccumulation factor (BAF) of SCCPs was 29.9, and C13 and Cl7, 8 congener groups tended to accumulate in the terrestrial vegetation. Regression analysis (BAFs=10.9×#C+5.6×#Cl-125.2, R=0.53, P<0.01) showed that the number of carbon and chlorine atoms influenced the bioaccumulative behaviour of SCCPs and suggested that the number of carbon atoms had a greater influence on the BAFs of SCCPs in the terrestrial ecosystem than did the number of chlorine atoms.

  6. Early diagenesis and trace element accumulation in North American Arctic margin sediments

    Science.gov (United States)

    Kuzyk, Zou Zou A.; Gobeil, Charles; Goñi, Miguel A.; Macdonald, Robie W.

    2017-04-01

    Concentrations of redox-sensitive elements (S, Mn, Mo, U, Cd, Re) were analyzed in a set of 27 sediment cores collected along the North American Arctic margin (NAAM) from the North Bering Sea to Davis Strait via the Canadian Archipelago. Sedimentary distributions and accumulation rates of the elements were used to evaluate early diagenesis in sediments along this section and to estimate the importance of this margin as a sink for key elements in the polar and global oceans. Distributions of Mn, total S and reduced inorganic S demonstrated that diagenetic conditions and thus sedimentary carbon turnover in the NAAM is organized regionally: undetectable or very thin layers (Canyon and Lancaster Sound; and thick layers (5-20 cm) of surface Mn enrichment occurred in the Beaufort Shelf, Canadian Archipelago, and Davis Strait. Inventories of authigenic S below the Mn-rich layer decreased about fivefold from Bering-Chukchi shelf and Barrow Canyon to Lancaster Sound and more than ten-fold from Bering-Chukchi shelf to Beaufort Shelf, Canadian Archipelago and Davis Strait. The Mn, total S and reduced inorganic S distributions imply strong organic carbon (OC) flux and metabolism in the Bering-Chukchi shelves, lower aerobic OC metabolism in Barrow Canyon and Lancaster Sound, and deep O2 penetration and much lower OC metabolism in the Beaufort Shelf, Canadian Archipelago, and Davis Strait. Accumulation rates of authigenic S, Mo, Cd, Re, and U displayed marked spatial variability along the NAAM reflecting the range in sedimentary redox conditions. Strong relationships between the accumulation rates and vertical carbon flux, estimated from regional primary production values and water depth at the coring sites, indicate that the primary driver in the regional patterns is the supply of labile carbon to the seabed. Thus, high primary production combined with a shallow water column (average 64 m) leads to high rates of authigenic trace element accumulation in sediments from the Bering

  7. The use of ground penetrating radar (GPR) in the investigation of historical quarry abandonment in Svalbard

    NARCIS (Netherlands)

    Koster, Benjamin; Kruse, Frigga

    2016-01-01

    This paper investigates historical quarry abandonment in Svalbard in the European High Arctic. A short-lived British marble quarry in Kongsfjorden lay deserted after 1920. We ask why this attempt at the large-scale development of High Arctic marble was unproductive; whether there are structural feat

  8. Atmospheric methane emissions coupled to a CO2-sink at an Arctic shelf seep area offshore NW Svalbard: Introducing the "Seep-Fertilization Hypothesis"

    Science.gov (United States)

    Greinert, Jens; Pohlman, John; Silyakova, Anna; Mienert, Jürgen; Ruppel, Carolyn; Casso, Michael

    2015-04-01

    Documented warming of intermediate waters by ~1C over the past 30 years along the western Svalbard margin has been suggested as a driver of climate-change induced dissociation of marine methane hydrate. However, recent evidence suggests methane release has been occurring for thousands of years near the upper limit of methane hydrate stability zone and that seasonal changes in bottom water temperature may be more important than longer-term warming of intermediate waters. However, the existence of hydrates at the upper limit of the gas hydrate zone has been based on modeling results only and gas hydrates have not been sampled successfully. Yearly studies, undertaken during RV Helmer Hanssen cruises as part of CAGE have shown that no significant amount of methane reaches the upper water column and is being released towards the atmosphere from this ca. 400m deep sites. The same is true for a very active seep area at the shelf break in 240m water depth where detailed hydroacoustic studies show fluctuating fluxes between 71 and 114 T/yr in total. Here we focus on studies conducted with the USGS Gas Analysis System (USGS-GAS). Continuous surface water methane and carbon dioxide concentrations and associated data are used to calculate sea-air fluxes with this cavity ring-down spectrometer-based analytical system. Only the shallow seep site (~90 m water depth) had appreciable methane in surface waters. We conducted an exhaustive survey of this site, mapping the full extent of the surface methane plume. To provide three-dimensional constraints, we acquired 65 vertical dissolved methane profiles to delineate the vertical and horizontal extent of the subsurface methane plume. The USGS-GAS data show that methane beyond the 'normal' background fluxes of ~1 µmol m-2 d-1 is elevated at the intensively bubbling shallow seep site (max. 35 µmol m-2 d-1) and near the shallow coastal zone where the fluxes over a large area reach 25 µmol m-2 d-1. Comparing coastal and seep fluxes on

  9. Lena River discharge events in sediments of Laptev Sea, Russian Arctic

    Science.gov (United States)

    Rivera, Janiel; Karabanov, Eugene B.; Williams, Douglas F.; Buchinskyi, Valeryi; Kuzmin, Michael

    2006-01-01

    To reconstruct the variability of freshwater discharge to the Arctic via the Lena River, 22 gravity cores were collected along two transects that extend from the delta floodplain onto the Laptev Sea shelf. High magnetic susceptibility (MS) signals appear to be good indicators for river sediment deposition. Sedimentation of this terrestrial material forms fluvial units distinguished by coarse grain size and high MS signal produced by the magnetic properties from the river-derived material. The criteria to distinguish marine units are low magnetic susceptibility signals when compared with fluvial units, lithological descriptions and granulometric analyses. Sedigraph granulometric analyses in combination with wet sieving analyses (grain size > 4 Φ) reveal changes in grain-size distributions along the cores that are well correlated with magnetic susceptibility data. Fluvial and marine units were found to alternate sequentially along the cores. Data from cores comprising two transects in the Laptev Sea revealed 17 total fluvial events during the last 2000 years. The Lena River-derived sediment bedload could be traced 34.5-47.5 km far from the delta edge of Bykovskaya branch showing direct impact of Lena River discharge to the Laptev Sea.

  10. Distribution and sources of polycyclic aromatic hydrocarbons in surface sediments from the Bering Sea and western Arctic Ocean.

    Science.gov (United States)

    Zhao, Mengwei; Wang, Weiguo; Liu, Yanguang; Dong, Linsen; Jiao, Liping; Hu, Limin; Fan, Dejiang

    2016-03-15

    To analyze the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) and evaluate their potential ecological risks, the concentrations of 16 PAHs were measured in 43 surface sediment samples from the Bering Sea and western Arctic Ocean. Total PAH (tPAH) concentrations ranged from 36.95 to 150.21 ng/g (dry weight). In descending order, the surface sediment tPAH concentrations were as follows: Canada Basin>northern Chukchi Sea>Chukchi Basin>southern Chukchi Sea>Aleutian Basin>Makarov Basin>Bering Sea shelf. The Bering Sea and western Arctic Ocean mainly received PAHs of pyrogenic origin due to pollution caused by the incomplete combustion of fossil fuels. The concentrations of PAHs in the sediments of the study areas did not exceed effects range low (ERL) values.

  11. Purification and characterization of a novel antifungal protein secreted by Penicillium chrysogenum from an Arctic sediment.

    Science.gov (United States)

    Chen, Zhiteng; Ao, Jingqun; Yang, Wenchuan; Jiao, Liping; Zheng, Tianling; Chen, Xinhua

    2013-12-01

    A fungal strain, Penicillium chrysogenum A096, was isolated from an Arctic sediment sample. Its culture supernatant inhibited mycelial growth of some plant pathogenic fungi. After saturation of P. chrysogenum A096 culture supernatant with ammonium sulfate and ion exchange chromatography, a novel antifungal protein (Pc-Arctin) was purified and identified by matrix assisted laser desorption ionization-time of flight-time of flight-mass spectrometry (MALDI-TOF-TOF-MS). The gene encoding for Pc-Arctin consisting of 195 nucleotides was cloned from P. chrysogenum A096 to confirm the mass spectrometry result. Pc-Arctin displays antifungal activity against Paecilomyces variotii, Alternaria longipes, and Trichoderma viride at minimum inhibitory concentrations (MIC) of 24, 48, and 192 ng/disc, respectively. Pc-Arctin was most sensitive to proteinase K and then to trypsin but insensitive to papain. Pc-Arctin possesses high thermostability and cannot be antagonized by common surfactants, except for sodium dodecyl sulfate (SDS). Divalent ions, such as Mn(2+), Mg(2+), and Zn(2+), inhibited the antifungal activity of Pc-Arctin. Hemagglutination assays showed that Pc-Arctin had no hemagglutinating or hemolytic activity against red blood cells (RBC) from rabbits, rats, and guinea pigs. Therefore, Pc-Arctin from Arctic P. chrysogenum may represent a novel antifungal protein with potential for application in controlling plant pathogenic fungal infection.

  12. 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.

  13. Penicillium mycobiota in Arctic subglacial ice

    DEFF Research Database (Denmark)

    Sonjak, S.; Frisvad, Jens Christian; Gunde-Cimerman, N.

    2006-01-01

    , representing on the average half of all isolated strains from all three glaciers. The other most frequently isolated species were P. bialowiezense, P. chrysogenum, P. thomii, P. solitum, P. palitans, P. echinulatum, P. polonicum, P. commune, P. discolor, P. expansum, and new Penicillium species (sp. 1). Twelve...... to be inhabited exclusively by heterotrophic bacteria. In this study we report on the very high occurrence (up to 9000 CFU L-1) and diversity of filamentous Penicillium spp. in the sediment-rich subglacial ice of three different polythermal Arctic glaciers (Svalbard, Norway). The dominant species was P. crustosum...... more Penicillium species were occasionally isolated. The fungi isolated produced consistent profiles of secondary metabolites, not different from the same Penicillium species from other habitats. This is the first report on the presence of large populations of Penicillium spp. in subglacial sediment...

  14. Environmental Levels and Trends of 1,2-dichloroethane, vinyl chloride and chloroform in water, sediment and biota for the European and Arctic regions: literature study

    NARCIS (Netherlands)

    Korytar, P.; Leslie, H.A.

    2005-01-01

    Data on concentrations of chloroform, 1,2-dichloroethane and vinyl chloride in European and Arctic waters, sediments and biota were collected from scientific literature and monitoring programmes for the period 1980–2005 and are presented in this report.

  15. Sediment dynamics in paired High Arctic lakes revealed from high-resolution swath bathymetry and acoustic stratigraphy surveys

    Science.gov (United States)

    Normandeau, A.; Lamoureux, S. F.; Lajeunesse, P.; Francus, P.

    2016-09-01

    High Arctic lakes are commonly used for paleoclimatic reconstructions because they are particularly sensitive to climate variability. However, the processes leading to sediment deposition and distribution in these lakes are often poorly understood. Here for the first time in the Canadian High Arctic, we present original data resulting from swath bathymetry and subbottom surveys carried out on two lakes at Cape Bounty, Melville Island. The results reveal the dynamic nature of the lakes, in which mass movement deposits and bedforms on the deltas reflect frequent slope instabilities and hyperpycnal flow activity. The analysis of the mass movement deposits reveals that small blocky debris flows/avalanches, debris flows, and a slide occurred during the Holocene. These mass movements are believed to have been triggered by earthquakes and potentially by permafrost thawing along the shoreline. Altogether, these mass movement deposits cover more than 30% of the lake floors. Additionally, the river deltas on both lakes were mapped and reveal the presence of several gullies and bedforms. The presence of gullies along the delta front indicates that hyperpycnal flows generated at the river mouth can transport sediment in different trajectories downslope, resulting in a different sediment accumulation pattern and record. The dynamic nature of these two lakes suggests that further analysis on sediment transport and distribution within Arctic lakes is required in order to improve paleoclimatic reconstructions.

  16. Composition index of n-alkanes and paleoenvironmental study in sediments of the Arctic

    Institute of Scientific and Technical Information of China (English)

    Lu Bing; Zhou Huaiyang; Wang Zipan; Lu Douding

    2001-01-01

    This paper reports different concentration patterns of n-alkanes distribution in the sediments from the Chukchi Sea, the Bering Sea in the Arctic. Factor statistical analysis method is used for studying the source of n-alkanes and paleoenviroment. The result shows that n-alkanes is in the range of nC15~nC33 and n-alkane distribution patterns are characterized by two modes. The first mode belongs to the higher molecular with MH being nC25~ nC27, CPI> 1 and with remarkable odd-even dominance.They are of terrigenous plant origin. The second one belongs to lower carbon range with MH being nC17 ~nC20, CPI> 1 and with indistinct odd-even dominance. Therefore they are contributed by marine biological inputs. The contribution of land origin is larger than that of marine source. Pr/Ph is lower than 1 in the investigated area, which indicates the depositional environment of reducing reaction with lower oxygen. The result of factor analysis has good agreement with composition characteristics of n-alkanes in the sediment.

  17. Monitoring of greenhouse gases and aerosols at Svalbard and Birkenes

    Energy Technology Data Exchange (ETDEWEB)

    Myhre, C.L.; Hermansen, O.; Fjaeraa, A.M.; Lunder, C.; Fiebig, M.; Schmidbauer, N.; Krognes, T.; Stebel, K.

    2012-07-01

    The report summaries the activities and results of the greenhouse gas monitoring at the Zeppelin and observatory situated on Svalbard in Arctic Norway during the period 2001-2010 and the greenhouse gas monitoring and aerosol observations from Birkenes for 2010. The monitoring programme is performed by the NILU - Norwegian Institute for Air Research and funded by the Norwegian Pollution Control Authority (SFT) (now Climate and Pollution Agency) and NILU - Norwegian Institute for Air Research.(Author)

  18. Surface-enhanced in-situ Raman-sensor applied in the arctic area for analyses of water and sediment

    Science.gov (United States)

    Kolomijeca, Anna; Kwon, Yong-Hyok; Kronfeldt, Heinz-Detlef

    2012-06-01

    Investigations on the seafloor in the arctic area are of great scientific interest as well as of progressive economic importance. Therefore, measurements in the water column and of sediments were carried out by applying different analytical methods. In JCR 253 arctic cruise a microsystem diode laser with reflection Bragg grating emitting at 671 nm was introduced and integrated into an optode housing which was laboratory pressure tested up to 200 bar. The connection to the mobile spectrometer is realized through an optical fiber. All performed measurements were carried out on the James-Clark-Ross research vessel during a three week experiment in August 2011. Conventional Raman spectra and SERS spectra of arctic surface water and sediment acquired from locations around 78° N and 9° E will be presented. Selected SERS substrates developed for SERS measurements in sea-water were tested for their capability to detect different substances in the water down to very small (pmol/l) concentrations. Additionally, the applicability of shifted excitation Raman difference spectroscopy (SERDS) and a combination of SERS with SERDS for analytical applications during sea-trials for in-situ analyses of sea-water and sediments will be discussed.

  19. Assessment of crude oil biodegradation in arctic seashore sediments: effects of temperature, salinity, and crude oil concentration.

    Science.gov (United States)

    Sharma, Priyamvada; Schiewer, Silke

    2016-08-01

    The expected increase in offshore oil exploration and production in the Arctic may lead to crude oil spills along arctic shorelines. To evaluate the potential effectiveness of bioremediation to treat such spills, oil spill bioremediation in arctic sediments was simulated in laboratory microcosms containing beach sediments from Barrow (Alaska), spiked with North Slope Crude, and incubated at varying temperatures and salinities. Biodegradation was measured via respiration rates (CO2 production); volatilization was quantified by gas chromatography/mass spectrophotometry (GC/MS) analysis of hydrocarbons sorbed to activated carbon, and hydrocarbons remaining in the sediment were quantified by GC/flame ionization detector (FID). Higher temperature leads to increased biodegradation by naturally occurring microorganisms, while the release of volatile organic compounds was similar at both temperatures. Increased salinity had a small positive impact on crude oil removal. At higher crude oil dosages, volatilization increased, however CO2 production did not. While only a small percentage of crude oil was completely biodegraded, a larger percentage was volatilized within 6-9 weeks.

  20. Psychrophilic sulfate-reducing bacteria isolated from permanently cold Arctic marine sediments: description of Desulfofrigrus oceanense gen. nov., sp nov., Desulfofrigus fragile sp nov., Desulfofaba gelida gen. nov., sp nov., Desulfotalea psychrophila gen. nov., sp nov and Desulfotalea arctica sp

    DEFF Research Database (Denmark)

    Knoblauch, C.; Sahm, K.; Jørgensen, BB

    1999-01-01

    Five psychrophilic, Gram-negative, sulfate-reducing bacteria were isolated from marine sediments off the coast of Svalbard. All isolates grew at the in situ temperature of -1.7 degrees C. In batch cultures, strain PSv29(T) had the highest growth rate at 7 degrees C, strains ASv26(T) and LSv54(T...

  1. Isolation and phylogenetic assignation of actinomycetes in the marine sediments from the Arctic Ocean

    Institute of Scientific and Technical Information of China (English)

    YU Yong; LI Huirong; ZENG Yinxin; CHEN Bo

    2005-01-01

    Actinomycetes in five marine sediments collected from the Arctic Ocean at depths of 43 to 3 050 m were cultivated using a variety of media. A total of 61 actinomycete colonies with substrate mycelia only were observed, and no colonies with aerial mycelia were observed under aerobic conditions at 15 ℃. From these colonies, 28 were selected to represent different morphological types.Denaturing gradient gel electrophoresis (DGGE) was used to check the purity of isolates and select representatives for subsequent sequencing. Phylogentic analyses based on nearly full-length 16S ribosomal RNA gene (rDNA) sequences indicated that the actinomycetes isolated were accommodated within genus Rhodococcus of family Nocardiaceae, genus Dietzia of family Dietziaceae,genera Janibacter and Terrabacter of family Instrasporangiaceae and genera Kocuria and Arthrobacter of family Micrococcaceae. One of the strains (P27-24) from the deep-sea sediment at depth of 3 050 m was found to be identical in 16S rDNA sequence(1474/1474)with the radiation-resistant Kocuria rosea ATCC 187T isolated from air. More than halfofthe isolates showed the similarities ranging from 99.5% to 99.9% in 16S rDNA sequence to dibenzofran-degrading, butyl 2-ethylhexanoate-hydrolysising and nitrile-metabolizing actinomycetes. All the strains isolated were psychrotolerant bacteria and grew better on the media prepared with natural seawater than on the media prepared with deionized water. Three of them (Dietzia sp. P27-10, Rhodococcus sp. S11-3 and Rhodococcus sp.P11-5)had an obligate growth requirement for salt, confirming that these strains are indigenous marine actinomycetes.

  2. Viable Species of Flamella (Amoebozoa: Variosea) Isolated from Ancient Arctic Permafrost Sediments.

    Science.gov (United States)

    Shmakova, Lyubov; Bondarenko, Natalya; Smirnov, Alexey

    2016-02-01

    Six viable strains of amoebae belonging to the genus Flamella (Amoebozoa, Variosea) were isolated from permafrost sediments sampled in the Russian Arctic region. Two of them are from late Pleistocene permafrost in North-East Siberia, and four--from Holocene and late Pleistocene in North-West Siberia. Light- and electron-microscopic study and molecular phylogeny show that these isolates represent two new species belonging to the genus Flamella. Both species are cyst-forming. This is a remarkable case of high resistance of protozoan cysts, allowing them to survive and recover an amoebae population after a very long, geologically significant period of rest; a "snapshot" of evolution in time. This study directly shows for the first time that amoeba cysts can be conserved not only for years and decades but for many thousand years and then recover, contributing to the formation of an active microbial community. We propose to name the new species as Flamella pleistocenica n.sp. and Flamella beringiania n.sp. Phylogenetic analysis shows that the genus Flamella is a robust and potentially species-rich group of Variosea.

  3. Science as national belonging: The construction of Svalbard as a Norwegian space.

    Science.gov (United States)

    Roberts, Peder; Paglia, Eric

    2016-12-01

    This article examines how science has been employed to establish, maintain, and contest senses of belonging on Svalbard, an Arctic archipelago administered by Norway since 1925 under an international treaty. Our central argument is that the process of constructing Svalbard as a space belonging to Norway has long been intertwined with the processes of describing and representing the archipelago and that participating in those processes has also permitted other states to articulate their own narratives of belonging - on Svalbard in particular and in the Arctic more generally. We deploy the concept of belonging to capture a sense of legitimate presence and stakeholdership that we do not believe can be adequately captured by narrow concepts of sovereignty. Norway's historic and current use of science validates (and even naturalizes) its rule over Svalbard. At the same time, other states use science on Svalbard to articulate geopolitical scripts that portray them as stakeholders in an Arctic that is of transregional relevance due to the effects of climate change.

  4. Loss of sea ice during winter north of Svalbard

    Directory of Open Access Journals (Sweden)

    Ingrid H. Onarheim

    2014-06-01

    Full Text Available Sea ice loss in the Arctic Ocean has up to now been strongest during summer. In contrast, the sea ice concentration north of Svalbard has experienced a larger decline during winter since 1979. The trend in winter ice area loss is close to 10% per decade, and concurrent with a 0.3°C per decade warming of the Atlantic Water entering the Arctic Ocean in this region. Simultaneously, there has been a 2°C per decade warming of winter mean surface air temperature north of Svalbard, which is 20–45% higher than observations on the west coast. Generally, the ice edge north of Svalbard has retreated towards the northeast, along the Atlantic Water pathway. By making reasonable assumptions about the Atlantic Water volume and associated heat transport, we show that the extra oceanic heat brought into the region is likely to have caused the sea ice loss. The reduced sea ice cover leads to more oceanic heat transferred to the atmosphere, suggesting that part of the atmospheric warming is driven by larger open water area. In contrast to significant trends in sea ice concentration, Atlantic Water temperature and air temperature, there is no significant temporal trend in the local winds. Thus, winds have not caused the long-term warming or sea ice loss. However, the dominant winds transport sea ice from the Arctic Ocean into the region north of Svalbard, and the local wind has influence on the year-to-year variability of the ice concentration, which correlates with surface air temperatures, ocean temperatures, as well as the local wind.

  5. 231Pa/230Th records of Arctic/Atlantic interchange in Fram Strait

    Science.gov (United States)

    Hoffmann, S. S.; McDermott, K. J.; McManus, J. F.; Mukasa, S. B.

    2014-12-01

    Fram Strait, the Arctic Ocean's only deep passage for exchange with lower latitude oceans, today serves as a conduit for waters flowing north into the Arctic Ocean and south into the Atlantic. Reconstruction of circulation patterns and strength at depth in the strait can help to clarify the history of Arctic/Atlantic deep water exchange and Arctic contributions to global meridional overturning circulation. We will present new sedimentary measurements of radioisotopes 231Pa and 230Th to provide information on this exchange in the past and its relationship to sedimentation and climatic events. Coretop and downcore 231Pa/230Th ratios from Arctic sediments indicate that 231Pa has been exported from the central Arctic basin throughout the Holocene and deglaciation. Fram Strait represents a possible sink for this "missing" 231Pa. Preliminary results from ODP Holes 908A and 909A, at 1274 m and 2519 m water depths respectively in the central strait, suggest that ratios in this region during the Holocene have varied between ~0.106 (above the 231Pa/230Th production ratio of 0.093 in seawater, indicating net import of 231Pa)and ~0.055 (well below the production ratio, indicating net export of 231Pa). Further measurements in cores from the Greenland and Svalbard continental slopes will give a fuller regional picture of 231Pa deposition and transport across the strait.

  6. Macromolecular composition of terrestrial and marine organic matter in sediments across the East Siberian Arctic Shelf

    Science.gov (United States)

    Sparkes, Robert B.; Doğrul Selver, Ayça; Gustafsson, Örjan; Semiletov, Igor P.; Haghipour, Negar; Wacker, Lukas; Eglinton, Timothy I.; Talbot, Helen M.; van Dongen, Bart E.

    2016-10-01

    Mobilisation of terrestrial organic carbon (terrOC) from permafrost environments in eastern Siberia has the potential to deliver significant amounts of carbon to the Arctic Ocean, via both fluvial and coastal erosion. Eroded terrOC can be degraded during offshore transport or deposited across the wide East Siberian Arctic Shelf (ESAS). Most studies of terrOC on the ESAS have concentrated on solvent-extractable organic matter, but this represents only a small proportion of the total terrOC load. In this study we have used pyrolysis-gas chromatography-mass spectrometry (py-GCMS) to study all major groups of macromolecular components of the terrOC; this is the first time that this technique has been applied to the ESAS. This has shown that there is a strong offshore trend from terrestrial phenols, aromatics and cyclopentenones to marine pyridines. There is good agreement between proportion phenols measured using py-GCMS and independent quantification of lignin phenol concentrations (r2 = 0.67, p < 0.01, n = 24). Furfurals, thought to represent carbohydrates, show no offshore trend and are likely found in both marine and terrestrial organic matter. We have also collected new radiocarbon data for bulk OC (14COC) which, when coupled with previous measurements, allows us to produce the most comprehensive 14COC map of the ESAS to date. Combining the 14COC and py-GCMS data suggests that the aromatics group of compounds is likely sourced from old, aged terrOC, in contrast to the phenols group, which is likely sourced from modern woody material. We propose that an index of the relative proportions of phenols and pyridines can be used as a novel terrestrial vs. marine proxy measurement for macromolecular organic matter. Principal component analysis found that various terrestrial vs. marine proxies show different patterns across the ESAS, and it shows that multiple river-ocean transects of surface sediments transition from river-dominated to coastal-erosion-dominated to marine

  7. The geomorphological effect of cornice fall avalanches in the Longyeardalen valley, Svalbard

    Science.gov (United States)

    Eckerstorfer, M.; Christiansen, H. H.; Rubensdotter, L.; Vogel, S.

    2013-09-01

    The study of snow avalanches and their geomorphological effect in the periglacial parts of the cryosphere is important for enhanced geomorphological process understanding as well as hazard-related studies. Only a few field studies, and particularly few in the High Arctic, have quantified avalanche sedimentation. Snow avalanches are traditionally ranked behind rockfall in terms of their significance for mass-wasting processes of rockslopes. Cornice fall avalanches are at present the most dominant snow avalanche type at two slope systems, called Nybyen and Larsbreen, in the valley Longyeardalen in central Svalbard. Both slope systems are on northwest-facing lee slopes underneath a large summit plateau, with annual cornices forming on the top. High-frequency and magnitude cornice fall avalanching is observed by daily automatic time-lapse photography. In addition, rock debris sedimentation by cornice fall avalanches was measured directly in permanent sediment traps or by snow inventories. The results from a maximum of seven years of measurements in a total of 13 catchments show maximum mean rock debris sedimentation rates ranging from 8.2 to 38.7 kg m-2 at Nybyen, and from 0.8 to 55.4 kg m-2 at Larsbreen. Correspondingly, avalanche fan surfaces accreted from 2.6 to 8.8 mm yr-1 at Nybyen, and from 0.2 to 13.9 mm yr-1 at Larsbreen. This comparably efficient rockslope mass wasting is due to collapsing cornices producing cornice fall avalanches containing large amounts of rock debris throughout the entire winter. The rock debris of different origin stems from the plateau crests, the adjacent free rock face and the transport pathway, accumulating distinct avalanche fans at both slope systems. Cornice fall avalanche sedimentation also contributed to the development of a rock glacier at the Larsbreen site during the Holocene. We have recorded present maximum rockwall retreat rates of 0.9 mm yr-1 at Nybyen, but as much as 6.7 mm yr-1 at Larsbreen, while average Holocene

  8. The geomorphological effect of cornice fall avalanches in the Longyeardalen valley, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Eckerstorfer

    2013-09-01

    Full Text Available The study of snow avalanches and their geomorphological effect in the periglacial parts of the cryosphere is important for enhanced geomorphological process understanding as well as hazard-related studies. Only a few field studies, and particularly few in the High Arctic, have quantified avalanche sedimentation. Snow avalanches are traditionally ranked behind rockfall in terms of their significance for mass-wasting processes of rockslopes. Cornice fall avalanches are at present the most dominant snow avalanche type at two slope systems, called Nybyen and Larsbreen, in the valley Longyeardalen in central Svalbard. Both slope systems are on northwest-facing lee slopes underneath a large summit plateau, with annual cornices forming on the top. High-frequency and magnitude cornice fall avalanching is observed by daily automatic time-lapse photography. In addition, rock debris sedimentation by cornice fall avalanches was measured directly in permanent sediment traps or by snow inventories. The results from a maximum of seven years of measurements in a total of 13 catchments show maximum mean rock debris sedimentation rates ranging from 8.2 to 38.7 kg m−2 at Nybyen, and from 0.8 to 55.4 kg m−2 at Larsbreen. Correspondingly, avalanche fan surfaces accreted from 2.6 to 8.8 mm yr−1 at Nybyen, and from 0.2 to 13.9 mm yr−1 at Larsbreen. This comparably efficient rockslope mass wasting is due to collapsing cornices producing cornice fall avalanches containing large amounts of rock debris throughout the entire winter. The rock debris of different origin stems from the plateau crests, the adjacent free rock face and the transport pathway, accumulating distinct avalanche fans at both slope systems. Cornice fall avalanche sedimentation also contributed to the development of a rock glacier at the Larsbreen site during the Holocene. We have recorded present maximum rockwall retreat rates of 0.9 mm yr−1 at Nybyen, but as much as 6.7 mm yr−1 at

  9. Flocculation alters the distribution and flux of melt-water supplied sediments and nutrients in the Arctic

    DEFF Research Database (Denmark)

    Markussen, Thor Nygaard; Andersen, Thorbjørn Joest; Ernstsen, Verner Brandbyge;

    In the Arctic, thawing permafrost and increased melting of glaciers are important drivers for changes in fine-grained sediment supply and biogeochemical fluxes from land to sea. Flocculation of particles is a controlling factor for the magnitude of fluxes and deposition rates in the marine...... environment but comparatively little is known about the flocculation processes in the Arctic. We investigated flocculation dynamics from a melt-water river in the inner Disko Fjord, West Greenland. A novel, laser-illuminated camera system significantly improved the particle size measurement capabilities...... and settling tubes were sampled to enable sub-sampling of different floc size fractions. Flocculation was observed during periods with low turbulent shear and also at the front of the fresh water plume resulting in significant volumes of large sized flocs at depth below the plume. The floc sizes and volumes...

  10. Late Pleistocene glacio-marine sedimentation in the Chukchi Sea, the western Arctic Ocean

    Science.gov (United States)

    Yoon, Seok-Hoon; Joe, Young-Jin; Nam, Seung-Il

    2013-04-01

    In this study, we present the results of sedimentary and echo facies analyses of gravity cores and high-resolution sub-bottom profiling (SBP) data obtained during the 2011 Arctic expedition of R/V Araon (operated by KOPRI) in the Chukchi Sea, the western part of the Arctic Ocean. The gravity cores (248-548 cm long) at 3 stations were collected from the continental shelf and slope areas of the sea, and X-radiographs of sediment slabs were taken from the lengthwise-cut split cores to observe sedimentary structures. Grain size of core sediment was analyzed using standard sieves and a Micrometrics Sedigraph 5000D. High-resolution sub-bottom profiling (SBP) survey was also deployed during the Araon cruise to obtain information on seafloor topography and acoustic characteristics of subsurface sedimentary sequences. On the SBP data (ca. 70 m of the penetration depth), 3 stratigraphic units (SU-1, 2, 3 in ascending order) are recognized by 2 distinctive reflectors within the sequence. In some places, the lowermost boundary (5-20 m deep below seafloor) between SU-1 and 2 is characterized by channel-shaped erosional topography, which is interpreted to have been originated from incision by grounded glaciers or fluvial channels during the sea-level lowstand, most probably LGM. The boundary between SU-2 and 3 is characterized by a prolonged reflection with a relatively flat and low-relief topography in the inner continental shelf, whereas it gradually changes into a higher-relief reflector with small hummocks in the outer shelf and slope areas. Such acoustic and topographic characters are interpreted to indicate the irregular surface of cohesive mass-flow deposits (e.g. debrites and slump deposits). More specifically, the acoustic characters in the SBP data are classified into 5 echo facies on the basis of clarity, continuity, and shape of bottom and sub-bottom echoes together with seafloor topography. Echo facies IIA is most prominent type in SU-3 recorded from the continental

  11. Sensitivity to long-term climate change of subpermafrost groundwater systems in Svalbard

    NARCIS (Netherlands)

    Haldorsen, S.; Heim, M.; Dale, A.; Landvik, J.Y.; Ploeg, van der M.J.; Leijnse, A.; Salvigsen, O.; Ove Hagen, J.; Banks, D.

    2010-01-01

    Deep subpermafrost aquifers are highly climate-dependent, with the permafrost as an aquitard preventing groundwater recharge and discharge. A study from the high-arctic island of Spitsbergen, Svalbard, shows that during a glacial to interglacial phase, both the permafrost and the glacier regime will

  12. Minor impact of ocean acidification to the composition of the active microbial community in an Arctic sediment.

    Science.gov (United States)

    Tait, Karen; Laverock, Bonnie; Shaw, Jennifer; Somerfield, Paul J; Widdicombe, Steve

    2013-12-01

    Effects of ocean acidification on the composition of the active bacterial and archaeal community within Arctic surface sediment was analysed in detail using 16S rRNA 454 pyrosequencing. Intact sediment cores were collected and exposed to one of five different pCO(2) concentrations [380 (present day), 540, 750, 1120 and 3000 μatm] and RNA extracted after a period of 14 days exposure. Measurements of diversity and multivariate similarity indicated very little difference between pCO(2) treatments. Only when the highest and lowest pCO(2) treatments were compared were significant differences evident, namely increases in the abundance of operational taxonomic units most closely related to the Halobacteria and differences to the presence/absence structure of the Planctomycetes. The relative abundance of members of the classes Planctomycetacia and Nitrospira increased with increasing pCO(2) concentration, indicating that these groups may be able to take advantage of changing pH or pCO(2) conditions. The modest response of the active microbial communities associated with these sediments may be due to the low and fluctuating pore-water pH already experienced by sediment microbes, a result of the pH buffering capacity of marine sediments, or due to currently unknown factors. Further research is required to fully understand the impact of elevated CO(2) on sediment physicochemical parameters, biogeochemistry and microbial community dynamics.

  13. Untargeted Screening and Distribution of Organo-Iodine Compounds in Sediments from Lake Michigan and the Arctic Ocean.

    Science.gov (United States)

    Peng, Hui; Chen, Chunli; Cantin, Jenna; Saunders, David M V; Sun, Jianxian; Tang, Song; Codling, Garry; Hecker, Markus; Wiseman, Steve; Jones, Paul D; Li, An; Rockne, Karl J; Sturchio, Neil C; Cai, Minghong; Giesy, John P

    2016-09-20

    The majority of halogenated organic compounds present in the environment remain unidentified. To address this data gap, we recently developed an untargeted method (data-independent precursor isolation and characteristic fragment; DIPIC-Frag) for identification of unknown organo-bromine compounds. In this study, the method was adapted to enable untargeted screening of natural and synthetic organo-iodine compounds (NSOICs) in sediments. A total of 4,238 NSOIC peaks were detected in sediments from Lake Michigan. Precursor ions and formulas were determined for 2,991 (71%) of the NSOIC peaks. These compounds exhibited variations in abundances (<10(3) to ∼10(7)), m/z values (206.9304-996.9474), retention times (1.0-29.7 min), and number of iodine atoms (1-4). Hierarchical cluster analysis showed that sediments in closer proximity exhibited similar profiles of NSOICs. NSOICs were screened in 10 samples of sediment from the Arctic Ocean to compare the profiles of NSOICs between freshwater and marine sediments. A total of 3,168 NSOIC peaks were detected, and profiles of NSOICs in marine sediments were clearly distinct from Lake Michigan. The coexistence of brominated and iodinated analogues indicated that some NSOICs are of natural origin. Different ratios of abundances of iodinated compounds to brominated analogues were observed and proposed as a marker to distinguish sources of NSOICs.

  14. Marinomonas profundimaris sp. nov., isolated from deep-sea sediment sample of the Arctic Ocean.

    Science.gov (United States)

    Bai, Xiuhua; Lai, Qiliang; Dong, Chunming; Li, Fuying; Shao, Zongze

    2014-09-01

    A taxonomic study was carried out on strain D104(T), which was isolated from deep-sea subsurface sediment sample from the Arctic Ocean. The bacterium was found to be Gram-negative, oxidase negative and catalase weakly positive, rod shaped, motile by means of polar flagellum. The organism grows between 4 and 37 °C (optimum 25-28 °C) and 0.5-6 % NaCl (optimum 3 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain D104(T) belongs to the genus Marinomonas, with highest sequence similarities of 97.7 % to Marinomonas ushuaiensis DSM 15871(T), followed by M. dokdonensis DSW10-10(T) (96.9 %), M. arenicola KMM 3893(T) (96.7 %), M. arctica 328(T) (96.6 %) and other 18 species of the genus Marinomonas (94.4-96.5 %). The average nucleotide identity and estimated DNA-DNA hybridization values between strain D104(T) and M. ushuaiensis DSM 15871(T) were 84.24 % and 20.80 ± 2.33 % respectively. The principal fatty acids were C16:0, sum in feature 3 (C16:1 ω7c/C16:1 ω6c), sum in feature 8 (C18:1 ω7c/C18:1 ω6c) and C12:1 3OH. The G + C content of the chromosomal DNA was determined to be 44.8 mol%. The respiratory quinone was found to be Q8 (100 %). Polar lipids include phosphatidylglycerol and phosphatidylethanolamine as major phospholipids and aminolipid and phospholipid as minor components. The results of the genotypic and phenotypic analyses indicate that strain D104(T) represents a novel species of the genus Marinomonas, for which the name Marinomonas profundimaris sp. nov. is proposed, with the type strain D104(T) (=MCCC 1A07573(T) = LMG 27696(T)).

  15. Correlating microbial community profiles with geochemical data in highly stratified sediments from the Arctic Mid-Ocean Ridge.

    Science.gov (United States)

    Jorgensen, Steffen Leth; Hannisdal, Bjarte; Lanzén, Anders; Baumberger, Tamara; Flesland, Kristin; Fonseca, Rita; Ovreås, Lise; Steen, Ida H; Thorseth, Ingunn H; Pedersen, Rolf B; Schleper, Christa

    2012-10-16

    Microbial communities and their associated metabolic activity in marine sediments have a profound impact on global biogeochemical cycles. Their composition and structure are attributed to geochemical and physical factors, but finding direct correlations has remained a challenge. Here we show a significant statistical relationship between variation in geochemical composition and prokaryotic community structure within deep-sea sediments. We obtained comprehensive geochemical data from two gravity cores near the hydrothermal vent field Loki's Castle at the Arctic Mid-Ocean Ridge, in the Norwegian-Greenland Sea. Geochemical properties in the rift valley sediments exhibited strong centimeter-scale stratigraphic variability. Microbial populations were profiled by pyrosequencing from 15 sediment horizons (59,364 16S rRNA gene tags), quantitatively assessed by qPCR, and phylogenetically analyzed. Although the same taxa were generally present in all samples, their relative abundances varied substantially among horizons and fluctuated between Bacteria- and Archaea-dominated communities. By independently summarizing covariance structures of the relative abundance data and geochemical data, using principal components analysis, we found a significant correlation between changes in geochemical composition and changes in community structure. Differences in organic carbon and mineralogy shaped the relative abundance of microbial taxa. We used correlations to build hypotheses about energy metabolisms, particularly of the Deep Sea Archaeal Group, specific Deltaproteobacteria, and sediment lineages of potentially anaerobic Marine Group I Archaea. We demonstrate that total prokaryotic community structure can be directly correlated to geochemistry within these sediments, thus enhancing our understanding of biogeochemical cycling and our ability to predict metabolisms of uncultured microbes in deep-sea sediments.

  16. Norwegian fisheries in the Svalbard zone since 1980. Regulations, profitability and warming waters affect landings

    Science.gov (United States)

    Misund, Ole Arve; Heggland, Kristin; Skogseth, Ragnheid; Falck, Eva; Gjøsæter, Harald; Sundet, Jan; Watne, Jens; Lønne, Ole Jørgen

    2016-09-01

    The Svalbard archipelago in the High Arctic is influenced by cold Arctic water masses from the north-east and the warm West Spitsbergen Current flowing northwards along its western coast. The eastern waters and the fjords are normally frozen during the winter months, while the coastal waters west of the archipelago remain open. Norwegian fishers have been harvesting from Svalbard waters for decades and detailed records of catches exists from 1980 onwards. We analyze the catch records from the Svalbard zone (approximately ICES area IIb). The large fishery for capelin in summer yielding annual catches up to 737 000 tons was closed by a Norwegian fishery regulation in the mid nineteen nineties. Demersal fisheries have been continuous, and the results clearly indicate a northward trend in landings of Northeast Arctic cod, haddock, ling and Atlantic halibut. Fisheries of Northern shrimp have been more variable and shown no clear geographic trends. A "gold rush" fishery for scallops north of Svalbard lasted for about 10 years (1986-1995) only, and ended due to low profitably. These results are discussed in relation to the possibility of further northward extension of fisheries subjected to climate change.

  17. Desultovibrio frigidus sp nov and Desulfovibrio ferfireducens sp nov., psychrotolerant bacteria isolated from Arctic fiord sediments (Svalbard) with the ability to reduce Fe(III)

    DEFF Research Database (Denmark)

    Vandieken, V.; Knoblauch, C.; Jørgensen, BB

    2006-01-01

    (.)0-95(.)7% 16S rRNA gene sequence similarity), Strains 18(T) and 77, exhibiting 99(.)9% sequence similarity, represent a novel species for which the name Desulfovibrio frigidus sp. nov. is proposed. The type strain is strain 18(T) (=DSM 17176(T)=jCM 12924(T)). Strain 61(T) was closely related to strains 18(T...

  18. Pink marine sediments reveal rapid ice melt and Arctic meltwater discharge during Dansgaard-Oeschger warmings.

    Science.gov (United States)

    Rasmussen, Tine L; Thomsen, Erik

    2013-01-01

    The climate of the last glaciation was interrupted by numerous abrupt temperature fluctuations, referred to as Greenland interstadials and stadials. During warm interstadials the meridional overturning circulation was active transferring heat to the north, whereas during cold stadials the Nordic Seas were ice-covered and the overturning circulation was disrupted. Meltwater discharge, from ice sheets surrounding the Nordic Seas, is implicated as a cause of this ocean instability, yet very little is known regarding this proposed discharge during warmings. Here we show that, during warmings, pink clay from Devonian Red Beds is transported in suspension by meltwater from the surrounding ice sheet and replaces the greenish silt that is normally deposited on the north-western slope of Svalbard during interstadials. The magnitude of the outpourings is comparable to the size of the outbursts during the deglaciation. Decreasing concentrations of ice-rafted debris during the interstadials signify that the ice sheet retreats as the meltwater production increases.

  19. Relatively high antibiotic resistance among heterotrophic bacteria from arctic fjord sediments than water - Evidence towards better selection pressure in the fjord sediments

    Science.gov (United States)

    Hatha, A. A. Mohamed; Neethu, C. S.; Nikhil, S. M.; Rahiman, K. M. Mujeeb; Krishnan, K. P.; Saramma, A. V.

    2015-12-01

    The objective of this study was to determine the prevalence of antibiotic resistance among aerobic heterotrophic bacteria and coliform bacteria from water and sediment of Kongsfjord. The study was based on the assumption that arctic fjord environments are relatively pristine and offer very little selection pressure for drug resistant mutants. In order to test the hypothesis, 200 isolates belonging to aerobic heterotrophic bacteria and 114 isolates belonging to coliforms were tested against 15 antibiotics belonging to 5 different classes such as beta lactams, aminoglycosides, quinolones, sulpha drugs and tetracyclines. Resistance to beta lactam and extended spectrum beta lactam (ESBL) antibiotics was considerably high and they found to vary significantly (p antibiotic resistance against ESBL's extent and diversity of antibiotic resistance (as revealed by multiple antibiotic resistance index and resistance patterns), was high in the aerobic heterotrophic bacteria. Most striking observation was that isolates from fjord sediments (both heterotrophic bacteria and coliforms) in general showed relatively high prevalence of antibiotic resistance against most of the antibiotics tested, indicating to better selection pressure for drug resistance mutants in the fjord sediments.

  20. Levels of toxaphene congeners in white whales (Delphinapterus leucas) from Svalbard, Norway.

    Science.gov (United States)

    Andersen, G; Føreid, S; Skaare, J U; Jenssen, B M; Lydersen, C; Kovacs, K M

    2006-03-15

    This study reports concentrations of three pesticide toxaphene congeners (CHBs; CHB-26, -50 and -62) from the blubber of ten adult, male white whales (Delphinapterus leucas) from Svalbard, Norway. The CHB congeners that occurred at the highest levels in the blubber of the white whales were, as expected, CHB-26 (4636+/-1992 (SD) ng/g l.w.) and CHB-50 (6579+/-2214 ng/g l.w.); CHB-62 (232+/-231 ng/g l.w.) was also present, but at much lower concentrations. The mean level of the sum of the three CHBs (SigmaCHBs = 11,447+/-4208 ng/g l.w.) in this study is more than twice the mean concentrations of the well-known organochlorine (OC) pollutants SigmaDDTs (sum of pp'-DDT, pp'-DDE, pp'-DDD) and SigmaPCBs (sum of 27 PCB congeners) previously reported from the same individual white whales. The concentrations of CHBs in white whales from Svalbard are at the high end of the range for concentrations of these compounds compared to other Arctic white whale populations. Additionally, the contribution of CHBs to the overall OC burden is larger in white whales from Svalbard compared with their counterparts from other areas in the Arctic. Male white whales from Svalbard have several orders of magnitude higher concentrations of SigmaCHBs compared to seals and polar bears (Ursus maritimus) from the same area. The high levels of CHBs in these whales, and their dominance in the OC pattern, suggests that white whales in Svalbard are exposed to high levels of this group of contaminants. Further studies are needed to investigate possible effects of CHBs and other OC contaminants on the white whale population in Svalbard.

  1. Organic carbon and nitrogen isotopes in surface sediments from the western Arctic Ocean and their implications for sedimentary environments

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhihua; SHI Xuefa; CAI Deling; HAN Yibing; YANG Zuosheng

    2006-01-01

    Surface sediments from the Chukchi Sea and adjacent arctic deep sea were investigated for organic carbon and nitrogen isotopes (in δ13Corg and δ15Norg) as well as biogenic silica (BSiO2). δ13Corg and δ15Norg values of surface sediments in the study area fall between the end-member values of marine and terrestrial organic matter from the surrounding lands and seas, their variations reflect the changes of marine productivity and terrestrial supply in the study area. BSiO2 shows a similar distribution pattern with δ13Corg and δ15Norg, and can be used as an indicator of marine productivity. In the central-west Chukchi Sea and the Chukchi Rise, sediments have higher δ13Corg, δ15Norg and BSiO2 values, indicating the region has high marine productivity influenced by the nutrient-rich branches of the Pacific waters. In the coastal zone off northwestern Alaska, δ13Corg and δ15Norg values become lighter, indicating a weakening marine productivity and an increasing terrigenous supply due to the effects of the least nutrient-rich branch of the Pacific waters. In the north and the northeast of the study area (including the Chukchi Plateau, the Canada Basin and the Beaufort shelf), δ13Corg, δ15Norg and BSiO2 have the lowest values, and the terrigenous organic matter becomes dominant in surface sediments because this region has the longest ice-covered duration, the least nutrient-rich seawater and the increasing supply of terrestrial materials from the Mackenzie River and the northern Alaska under the action of the clockwise Beaufort gyre. Because the subarctic Pacific waters are continuously discharged into the central basin of the Arctic Ocean through the study area, the nutrient pool in the Chukchi Sea can be considered as a typical open system, the ratio of δ15N to BSiO2 content show some tracers that the level of nutrient utilization is contrary to nutrient supply and marine productivity formed in seawater.

  2. Hydrography of the West Spitsbergen Current, Svalbard Branch: Autumn 2001

    Science.gov (United States)

    Cokelet, Edward D.; Tervalon, Nicole; Bellingham, James G.

    2008-01-01

    The Atlantic inflow is the primary source of water and heat to the Arctic Ocean. A large portion enters through Fram Strait where it splits into the Yermak and Svalbard Branches. In October to November 2001 the USCGC Healy occupied five oceanographic transects across the Svalbard Branch west and north of Spitsbergen. Temperature and salinity sections show the warm, salty Atlantic Water cooling and freshening as it flows along the continental slope for 553 km. The temperature in the upper 500 m of the water column decreased by 0.25°C/(100 km) implying a heat flux across the sea surface of up to 520 W/m2 if one assumes a nominal current of speed of 0.1 m/s. A temperature-salinity (T-S) analysis shows that the shape of the T-S curves can be explained in terms of the ratio of the atmospheric-to-ice-melt heat flux. The observations imply that ice melt accounts for progressively more surface cooling as the flow moves toward the Arctic Ocean. An autonomous underwater vehicle completed a vertical section in the region of maximum water mass gradient and revealed layer interleaving in fine detail. Data from this cruise extend a long time series of Atlantic layer source temperature beginning in 1910 (Saloranta and Haugan, 2001). The extended observations show that after the temperature of the Atlantic layer inflow reached a peak in 1992, it cooled to a minimum in 1998 and rose again through 2001.

  3. Distribution of molluscan remains in the sediment of the Chukchi Sea and its vicinity, the Arctic

    Institute of Scientific and Technical Information of China (English)

    Gao Aiguo; Xu Fengshan; Sun Haiqing; Li Lon

    2003-01-01

    The result of an analysis of mollusca remains collected from the Chukchi Sea, Beaufort Sea and Bering Sea in the First Chinese National Arctic Research Expedition, from July to September,1999 is presented. Seventeen species of mollusca have been identified, which belong to two classes: Bivalvia and Gastropoda. The compositions of the mollusca are very simple. According to the distribution pattern two groups may be distinguished among molluscan species. The Pan-Arctic and circumboreal group comprises Nuculana pernula, N. radiata, Nucula bellotii, Astarte montagui, Seripes groenlandicus, Macoma calcarea, M. moesta alaskana, Liocyma fluctuosa, Mya pseudoarenaria and Turritella polaris. Three species, Cyclocardia crebricos tata, Trichotrois coronata and Argobuccinum oregonense are components of the Pan-Arctic and Pacific boreal group. With regard to feeding habits, detritus feeders dominate. There are 7 species of detritus feeders, i.e. , Nuculana pernula, N. radiata,Nucula bellotii , Macoma calcarea , M. moesta alaskana , Macoma sp. and Trichotropis coronata . Detritus feeders are dominant with regard to the numbers of species as well as to the frequency of occurrence. Macoma calcarea is the most abundant species.

  4. The importance of tidewater glaciers for marine mammals and seabirds in Svalbard, Norway

    Science.gov (United States)

    Lydersen, Christian; Assmy, Philipp; Falk-Petersen, Stig; Kohler, Jack; Kovacs, Kit M.; Reigstad, Marit; Steen, Harald; Strøm, Hallvard; Sundfjord, Arild; Varpe, Øystein; Walczowski, Waldek; Weslawski, Jan Marcin; Zajaczkowski, Marek

    2014-01-01

    Approximately 60% of Svalbard's land areas are glaciated at the present time. The Archipelago has more than 1100 glaciers (> 1 km2) and 163 of these are “tidewater glaciers” - that is glaciers that terminate (with their calving front) at the sea. It has been known for a long time that these glacier front areas are important feeding areas for seabirds and marine mammals. Herein, we review current knowledge regarding the importance of these areas for these animals and reflect upon the processes that create these apparent “hotspots”. Kittiwakes Rissa tridactyla, routinely dominate avian assemblages in front of glaciers in Svalbard, but fulmars Fulmarus glacialis, ivory gulls Pagophila eburnea and glaucous gulls Larus hyperboreus also contribute to aggregations, which can sometimes comprise many thousands of individuals. The birds are often found in the so-called “brown zone”, which is an area in front of tidewater glaciers that is ice-free due to currents and muddy due to suspended sediments. Animals at these sites typically have their stomachs full of large zooplankton or fish. These brown zones are also foraging hotspots for Svalbard's ringed seals (Pusa hispida) and white whales (Delphinapterus leucas). Prime breeding habitat for ringed seals in Svalbard occurs deep in the fjords where ice pieces calved from the glacier fronts become frozen into land-fast sea-ice, promoting the accumulation of snow to a depth suitable for ringed seal females to dig out birth lairs above breathing holes in the ice. These pupping areas are important hunting areas for polar bears (Ursus maritimus) in spring, especially female bears with cubs of the year during the period following emergence from the winter/birthing den. Glacier-ice pieces floating in coastal areas are also important for all seal species in the region as dry platforms during moulting and also as general resting platforms for both birds and seals. During the last decade there have been several years with a

  5. Fluid composition of the sediment-influenced Loki's Castle vent field at the ultra-slow spreading Arctic Mid-Ocean Ridge

    Science.gov (United States)

    Baumberger, Tamara; Früh-Green, Gretchen L.; Thorseth, Ingunn H.; Lilley, Marvin D.; Hamelin, Cédric; Bernasconi, Stefano M.; Okland, Ingeborg E.; Pedersen, Rolf B.

    2016-08-01

    The hydrothermal vent field Loki's Castle is located in the Mohns-Knipovich bend (73°N) of the ultraslow spreading Arctic Mid-Ocean Ridge (AMOR) close to the Bear Island sediment fan. The hydrothermal field is venting up to 320° C hot black smoker fluids near the summit of an axial volcanic ridge. Even though the active chimneys have grown on a basaltic ridge, geochemical fluid data show a strong sedimentary influence into the hydrothermal circulation at Loki's Castle. Compelling evidence for a sediment input is given by high alkalinity, high concentrations of NH4+, H2, CH4, C2+ hydrocarbons as well as low Mn and Fe contents. The low δ13C values of CO2 and CH4 and the thermogenic isotopic pattern of the C2+ hydrocarbons in the high-temperature vent fluids clearly point to thermal degradation of sedimentary organic matter and illustrate diminution of the natural carbon sequestration in sediments by hydrothermal circulation. Thus, carbon-release to the hydrosphere in Arctic regions is especially relevant in areas where the active Arctic Mid-Ocean Ridge system is in contact with the organic matter rich detrital sediment fans.

  6. Magnetostratigraphy of sediments from Lake El'gygytgyn ICDP Site 5011-1: paleomagnetic age constraints for the longest paleoclimate record from the continental Arctic

    Directory of Open Access Journals (Sweden)

    E. M. Haltia

    2013-09-01

    Full Text Available Paleomagnetic measurements were performed on sediments drilled from ICDP Site 5011-1 in Lake El'gygytgyn (67°30' N, 172°05' E located in Far East Russian Arctic. The lake fills partly a crater formed by a meteorite impact 3.58 ± 0.04 Ma ago. Sediments from three parallel cores (5011-1A, 5011-1B and 5011-1C, recovered from the middle part of the lake, yielded a total of 355 m of sediment. Sediments are characterized by variable lithology, where intervals of homogenous and laminated sediments alternate, and mass movement deposits of variable thickness occur frequently along the sediment profile. Mineral magnetic investigation made on sediments enclosed in core catchers suggests that magnetic carrier in these sediments is partly maghemitized Ti-rich pseudo-single domain magnetite. Its detrital origin could be shown by mineral magnetic measurements and SEM-EDS analyses performed on mini-sized cylindrical rock samples, polished rock sections, creek sediments and magnetic extracts prepared from them. The intensity of the natural remanent magnetization (NRM in the sediments is mainly high with a range from about 1 to 1000 mA m−1. Most of the sediments carry a stable magnetization component interpreted as primary depositional remanent magnetization. Characteristic inclination data show alternating intervals of steep positive and negative inclinations that were used to assign magnetic polarity to the lake sediment profile. This was a rather straightforward procedure owing to the mainly high quality of data. The Matuyama/Gauss (2.608 Ma and Brunhes/Matuyama (0.780 Ma reversals were recognized in the sediments. Furthermore, during the Gauss chron the Mammoth and Kaena reversed subchrons, and during the Matuyama, the Olduvai and Jaramillo normal subchrons, as well as the Réunion and Cobb Mountain cryptochrons were identified. Sediment deposition rate is highest at the base of the sequence laid down in the beginning of Gauss chron, when deposition rate

  7. Regional variations in provenance and abundance of ice-rafted clasts in Arctic Ocean sediments: Implications for the configuration of late Quaternary oceanic and atmospheric circulation in the Arctic

    Science.gov (United States)

    Phillips, R.L.; Grantz, A.

    2001-01-01

    The composition and distribution of ice-rafted glacial erratics in late Quaternary sediments define the major current systems of the Arctic Ocean and identify two distinct continental sources for the erratics. In the southern Amerasia basin up to 70% of the erratics are dolostones and limestones (the Amerasia suite) that originated in the carbonate-rich Paleozoic terranes of the Canadian Arctic Islands. These clasts reached the Arctic Ocean in glaciers and were ice-rafted to the core sites in the clockwise Beaufort Gyre. The concentration of erratics decreases northward by 98% along the trend of the gyre from southeastern Canada basin to Makarov basin. The concentration of erratics then triples across the Makarov basin flank of Lomonosov Ridge and siltstone, sandstone and siliceous clasts become dominant in cores from the ridge and the Eurasia basin (the Eurasia suite). The bedrock source for the siltstone and sandstone clasts is uncertain, but bedrock distribution and the distribution of glaciation in northern Eurasia suggest the Taymyr Peninsula-Kara Sea regions. The pattern of clast distribution in the Arctic Ocean sediments and the sharp northward decrease in concentration of clasts of Canadian Arctic Island provenance in the Amerasia basin support the conclusion that the modem circulation pattern of the Arctic Ocean, with the Beaufort Gyre dominant in the Amerasia basin and the Transpolar drift dominant in the Eurasia basin, has controlled both sea-ice and glacial iceberg drift in the Arctic Ocean during interglacial intervals since at least the late Pleistocene. The abruptness of the change in both clast composition and concentration on the Makarov basin flank of Lomonosov Ridge also suggests that the boundary between the Beaufort Gyre and the Transpolar Drift has been relatively stable during interglacials since that time. Because the Beaufort Gyre is wind-driven our data, in conjunction with the westerly directed orientation of sand dunes that formed during

  8. Phylogenetic diversity and biological activity of actinobacteria isolated from the Chukchi Shelf marine sediments in the Arctic Ocean.

    Science.gov (United States)

    Yuan, Meng; Yu, Yong; Li, Hui-Rong; Dong, Ning; Zhang, Xiao-Hua

    2014-03-06

    Marine environments are a rich source of Actinobacteria and have the potential to produce a wide variety of biologically active secondary metabolites. In this study, we used four selective isolation media to culture Actinobacteria from the sediments collected from the Chukchi Shelf in the Arctic Ocean. A total of 73 actinobacterial strains were isolated. Based on repetitive DNA fingerprinting analysis, we selected 30 representatives for partial characterization according to their phylogenetic diversity, antimicrobial activities and secondary-metabolite biosynthesis genes. Results from the 16S rRNA gene sequence analysis indicated that the 30 strains could be sorted into 18 phylotypes belonging to 14 different genera: Agrococcus, Arsenicicoccus, Arthrobacter, Brevibacterium, Citricoccus, Janibacter, Kocuria, Microbacterium, Microlunatus, Nocardioides, Nocardiopsis, Saccharopolyspora, Salinibacterium and Streptomyces. To our knowledge, this paper is the first report on the isolation of Microlunatus genus members from marine habitats. Of the 30 isolates, 11 strains exhibited antibacterial and/or antifungal activity, seven of which have activities against Bacillus subtilis and Candida albicans. All 30 strains have at least two biosynthetic genes, one-third of which possess more than four biosynthetic genes. This study demonstrates the significant diversity of Actinobacteria in the Chukchi Shelf sediment and their potential for producing biologically active compounds and novel material for genetic manipulation or combinatorial biosynthesis.

  9. Formate, acetate, and propionate as substrates for sulfate reduction in sub-arctic sediments of Southwest Greenland

    DEFF Research Database (Denmark)

    Glombitza, Clemens; Jaussi, Marion; Røy, Hans;

    2015-01-01

    Volatile fatty acids (VFAs) are key intermediates in the anaerobic mineralization of organic matter in marine sediments. We studied the role of VFAs in the carbon and energy turnover in the sulfate reduction zone of sediments from the sub-arctic Godthåbsfjord (SW Greenland) and the adjacent...... continental shelf in the NE Labrador Sea. VFA porewater concentrations were measured by a new two-dimensional ion chromatography-mass spectrometry method that enabled the direct analysis of VFAs without sample pretreatment. VFA concentrations were low and surprisingly constant (4–6 μmol L−1 for formate...... to −16 kJ (mol formate)−1, −68 to −31 kJ (mol acetate)−1, and −124 to −65 kJ (mol propionate)−1. Thus, ΔGr is apparently not determining the in-situ VFA concentrations directly. However, at the bottom of the sulfate zone of the shelf station, acetoclastic sulfate reduction might operate at its energetic...

  10. Widespread methane seepage along the continental margin off Svalbard - from Bjørnøya to Kongsfjorden

    Science.gov (United States)

    Mau, S.; Römer, M.; Torres, M. E.; Bussmann, I.; Pape, T.; Damm, E.; Geprägs, P.; Wintersteller, P.; Hsu, C.-W.; Loher, M.; Bohrmann, G.

    2017-01-01

    Numerous articles have recently reported on gas seepage offshore Svalbard, because the gas emission from these Arctic sediments was thought to result from gas hydrate dissociation, possibly triggered by anthropogenic ocean warming. We report on findings of a much broader seepage area, extending from 74° to 79°, where more than a thousand gas discharge sites were imaged as acoustic flares. The gas discharge occurs in water depths at and shallower than the upper edge of the gas hydrate stability zone and generates a dissolved methane plume that is hundreds of kilometer in length. Data collected in the summer of 2015 revealed that 0.02–7.7% of the dissolved methane was aerobically oxidized by microbes and a minor fraction (0.07%) was transferred to the atmosphere during periods of low wind speeds. Most flares were detected in the vicinity of the Hornsund Fracture Zone, leading us to postulate that the gas ascends along this fracture zone. The methane discharges on bathymetric highs characterized by sonic hard grounds, whereas glaciomarine and Holocene sediments in the troughs apparently limit seepage. The large scale seepage reported here is not caused by anthropogenic warming. PMID:28230189

  11. Colonies of Gyrosigma eximium: a new phenomenon in Arctic tidal flats

    Directory of Open Access Journals (Sweden)

    Józef Wiktor

    2016-10-01

    Full Text Available For the first time at Svalbard, a colonial form of the tube-dwelling diatom Gyrosigma eximium was found in summer 2010 in the tidal flats on Spitsbergen at 78°N. The colonies take the form of conical, green structures that are 1–2 cm high and are associated with other diatom taxa and cyanobacteria (Oscillatoriaceae. The diatom colonies were associated with rich meiofauna and apparently act as cohesive factors for the fine sediment. In the Arctic tidal flats, this represents the first observation of long-term sediment stabilization and biological enrichment. Since this first observation, this species has apparently colonized broader areas in Advenentelva's tidal flat.

  12. An inter-laboratory investigation of the Arctic sea ice biomarker proxy IP25 in marine sediments: key outcomes and recommendations

    Directory of Open Access Journals (Sweden)

    S. T. Belt

    2013-09-01

    Full Text Available We describe the results of an inter-laboratory investigation into the identification and quantification of the Arctic sea ice biomarker proxy IP25 in marine sediments. 7 laboratories took part in the study, which consisted of the analysis of IP25 in a series of sediment samples from different regions of the Arctic, sub-Arctic and Antarctic, additional sediment extracts and purified standards. The results obtained allowed 4 key outcomes to be determined. First, IP25 was identified by all laboratories in sediments from the Canadian Arctic with inter-laboratory variation in IP25 concentration being substantially larger than within individual laboratories. This greater variation between laboratories was attributed to the difficulty in accurately determining instrumental response factors for IP25, despite provision of appropriate standards. Second, the identification of IP25 by 3 laboratories in sediment from SW Iceland that was believed to represent a blank, was interpreted as representing a better limit of detection or quantification for such laboratories, contamination or mis-identification. These alternatives could not be distinguished conclusively with the data available, although it is noted that the precision of these data was significantly poorer compared with the other IP25 concentration measurements. Third, 3 laboratories reported the occurrence of IP25 in a sediment sample from the Antarctic Peninsula even though this biomarker is believed to be absent from the Southern Ocean. This anomaly is attributed to a combined chromatographic and mass spectrometric interference that results from the presence of a di-unsaturated highly branched isoprenoid (HBI pseudo-homologue of IP25 that occurs in Antarctic sediments. Finally, data are presented that suggest that extraction of IP25 is consistent between Automated Solvent Extraction (ASE and sonication methods and that IP25 concentrations based on 7-hexylnonadecane as an internal standard are

  13. Quantitative and phylogenetic study of the Deep Sea Archaeal Group in sediments of the arctic mid-ocean spreading ridge

    Directory of Open Access Journals (Sweden)

    Steffen Leth eJørgensen

    2013-10-01

    Full Text Available In marine sediments archaea often constitute a considerable part of the microbial community, of which the Deep Sea Archaeal Group (DSAG is one of the most predominant. Despite their high abundance no members from this archaeal group have so far been characterized and thus their metabolism is unknown. Here we show that the relative abundance of DSAG marker genes can be correlated with geochemical parameters, allowing prediction of both the potential electron donors and acceptors of these organisms. We estimated the abundance of 16S rRNA genes from Archaea, Bacteria and DSAG in 52 sediment horizons from two cores collected at the slow-spreading Arctic Mid-Ocean Ridge, using qPCR. The results indicate that members of the DSAG make up the entire archaeal population in certain horizons and constitute up to ~ 50% of the total microbial community. The quantitative data were correlated to 30 different geophysical and geochemical parameters obtained from the same sediment horizons. We observed a significant correlation between the relative abundance of DSAG 16S rRNA genes and the content of organic carbon (p < 0.0001. Further, significant co-variation with iron oxide, and dissolved iron and manganese (all p < 0.0000, indicated a direct or indirect link to iron and manganese cycling. Neither of these parameters correlated with the relative abundance of archaeal or bacterial 16S rRNA genes, nor did any other major electron donor or acceptor measured. Phylogenetic analysis of DSAG 16S rRNA gene sequences reveals three monophyletic lineages with no apparent habitat-specific distribution. In this study we support the hypothesis that members of the DSAG are tightly linked to the content of organic carbon and directly or indirectly involved in the cycling of iron and/or manganese compounds. Further, we provide a molecular tool to assess their abundance in environmental samples and enrichment cultures.

  14. Chlorophyll a in Arctic sediments implies long persistence of algal pigments

    Science.gov (United States)

    Pirtle-Levy, Rebecca; Grebmeier, Jacqueline M.; Cooper, Lee W.; Larsen, Ingvar L.

    2009-08-01

    Sediment cores were collected from the shelf, slope, and basin of the Bering, Chukchi, and Beaufort Seas during May-June (under ice cover) and July-August (largely ice-free) 2004. Measurements of chlorophyll a (chl a), total organic carbon (TOC), and C/N ratios were made in surface and some subsurface core increments. Surface sediment chl a decreased with increasing water depth. Significant positive correlations were found between chl a and TOC and chl a and C/N ratios in the basin (>2000 m), but there were significant negative correlations between chl a and C/N ratios on the shelf (⩽200 m). Chl a values generally declined in down-core profiles, but in some deeper slope and basin cores, measurable inventories of subsurface chl a were present at depth. In some cases, these subsurface chlorophyll inventories coincident with peak activities of the anthropogenic radionuclide 137Cs were detected, which had maximal deposition following the atmospheric nuclear weapons testing era in the 1960s. A sedimentation rate independently determined for one of these cores using 210Pb was consistent with the depths of subsurface 137Cs peaks in slope sediments reflecting steady, relatively undisturbed deposition over a several-decade period. The depth of penetration of 137Cs in some continental slope sediments, together with detectable chl a, suggests that chl a can be buried in some of these deeper-water sediments under cold conditions for decadal periods in the absence of deposit feeders. Because organic deposition from the water column is episodic at high latitudes and concentrated following the spring bloom, these buried sources of organic materials, whether on the shelf or in deeper basin sediments, may ultimately be important for benthic invertebrates that could utilize this food source during times of the year when primary production flux from the overlying water column is reduced.

  15. Mass Flux of Water, Sediments and Chemical Constituents to the Laptev Sea of the Russian Arctic via the Lena River

    Science.gov (United States)

    Armstrong, S. J.; Karabonov, E. B.; Styles, R.; Buchinskyi, V.; Williams, D. F.; Kuzmin, M. I.

    2004-12-01

    The Lena River, one of the world's longest rivers, stretches from southern Siberia, north of Lake Baikal and is the second largest river contributing to the freshwater budget of the Arctic Ocean. During the summer of 2003, ADCP transects of the river's currents, bathymetry and acoustic backscatter were repeated for 500km reaches and at each major tributary, covering over 3,600km of the river's length. Concurrently, multi-parameter CTD casts, water chemistry and sediment concentrations were sampled. Preliminary results show water flow through the river increased with distance from the headwaters (150m3/s) and increased greatly with contributions from the many tributaries along the river's length, reaching a peak (over 37,000m3/s) 64km before the delta at Stolb. Approximately 94% of the Lena's discharge through the delta was accounted for using ADCP flow calculations from transects in three primary distributaries through the delta. To determine the influence of tidal pumping at the mouth, the principle navigation distributary (Bykovskaya) was resampled at the interface with the Laptev Sea, (mouth of Neelov Bay, near Tiksi), repeatedly over a 40-hour interval revealing a lunar semidiurnal period amplitude of oscillation in flow of the same order magnitude as the `subtidal' discharge. Well-mixed thermohaline profiles were evident in the ebb discharge, but during flood, the water was thermally stratified. The net flux through the mouth accounted for only 70% of the flow to the upper reaches of the same channel (Bykovskaya). A comparison with a historic record of Lena flow places the 2003 samples in phase and approximately equal to the 60-year average. The high resolution ADCP sampling of the currents and acoustic backscatter throughout the measured cross-sections were repeated two-three times per station. Net isopleths of flux will be constructed based on the average of the repeated ADCP transects. The net isopleths will then be used to extrapolate chemistry and

  16. Reconstruction of a high-resolution late holocene arctic paleoclimate record from Colville River delta sediments.

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, Kathryn Melissa; Lowry, Thomas Stephen

    2013-10-01

    This work was partially supported by the Sandia National Laboratories, Laboratory Directed Research and Development (LDRD) fellowship program in conjunction with Texas A&M University (TAMU). The research described herein is the work of Kathryn M. Schreiner (Katie) and her advisor, Thomas S. Bianchi and represents a concise description of Katies dissertation that was submitted to the TAMU Office of Graduate Studies in May 2013 in partial fulfillment of her doctorate of philosophy degree. High Arctic permafrost soils contain a massive amount of organic carbon, accounting for twice as much carbon as what is currently stored as carbon dioxide in the atmosphere. However, with current warming trends this sink is in danger of thawing and potentially releasing large amounts of carbon as both carbon dioxide and methane into the atmosphere. It is difficult to make predictions about the future of this sink without knowing how it has reacted to past temperature and climate changes. This project investigated long term, fine scale particulate organic carbon (POC) delivery by the high-Arctic Colville River into Simpsons Lagoon in the near-shore Beaufort Sea. Modern POC was determined to be a mixture of three sources (riverine soils, coastal erosion, and marine). Downcore POC measurements were performed in a core close to the Colville River output and a core close to intense coastal erosion. Inputs of the three major sources were found to vary throughout the last two millennia, and in the Colville River core covary significantly with Alaskan temperature reconstructions.

  17. Impacts of Ocean Acidification on Sediment Processes in Shallow Waters of the Arctic Ocean

    NARCIS (Netherlands)

    Gazeau, F.; van Rijswijk, P.; Pozzato, L.; Middelburg, J.J.

    2014-01-01

    Despite the important roles of shallow-water sediments in global biogeochemical cycling, the effects of ocean acidification on sedimentary processes have received relatively little attention. As high-latitude cold waters can absorb more CO2 and usually have a lower buffering capacity than warmer wat

  18. Impacts of ocean acidification on sediment processes in shallow waters of the Arctic Ocean

    NARCIS (Netherlands)

    Gazeau, F.; van Rijswijk, P.; Pozzato, L.; Middelburg, J.J.

    2014-01-01

    Despite the important roles of shallow-water sediments in global biogeochemical cycling, the effects of ocean acidification on sedimentary processes have received relatively little attention. As high-latitude cold waters can absorb more CO2 and usually have a lower buffering capacity than warmer wat

  19. Screening and Characterization of Cold-Active β-Galactosidase Producing Psychrotrophic Enterobacter ludwigii from the Sediments of Arctic Fjord.

    Science.gov (United States)

    Alikkunju, Aneesa P; Sainjan, Neethu; Silvester, Reshma; Joseph, Ajith; Rahiman, Mujeeb; Antony, Ally C; Kumaran, Radhakrishnan C; Hatha, Mohamed

    2016-10-01

    Low-temperature-tolerant microorganisms and their cold-active enzymes could be an innovative and invaluable tool in various industrial applications. In the present study, bacterial isolates from the sediment samples of Kongsfjord, Norwegian Arctic, were screened for β-galactosidase production. Among the isolates, KS25, KS85, KS60, and KS92 have shown good potential in β-galactosidase production at 20 °C. 16SrRNA gene sequence analysis revealed the relatedness of the isolates to Enterobacter ludwigii. The optimum growth temperature of the isolate was 25 °C. The isolate exhibited good growth and enzyme production at a temperature range of 15-35 °C, pH 5-10. The isolate preferred yeast extract and lactose for the maximum growth and enzyme production at conditions of pH 7.0, temperature of 25 °C, and agitation speed of 100 rpm. The growth and enzyme production was stimulated by Mn(2+) and Mg(2+) and strongly inhibited by Zn(2+), Ni(2+), and Cu(+). β-Galactosidases with high specific activity at low temperatures are very beneficial in food industry to compensate the nutritional problem associated with lactose intolerance. The isolate exhibited a remarkable capability to utilize clarified whey, an industrial pollutant, for good biomass and enzyme yield and hence could be well employed in whey bioremediation.

  20. Anoxic carbon degradation in Arctic sediments: Microbial transformations of complex substrates

    DEFF Research Database (Denmark)

    Arnosti, Carol; Finke, Niko; Larsen, Ole

    2005-01-01

    Complex substrates are degraded in anoxic sediments by the concerted activities of diverse microbial communities. To explore the effects of substrate complexity on carbon transformations in permanently cold anoxic sediments, four substrates—Spirulina cells, Isochrysis cells, and soluble high...... of carbon degradation diverged, with an additional 43%, 32%, 33%, and 8% of Isochrysis, Iso-Ex, Spirulina, and Spir-Ex carbon respired to CO2 over the next 750 h of incubation. Somewhat surprisingly, the soluble, carbohydrate-rich extracts did not prove to be more labile substrates than the whole cells from...... which they were derived. Although Spirulina and Iso-Ex differed in physical and chemical characteristics (solid/soluble, C/N ratio, lipid and carbohydrate content), nearly identical quantities of carbon were respired to CO2. In contrast, only 15% of Spir-Ex carbon was respired, despite the initial burst...

  1. Bioprospecting around Arctic islands: Marine bacteria as rich source of biocatalysts.

    Science.gov (United States)

    De Santi, Concetta; Altermark, Bjørn; de Pascale, Donatella; Willassen, Nils-Peder

    2016-03-01

    We have investigated the biotechnological potential of Arctic marine bacteria for their ability to produce a broad spectrum of cold-active enzymes. Marine bacteria exhibiting these features are of great interest for both fundamental research and industrial applications. Macrobiota, water and sediment samples have been collected during 2010 and 2011 expeditions around the Lofoten and Svalbard islands. Bacteria were isolated from this material and identified through 16S rRNA gene sequence analysis for the purpose of establishing a culture collection of marine Arctic bacteria. Herein, we present the functional screening for different extracellular enzymatic activities from 100 diversely chosen microbial isolates incubated at 4 and 20 °C. The production of esterase/lipase, DNase, and protease activities were revealed in 67, 53, and 56% of the strains, respectively, while 41, 23, 9, and 7% of the strains possessed amylase, chitinase, cellulase, and xylanase activities, respectively. Our findings show that phylogenetically diverse bacteria, including many new species, could be cultured from the marine arctic environment. The Arctic polar environment is still an untapped reservoir of biodiversity for bioprospecting.

  2. Frontal destabilization of Stonebreen, Edgeøya, Svalbard

    Science.gov (United States)

    Strozzi, Tazio; Kääb, Andreas; Schellenberger, Thomas

    2017-02-01

    In consideration of the strong atmospheric warming that has been observed since the 1990s in polar regions there is a need to quantify mass loss of Arctic ice caps and glaciers and their contribution to sea level rise. In polar regions a large part of glacier ablation is through calving of tidewater glaciers driven by ice velocities and their variations. The Svalbard region is characterized by glaciers with rapid dynamic fluctuations of different types, including irreversible adjustments of calving fronts to a changing mass balance and reversible, surge-type activities. For large areas, however, we do not have much past and current information on glacier dynamic fluctuations. Recently, through frequent monitoring based on repeat optical and synthetic aperture radar (SAR) satellite data, a number of zones of velocity increases have been observed at formerly slow-flowing calving fronts on Svalbard. Here we present the dynamic evolution of the southern lobe of Stonebreen on Edgeøya. We observe a slowly steady retreat of the glacier front from 1971 until 2011, followed by a strong increase in ice surface velocity along with a decrease of volume and frontal extension since 2012. The considerable losses in ice thickness could have made the tide-water calving glacier, which is grounded below sea level some 6 km inland from the 2014 front, more sensitive to surface meltwater reaching its bed and/or warm ocean water increasing frontal ablation with subsequent strong multi-annual ice-flow acceleration.

  3. Stratigraphy and Glacial-Marine Sediments of the Amerasian Basin, Central Arctic Ocean.

    Science.gov (United States)

    1981-02-01

    particles and conducting an electronic si/C analisis of the material that passed through the sieve A, using a I A 11 Coulter counter. I he (oulter...Ocean mechanists. Normal pelagic and glacially dericd fine matelital are glacial-marine sediment should he viewed as a complex process distributed...meatn prain si/(i \\;ei iiade heisseri iis ri r it( f xindil atrca fac sedimencrt I\\. PCs at h Ii 05 0-1irf~ifr I. live) 11it11%~ iisr I tii basic

  4. Response of fermentation and sulfate reduction to experimental temperature changes in temperate and Arctic marine sediments

    DEFF Research Database (Denmark)

    Finke, Niko; Jørgensen, Bo Barker

    2008-01-01

    Anaerobic degradation of organic material generally proceeds through a sequence of steps, including polymer hydrolysis, fermentation and respiration or methanogenesis. The intermediates, such as volatile fatty acids (VFA) or H(2), are generally maintained at low concentration, showing a close...... coupling of the terminal oxidation to fermentation. We exposed marine sediments to extreme temperature perturbations to study the nature and robustness of this coupling. Bacterial sulfate reduction and its dependence on fermentation were studied experimentally over a broad temperature range of -0.3 to 40...... optimum temperature was higher and did not change with incubation time. Up to a critical temperature, the concentrations of VFA remained low, acetate and

  5. Estimating the daily dry matter intake of Svalbard reindeer in late winter

    Directory of Open Access Journals (Sweden)

    Nicholas Tyler

    1987-06-01

    Full Text Available Svalbard reindeer (Rangifer tarandus platyrhynchus store large reserves of subcutaneous fat during summer and autumn which, it has been suggested, might be sufficient to meet a substantial part of their energy requirements during winter. An alternative suggestion, however, is that fat is not their main source of energy after all and, moreover, that the principal role of their fat reserves is for enhancing reproductive success rather than for substituting for forage (Tyler, in press. Is it realistic to suggest that these high arctic herbivores could meet the greater part of their energy requirements in winter by feeding, given that the aerial biomass of available forage in Svalbard in late winter is very low? This question was investigated by using a simple model to predict what rate of food intake Svalbard reindeer would have to achieve to maintain energy balance in late winter. The results were surprisingly low: pregnant and nonpregnant females could mett their daily energy demands by consuming 3.1 and 1.7 g dry matter per grazing minute, respectively. This supports the suggestion that Svalbard reindeer could live principally off forage in winter.

  6. Sea ice and primary production proxies in surface sediments from a High Arctic Greenland fjord

    DEFF Research Database (Denmark)

    Ribeiro, Sofia; Sejr, Mikael K; Limoges, Audrey;

    2017-01-01

    that IP25 records from fjords need to be carefully considered and not directly compared to marine settings. The sea ice-associated biomarker HBI III revealed an open-water signature, with highest concentrations near the mid-July ice edge. This proxy evaluation is an important step towards reliable......In order to establish a baseline for proxy-based reconstructions for the Young Sound-Tyrolerfjord system (Northeast Greenland), we analysed the spatial distribution of primary production and sea ice proxies in surface sediments from the fjord, against monitoring data from the Greenland Ecosystem...... Monitoring Programme. Clear spatial gradients in organic carbon and biogenic silica contents reflected marine influence, nutrient availability and river-induced turbidity, in good agreement with in situ measurements. The sea ice proxy IP25 was detected at all sites but at low concentrations, indicating...

  7. Reduced metabolic cost of locomotion in Svalbard rock ptarmigan (Lagopus muta hyperborea during winter.

    Directory of Open Access Journals (Sweden)

    John Lees

    Full Text Available The Svalbard rock ptarmigan, Lagopus muta hyperborea experiences extreme photoperiodic and climatic conditions on the Arctic archipelago of Svalbard. This species, however, is highly adapted to live in this harsh environment. One of the most striking adaptations found in these birds is the deposition, prior to onset of winter, of fat stores which may comprise up to 32% of body mass and are located primarily around the sternum and abdominal region. This fat, while crucial to the birds' survival, also presents a challenge in that the bird must maintain normal physiological function with this additional mass. In particular these stores are likely to constrain the respiratory system, as the sternum and pelvic region must be moved during ventilation and carrying this extra load may also impact upon the energetic cost of locomotion. Here we demonstrate that winter birds have a reduced cost of locomotion when compared to summer birds. A remarkable finding given that during winter these birds have almost twice the body mass of those in summer. These results suggest that Svalbard ptarmigan are able to carry the additional winter fat without incurring any energetic cost. As energy conservation is paramount to these birds, minimising the costs of moving around when resources are limited would appear to be a key adaptation crucial for their survival in the barren Arctic environment.

  8. U-Pb zircon geochronology of Caledonian age orthogneisses dredged from the Chukchi Borderland, Arctic Ocean.

    Science.gov (United States)

    Brumley, K.; Miller, E. L.; Mayer, L. A.; Wooden, J.; Grove, M.

    2012-04-01

    Over 500 kilos of metamorphic rock was dredged from outcrops along a steep normal fault scarp in the central Chukchi Borderland in 2009 (HLY0905) from water depths of between about 2500-1400m. The rocks in the dredge included broken angular cobbles and boulder-sized samples of amphibolites, orthogneisses, and granitoids of the same amphibolite facies metamorphic grade, as well as gravel to small cobble-sized ice rafted debris of various rock types. Zircons were separated from two of the orthogneiss samples, and single grain zircon U-Pb ages were determined by SHRIMP analysis to be 428 Ma ± 3.4 for both samples (N=60). Several zircon grains had distinct igneous cores that ranged in age from about 928-1200 Ma (n=7) with two older grains (1700, 1760 Ma). The Caledonian orogenic belt developed in the Ordovician to Devonian affecting northern Europe, Greenland and Arctic Canada. Caledonian deformational trends continue into the Arctic and disappear at the rifted margin of the Arctic Ocean. Syn-orogenic magmatism in the Barents region date deformation in this region during the Caledonian event to have occurred between about 450-410 Ma (Johansson et al., 2005; Gee et al., 2006; Gee and Tebenkov, 2004). Grenville age plutons (900-1250Ma) that were later involved in Caledonian deformation and intruded by 410-450 Ma aged plutons are found on western and eastern Svalbard (Johansson et al., 2005), eastern Greenland, and the Pearya Terrane of northern Ellesmere Island (Trettin,1986, 1992). The Franklinian basement of Arctic Alaska and Canada do not share these Grenvillian ages (Trentin et al, 1987). This suggests that the inherited zircon cores in the Chukchi Borderland orthogneisses were derived, at least in part, from an older Grenvillian basement like that of Pearya, Svalbard and parts of Greenland, or through sediments eroded from these sources, and later intruded by Caledonian aged granites. This constrains the pre-rift location of the Chukchi Borderland to be within the

  9. A Numerical Study of Pore Fluid and Gas Migration Patterns Within Arctic Shelf Sediments Associated With Relict Off-Shore Permafrost

    Science.gov (United States)

    Frederick, J. M.; Buffett, B. A.

    2012-12-01

    Permafrost-associated methane hydrate deposits along the shallow Arctic continental shelf are thought to be a relict of glacial periods, when a large volume of Earth's water was locked up in polar ice and sea levels were lower, exposing the continental shelves to sub-freezing temperatures. Because of the cold surface temperatures, hydrate deposits are potentially stable here at unusually shallow depths, creating an extensive near-surface carbon reservoir. However, re-submergence of the shelf due to rising sea levels since the last glacial maximum 18 kyr ago has brought a temperature change of roughly +18C to the surface sediments. The evolution of permafrost-associated methane hydrate deposits is potentially complex, and an understanding of the temperature field alone is not sufficient. Salt, which is concentrated in pore fluids when permafrost forms, substantially changes the growth and decay of both permafrost and methane hydrate. The permafrost, in particular, has a strong influence on the mobility of gas within the shelf sediments. In order to quantify these complex interactions we have developed a two-dimensional, finite-volume model for two-phase flow of pore fluid and methane gas within Arctic shelf sediments. We track the evolution of temperature, salinity, and pressure fields with prescribed boundary conditions, and account for latent heat of water ice formation during growth or decay of permafrost. The permeability structure of the sediments is coupled to changes in permafrost. The model can be run over several glacial cycles to simulate the natural environment in which Arctic hydrate deposits form, while also allowing us to explore the consequences of addition warming due to anthropogenic forcing. Preliminary results show that pore fluid and gas migration is strongly influenced by the permeability variations imposed by the overlying permafrost. When permafrost grows, high salinity pore fluids form as salt is excluded from ice. Increasing salinity

  10. Effect of temperature on sulphate reduction, growth rate and growth yield in five psychrophilic sulphate-reducing bacteria from Arctic sediments

    DEFF Research Database (Denmark)

    Knoblauch, C.; Jørgensen, BB

    1999-01-01

    Five psychrophilic sulphate-reducing bacteria (strains ASv26, LSv21, PSv29, LSv54 and LSv514) isolated from Arctic sediments were examined for their adaptation to permanently low temperatures, All strains grew at -1.8 degrees C, the freezing point of sea water, but their optimum temperature...... and T(opt). For strains LSv21 and LSv514, however, growth yields were highest at the lowest temperatures, around 0 degrees C. The results indicate that psychrophilic sulphate-reducing bacteria are specially adapted to permanently low temperatures by high relative growth rates and high growth yields...

  11. Generalized Geology of Svalbard (geo_sval)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This coverage includes arcs, polygons, and polygon labels that describe the generalized geologic age of surface outcrops of bedrock of Svalbard. It also includes...

  12. Episodic Neoglacial Cryosphere Expansion Reconstructed from 14C Ages of Ice-Entombed Plants on Svalbard

    Science.gov (United States)

    Miller, G. H.; Lehman, S.; Landvik, J. Y.

    2015-12-01

    The Northern Hemisphere cryosphere's response to the monotonic decline in summer insolation through the Holocene has been irregular expansion, interrupted by periods of retreat, culminating in the Little Ice Age, when most glaciers attained their maximum late Holocene dimensions. This non-linear response to near-linear forcing implies other factors modulate the radiative effects of the regular insolation decline. Understanding how the Earth system accomplishes this modulation is relevant to the development of reliable models for future climate change. Accurately dating the onset of persistent summer coolings across the Arctic is a first step toward developing this understanding. Here we report 52 precise radiocarbon dates on rooted plants emerging from beneath receding glaciers on Svalbard that define times when colder summers led to snowline depression and an expanded cryosphere. The earliest persistent depression of snowline documented by our dates occurred between 4.0 and 3.4 ka, but with little additional summer cooling until early in the first millennium AD. Episodes of subsequent summer cooling were centered on 240-340, 410-540 and 670-770 AD, followed by additional cooling between 1000 and 1230 AD, and between 1300 and 1470 AD. Cooling that occurred after 1470 AD, includes of the Little Ice Age when the Svalbard cryosphere reached its maximum Neoglacial dimensions. We suggest that in addition to insolation forcing, irregular reductions in the strength of the North Atlantic Current and expansions of Arctic Ocean sea ice were dominant factors that led to episodic snowline depression over Svalbard, but the extent to which these changes are linked to radiative forcing from volcanism or solar irradiance as opposed to unforced variability remains unclear. The widespread exposure of entombed plants dating from the first millennium AD suggests that Svalbard's average summer temperatures of the past century now exceed those of any century since at least 700 AD

  13. Tests for orbital influences on the geomagnetic field, and Quarternary magnetic records from North Atlantic and Arctic deep-sea sediments

    Science.gov (United States)

    Xuan, Chuang

    paleomagnetic data and facilitates the calculation of paleomagnetic directions and RPI proxies. This new software incorporates new methods of analysis, particularly in the generation of RPI proxies. U-channel NRM measurements at Integrated Ocean Drilling Program (IODP) Site U1304 yield continuous high resolution paleomagnetic records for the last ˜1.5 Ma. Sediments from IODP Site U1304 clearly recorded the Brunhes/Matuyama boundary, the Jaramillo subchron, and the Cobb Mountain subchron, as well as the Kamikatsura excursion and the Gardar excursion. Age model for the site is established by correlating IODP Site U1304 RPI record to the PISO-1500 RPI stack using automated dynamic programming method with limited number of tie points. No significant orbital periods were detected in RPI record from the site. Various evidences indicate that the episodic deposits of laminated diatom ooze throughout the IODP Site U1304 sediments, appear to dilute the magnetic concentrations of the sediments with elevated sedimentation rates, but do not debilitate the reliability of the acquired paleomagnetic direction and intensity data. Rock magnetic experiments carried out under various temperature ranges, along with scanning electron microscopy (SEM) and X-ray energy-dispersive spectroscopy (EDS) observations as well as X-ray diffraction (XRD) analyses, on bulk Arctic deep-sea sediments and magnetic extracts from seven cores collected by the Healy-Oden Trans-Arctic Expedition 2005 (HOTRAX05), indicate that (titano)magnetite and titanomaghemite are the magnetic remanence carriers. It appears that the titanomaghemite carries a chemical remanent magnetization (CRM) that is partially self-reversed relative to the detrital remanent magnetization (DRM) carried by the host titanomagnetite, causing the apparent magnetic 'excursions' in the Arctic deep-sea sediment records. The partial self-reversal could have been accomplished by ionic ordering during oxidation, thereby changing the balance of the magnetic

  14. Novel and Unexpected Microbial Diversity in Acid Mine Drainage in Svalbard (78° N), Revealed by Culture-Independent Approaches

    OpenAIRE

    Antonio García-Moyano; Andreas Erling Austnes; Anders Lanzén; Elena González-Toril; Ángeles Aguilera; Lise Øvreås

    2015-01-01

    Svalbard, situated in the high Arctic, is an important past and present coal mining area. Dozens of abandoned waste rock piles can be found in the proximity of Longyearbyen. This environment offers a unique opportunity for studying the biological control over the weathering of sulphide rocks at low temperatures. Although the extension and impact of acid mine drainage (AMD) in this area is known, the native microbial communities involved in this process are still scarcely studied and uncharact...

  15. Intense photooxidative degradation of planktonic and bacterial lipids in sinking particles collected with sediment traps across the Canadian Beaufort Shelf (Arctic Ocean

    Directory of Open Access Journals (Sweden)

    J.-F. Rontani

    2012-06-01

    Full Text Available The lipid content of seven samples of sinking particles collected with sediment traps moored at ~100 m depth in summer and fall across the Canadian Beaufort Shelf (Arctic Ocean was investigated. Our main goal was to quantify and characterize the biotic and abiotic degradation processes that acted on sinking material during these periods. Diatoms, which dominated the phytoplanktonic assemblage in every trap sample, appeared to be remarkably sensitive to Type II (i.e. involving singlet oxygen photodegradation processes in summer, but seemed to be relatively unaffected by biotic degradation at the same time. Hence, the relative recalcitrance of phytodetritus towards biodegradation processes during the Arctic midnight sun period was attributed to the strong photodegradation state of heterotrophic bacteria, which likely resulted from the efficient transfer of singlet oxygen from photodegraded phytoplanktonic cells to attached bacteria. In addition, the detection in trap samples of photoproducts specific to wax ester components found in herbivorous copepods demonstrated that zooplanktonic faecal material exported out of the euphotic zone in summer were as well affected by Type II photodegradation processes. By contrast, sinking particles collected during the autumn were not influenced by any light-driven stress. Further chemical analyses showed that photodegraded sinking particles contained an important amount of intact hydroperoxides, which could then induce a strong oxidative stress in underlying sediments.

  16. Climatology of aerosol optical properties in Northern Norway and Svalbard

    Directory of Open Access Journals (Sweden)

    Y.-C. Chen

    2012-10-01

    Full Text Available We present comparisons between estimates of the aerosol optical thickness and the Ångström exponent in Northern Norway and Svalbard based on data from AERONET stations at Andenes (69° N, 16° E, 379 m altitude and Hornsund (77° N, 15° E, 10 m altitude for the period 2008–2010. The three-year annual mean values for the aerosol optical thickness at 500 nm τ(500 at Andenes and Hornsund were 0.11 and 0.10, respectively. At Hornsund, there was less variation of the monthly mean value of τ(500 than at Andenes. The annual mean values of the Ångström exponent α at Andenes and Hornsund were 1.18 and 1.37, respectively. At Andenes and Hornsund α was found to be larger than 1.0 in 68% and 93% of the observations, respectively, indicating that fine-mode particles were dominating at both sites. Both sites had a similar seasonal variation of the aerosol size distribution although one site is in an Arctic area while the other site is in a sub-arctic area.

  17. Late Quaternary sea-ice history of northern Fram Strait/Arctic Ocean

    Science.gov (United States)

    Kremer, Anne; Stein, Rüdiger; Fahl, Kirsten; Matthießen, Jens; Forwick, Matthias; O'Regan, Matt

    2016-04-01

    One of the main characteristics of the Arctic Ocean is its seasonal to perennial sea-ice cover. Variations of sea-ice conditions affect the Earth's albedo, primary production, rate of deep-water etc.. During the last decades, a drastic decrease in sea ice has been recorded, and the causes of which, i.e., natural vs. anthropogenic forcings, and their relevance within the global climate system, are subject of intense scientific and societal debate. In this context, records of past sea-ice conditions going beyond instrumental records are of major significance. These records may help to better understand the processes controlling natural sea-ice variability and to improve models for forecasts of future climatic conditions. During RV Polarstern Cruise PS92 in summer 2015, a 860 cm long sediment core (PS92/039-2) was recovered from the eastern flank of Yermak Plateau north of the Svalbard archipelago (Peeken, 2015). Based on a preliminary age model, this sediment core probably represents the time interval from MIS 6 to MIS 1. This core, located close to the modern summer ice edge, has been selected for reconstruction of past Arctic sea-ice variability based on specific biomarkers. In this context, we have determined the ice-algae-derived sea-ice proxy IP25 (Belt et al., 2007), in combination with other biomarkers indicative for open-water conditions (cf., Müller et al., 2009, 2011). Furthermore, organic carbon fluxes were differentiated using specific biomarkers indicative for marine primary production (brassicasterol, dinosterol) and terrigenous input (campesterol, β-sitosterol). In this poster, preliminary results of our organic-geochemical and sedimentological investigations are presented. Distinct fluctuations of these biomarkers indicate several major, partly abrupt changes in sea-ice cover in the Yermak Plateau area during the late Quaternary. These changes are probably linked to changes in the inflow of Atlantic Water along the western coastline of Svalbard into

  18. Nitrate stable isotopes and major ions in snow and ice samples from four Svalbard sites

    Directory of Open Access Journals (Sweden)

    Carmen P. Vega

    2015-04-01

    Full Text Available Increasing reactive nitrogen (Nr deposition in the Arctic may adversely impact N-limited ecosystems. To investigate atmospheric transport of Nr to Svalbard, Norwegian Arctic, snow and firn samples were collected from glaciers and analysed to define spatial and temporal variations (1–10 years in major ion concentrations and the stable isotope composition (δ15N and δ18O of nitrate (NO3- across the archipelago. The δ15N NO3- and δ18ONO3- averaged −4‰ and 67‰ in seasonal snow (2010–11 and −9‰ and 74‰ in firn accumulated over the decade 2001–2011. East–west zonal gradients were observed across the archipelago for some major ions (non-sea salt sulphate and magnesium and also for δ15NNO3- and δ18ONO3- in snow, which suggests a different origin for air masses arriving in different sectors of Svalbard. We propose that snowfall associated with long-distance air mass transport over the Arctic Ocean inherits relatively low δ15NNO3- due to in-transport N isotope fractionation. In contrast, faster air mass transport from the north-west Atlantic or northern Europe results in snowfall with higher δ15NNO3- because in-transport fractionation of N is then time-limited.

  19. COMPARING FIELD PERFORMANCES OF DENUDER TECHNIQUES IN THE HIGH ARCTIC

    Science.gov (United States)

    A field evaluation between two annular denuder system configurations was conducted during the spring of 2003 in the marine Arctic (Ny-Ålesund, Svalbard). The IIA annular denuder system (ADS) employs a series of five single channel annular denuders, a cyclone and a filter pack to ...

  20. Concentrations and patterns of organochlorine contaminants in white whales (Delphinapterus leucas) from Svalbard, Norway.

    Science.gov (United States)

    Andersen, G; Kovacs, K M; Lydersen, C; Skaare, J U; Gjertz, I; Jenssen, B M

    2001-01-17

    Blubber was collected from live-captured, adult male white whales (Delphinapterus leucas) from Svalbard, Norway, and analysed for levels and patterns of organochlorine (OC) contaminants. The OC compounds analysed were HCB, dieldrin, sigmaHCH (alpha-HCH, beta-HCH and gamma-HCH), sigmaChl (heptachlor epoxide, oxychlordane, cis-chlordane, trans-nonachlor, and cis-nonachlor), sigmaDDT (pp'-DDT, pp'-DDE and pp'-DDD) and sigmaPCB (27 PCB congeners). The major OC compounds detected in the blubber were sigmaPCB (5103+/-1874 ng/g l.w.) and sigmaDDT (5108+/-1089 ng/g l.w.), which made up 70% of the sigmaOC. These compounds were followed in prevalence by sigmaChl (2872+/-1177 ng/g l.w.), which contributed 20% of the sigmaOC burden. SigmaHCH, HCB and dieldrin were present, but at low concentrations. This OC pattern is typical of top predators in Arctic marine food chains. OC levels in white whales from Svalbard are lower than white whales from the St Lawrence River in Canada and are generally similar to values reported previously for other Arctic white whale stocks. Some geographic patterns in relative prevalence of various OC compounds appear to be quite consistent among various marine mammal species in the Arctic. PCB and DDT concentrations in Svalbard's white whales are below the levels that are thought to have negative effects on reproduction or the immune system.

  1. Western Arctic Vulnerability to Warming over the past 3.6 Myr: Lessons from sediments drilled at Lake El'gygytgyn, Western Beringia

    Science.gov (United States)

    Brigham-Grette, J.; Melles, M.; Minyuk, P.; Lake El'gygytgyn Science Team

    2011-12-01

    International Continental Deep drilling (ICDP) at Lake El'gygytgyn (67_30' N, 172_05' E; "Lake E"), recovered lacustrine sediments dating back to 3.6 Ma that provides the first time-continuous Pliocene-Pleistocene paleoclimate record of different interglacials from the terrestrial Arctic. While discontinuous, spatially diverse Pliocene and Pleistocene marine interglacial records are known from the arctic borderlands at the outcrop scale, the Lake El'gygytgyn record is critically important understanding the western Arctic landscape response to different forcing factors operating across the Arctic since the mid-Pliocene warm period. The record is important for evaluating the sensitivity of the Arctic region and to provide a template of Arctic climate variability that can be compared to other regions. Lake E modeling is framed around suites of sensitivity tests of Beringian climate response to the full range of forcing experienced over the last ~3.5 million years using a nested Global-Regional Climate Model (GCM-RCM). The Pliocene portion of the lake record (~3.6-3.0 Ma; a time when atmospheric CO2 levels may have been like today) has nearly twice the sedimentation rate as later Quaternary intervals, partly as a consequence of basin infilling but also presumably due to more rainfall and more active rivers at that time. Studies of spores and pollen from this portion of the core (samples every ~10k) show that the area was once dominated by trees, providing us with the pace of variability in Pliocene Arctic forests, which included species of pine, larch, spruce, fir, alder, and hemlock. Hemlock and tree pine pollen is exceptional for this latitude but the assemblage implies July temperatures nearly 8 degrees warmer than today with ~3 times the annual precipitation. Modeling suggests sustained forests at Lake E in both cold and warm orbits during this interval. The record includes a strong M2 cooling event to conditions like today at ~3.3 Ma, but not glacial climates as

  2. Can we use crevasse fill ridges for identifying undocumented surge behavior in Svalbard?

    Science.gov (United States)

    Farnsworth, W. R.; Ingolfsson, O.; Schomacker, A.; Retelle, M.

    2015-12-01

    Documenting glaciers that exhibit surge type behavior is crucial, especially as we attempt to use evidence of ice front fluctuations for reconstructing past climate oscillations. Controversy exists regarding the relationship between surge activity and climatic processes such as mass balance. This project identifies undocumented surge type glaciers in Svalbard based on the presence of crevasse fill ridges (CFRs) visible in glacier forelands. Although it is acknowledged that many Svalbard outlet glaciers surge, estimates vary greatly as to the actual number of surge- type glaciers in Svalbard, and their distribution pattern is not well understood. A detailed survey of recent (2008-2011), high resolution imagery from Toposvalbard, provided by the Norwegian Polar Institute, allowed for a rapid analysis of Svalbard outlet glaciers. Using CFRs as indicators of surge behavior has almost doubled the amount of potential surge-type glaciers in central Spitsbergen. This method also highlights numerous other glaciers of potential surge type behavior throughout the archipelago. Limits to the CFR identification method are discussed. Additionally as the forelands of previously reported surge type glaciers were analyzed for CFRs, it was evident that the surge indicators were only present in approximately half of the forelands. Numerous factors control the formation and preservation of CFRs including; glacier size, bedrock lithology, subglacial sediments and clast size as well as glacial fluvial run-off. This poster focuses on the controlling factors for CFR formation and preservation as well as other potential methods for effectively identifying surge behavior.

  3. The influence of cruise ship emissions on air pollution in Svalbard

    Science.gov (United States)

    Eckhardt, Sabine; Hermansen, Ove; Grythe, Henrik; Fiebig, Markus; Stebel, Kerstin; Cassiani, Massimo; Baecklund, Are; Stohl, Andreas

    2013-04-01

    We have analyzed whether tourist cruise ships have an influence on measured sulfur dioxide (SO2), ozone (O3), Aitken mode particle and equivalent black carbon (EBC) concentrations at Ny Ålesund and Zeppelin Mountain on Svalbard in the Norwegian Arctic, during summer. We separated the measurement data set into periods when ships were present and periods when no ships were present in the Kongsfjord area, according to a long-term record of the number of passengers visiting Ny Ålesund. We show that when ships with more than 50 passengers cruise in the Kongsfjord, measured daytime-mean concentrations of 60-nm particles and EBC in summer show enhancements of 72 and 45% relative to values when no ships are present. Even larger enhancements of 81 and 72% were found for stagnant conditions. In contrast, O3 concentrations were 5% lower on average and 7% lower under stagnant conditions, due to titration of O3 with the emitted nitric oxide (NO). The differences between the two data subsets are largest for the highest measured percentiles while relatively small differences were found for the median concentrations, indicating that ship plumes are sampled relatively infrequently even when ships are generally present but carry high concentrations. We estimate that the ships increased the total summer mean concentrations of SO2, 60-nm particles and EBC by 15, 18 and 11%, respectively. Our findings have two important implications: Firstly, even at such a remote Arctic observatory as Zeppelin, the measurements can be influenced by tourist ship emissions. Careful data screening is recommended before summer-time Zeppelin data is used for data analysis or for comparison with global chemistry transport models. However, Zeppelin remains one of the most valuable Arctic observatories, as most other Arctic observatories face even larger local pollution problems. Secondly, given landing statistics of tourist ships on Svalbard, it is suspected that large parts of the Svalbard archipelago are

  4. In search for coastal amplification of rock weathering in polar climates - pilot Schmidt hammer rock tests surveys from sheltered fjords of Svalbard and tsunami-affected coasts of Western Greenland.

    Science.gov (United States)

    Strzelecki, Matt

    2014-05-01

    Recent decade has seen the major advance in Arctic coastal geomorphology due to research progress along ice-rich permafrost coastlines of Siberia, Alaska and NW Canada. On the contrary little attention was paid to Arctic rocky coastlines and their response to the reduction of sea ice cover and increased number of storms reaching Arctic region. In this paper I present results from a pilot survey of rock resistance using Schmidt Hammer Rock Tests across rocky cliffs and shore platforms developed in: - sheltered bays of Billefjorden, Svalbard characterised by prolonged sea-ice conditions and very limited operation of wave and tidal action - Vaigat Strait and Isfjorden in W Greenland influenced by landslide-triggered tsunamis and waves induced by ice-berg roll events. The aim of a pilot study was to test the hypothesized coastal impact on the rate of rock weathering in polar climates. To do so I characterise the changes in the rock resistance on the following coastal landforms: - modern and uplifted wave-washed abrasion platforms- focusing on a relation between the degree of rock surface weathering and the distance from the shoreline as well as thickness of sediment cover on shore platform surface - modern and uplifted rocky cliffs - focusing on a relation between the degree of rock surface weathering and the distance from the shoreline as well as difference in height above the sea level and relation to rock lithology. The results present another line of argument supporting intensification of rock weathering processes in the Arctic coastal zone. This work is a contribution to the National Science Centre in Poland research project no. 2011/01/B/ST10/01553.

  5. Cretaceous Arctic magmatism: Slab vs. plume? Or slab and plume?

    Science.gov (United States)

    Gottlieb, E. S.; Miller, E. L.; Andronikov, A. V.; Brumley, K.; Mayer, L. A.; Mukasa, S. B.

    2010-12-01

    Tectonic models for the Cretaceous paleogeographic evolution of the Arctic Ocean and its adjacent landmasses propose that rifting in the Amerasia Basin (AB) began in Jura-Cretaceous time, accompanied by the development of the High Arctic Large Igneous Province (HALIP). During the same timespan, deformation and slab-related magmatism, followed by intra-arc rifting, took place along the Pacific side of what was to become the Arctic Ocean. A compilation and comparison of the ages, characteristics and space-time variation of circum-Arctic magmatism allows for a better understanding of the role of Pacific margin versus Arctic-Atlantic plate tectonics and the role of plume-related magmatism in the origin of the Arctic Ocean. In Jura-Cretaceous time, an arc built upon older terranes overthrust the Arctic continental margins of North America and Eurasia, shedding debris into foreland basins in the Brooks Range, Alaska, across Chukotka, Russia, to the Lena Delta and New Siberian Islands region of the Russian Arctic. These syn-tectonic sediments have some common sources (e.g., ~250-300 Ma magmatic rocks) as determined by U-Pb detrital zircon geochronology. They are as young as Valanginian-Berriasian (~136 Ma, Gradstein et al., 2004) and place a lower limit on the age of formation of the AB. Subsequent intrusions of granitoid plutons, inferred to be ultimately slab-retreat related, form a belt along the far eastern Russian Arctic continental margin onto Seward Peninsula and have yielded a continuous succession of zircon U-Pb ages from ~137-95 Ma (n=28) and a younger suite ~91-82 Ma (n=16). All plutons dated were intruded in an extensional tectonic setting based on their relations to wall-rock deformation. Regional distribution of ages shows a southward migration of the locus of magmatism during Cretaceous time. Basaltic lavas as old as 130 Ma and as young as 80 Ma (40Ar/39Ar)) erupted across the Canadian Arctic Islands, Svalbard and Franz Josef Land and are associated with

  6. Unexpected increase in elemental carbon values over the last 30 years observed in a Svalbard ice core

    Directory of Open Access Journals (Sweden)

    M. M. Ruppel

    2014-05-01

    Full Text Available Black carbon (BC is a light-absorbing particle that warms the atmosphere–Earth system. The climate effects of BC are amplified in the Arctic where its deposition on light surfaces decreases the albedo and causes earlier melt of snow and ice. Despite its suggested significant role in Arctic climate warming there is little information on BC concentrations and deposition in the past. Here we present results on BC (here operationally defined as elemental carbon (EC concentrations and deposition on a Svalbard glacier between 1700 and 2004. The inner part of a 125 m deep ice core from Holtedahlfonna glacier (79°8' N, 13°16' E, 1150 m a.s.l. was melted, filtered through a quartz fibre filter and analysed for EC using a thermal optical method. The EC values started to increase after 1850 and peaked around 1910, similar to ice core records from Greenland. Strikingly, the EC values again increase rapidly between 1970 and 2004. This rise is not seen in Greenland ice cores and it seems to contradict atmospheric BC measurements indicating generally decreasing atmospheric BC concentrations since 1989 in the Arctic. Several hypotheses, such as changes in scavenging efficiencies, post-depositional processes and differences in the vertical distribution of BC in the atmosphere, are discussed for the differences between the Svalbard and Greenland ice core records, and the ice core and atmospheric measurements in Svalbard. In addition, the divergent BC trends between Greenland and Svalbard ice cores may be caused by differences in the analytical methods used, including the operational definitions of quantified particles, and detection efficiencies of different-sized BC particles. Regardless of the cause of the increasing EC values in the recent decades, the results have significant implications for the past radiative energy balance at the coring site.

  7. Erosion of soil organic carbon at high latitudes and its delivery to Arctic Ocean sediments: New source to sink insight from radiocarbon dating

    Science.gov (United States)

    Hilton, Robert; Galy, Valier; Gaillardet, Jerome; Dellinger, Mathieu; Bryant, Charlotte; O'Regan, Matt; Grocke, Darren; Coxall, Helen

    2016-04-01

    Soils of the northern high latitudes store carbon over thousands of years and contain almost double the carbon stock of the atmosphere. Erosion processes can mobilise this pre-aged soil organic carbon from the landscape and supply it to rivers. If it escapes degradation during river transport and is delivered to the coastal ocean, this carbon may be sequestered for much longer periods of time (>104 yr) as a geological CO2 sink. Despite this recognition, the erosional flux and fate of particulate organic carbon (POC) in large rivers draining the high latitudes remains poorly constrained. Using radiocarbon activity, we quantify POC source, flux and fate in the Mackenzie River, the main sediment supplier to the Arctic Ocean. When combined with stable carbon isotopes and element ratios, the radiocarbon activity of POC allows us to distinguish inputs of POC from sedimentary rocks and quantify the average age of biospheric POC (from vegetation and soil) transported through the river system. We find that the eroded biospheric POC has resided in the basin for millennia, with a mean radiocarbon age of 5800±800 years. This is much older than large tropical rivers where we have equivalent data (Amazon River, Ganges River), and likely reflects the longer residence time of organic matter in cold, wet, high latitude soils. Based on the measured biospheric POC content and annual sediment flux, we calculate a biospheric POC flux of 2.2 (+1.3/-0.9) TgC yr-1 from the Mackenzie River. This is the largest input of aged organic carbon to the Arctic Ocean, more than the combined POC flux from the Eurasian Rivers. Offshore, we use a marine core to investigate organic carbon burial over the Holocene period. Radiocarbon measurements of bulk organic carbon reveal a significant offset from benthic foraminifera radiocarbon ages throughout the core, which is dependent upon the grain size of the sediments. Organic matter in sediments >63μm are offset from foraminifera by ˜ 6,000 14C years

  8. Seasonal differences in jump performance in the Svalbard rock ptarmigan (Lagopus muta hyperborea

    Directory of Open Access Journals (Sweden)

    John J. Lees

    2014-07-01

    Full Text Available Fat storage is essential to the survival of many bird species, providing energy reserves, but can have an effect on locomotor performance with an associated potential increase in predation risk. In particular, the ability to initiate flight through jumping is critical to predator avoidance and may be influenced by changes in body mass (Mb. Here we investigate seasonal differences in the jump take-off performance of high Arctic Svalbard rock ptarmigan (Lagopus muta hyperborea resulting from around a 50% increase in Mb during winter as a result of fat deposition. Using force-plate data and videography, we reveal that, in the absence of alterations to take-off angle, winter Svalbard rock ptarmigan are unable to increase hind-limb power output during jumping to compensate for their increased Mb. As a result, peak take-off velocity is reduced by 42% and jump duration is also extended during winter. The consequences of reduced jumping performance upon Svalbard ptarmigan during winter may be relatively small given their low risk of predation during this season. It may be, however, that the observed reduction in jumping performance when fat may contribute to the sub-maximal pattern of fat acquisition observed in other bird species.

  9. India in the Arctic: Science, Geopolitics and Soft Power - Perspectives on Contemporary Indian Foreign Policy

    OpenAIRE

    Gewelt, Alexander

    2016-01-01

    This thesis is an analysis of contemporary Indian foreign policy from the vantage point of India’s recent engagements in the Arctic. By analysing what is argued to be an ‘Indian Arctic discourse’ that emerged between India’s first expedition to Svalbard in 2007 and the following accession to observer status in the Arctic Council in 2013, this thesis explores how this discourse frames the Arctic within a broader Indian foreign policy perspective. The Indian Arctic discourse establishes India a...

  10. Conflict and order in Svalbard waters

    OpenAIRE

    Pedersen, Torbjørn

    2008-01-01

    The papers of the thesis are not available in Munin: 1. Pedersen, Torbjørn (2006): «The Svalbard Continental Shelf Controversy: Legal Disputes and Political Rivalries», Ocean Development & International Law, 37 (3-4): 339-358 (publisher's restrictions - Taylor & Francis). Available at http://dx.doi.org/10.1080/00908320600800960 2. Pedersen, Torbjørn & Tore Henriksen: «Svalbard's Maritime Zones: The End of Legal Uncertainty?» (submitted version). Later published: International Journal o...

  11. Stable isotopes and Digital Elevation Models to study nutrient inputs in high-Arctic lakes

    Science.gov (United States)

    Calizza, Edoardo; Rossi, David; Costantini, Maria Letizia; Careddu, Giulio; Rossi, Loreto

    2016-04-01

    Ice cover, run-off from the watershed, aquatic and terrestrial primary productivity, guano deposition from birds are key factors controlling nutrient and organic matter inputs in high-Arctic lakes. All these factors are expected to be significantly affected by climate change. Quantifying these controls is a key baseline step to understand what combination of factors subtends the biological productivity in Arctic lakes and will drive their ecological response to environmental change. Basing on Digital Elevation Models, drainage maps, and C and N elemental content and stable isotope analysis in sediments, aquatic vegetation and a dominant macroinvertebrate species (Lepidurus arcticus Pallas 1973) belonging to Tvillingvatnet, Storvatnet and Kolhamna, three lakes located in North Spitsbergen (Svalbard), we propose an integrated approach for the analysis of (i) nutrient and organic matter inputs in lakes; (ii) the role of catchment hydro-geomorphology in determining inter-lake differences in the isotopic composition of sediments; (iii) effects of diverse nutrient inputs on the isotopic niche of Lepidurus arcticus. Given its high run-off and large catchment, organic deposits in Tvillingvatnet where dominated by terrestrial inputs, whereas inputs were mainly of aquatic origin in Storvatnet, a lowland lake with low potential run-off. In Kolhamna, organic deposits seem to be dominated by inputs from birds, which actually colonise the area. Isotopic signatures were similar between samples within each lake, representing precise tracers for studies on the effect of climate change on biogeochemical cycles in lakes. The isotopic niche of L. aricticus reflected differences in sediments between lakes, suggesting a bottom-up effect of hydro-geomorphology characterizing each lake on nutrients assimilated by this species. The presented approach proven to be an effective research pathway for the identification of factors subtending to nutrient and organic matter inputs and transfer

  12. Chlorinated hydrocarbon contaminants in arctic marine mammals.

    Science.gov (United States)

    Norstrom, R J; Muir, D C

    1994-09-16

    By 1976, the presence of chlorinated hydrocarbon contaminants (CHCs) had been demonstrated in fur seal (Callorhinus ursinus), ringed seal (Phoca hispida), hooded seal (Cystophora cristata), bearded seal (Erignathus barbatus), walrus (Obdobenus rosmarus divergens), beluga (Delphinapterus leucas), porpoise (Phocoena phocoena) and polar bear (Ursus maritimus) in various parts of the Arctic. In spite of this early interest, very little subsequent research on contaminants in Arctic marine mammals was undertaken until the mid-1980s. Since that time, there has been an explosion of interest, resulting in a much expanded data base on contaminants in Arctic marine mammals. Except in the Russian Arctic, data have now been obtained on the temporospatial distribution of PCBs and other contaminants in ringed seal, beluga and polar bear. Contaminants in narwhal (Monodon monoceros) have also now been measured. On a fat weight basis, the sum of DDT-related compounds (S-DDT) and PCB levels are lowest in walrus (St. Lawrence and ringed seal in the Baltic Sea, indicate that overall contamination of the Arctic marine ecosystem is 10-50 times less than the most highly contaminated areas in the northern hemisphere temperate latitude marine environment. Geographic distribution of residue levels in polar bears indicates a gradual increase from Alaska east to Svalbard, except PCB levels are significantly higher in eastern Greenland and Svalbard. Information on temporal trends is somewhat contradictory.(ABSTRACT TRUNCATED AT 400 WORDS)

  13. Thermal structure of Svalbard glaciers and implications for thermal switch models of glacier surging

    Science.gov (United States)

    Sevestre, Heïdi; Benn, Douglas I.; Hulton, Nicholas R. J.; Bælum, Karoline

    2015-10-01

    Switches between cold- and warm-based conditions have long been invoked to explain surges of High Arctic glaciers. Here we compile existing and new data on the thermal regime of six glaciers in Svalbard to test the applicability of thermal switch models. Two of the large glaciers of our sample are water terminating while one is land terminating. All three have a well-known surge history. They have a thick basal layer of temperate ice, superimposed by cold ice. A cold terminus forms during quiescence but is mechanically removed by calving on tidewater glaciers. The other three glaciers are relatively small and are either entirely cold or have a diminishing warm core. All three bear evidence of former warm-based thermal regimes and, in two cases, surge-like behavior during the Little Ice Age. In Svalbard, therefore, three types of glaciers have switched from slow to fast flow: (1) small glaciers that underwent thermal cycles during and following the Little Ice Age (switches between cold- and warm-based conditions), (2) large terrestrial glaciers which remain warm based throughout the entire surge cycle but develop cold termini during quiescence, and (3) large tidewater glaciers that remain warm based throughout the surge cycle. Our results demonstrate that thermal switching cannot explain the surges of large glaciers in Svalbard. We apply the concept of enthalpy cycling to the spectrum of surge and surge-like behavior displayed by these glaciers and demonstrate that all Svalbard surge-type glaciers can be understood within a single conceptual framework.

  14. Islands of the Arctic

    Science.gov (United States)

    Dowdeswell, Julian; Hambrey, Michael

    2002-11-01

    The Arctic islands are characterized by beautiful mountains and glaciers, in which the wildlife lives in delicate balance with its environment. It is a fragile region with a long history of exploration and exploitation that is now experiencing rapid environmental change. All of these themes are explored in Islands of the Arctic, a richly illustrated volume with superb photographs from the Canadian Arctic archipelago, Greenland, Svalbard and the Russian Arctic. It begins with the various processes shaping the landscape: glaciers, rivers and coastal processes, the role of ice in the oceans and the weather and climate. Julian Dowdeswell and Michael Hambrey describe the flora and fauna in addition to the human influences on the environment, from the sustainable approach of the Inuit, to the devastating damage inflicted by hunters and issues arising from the presence of military security installations. Finally, they consider the future prospects of the Arctic islands Julian Dowdeswell is Director of the Scott Polar Research Institute and Professor of Physical Geography at 0he University of Cambridge. He received the Polar Medal from Queen Elizabeth for his contributions to the study of glacier geophysics and the Gill Memorial Award from the Royal Geographical Society. He is chair of the Publications Committee of the International Glaciological Society and head of the Glaciers and Ice Sheets Division of the International Commission for Snow and Ice. Michael Hambrey is Director of the Centre for Glaciology at the University of Wales, Aberystwyth. A past recipient of the Polar Medal, he was also given the Earth Science Editors' Outstanding Publication Award for Glaciers (Cambridge University Press). Hambrey is also the author of Glacial Environments (British Columbia, 1994).

  15. Geochemical signatures of sediments documenting Arctic sea-ice and water mass export through Fram Strait since the Last Glacial Maximum

    Science.gov (United States)

    Maccali, Jenny; Hillaire-Marcel, Claude; Carignan, Jean; Reisberg, Laurie C.

    2013-03-01

    Elemental (Ca, Zr, Th, etc.) and radiogenic isotope (Pb, Nd, Sr) measurements in leachates and residues from deep-sea sediments of core MC16 (WarmPast Program) in central Fram Strait were used to document the geochemical signatures of outflowing Arctic water masses and ice rafted debris (IRD) since the Last Glacial Maximum. In addition, the elemental distribution among the three main sedimentary fractions (terrigenous, biogenic and authigenic) was quantified. Elements dominated by the terrigenous fraction display a change at ˜13 ka assigned to an early Younger Dryas (YD) event. In the authigenic fraction, migration of the redox front, perhaps spurred by discontinuous delivery of organic matter to the sediment, has led to the mobility of elements such as Mn. Fe contents display lesser variability within the sediment suggesting that Fe experienced only minor redox-related redistribution. Authigenic Pb and Nd, thought to be hosted primarily by Fe-oxyhydroxides, also show little evidence of mobility, suggesting that their isotopic compositions should reliably record the isotopic compositions of past bottom water. We have broadly identified the isotopic signatures of the three major source areas of IRD, the Russian, Canadian and Greenland margins. The elemental and isotopic residue records from core MC16 display distinct trends prior to and after the YD. The pre-YD interval, with ɛNd values between -10.1 and -13.2, and 87Sr/86Sr ratios from 0.715 to 0721, reflects a mixture of IRD from the Russian and Canadian margins. The YD episode stands out with sediments originating mostly from the Canadian end-member, displaying the lowest ɛNd values and highest 87Sr/86Sr ratios. This suggests enhanced sea-ice production and/or drifting along the Beaufort Gyre at that time. The post-YD interval, i.e. the Holocene, is characterized by a less variable mixture of IRD material, with ɛNd values and 87Sr/86Sr ratios centred at -12.2 and 0.718 respectively. This material was derived

  16. Microplastics in Arctic polar waters: the first reported values of particles in surface and sub-surface samples

    Science.gov (United States)

    Lusher, Amy L.; Tirelli, Valentina; O'Connor, Ian; Officer, Rick

    2015-10-01

    Plastic, as a form of marine litter, is found in varying quantities and sizes around the globe from surface waters to deep-sea sediments. Identifying patterns of microplastic distribution will benefit an understanding of the scale of their potential effect on the environment and organisms. As sea ice extent is reducing in the Arctic, heightened shipping and fishing activity may increase marine pollution in the area. Microplastics may enter the region following ocean transport and local input, although baseline contamination measurements are still required. Here we present the first study of microplastics in Arctic waters, south and southwest of Svalbard, Norway. Microplastics were found in surface (top 16 cm) and sub-surface (6 m depth) samples using two independent techniques. Origins and pathways bringing microplastic to the Arctic remain unclear. Particle composition (95% fibres) suggests they may either result from the breakdown of larger items (transported over large distances by prevailing currents, or derived from local vessel activity), or input in sewage and wastewater from coastal areas. Concurrent observations of high zooplankton abundance suggest a high probability for marine biota to encounter microplastics and a potential for trophic interactions. Further research is required to understand the effects of microplastic-biota interaction within this productive environment.

  17. The shallow benthic food web structure in the high Arctic does not follow seasonal changes in the surrounding environment

    Science.gov (United States)

    Kędra, Monika; Kuliński, Karol; Walkusz, Wojciech; Legeżyńska, Joanna

    2012-12-01

    Seasonality, quality and quantity of food resources strongly affect fitness and survival of polar fauna. Most research conducted in polar areas has been carried out during the summer, rarely including aspects of seasonality; therefore, there are gaps in our knowledge of the structure of food webs in the Arctic, particularly information is lacking on the possible shifts in winter feeding strategies of organisms. This study is the first to compare potential shifts in benthic food-web structure between winter and summer in a shallow-water Arctic fjord (Kongsfjorden, Svalbard). Winter data were collected in March when conditions are representative of winter and when Arctic shallow benthic fauna is likely to be most affected by absence of fresh food supply as opposed to summer (August). Samples of particulate suspended organic matter (POM), settled organic matter, surface sediment and benthic organisms were taken and analyzed for stable isotopes signatures (δ13C and δ15N). Four relative trophic levels (TL) were distinguished in both winter and summer, and no differences in the structure of benthic food web were found between seasons. Our study shows that the shallow sublittoral benthos depends on primary production, fresh and reworked settled organic matter and, to a certain degree, on terrestrial input. We also demonstrate that shallow water polar benthic fauna is characterized by a high level of omnivory and feeds at multiple trophic levels showing strong resilience to changing seasonal conditions.

  18. Light-absorbing impurities in Arctic snow

    Directory of Open Access Journals (Sweden)

    S. J. Doherty

    2010-08-01

    Full Text Available Absorption of radiation by ice is extremely weak at visible and near-ultraviolet wavelengths, so small amounts of light-absorbing impurities in snow can dominate the absorption of solar radiation at these wavelengths, reducing the albedo relative to that of pure snow, contributing to the surface energy budget and leading to earlier snowmelt. In this study Arctic snow is surveyed for its content of light-absorbing impurities, expanding and updating the 1983–1984 survey of Clarke and Noone. Samples were collected in Alaska, Canada, Greenland, Svalbard, Norway, Russia, and the Arctic Ocean during 2005–2009, on tundra, glaciers, ice caps, sea ice, frozen lakes, and in boreal forests. Snow was collected mostly in spring, when the entire winter snowpack is accessible for sampling. Sampling was carried out in summer on the Greenland ice sheet and on the Arctic Ocean, of melting glacier snow and sea ice as well as cold snow. About 1200 snow samples have been analyzed for this study.

    The snow is melted and filtered; the filters are analyzed in a specially designed spectrophotometer system to infer the concentration of black carbon (BC, the fraction of absorption due to non-BC light-absorbing constituents and the absorption Ångstrom exponent of all particles. The reduction of snow albedo is primarily due to BC, but other impurities, principally brown (organic carbon, are typically responsible for ~40% of the visible and ultraviolet absorption. The meltwater from selected snow samples was saved for chemical analysis to identify sources of the impurities. Median BC amounts in surface snow are as follows (nanograms of carbon per gram of snow: Greenland 3, Arctic Ocean snow 7, melting sea ice 8, Arctic Canada 8, Subarctic Canada 14, Svalbard 13, Northern Norway 21, Western Arctic Russia 26, Northeastern Siberia 17. Concentrations are more variable in the European Arctic than in Arctic Canada or the Arctic Ocean, probably because of the proximity

  19. Biosignatures in chimney structures and sediment from the Loki's Castle low-temperature hydrothermal vent field at the Arctic Mid-Ocean Ridge.

    Science.gov (United States)

    Jaeschke, Andrea; Eickmann, Benjamin; Lang, Susan Q; Bernasconi, Stefano M; Strauss, Harald; Früh-Green, Gretchen L

    2014-05-01

    We investigated microbial life preserved in a hydrothermally inactive silica–barite chimney in comparison with an active barite chimney and sediment from the Loki's Castle low-temperature venting area at the Arctic Mid-Ocean Ridge (AMOR) using lipid biomarkers. Carbon and sulfur isotopes were used to constrain possible metabolic pathways. Multiple sulfur (dδ34S, Δ33S) isotopes on barite over a cross section of the extinct chimney range between 21.1 and 22.5 % in δ34S, and between 0.020 and 0.034 % in Δ33S, indicating direct precipitation from seawater. Biomarker distributions within two discrete zones of this silica–barite chimney indicate a considerable difference in abundance and diversity of microorganisms from the chimney exterior to the interior. Lipids in the active and inactive chimney barite and sediment were dominated by a range of 13C-depleted unsaturated and branched fatty acids with δ13C values between -39.7 and -26.7 %, indicating the presence of sulfur-oxidizing and sulfate-reducing bacteria. The majority of lipids (99.5 %) in the extinct chimney interior that experienced high temperatures were of archaeal origin. Unusual glycerol monoalkyl glycerol tetraethers (GMGT) with 0–4 rings were the dominant compounds suggesting the presence of mainly (hyper-) thermophilic archaea. Isoprenoid hydrocarbons with δ13C values as low as -46 % also indicated the presence of methanogens and possibly methanotrophs.

  20. Sea ice dynamics influence halogen deposition to Svalbard

    Directory of Open Access Journals (Sweden)

    A. Spolaor

    2013-03-01

    Full Text Available Sea ice is an important parameter in the climate system and its changes impact upon the polar albedo and the atmospheric and oceanic circulation. Iodine (I and bromine (Br have been measured in a shallow ice core drilled at the summit of the Holtedahlfonna glacier (Northwest Spitsbergen, Svalbard. Changing I concentrations can be linked to the spring maximum sea ice extension. Bromine enrichment, indexed to the Br/Na sea water mass ratio, appears to be influenced by changes in the seasonal sea ice area. I is emitted from marine biota and so the retreat of spring sea ice coincides with enlargement of the open ocean surface which enhances marine primary production and consequent I emission. The observed Br enrichment can be explained by greater Br emissions during the Br explosion that have been observed to occur above first year sea ice during the early springtime. In this work we present the first comparison between halogens in surface snow and Arctic sea ice extension. Although further investigation is required to characterize potential depositional and post-depositional processes, these preliminary findings suggest that I and Br can be linked to variability in the spring maximum sea ice extension and seasonal sea ice surface area.

  1. Sea ice dynamics influence halogen deposition to Svalbard

    Directory of Open Access Journals (Sweden)

    A. Spolaor

    2013-10-01

    Full Text Available Sea ice is an important parameter in the climate system and its changes impact upon the polar albedo and atmospheric and oceanic circulation. Iodine (I and bromine (Br have been measured in a shallow firn core drilled at the summit of the Holtedahlfonna glacier (Northwest Spitsbergen, Svalbard. Changing I concentrations can be linked to the March–May maximum sea ice extension. Bromine enrichment, indexed to the Br / Na sea water mass ratio, appears to be influenced by changes in the seasonal sea ice area. I is emitted from marine biota and so the retreat of March–May sea ice coincides with enlargement of the open-ocean surface which enhances marine primary production and consequent I emission. The observed Br enrichment could be explained by greater Br emissions during the Br explosions that have been observed to occur mainly above first year sea ice during the early springtime. In this work we present the first comparison between halogens in surface snow and Arctic sea ice extension. Although further investigation is required to characterize potential depositional and post-depositional processes, these preliminary findings suggest that I and Br can be linked to variability in the spring maximum sea ice extension and seasonal sea ice surface area.

  2. Long-term temperature trends and variability on Spitsbergen: the extended Svalbard Airport temperature series, 1898–2012

    Directory of Open Access Journals (Sweden)

    Øyvind Nordli

    2014-01-01

    Full Text Available One of the few long instrumental records available for the Arctic is the Svalbard Airport composite series that hitherto began in 1911, with observations made on Spitsbergen, the largest island in the Svalbard Archipelago. This record has now been extended to 1898 with the inclusion of observations made by hunting and scientific expeditions. Temperature has been observed almost continuously in Svalbard since 1898, although at different sites. It has therefore been possible to create one composite series for Svalbard Airport covering the period 1898–2012, and this valuable new record is presented here. The series reveals large temperature variability on Spitsbergen, with the early 20th century warming as one striking feature: an abrupt change from the cold 1910s to the local maxima of the 1930s and 1950s. With the inclusion of the new data it is possible to show that the 1910s were colder than the years at the start of the series. From the 1960s, temperatures have increased, so the present temperature level is significantly higher than at any earlier period in the instrumental history. For the entire period, and for all seasons, there are positive, statistically significant trends. Regarding the annual mean, the total trend is 2.6°C/century, whereas the largest trend is in spring, at 3.9°C/century. In Europe, it is the Svalbard Archipelago that has experienced the greatest temperature increase during the latest three decades. The composite series may be downloaded from the home page of the Norwegian Meteorological Institute and should be used with reference to the present article.

  3. Climate and environmental changes during the last 2000 years on Barentsøya and Edgeøya (E-Svalbard).

    Science.gov (United States)

    Hoek, Wim; Woelders, Lineke; Akkerman, Keechy; van Hoof, Tom; Moller Just, Rikke; Wagner-Cremer, Friederike

    2016-04-01

    The Svalbard archipelago is positioned at the northern limb of the Atlantic Gulf Stream and, therefore, highly sensitive to climate changes related to changes in ocean circulation. At present, a strong climate gradient from SW-NE Svalbard illustrates the Atlantic influence. While from Spitsbergen (W-Svalbard) several palaeoclimate records are available, while palaeoclimate records from Barentsøya and Edgeøya (E-Svalbard) are lacking. During the 2015 SEES expedition (http://www.sees.nl/) the first lake sediment records from Barentsøya and Edgeøya (E Svalbard) have been collected. The lakes, formed in isolation basins on dolorite plateaus, were selected based on their elevation. Based on published isostatic rebound values, the lakes became disconnected from the sea around 3000 years ago. Since then the lakes recorded biological production changes which are clearly reflected in the lithology of the cores. The presence of abundant plant macro fossils including Salix polaris leaf remains allows for plant palaeophysiological palaeoclimate estimates, which together with pollen and diatom analysis provides a high detail palaeoenvironmental reconstruction for the last 2000 years. Age assessment of the sediments is based on Pb210 and AMS C14 dating on botanical macrofossils, while we also have indications for the presence of Icelandic tephra.

  4. Bathymetric variations in vertical distribution patterns of meiofauna in the surface sediments of the deep Arctic ocean (HAUSGARTEN, Fram strait)

    Science.gov (United States)

    Górska, Barbara; Grzelak, Katarzyna; Kotwicki, Lech; Hasemann, Christiane; Schewe, Ingo; Soltwedel, Thomas; Włodarska-Kowalczuk, Maria

    2014-09-01

    Deep-sea benthic communities and their structural and functional characteristics are regulated by surface water processes. Our study focused on the impact of changes in water depth and food supplies on small-sized metazoan bottom-fauna (meiobenthos) along a bathymetric transect (1200-5500 m) in the western Fram Strait. The samples were collected every summer season from 2005 to 2009 within the scope of the HAUSGARTEN monitoring program. In comparison to other polar regions, the large inflow of organic matter to the sea floor translates into relatively high meiofaunal densities in this region. Densities along the bathymetric gradient range from approximately 2400 ind. 10 cm-2 at 1200 m to approximately 300 ind. 10 cm-2 at 4000 m. Differences in meiofaunal distribution among sediment layers (i.e., vertical profile) were stronger than among stations (i.e., bathymetric gradient). At all the stations meiofaunal densities and number of taxa were the highest in the surface sediment layer (0-1 cm), and these decreased with increasing sediment depth (down to 4-5 cm). However, the shape of the decreasing pattern differed significantly among stations. Meiofaunal densities and taxonomic richness decreased gradually with increasing sediment depth at the shallower stations with higher food availability. At deeper stations, where the availability of organic matter is generally lower, meiofaunal densities decreased sharply to minor proportions at sediment depths already at 2-3 cm. Nematodes were the most abundant organisms (60-98%) in all the sediment layers. The environmental factors best correlated to the vertical patterns of the meiofaunal community were sediment-bound chloroplastic pigments that indicate phytodetrital matter.

  5. The Auroral Station in Adventdalen, Svalbard

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper describes the Auroral Station in Adventdalen near Longyearbyen, Svalbard (78°N, 15°E). The main instruments at the site are for optical observation of aurora and airglow, but magnetic and radar observations are also carried out. Emission spectra show the difference between the dayside and nightside optical aurora. A newly compiled mesospheric temperature series from the station is also presented, derived through 20 years of spectral measurements of the hydroxyl airglow layer.

  6. Autochthonous and allochthonous contributions of organic carbon to microbial food webs in Svalbard fjords

    KAUST Repository

    Holding, Johnna M.

    2017-03-27

    Rising temperatures in the Arctic Ocean are causing sea ice and glaciers to melt at record breaking rates, which has consequences for carbon cycling in the Arctic Ocean that are yet to be fully understood. Microbial carbon cycling is driven by internal processing of in situ produced organic carbon (OC), however recent research suggests that melt water from sea ice and glaciers could introduce an allochthonous source of OC to the microbial food web with ramifications for the metabolic balance of plankton communities. In this study, we characterized autochthonous and allochthonous sources of OC to the Western Svalbard fjord system using stable isotopes of carbon. We quantified δ13C of eukaryotic and prokaryotic planktonic groups using polar lipid-derived fatty acids as biomarkers in addition to measuring δ13C of marine particulate OC and dissolved OC from glacial runoff. δ13C of bacteria (−22.5‰) was higher than that of glacial runoff OC (−28.5‰) and other phytoplankton groups (−24.7 to −29.1‰), which suggests that marine bacteria preferentially use a third source of OC. We present a Bayesian three-source δ13C mixing model whereby ∼ 60% of bacteria carbon is derived from OC in sea ice, and the remaining carbon is derived from autochthonous production and glacial-derived OC. These results suggest that subsidies of OC from melting glaciers will not likely influence microbial carbon cycling in Svalbard fjords in the future and that further research is needed to determine the effects of melting sea ice on microbial carbon cycling in fjord systems and elsewhere in the Arctic Ocean.

  7. Biomonitoring polluted sediments in Arctic regions - possibilities and challenges using benthic foraminifera. Case studies from northern Norway

    Science.gov (United States)

    Skirbekk, Kari; Dijkstra, Noortje; Junttila, Juho; Sternal, Beata; Pedersen, Kristine Bondo; Forwick, Matthias; Carroll, JoLynn

    2016-04-01

    Biomonitoring pollution in marine environments using benthic foraminifera assemblages have proven to be a valid method for many regions. Two important reasons for their suitability are their sensitivity to changes in the environment and their rapid response time due to short life cycles. In addition, they are preserved in the sedimentary record, allowing for baseline studies of conditions prior to introduction of contaminants. Species of benthic foraminifera that appear to tolerate polluted sediments are referred to as opportunistic species. This notion is in general used for species able to dominate environments that are too stressful for most species. The high latitude setting of the northern Norwegian coastal zone experience high seasonality and, hence, largely changing conditions throughout a year: variations in water mass domination, freshwater influence, temperature and current velocity. It is possible that an environment like this is inhibited by a higher amount of opportunistic species generally thriving under high stress conditions. This might make the use of benthic foraminifera for biomonitoring more challenging, as the faunal compositions may be a result of a complex set of processes. Consequently, large datasets are necessary in order to make reliable conclusions, which in time may be used as generalized guidelines for biomonitoring in this geographical area. Here, we present preliminary results of benthic foraminiferal assemblages from two sites in Finnmark, northern Norway, which have been exposed to pollution. The main site is Repparfjorden, where the inner parts of the fjord were used as a submarine waste deposal site for mine tailings from a local copper mine during the 1970´s. Results from four marine sediment cores (10-20 cm long) containing sediments classified to be in moderate to very bad state (according to Norwegian sediment quality criteria) are presented. The contamination is seen in intervals of elevated copper content dated to the 1970

  8. Constraining the Time-Scale of Interaction of Sea Ice Sediments and Surface Sea Water in the Arctic Ocean Using Short-Lived Radionuclide Tracers

    Science.gov (United States)

    Baskaran, M.; Andersson, P. S.; Jweda, J.; Dahlqvist, R.; Ketterer, M. E.

    2007-12-01

    We measured the activities of short-lived radionuclides (Th-234, Be-7, Po-210, Pb-210, Cs-137, Th-234, Ra-226 and Ra-228) and concentrations of several elements (Be, Pb, Fe, Al, Co, Ni, Cu and Zn) on a suite of ice-rafted sediments (IRS) collected during BERINGIA-2005 in the Western Arctic Ocean. A suite of water samples were also collected and analyzed for particulate and dissolved Be-7, Po-210, Pb-210, Th-234, Ra-226 and Ra-228. The activities of Be-7 and Pb-210 in the IRS are 1-2 orders of magnitude higher than those reported in the source sediments. Presence of excess Th-234 in the IRS indicates that the removal of Th-234 from surface seawater took place on time scales comparable to the mean-life of Th-234. While the Po-210/Pb-210 activity ratios in the source sediments (1.0) and the atmospheric depositional input (~0.1) are known, varying ratios of 0.78 to 1.0 were found in the IRS. This ratio can be utilized to obtain the residence time of the IRS in sea ice. The activity of Ra-226 and Ra-228 in all the IRS is nearly constant (within a factor of 1.6) and are comparable to the benthic sediments in the source region. The activities of atmospherically-delivered radionuclides, Be-7 and Pb-210, in IRS varied by factors of ~4.5 and 9, respectively, and this variation is attributed to differences in the extent of interaction of surface water with IRS and differences in the mean-lives of these nuclides. While significant enrichment of Be-7 and Pb-210 has been found, there is no enrichment of stable Pb or Be. The Al-normalized enrichment factor for elements measured (Co, Ni, Cu, Zn, Pb and Be) indicate that there is no significant enrichment of these elements, with Al-normalized enrichment factors less than 1.3.

  9. Estimates of future warming-induced methane emissions from hydrate offshore west Svalbard for a range of climate models

    OpenAIRE

    2015-01-01

    Methane hydrate close to the hydrate stability limit in seafloor sediment could represent an important source of methane to the oceans and atmosphere as the oceans warm. We investigate the extent to which patterns of past and future ocean-temperature fluctuations influence hydrate stability in a region offshore West Svalbard where active gas venting has been observed. We model the transient behavior of the gas hydrate stability zone at 400–500 m water depth (mwd) in response to past temperatu...

  10. Waste Disposal Practices of the Former Soviet Union in the Arctic Environment

    Science.gov (United States)

    1994-06-24

    Basin eventually opened the pathway for exchange of waters between the Arctic and Atlantic oceans. The cold- oxygen rich waters from the Arctic ventilate...waters sink as an oxygen rich dense watermass contributing to Availa bilty Codes the renewal of water masses of the global ocean and to the Avail anu...marine sequences which he suggests may have originated from the Caledonides of Svalbard. The rocks in this geologic provenance range from Proterozoic to

  11. Last glacial ice sheet dynamics and deglaciation on Svalbard inferred from fjord records (Invited)

    Science.gov (United States)

    Forwick, M.; Vorren, T. O.; Baeten, N. J.; Hansen, T.; Kempf, P.; Velle, J. H.; Laberg, J.

    2013-12-01

    Swath bathymetry, high-resolution sub-bottom profiles and sediment cores from fjords on north and west Svalbard document a variety of glacigenic landforms and sedimentary processes, providing valuable insights into the dynamics of the northwestern parts of the Svalbard Barents Sea Ice Sheet during the last glacial. Glacial linear features oriented parallel to most fjord axes are identified on swath-bathymetry and high-resolution sub-bottom profiler data. They provide evidence of locally fast-flowing grounded ice draining the northwestern parts of the Svalbard Barents Sea Ice Sheet to the shelf breaks off north and west Svalbard. Eskers overlying glacial lineations reveal the existence of englacial or sub-glacial drainage systems that developed after the termination of fast ice flow. Iceberg ploughmarks suggest that parts of the deglaciation occurred by iceberg calving. Multiple transverse ridges, e.g. grounding zone wedges and moraines, indicate that multiple halts and/or readvances interrupted the deglaciations of the fjords. This includes relatively small moraines, probably deposited during halts and/or readvances in consecutive winters, thus, allowing the calculation of annual retreat rates of the ice fronts in certain fjord areas. Their regular spacing may suggest that e.g. parts of Billefjorden, Smeerenburgfjorden and Woodfjorden were deglaciated at relatively constant rates of at least 140 m/year. However, the deglaciation of van Keulenfjorden accelerated from approx. 80 m/year to about 190 m/year. Lithological analyses allow the study of sub-glacial, glacier-proximal and glacier-distal sedimentary processes and environments, as well as the identification of influences from various sediment sources. They reveal, furthermore, that the deglaciations of multiple fjords terminated quasi-synchronously around 11,200 cal. years BP, but that significant local delays of up to several thousand years occurred. We present examples of the above mentioned landforms

  12. Quaternary Arctic Climate Change of the past 2.8 Ma as reconstructed from sediments of Lake El'gygytgyn, NE Russia (Invited)

    Science.gov (United States)

    Wennrich, V.; Melles, M.; Brigham-Grette, J.; Minyuk, P.; Nowaczyk, N. R.; Deconto, R. M.; Anderson, P. A.; Andreev, A. A.; Haltia, E.; Kukkonen, M.; Lozhkin, A. V.; Rosen, P.; Tarasov, P. E.

    2013-12-01

    Scientific deep drilling at Lake El'gygtygyn in Chukotka, northeastern Russia (67.5° N, 172° E) revealed the first high-resolution record of environmental history in the Arctic that spans the past 3.6 Ma continuously (Melles et al. 2012, Brigham-Grette et al. 2013). In this presentation we focus on the end-member glacial and interglacial climatic conditions of the past 2.8 Ma as clearly reflected in the pelagic lake sediments recovered. Peak glacial conditions, when mean annual air temperatures at least 3.3 (×0.9) °C lower than today led to perennial lake ice (Nolan 2013), first appeared at Lake El'gygytgyn 2.602 - 2.598 Ma ago, during marine isotope stage (MIS) 104. These pervasive glacial episodes gradually increase in frequency from ~2.3 to ~1.8 Ma, eventually concurring with all glacials and several stadials reflected globally in stacked marine isotope records. Particularly warm interglacials, in contrast, experienced a long ice-free season and enhanced nutrient supply from the catchment, which allowed for significantly higher primary production than today. These settings were most pronounced for MIS 11c, 31, 49, 55, 77, 87, 91, and 93. Their exceptional character becomes evident based upon pollen-based climate reconstructions in selected interglacials, showing that the mean temperature of the warmest month and the annual precipitation during the thermal maxima of MIS 11c and 31 ('super' interglacials) were 4-5 °C and ~300 mm higher than those of MIS 1 and 5e ('normal' interglacials), respectively. According to climate simulations, the exceptional warm and moist climates at least during MIS 11c cannot be explained by the natural variability in Earth's orbital parameters and greenhouse gas concentrations alone. A remarkable coincidence of the super interglacials at Lake El'gygytgyn with diatomite layers in the Antarctic ANDRILL 1B, which reflect periods of a diminished West Antarctic Ice Sheet (WAIS) (Naish et al. 2009, Pollard and DeConto 2009), suggests

  13. Goose-mediated nutrient enrichment and planktonic grazer control in arctic freshwater ponds

    NARCIS (Netherlands)

    Van Geest, G.J.; Hessen, D.O.; Spierenburg, P.; Dahl-Hansen, G.A.P.; Christensen, G.; Brehm, Michaela; Loonen, M.J.J.E.; Faerovig, P.J.; Van Donk, E.

    2007-01-01

    A dramatic increase in the breeding population of geese has occurred over the past few decades at Svalbard. This may strongly impact the fragile ecosystems of the Arctic tundra because many of the ultra-oligotrophic freshwater systems experience enrichment from goose feces. We surveyed 21 shallow tu

  14. Petrophysical characterization of the lacustrine sediment succession drilled in Lake El'gygytgyn, Far East Russian Arctic

    Directory of Open Access Journals (Sweden)

    A. C. Gebhardt

    2013-08-01

    Full Text Available Seismic profiles of Far East Russian Lake El'gygytgyn, formed by a meteorite impact some 3.6 million years ago, show a stratified sediment succession that can be separated into subunits Ia and Ib at approximately 167 m below lake floor (=~3.17 Ma. The upper (Ia is well-stratified, while the lower is acoustically more massive and discontinuous. The sediments are intercalated with frequent mass movement deposits mainly in the proximal areas, while the distal region is almost free of such deposits at least in the upper part. In spring 2009, a long core drilled in the lake center within the framework of the International Continental Scientific Drilling Program (ICDP penetrated the entire lacustrine sediment succession down to ~320 m below lake floor and about 200 m farther into the meteorite-impact-related bedrock. Downhole logging data down to 390 m below lake floor show that the bedrock and the lacustrine part differ significantly in their petrophysical characteristics. The contact between the bedrock and the lacustrine sediments is not abrupt, but rather transitional with a variable mixture of impact-altered bedrock clasts in a lacustrine matrix. Physical and chemical proxies measured on the cores can be used to divide the lacustrine part into five different statistical clusters. These can be plotted in a redox-condition vs. input-type diagram, with total organic carbon content and magnetic susceptibility values indicating anoxic or oxic conditions and with the Si / Ti ratio representing more clastic or more biogenic input. Plotting the clusters in this diagram allows identifying clusters that represent glacial phases (cluster I, super interglacials (cluster II, and interglacial phases (clusters III and IV.

  15. Petrophysical characterization of the lacustrine sediment succession drilled in Lake El'gygytgyn, Far East Russian Arctic

    Directory of Open Access Journals (Sweden)

    A. C. Gebhardt

    2013-01-01

    Full Text Available Seismic profiles of Far East Russian Lake El'gygytgyn which was formed by a meteorite impact some 3.6 million years ago show a stratified sediment succession that can be separated into Subunits Ia and Ib at approximately 167 m below lake floor (= ∼ 3.17 Ma. The former is well-stratified, while the latter is acoustically more massive. The sediments are intercalated with frequent mass movement deposits mainly in the proximal parts, while the distal part is almost free of such deposits at least in the upper part. In spring 2009, a long core drilled in the lake center within the framework of the International Continental Scientific Drilling Program (ICDP penetrated the entire lacustrine sediment succession down to ~ 320 m below lake floor and about 200 m further into the meteorite-impact related bedrock. Downhole logging data down to 390 m below lake floor show that the bedrock and the lacustrine part of the core differ largely in their petrophysical characteristics. The contact between the bedrock and the lacustrine sediments is not abrupt, but rather transitional with a mixture of impact-altered bedrock clasts in a lacustrine matrix with varying percentages. Physical and chemical proxies measured on the cores can be used to divide the lacustrine part into five different clusters. These can be plotted in a redox-condition vs. input type diagram with total organic carbon content and magnetic susceptibility values indicating anoxic or oxic conditions and with the Si/Ti ratio representing more clastic or more biogenic input. Plotting the clusters in this diagram allows identifying clusters that represent glacial phases (Cluster I, super interglacials (Cluster II, and interglacial phases (Clusters III and IV.

  16. Coring and High-Resolution Imaging of the Permian-Triassic Boundary in Deltadalen, Svalbard

    Science.gov (United States)

    Planke, Sverre

    2016-04-01

    The Permian-Triassic extinction was likely triggered by the voluminous igneous activity of the Siberian Traps. There are, however, limited information available about the effects of the Siberian Traps volcanism in Permian to Triassic sedimentary successions outside Siberia. We drilled two boreholes across the Permian-Triassic boundary (PTB) in Deltadalen, Svalbard, in August 2014, to better document the extinction event and environmental changes in the sedimentary succession in this region. Even though the PTB event is studied in several outcrops to varying degree if scrutiny on Svalbard, a scientific core is important for understanding the details of the PTB event, as outcrops may not permit studies at the appropriate levels of resolution, exposure or confidence. The Deltadalen site was chosen as an optimal drilling location after field work in the Isfjorden area in 2013 and early 2014. The almost 100 m deep holes were fully cored and penetrated the Triassic Vikinghøgda Formation (about 85 m recovered) and the Permian Kapp Starostin Formation (about 15 m). The main lithologies include Permian chert-rich green glauconitic sandstones and Triassic mudstones. A 10 m thick sedimentary reference outcrop section across the PTB was further logged and sampled in a nearby river valley. A comprehensive core analysis program is now underway. High-resolution XRF, MST and hyperspectral core scanning has been completed along the entire core surface, while high-resolution CT scanning has been carried out for whole core sections. The DD-1 core has subsequently been split, photographed, described, and sampled for geochemical, micropaleontological, petrological and magnetic analyses. Almost 10 bentonite layers have furthermore been sampled for volcanological and geochronological studies. Our goal is that the cores will become an important future reference section of the PTB in Svalbard and the high-Arctic, and help constrain the extent of the regional effects of explosive volcanism

  17. On the issue of the Precambrian basement of the Arctic shelf

    Science.gov (United States)

    Vernikovsky, Valery A.; Korago, Evgeny A.; Proskurnin, Vasily F.; Sobolev, Nikolay N.

    2015-04-01

    Many researchers of the geological structures of the Russian Arctic concluded that the basements of the terranes composing the Arctic shelf and continental slopes have a Precambrian age. It is assumed that these terranes are actually fragments of the ancient Arctida paleocontinent [Zonenshain, Natapov, 1987] that broke up as a result of rifting and its separate plates and terranes either were overlain by continental margins sediments or included in the fold belts in the periphery of the ocean. In the western part of the Russian Arctic, a Grenvillian and Mesoproterozoic basement was demonstrated for Svalbard, Novaya Zemlya and Taimyr Peninsula, and at least a Neoproterozoic basement was established for structures in the basement of Severnaya Zemlya archipelago. In the eastern part of the Russian Arctic, such proofs were almost nonexistent. In recent years, new information was obtained concerning the continental nature and Precambrian age of the basement crust of the New Siberian Islands and De Long archipelagos as well as probably the Mendeleev Ridge. For the New Siberian Islands and De Long archipelagos, a whole series of geochronological evidence was obtained in addition to geological data (horizontally bedding Early Paleozoic passive continental margin sediments (Cambrian, Ordovician) at Bennett Island). In magmatic and tuffaceous-sedimentary rocks of Henrietta and Zhokhov islands we discovered zircons that had formed from magmatic crystallization in the Late Neoproterozoic. New U-Pb data for zircons from rocks of these islands do not contradict isotopic dating obtained earlier by other methods - Ar/Ar and Sm/Nd in different laboratories. Considering different closure temperatures for isotopic systems, these new results complement each other. On the islands of the eastern sector of the Russian Arctic, a Neoproterozoic complex of rocks is most certainly established in the basement of the mesozoides of Vrangel Island. Here were discovered metamorphosed volcanics

  18. Coupled Response of Bacterial Production to a Wind-induced Fall Phytoplankton Bloom and Sediment Resuspension in the Chukchi Sea Shelf, Western Arctic Ocean

    Directory of Open Access Journals (Sweden)

    Mario Uchimiya

    2016-11-01

    Full Text Available Heterotrophic bacterial abundance and production, dissolved free amino acid (DFAA and dissolved combined amino acid (DCAA concentrations, and other microbial parameters were determined for seawater samples collected at a fixed station (maximum water depth, 56 m deployed on the Chukchi Sea Shelf, in the western Arctic Ocean, during a 16-day period in September 2013. During the investigation period, the sampling station experienced strong winds and a subsequent phytoplankton bloom, which was thought to be triggered by enhanced vertical mixing and upward nutrient fluxes. In this study, we investigated whether bacterial and dissolved amino acid parameters changed in response to these physical and biogeochemical events. Bacterial abundance and production in the upper layer increased with increasing chlorophyll a concentration, despite a concomitant decrease in seawater temperature from 3.2°C to 1.5°C. The percentage of bacteria with high nucleic acid content during the bloom was significantly higher than that during the prebloom period. The ratio of the depth-integrated (0–20 m bacterial production to primary production differed little between the prebloom and bloom period, with an overall average value of 0.14 ± 0.03 (± standard deviation, n = 8. DFAA and DCAA concentrations varied over a limited range throughout the investigation, indicating that the supply and consumption of labile dissolved amino acids were balanced. These results indicate that there was a tightly coupled, large flow of organic carbon from primary producers to heterotrophic bacteria during the fall bloom. Our data also revealed that bacterial production and abundance were high in the bottom nepheloid (low transmittance layer during strong wind events, which was associated with sediment resuspension due to turbulence near the seafloor. The impacts of fall wind events, which are predicted to become more prominent with the extension of the ice-free period, on bacterial

  19. Multiyear Survey of the Distribution and Fate of Biomarkers in the Atlantic Arctic Ocean

    Science.gov (United States)

    Fietz, S.; Rosell Mele, A.; Rueda, G.; Martinez Garcia, A.; Hambach, B.; Viladrich, N.; Barrera Sansón, A.; Rossi, S.; Ziveri, P.

    2010-12-01

    Biogeochemical signatures derived from organisms thriving in the ocean water column are driven by environmental conditions, with highly complex processes linking primary and export productivity. Organic matter input, in-situ production and fate depend on conditions such as sea surface temperature, ice-cover and freshwater input, mixing/stratification regime, fertilization and acidification etc. for which important changes are predicted in subpolar and polar environments. However, the spatial and interannual variability of organic matter distribution and their driving environmental factors in these vast oceanic regions are not fully determined or understood. To gain some new insights into these issues in the Arctic region we have participated in a multiyear survey, based on four summer cruises from 2005 to 2009 following latitudinal transects from the North Atlantic to the Fram Strait, and longitudinal transects from Greenland to Svalbard and collected particulate matter in the water column as well as twenty surface sediments. We focus on biogeochemical markers for terrestrial matter input (e.g., n-alkanes, branched GDGTs), for in-situ productivity and pelagic community composition (e.g., photosynthetic pigments, alkenones, isoprenoid GDGTs) and food-web structure (e.g., fatty acids, sterols). We also collected samples to determine the distribution of specific algal groups (coccolithophores) in this region. Results from the 2008 and 2009 surveys will be presented. Our aim is to compare the organic matter signatures in the upper water column to those in the exported matter that reaches deep water masses and surface sediments.

  20. Managing visitor sites in Svalbard: from a precautionary approach towards knowledge-based management

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    Kirstin Fangel

    2012-05-01

    Full Text Available Increased tourism in the Arctic calls for more knowledge to meet management challenges. This paper reviews existing knowledge of the effects of human use on vegetation, fauna and cultural heritage in Svalbard, and it addresses the need for site-specific knowledge for improved management. This paper draws upon scientific studies, knowledge held by management authorities and local people, the Governor's database on visitors and visited sites and our own data from landing sites we visited. There is a certain level of basic knowledge available, allowing us to roughly grade the vulnerability of sites. However, there is a thorough lack of site-specific data related to the management of single locations or groups of similar locations. Future research needs to address specific on-site challenges in the management of visitor sites. Relevant management models and measures are discussed. We contend that a shift away from a blanket application of the precautionary principle and towards a more integrated, site-specific and evidence-based management plan will contribute to more trusted and reliable, and thereby acceptable among stakeholders, decisions in the management of growing tourism activity in Svalbard.

  1. Frost flower chemical signature in winter snow on Vestfonna ice cap, Nordaustlandet, Svalbard

    Directory of Open Access Journals (Sweden)

    E. Beaudon

    2009-07-01

    Full Text Available The chemistry of snow and ice cores from Svalbard is influenced by variations in local sea ice margin and distance to open water. Snow pits sampled at two summits of Vestfonna ice cap (Nordaustlandet, Svalbard, exhibit spatially heterogeneous soluble ions concentrations despite similar accumulation rates, reflecting the importance of small-scale weather patterns on this island ice cap. The snow pack on the western summit shows higher average values of marine ions and a winter snow layer that is relatively depleted in sulphate. One part of the winter snow pack exhibits a [SO42-/Na+] ratio reduced by two thirds compared with its ratio in sea water. This low sulphate content in winter snow is interpreted as the signature of frost flowers, which are formed on young sea ice when offshore winds predominate. Frost flowers have been described as the dominant source of sea salt to aerosol and precipitation in ice cores in coastal Antarctica but this is the first time their chemical signal has been described in the Arctic. The eastern summit does not show any frost flower signature and we interpret the unusually dynamic ice transport and rapid formation of thin ice on the Hinlopen Strait as the source of the frost flowers.

  2. Past and future thermal characteristics of permafrost in Svalbard

    Science.gov (United States)

    Etzelmueller, B.; Isaksen, K.; Schuler, T. V.; Benestad, R.

    2009-04-01

    Within the EU-funded PACE project a 102 m deep borehole was drilled at Janssonhaugen, Svalbard, in 1998. The boreholes penetrate Cretaceous sandstone bedrock with low ice content overlain by a thin (0.2-0.5 m) weathering layer containing no organic material, the ground surface has no vegetation, and during winter snow cover is thin or completely absent due to deflation. Thus, a high correlation is observed between air temperature and ground surface temperature and the climate signal that penetrates the ground shows little disturbance by near-surface latent heat effects. The site is representative for the mountains in the area. The 10-year long series show that the permafrost has warmed considerably. Significant warming is detectable down to at least 60 m depth, and present decadal warming rate at the permafrost surface are on the order of 0.07 °C yr-1, with indications of accelerated warming during the last decade (Isaksen et al. 2007). In this study we have calibrated a surface temperature driven 1D-heat flow model with phase transitions to the temperature measurements in the borehole. This model was then forced by ground surface temperatures derived either from historical observed air temperature data for the 20th Century and an empirical statistical downscaled ensemble covering the 21st Century. The latter is based on the multi-model World Climate Research Programme (WCRP) Coupled Model Intercomparison Project (CMIP3) of the most recent Special Report Emission Scenario (SRES) A1b (in which atmospheric CO2 reaches 720 parts per million by 2100) produced for the Intergovernmental Panel on Climate Change (IPCC) Assessment Report 4 (AR4). The presentation demonstrate the possible impact of projected higher air temperatures in the high Arctic on the ground thermal regime, and geomorphological and geotechnical consequences will be discussed.

  3. Persistent organic pollutants in biota samples collected during the Ymer-80 expedition to the Arctic

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    Henrik Kylin

    2015-10-01

    Full Text Available During the 1980 expedition to the Arctic with the icebreaker Ymer, a number of vertebrate species were sampled for determination of persistent organic pollutants. Samples of Arctic char (Salvelinus alpinus, n=34, glaucous gull (Larus hyperboreus, n=8, common eider (Somateria mollissima, n=10, Brünnich's guillemot (Uria lomvia, n=9, ringed seal (Pusa hispida, n=2 and polar bear (Ursus maritimus, n=2 were collected. With the exception of Brünnich's guillemot, there was a marked contamination difference of birds from western as compared to eastern/northern Svalbard. Samples in the west contained a larger number of polychlorinated biphenyl (PCB congeners and also polychlorinated terphenyls, indicating local sources. Brünnich's guillemots had similar pollutant concentrations in the west and east/north; possibly younger birds were sampled in the west. In Arctic char, pollutant profiles from lake Linnévatn (n=5, the lake closest to the main economic activities in Svalbard, were similar to profiles in Arctic char from the Shetland Islands (n=5, but differed from lakes to the north and east in Svalbard (n=30. Arctic char samples had higher concentrations of hexachlorocyclohexanes (HCHs than the marine species of birds and mammals, possibly due to accumulation via snowmelt. Compared to the Baltic Sea, comparable species collected in Svalbard had lower concentrations of PCB and dichlorodiphenyltrichloroethane (DDT, but similar concentrations indicating long-range transport of hexachlorobenzene, HCHs and cyclodiene pesticides. In samples collected in Svalbard in 1971, the concentrations of PCB and DDT in Brünnich's guillemot (n=7, glaucous gull (n=2 and polar bear (n=2 were similar to the concentrations found in 1980.

  4. Warming of the West Spitsbergen Current and sea ice north of Svalbard

    Directory of Open Access Journals (Sweden)

    Jan Piechura

    2009-06-01

    Full Text Available This research was supported by a grant from the Fifth European Union Frame-work Programme project ASOF-N, contract EVK2-CT-200200139, the Sixth Frame-work Programme DAMOCLES, contract 018509GOCE, and grants from the Polish Ministry of Science and Higher Education, decisions 61/N-IPY/2007/0 and 175/IPY/2007/01.AbstractAccording to the results of recent research, besides the atmospheric circulation, it is heat transport to the Arctic Ocean (AO by ocean currents, the West Spitsbergen Current (WSC in particular, that is playing a significant role in the process of Arctic warming. Data collected by the Institute of Oceanology, Polish Academy of Sciences (IO PAS, in the Norwegian and Greenland Seas, and Fram Strait during the last 20 years reveal considerable changes in the amount of heat transported by the WSC into the Arctic Ocean. An increase in Atlantic Water (AW temperature and the intensification of heat transport were observed in 2004-06; after this period, both parameters decreased. The aim of this study was to find out whether the fluctuations in heat input by the WSC have influenced the sea-ice distribution around Svalbard. In fact they do, but oceanic heat transport should nonetheless be regarded as just one of many processes influencing sea-ice behaviour.

  5. Seasonal variation in accumulation of persistent organic pollutants in an Arctic marine benthic food web

    Energy Technology Data Exchange (ETDEWEB)

    Evenset, A., E-mail: anita.evenset@akvaplan.niva.no [Akvaplan-niva. Fram Centre, Tromsø (Norway); University of Tromsø, The Arctic University of Norway, Tromsø (Norway); Hallanger, I.G. [University of Tromsø, The Arctic University of Norway, Tromsø (Norway); Tessmann, M. [Akvaplan-niva. Fram Centre, Tromsø (Norway); Institute for Hydrobiology and Fisheries Research, University of Hamburg (Germany); Warner, N. [Norwegian Institute for Air Research, Fram Centre, Tromsø (Norway); Ruus, A. [Norwegian Institute for Water Research, Oslo (Norway); Borgå, K. [Norwegian Institute for Water Research, Oslo (Norway); Department of Biosciences, P.O. Box 1066, Blindern 0316, Oslo (Norway); Gabrielsen, G.W. [Norwegian Polar Institute, Fram Centre, Tromsø (Norway); Christensen, G. [Akvaplan-niva. Fram Centre, Tromsø (Norway); Renaud, P.E. [Akvaplan-niva. Fram Centre, Tromsø (Norway); University Centre in Svalbard, Longyearbyen (Norway)

    2016-01-15

    The aim of the present study was to investigate seasonal variation in persistent organic pollutant (POP) concentrations, as well as food-web biomagnification, in an Arctic, benthic marine community. Macrozoobenthos, demersal fish and common eiders were collected both inside and outside of Kongsfjorden, Svalbard, during May, July and October 2007. The samples were analysed for a selection of legacy chlorinated POPs. Overall, low levels of POPs were measured in all samples. Although POP levels and accumulation patterns showed some seasonal variation, the magnitude and direction of change was not consistent among species. Overall, seasonality in bioaccumulation in benthic biota was less pronounced than in the pelagic system in Kongsfjorden. In addition, the results indicate that δ{sup 15}N is not a good predictor for POP-levels in benthic food chains. Other factors, such as feeding strategy (omnivory, necrophagy versus herbivory), degree of contact with the sediment, and a high dependence on particulate organic matter (POM), with low POP-levels and high δ{sup 15}N-values (due to bacterial isotope enrichment), seem to govern the uptake of the different POPs and result in loads deviating from what would be expected consulting the trophic position alone. - Highlights: • Seasonal variation in POP biomagnification was investigated in a benthic food web. • Levels of POPs are generally low in benthic species from Kongsfjorden, Svalbard. • POP-concentrations varied with season, but direction of change varied among taxa. • No POP-biomagnification, except for cis-nonachlor, was detected in this study. • δ{sup 15}N-values does not seem to be a good proxy for trophic level in macrozoobenthos.

  6. Gas hydrate distribution and hydrocarbon maturation north of the Knipovich Ridge, western Svalbard margin

    Science.gov (United States)

    Dumke, Ines; Burwicz, Ewa B.; Berndt, Christian; Klaeschen, Dirk; Feseker, Tomas; Geissler, Wolfram H.; Sarkar, Sudipta

    2016-03-01

    A bottom-simulating reflector (BSR) occurs west of Svalbard in water depths exceeding 600 m, indicating that gas hydrate occurrence in marine sediments is more widespread in this region than anywhere else on the eastern North Atlantic margin. Regional BSR mapping shows the presence of hydrate and free gas in several areas, with the largest area located north of the Knipovich Ridge, a slow spreading ridge segment of the Mid Atlantic Ridge system. Here heat flow is high (up to 330 mW m-2), increasing toward the ridge axis. The coinciding maxima in across-margin BSR width and heat flow suggest that the Knipovich Ridge influenced methane generation in this area. This is supported by recent finds of thermogenic methane at cold seeps north of the ridge termination. To evaluate the source rock potential on the western Svalbard margin, we applied 1-D petroleum system modeling at three sites. The modeling shows that temperature and burial conditions near the ridge were sufficient to produce hydrocarbons. The bulk petroleum mass produced since the Eocene is at least 5 kt and could be as high as ~0.2 Mt. Most likely, source rocks are Miocene organic-rich sediments and a potential Eocene source rock that may exist in the area if early rifting created sufficiently deep depocenters. Thermogenic methane production could thus explain the more widespread presence of gas hydrates north of the Knipovich Ridge. The presence of microbial methane on the upper continental slope and shelf indicates that the origin of methane on the Svalbard margin varies spatially.

  7. Poland and the Arctic: Between Science and Diplomacy

    OpenAIRE

    Graczyk, Piotr

    2012-01-01

    Poland has noticeably increased its activity in Arctic affairs in recent years. Although the first Polish research facilities on Svalbard were established back in the 1950s (by virtue of being a party to the Treaty concerning Spitsbergen) and the country has been involved in the Arctic environmental cooperation since its inception in the early 1990s, it was not until 2006/2007 when a policy shift towards assumption of a more ambitious role could be observed. The current Polish activity in the...

  8. Recent Levels of Technetium-99 in Seawater at the West Coast of Svalbard

    Directory of Open Access Journals (Sweden)

    Sebastian Gerland

    2002-01-01

    Full Text Available Seawater from the western coast of Svalbard was sampled in the spring and summer of 2000 to determine levels of technetium-99 (99Tc, a conservative-behaving, manmade radionuclide originating from European nuclear reprocessing plants. This paper deals with the recent levels of this radionuclide in seawater and with the link between an Arctic fjord, Kongsfjorden, and the Western Spitsbergen Current (WSC, investigated using 99Tc results. By means of the WSC, the 99Tc radionuclides ultimately reach the eastern Fram Strait west of Spitsbergen (the largest island of the Svalbard archipelago. Results from oceanographic modelling and sea ice observations indicate a direct coupling between Kongsfjorden and the area west of it. The findings in connection with new radionuclide results presented in this paper concur with these assumptions. Furthermore they indicate that the inner part of Kongsfjorden is also well linked to the WSC. Surface seawater from the central part of the WSC, sampled during a cruise with RV Polarstern in the summer of 2000, shows a higher level of 99Tc than those measured in Kongsfjorden in spring 2000. However, all levels measured in surface water are of the same order of magnitude. Data from sampling of deeper water in the WSC area provide information pertaining to the lateral distribution of 99Tc. The results, along with additional data from spring 2001, indicate that Kongsfjorden is suitable for monitoring the levels of 99Tc arriving in the European Arctic and that the sheltered setting of this fjord does not necessarily provide protection against pollution from the open sea.

  9. Monte Carlo modelling projects the loss of most land-terminating glaciers on Svalbard in the 21st century under RCP 8.5 forcing

    Science.gov (United States)

    Möller, Marco; Navarro, Francisco; Martín-Español, Alba

    2016-09-01

    The high Arctic archipelagos around the globe are among the most strongly glacierized landscapes on Earth apart from the Greenland and Antarctic ice sheets. Over the past decades, the mass losses from land ice in the high Arctic regions have contributed substantially to global sea level rise. Among these regions, the archipelago of Svalbard showed the smallest mass losses. However, this could change in the coming decades, as Svalbard is expected to be exposed to strong climate warming over the 21st century. Here we present extensive Monte Carlo simulations of the future ice-mass evolution of 29 individual land-terminating glaciers on the Svalbard archipelago under an RCP 8.5 climate forcing. An extrapolation of the 29 sample glaciers to all land-terminating glaciers of the archipelago suggests an almost complete deglaciation of the region by 2100. Under RCP 8.5, 98% of the land-terminating glaciers will have declined to less than one tenth of their initial size, resulting in a loss of 7392 ± 2481 km2 of ice coverage.

  10. Benthic algal vegetation in Isfjorden, Svalbard

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    Stein Fredriksen

    2015-08-01

    Full Text Available Benthic algal vegetation was investigated at 10 sites in Isfjorden, Svalbard. Five sites were visited during summer 2010 and five during summer 2012. Both the littoral and sublittoral vegetation were sampled, the littoral by hand-picking and use of a throwable rake and the sublittoral using a triangular dredge. A total of 88 different taxa were registered, comprising 17 Chlorophyta, 40 Ochrophyta, 30 Rhodophyta and the Xantophyceae Vaucheria sp. The green algae Ulvaria splendens (Ruprecht Vinogradova was recorded in Svalbard for the first time. Most of the sites consisted of hard bottom substrate, but one site, Kapp Wijk, consisted of loose-lying calcareous red algae (rhodoliths and had species not recorded elsewhere. The sublittoral at the other sites was dominated by kelp. Molecular analysis confirmed the presence of the red alga Ceramium virgatum and a dwarf form of the brown alga Fucus vesiculosus. This study provides a baseline for future studies investigating changes in the vegetation due to environmental changes.

  11. Temperature characteristics of bacterial sulfate reduction in continental shelf and slope sediments

    Directory of Open Access Journals (Sweden)

    J. E. Sawicka

    2012-08-01

    Full Text Available The temperature responses of sulfate-reducing microbial communities were used as community temperature characteristics for their in situ temperature adaptation, their origin, and dispersal in the deep sea. Sediments were collected from a suite of coastal, continental shelf, and slope sediments from the southwest and southeast Atlantic and permanently cold Arctic fjords from water depths ranging from the intertidal zone to 4327 m. In situ temperatures ranged from 8 °C on the shelf to −1 °C in the Arctic. Temperature characteristics of the active sulfate-reducing community were determined in short-term incubations with 35S-sulfate in a temperature gradient block spanning a temperature range from 0 to 40 °C. An optimum temperature (Topt between 27 °C and 30 °C for the South Atlantic shelf sediments and for the intertidal flat sediment from Svalbard was indicative of a psychrotolerant/mesophilic sulfate-reducing community, whereas Topt ≤20 °C in South Atlantic slope and Arctic shelf sediments suggested a predominantly psychrophilic community. High sulfate reduction rates (20–50% at in situ temperatures compared to those at Topt further support this interpretation and point to the importance of the ambient temperature regime for regulating the short-term temperature response of sulfate-reducing communities. A number of cold (<4 °C continental slope sediments showed broad temperature optima reaching as high as 30 °C, suggesting the additional presence of apparently mesophilic sulfate-reducing bacteria. Since the temperature characteristics of these mesophiles do not fit with the permanently cold deep-sea environment, we suggest that these mesophilic microorganisms are of allochthonous origin and transported to this site. It is likely that they were deposited along with the mass-flow movement of warmer shelf-derived sediment. These data therefore suggest that temperature

  12. Genetics differentiation between Arctic and Antarctic monothalamous foraminiferans

    DEFF Research Database (Denmark)

    Pawlowski, Jan; Majewski, Wojciech; Longet, David;

    2008-01-01

    Monothalamous (single-chambered) foraminifers are a major component of the benthic meiofauna in high latitude regions. Several morphologically similar species are common in the Arctic and Antarctic. However, it is uncertain whether these morphospecies are genetically identical, or whether...... their accurate identification is compromised by a lack of distinctive morphological features. To determine the relationship between Arctic and Antarctic species, we have compared SSU rDNA sequences of specimens belonging to four morphotaxa: Micrometula, Psammophaga, Gloiogullmia, and one morphospecies...... Hippocrepinella hirudinea from western Svalbard (Arctic) and McMurdo Sound (Antarctic). Wherever possible, we include in our analyses representatives of these taxa from the deep Arctic and Southern Oceans, as well as from Northern European fjords. We found that in all cases, the bipolar populations were clearly...

  13. Amsterdamøya: a key site for the post-glacial of Svalbard

    Science.gov (United States)

    Bakke, Jostein; Balascio, Nicholas; van der Bilt, Willem; D`Andrea, William; Bradley, Raymond; Gjerde, Marthe; Hormes, Anne; Olafsdottir, Sædis; Røthe, Torgeir; Vasskog, Kristian; De Wet, Greg; Werner, Johannes

    2016-04-01

    No other place on Earth is changing as fast as the Arctic in terms of climate. On average this region is warming twice as fast as the global average with a seasonal bias towards winter. A major retreat in sea ice extent accompanied by an even more massive thinning represents one of the most robust trends in the Arctic. This trend is anticipated to continue in the decades to come and, according to some models, will leave the Arctic Ocean open during summer some time between 2050-2100. Unabated reduction in the spring-snow cover represents another significant trend. The current warming is also expressed in the massive melting of the Greenland ice sheet as well as local glaciers and ice caps in the Arctic, which causes increased freshwater influx to the Arctic Ocean and adjacent seas. Climate modeling and scenarios are improving and becoming of growing importance, but without a firmer understanding of natural climate variability over longer timescale it is still hard to evaluate and best read the output from these models. In the SHIFTS project we have done an unparalleled effort to overcome this quandary, providing necessary empirical data on past climate which is critical for assessing past changes in atmospheric circulation patterns controlling Arctic hydroclimate. Our study site is located at the northwestern corner of Svalbard on the Island of Amsterdamøya, a site sensitive to changes in both oceanic and atmospheric forcing, at tail of the westward moving branch of the North Atlantic current. Here we have cored several lakes with the goal of providing quantitative data on temperature, hydrology and winter precipitation for the Holocene. Our approach has been to combine reconstruction of glaciers with lipid biomarkers and hydrogen isotopes with the goal of unravel the underlying signature of past climate in the Arctic. Chronological control is secured by radiocarbon dates on macrofossils combined with measurement of paleomagnetic secular variations. Here we

  14. Pulses of movement across the sea ice: population connectivity and temporal genetic structure in the arctic fox.

    Science.gov (United States)

    Norén, Karin; Carmichael, Lindsey; Fuglei, Eva; Eide, Nina E; Hersteinsson, Pall; Angerbjörn, Anders

    2011-08-01

    Lemmings are involved in several important functions in the Arctic ecosystem. The Arctic fox (Vulpes lagopus) can be divided into two discrete ecotypes: "lemming foxes" and "coastal foxes". Crashes in lemming abundance can result in pulses of "lemming fox" movement across the Arctic sea ice and immigration into coastal habitats in search for food. These pulses can influence the genetic structure of the receiving population. We have tested the impact of immigration on the genetic structure of the "coastal fox" population in Svalbard by recording microsatellite variation in seven loci for 162 Arctic foxes sampled during the summer and winter over a 5-year period. Genetic heterogeneity and temporal genetic shifts, as inferred by STRUCTURE simulations and deviations from Hardy-Weinberg proportions, respectively, were recorded. Maximum likelihood estimates of movement as well as STRUCTURE simulations suggested that both immigration and genetic mixture are higher in Svalbard than in the neighbouring "lemming fox" populations. The STRUCTURE simulations and AMOVA revealed there are differences in genetic composition of the population between summer and winter seasons, indicating that immigrants are not present in the reproductive portion of the Svalbard population. Based on these results, we conclude that Arctic fox population structure varies with time and is influenced by immigration from neighbouring populations. The lemming cycle is likely an important factor shaping Arctic fox movement across sea ice and the subsequent population genetic structure, but is also likely to influence local adaptation to the coastal habitat and the prevalence of diseases.

  15. Terrestrial slopes in northern high latitudes: A paradigm shift regarding sediment origin, composition, and dynamic evolution

    Science.gov (United States)

    Lønne, Ida

    2017-01-01

    High-Arctic terrestrial slopes have received limited systematic research interest, but increased vulnerability related to regional warming has driven the call for better knowledge of the dynamics of these systems. Studies of sediment transport from a plateau area in Adventdalen, Svalbard, and associated slopes extending to sea level demonstrate that glacial processes play a more prominent role than earlier anticipated, - especially the impact of glacial meltwater. Traces of drainage at the plateau and the dissection of the plateau edge and upper slope were clearly initiated during various stages of Late Glacial runoff. Further, there is a close association between the sediment distribution and composition at the plateau and the evolution of various types of slopes. The reconstructed sedimentation history shows that the landscape will undergo four stages with contrasting modes of sediment transport: 1) subglacial processes related to active ice, 2) processes related to the margin of active ice, 3) processes related to the melting of inactive ice, and 4) nonglacial processes. These stages form four successions, referred to as supply regimes A-D, which control the supply of water and sediments to a given slope segment. In this landscape, traces of glacial meltwater occur at most altitudes, in "odd" positions and in slope segments "without" catchments. The associated depocenters (isolated, composite or coalescing into aprons), are often outsized compared to the apparent slope catchment. Reworked glacial sediments form a significant part of the slope-debris but are covered partly or entirely by products of physical weathering. Colluvium, senso stricto, thus masks a distinct system shift related to the local termination of glacial meltwater. Consequently, the weathering part of the slope sediment budget in this region is considerably overestimated.

  16. Temperature characteristics of bacterial sulfate reduction in continental shelf and slope sediments

    Directory of Open Access Journals (Sweden)

    J. E. Sawicka

    2012-01-01

    Full Text Available The temperature responses of sulfate-reducing microbial communities were used as fingerprints for their in situ temperature adaptation, their origin, and dispersal in the deep-sea. Sediments were collected from a suite of coastal, continental shelf, and slope sediments from the southwest and southeast Atlantic and permanently cold Arctic fjords from water depths ranging from the intertidal zone to 4327 m. In situ temperatures ranged from 8 °C on the shelf to 1 °C on the lower slope and in the Arctic. Temperature characteristics of the active sulfate-reducing community were determined in short-term incubations with 35S-sulfate in a temperature gradient block spanning a temperature range from 0 to 40 °C. An optimum temperature (Topt between 27 °C and 30 °C for the South Atlantic shelf sediments and for the intertidal flat sediment from Svalbard was indicative of a psychrotolerant/mesophilic sulfate-reducing community, whereas Topt ≤ 20 °C in South Atlantic slope and Arctic shelf sediments suggested a predominantly psychrophilic community. High sulfate reduction rates (20–50% at in-situ temperatures compared to those at Topt further support this interpretation, and point to the importance of the ambient temperature regime for regulating the short-term temperature response of sulfate-reducing communities. A number of cold (<4 °C continental slope sediments showed broad temperature optima reaching as high as 30 °C suggesting the additional presence of apparently mesophilic sulfate-reducing bacteria. Since the temperature characteristics of these mesophiles do not fit with the permanently cold deep-sea environment, we suggest that these mesophilic microorganisms are of allochthonous origin and transported to this site. It is likely that they were deposited along with the mass-flow movement of warmer shelf-derived sediment. These data therefore suggest that temperature

  17. Long-term changes in pigmentation of arctic Daphnia provide potential for reconstructing aquatic UV exposure

    Science.gov (United States)

    Nevalainen, Liisa; Rantala, Marttiina V.; Luoto, Tomi P.; Ojala, Antti E. K.; Rautio, Milla

    2016-07-01

    Despite the biologically damaging impacts of solar ultraviolet radiation (UV) in nature, little is known about its natural variability, forcing mechanisms, and long-term effects on ecosystems and organisms. Arctic zooplankton, for example the aquatic keystone genus Daphnia (Crustacea, Cladocera) responds to biologically damaging UV by utilizing photoprotective strategies, including pigmentation. We examined the preservation and content of UV-screening pigments in fossil Daphnia remains (ephippia) in two arctic lake sediment cores from Cornwallis Island (Lake R1), Canada, and Spitsbergen (Lake Fugledammen), Svalbard. The aims were to document changes in the degree of UV-protective pigmentation throughout the past centuries, elucidate the adaptive responses of zooplankton to long-term variations in UV exposure, and estimate the potential of fossil zooplankton pigments in reconstructing aquatic UV regimes. The spectroscopic absorbance measurements of fossil Daphnia ephippia under UV (280-400 nm) and visible light (400-700 nm) spectral ranges indicated that melanin (absorbance maxima at UV wavebands 280-350 nm) and carotenoids (absorbance maxima at 400-450 nm) pigments were preserved in the ephippia in both sediment cores. Downcore measurements of the most important UV-protective pigment melanin (absorbance measured at 305 and 340 nm) showed marked long-term variations in the degree of melanisation. These variations likely represented long-term trends in aquatic UV exposure and were positively related with solar radiation intensity. The corresponding trends in melanisation and solar activity were disrupted at the turn of the 20th century in R1, but remained as strong in Fugledammen. The reversed trends in the R1 core were simultaneous with a significant aquatic community reorganization taking place in the lake, suggesting that recent environmental changes, likely related to climate warming had a local effect on pigmentation strategies. This time horizon is also

  18. Last glacial ice-sheet dynamics and deglaciation on Svalbard inferred from fjord records

    Science.gov (United States)

    Forwick, Matthias; Baeten, Nicole J.; Bunin, Elizabeth; Hansen, Trude; Kempf, Philipp; Velle, Julie H.; Sverre Laberg, Jan

    2015-04-01

    Various glacigenic landforms and sedimentary processes identified in the Spitsbergen fjords provide valuable insights into the dynamics of the northwestern parts of the Svalbard Barents Sea Ice Sheet during the last glacial. Glacial linear features oriented parallel to most fjord axes are identified on swath-bathymetry and high-resolution sub-bottom profiler data. They provide evidence of locally fast-flowing grounded ice draining the northwestern parts of the Svalbard Barents Sea Ice Sheet to the shelf breaks off north and west Svalbard. Eskers overlying glacial lineations reveal the existence of englacial or sub-glacial drainage systems that developed after the termination of fast ice flow. Iceberg ploughmarks suggest that parts of the deglaciation occurred by iceberg calving. Multiple transverse ridges, e.g. grounding zone wedges and moraines, indicate that multiple halts and/or readvances interrupted the deglaciations of the fjords. This includes relatively small moraines, probably deposited during halts and/or readvances in consecutive winters, thus, allowing the calculation of annual retreat rates of the ice fronts in certain fjord areas. Their regular spacing may suggest that e.g. parts of Billefjorden, Smeerenburgfjorden and Woodfjorden were deglaciated at relatively constant rates of at least 140 m/year. However, the deglaciation of van Keulenfjorden accelerated from approx. 80 m/year to about 190 m/year. Lithological analyses allow the study of sub-glacial, glacier-proximal and glacier-distal sedimentary processes and environments, as well as the identification of influences from various sediment sources. They reveal, furthermore, that the deglaciations of multiple fjords terminated quasi-synchronously around 11,200 cal. years BP, but that significant local delays of up to several thousand years occurred.

  19. Pan-Arctic patterns in black carbon sources and fluvial discharges deduced from radiocarbon and PAH source apportionment markers in estuarine surface sediments

    Science.gov (United States)

    Elmquist, Marie; Semiletov, Igor; Guo, Laodong; Gustafsson, Örjan

    2008-06-01

    A pan-arctic geospatial picture of black carbon (BC) characteristics was obtained from the seven largest arctic rivers by combining with molecular combustion markers (polycyclic aromatic hydrocarbons) and radiocarbon (14C) analysis. The results suggested that the contribution from modern biomass burning to BC ranged from low in the Yukon (8%) and Lena (5%) Rivers to high in the Yenisey River (88%). The Mackenzie River contributed almost half of the total arctic fluvial BC export of 202 kton a-1 (kton = 109 g), with the five Russian-Arctic rivers contributing 10-36 kton a-1 each. The 14C-based source estimate of fluvially exported BC to the Arctic Ocean, weighted by the riverine BC fluxes, amount to about 20% from vegetation/biofuel burning and 80% from 14C-extinct sources such as fossil fuel combustion and relict BC in uplifted source rocks. Combining these pan-arctic data with available estimates of BC export from other rivers gave a revised estimate of global riverine BC export flux of 26 × 103 kton a-1. This is twice higher than a single previous estimate and confirms that river export of BC is a more important pathway of BC to the oceans than direct atmospheric deposition.

  20. Unmanned Aerial Systems during the Coordinated Investigation of Climate-Cryosphere Interaction at Svalbard, Norway

    Science.gov (United States)

    Burkhart, J. F.; Bates, T. S.; Quinn, P.; Storvold, R.; Herber, A.; Vitale, V.; Lesenkov, S.; Cicci/Vauuav Science Team

    2011-12-01

    During Spring 2011 an intensive investigation of climate-cryosphere interaction was conducted in Svalbard, Norway. A primary objective of the campaign was to investigate processes related to the deposition of aerosols to the Arctic cryosphere. Moreover, the campaign provided a first-time opportunity to test several novel data acquisition platforms. Of interest to this session are the three Unmanned Aerial System (UAS) platforms that flew cooperatively with oversight from the Norwegian Civil Aviation Authority (CAA). The campaign presented the unique opportunity for a CAA to regulate UAS platforms; both private and foreign government-owned aircraft (Norway, USA, and Russia). Further, it highlighted challenges, both political and logistical, related to conducting such an operation. We present an overview of the 'Coordinated Investigation of Climate-Cryosphere Interaction' campaign, and highlight the novel and valuable contributions from each of the UAS platforms. Our presentation includes an overview of the different platform capabilities, a discussion of the scientific merits of the platforms, insight into the political process for UAS operations in the Arctic, and a summary of the acquired contributions toward the goals of the CICCI project.

  1. Constraints on sea to air emissions from methane clathrates in the vicinity of Svalbard

    Science.gov (United States)

    Pisso, Ignacio; Vadakkepuliyambatta, Sunil; Platt, Stephen Matthew; Eckhardt, Sabine; Allen, Grant; Pitt, Joseph; Silyakova, Anna; Hermansen, Ove; Schmidbauer, Norbert; Mienert, Jurgen; Myhre, Cathrine Lund; Stohl, Andreas

    2016-04-01

    Methane stored in the seabed in the form of clathrates has the potential to be released into the atmosphere due to ongoing ocean warming. The Methane Emissions from Arctic Ocean to Atmosphere (MOCA, http://moca.nilu.no/) proje sct conducted measurement campaigns in the vicinity of Svalbard during the summers of 2014 and 2015 in collaboration with the Centre for Arctic Gas Hydrate, Environment and Climate (CAGE, https://cage.uit.no/) and the MAMM (https://arcticmethane.wordpress.com) project . The extensive set of measurements includes air (BAe 146) and ship (RV Helmer Hansen) borne methane concentrations, complemented with the nearby monitoring site at Zeppelin mountain. In order to assess the atmospheric impact of emissions from seabed methane hydrates, we characterised the local and long range atmospheric transport during the aircraft campaign and different scenarios for the emission sources. We present a range of upper bounds for the CH4 emissions during the campaign period as well as the methodologies used to obtain them. The methodologies include a box model, Lagrangian transport and elementary inverse modelling. We emphasise the analysis of the aircraft data. We discuss in detail the different methodologies used for determining the upper flux bounds as well as its uncertainties and limitations. The additional information provided by the ship and station observations will be briefly mentioned.

  2. Salix polaris growth responses to active layer detachment and solifluction processes in High Arctic.

    Science.gov (United States)

    Siekacz, Liliana

    2015-04-01

    participation of missing and partially missing rings. Share of missing rings in shrubs growing within an active layer detachment on the valley slope reached 16,22% and 15,36%. Even higher variation is observed in partially missing rings which account for 31,07% within detachment and 23,39% on surrounding slope. Those values are more than twice higher comparing to the valley floor. There is also noticeable difference between detachment and surrounding slope indicating that wedging rings are an effect of mechanical stress that is higher within the detachment. Comparing growth patterns in aboveground and belowground plant parts different growth allocation is noticed. Years of detachment event growth rings were present only in aboveground parts. It is supposed that mechanical stress delays the onset of the growing season similarly to low temperatures (Buchwał et al., 2013), resulting in not enough time to fully allocate resources for growth in the belowground parts. Growth pattern is extremely irregular, indicating that the slope is in constant movement, which disrupts growth conditions. Analyzed shrubs showed two possible event years: 2006 and 2008, with the highest participation of missing and partially missing rings. Air and ground temperature data were also analyzed and confirmed that active layer detachment happened in 2006. REFERENCES Buchwał A, Rachlewicz G, Fonti P, Cherubini P, Gärtner H, (2013) Temperature modulates intra-plant growth of Salix Polaris from a high Arctic site (Svalbard). Polar Biol 36:1305-1318. Hagen J O, Liestøl O, Roland E, Jørgensen T, (1993) Glacier atlas of Svalbard and Jan Mayen. Norsk Polarinstitutt Meddelelser 129: 160. Rachlewicz G, (2009) Contemporary sediment fluxes and relief changes in high Arctic glacierized valley systems (Billefjorden, Central Spitsbergen). Wyd. Nauk. UAM Poznań, seria Geografia 87:204. Schweingruber FH, Poschlod P, (2005) Growth rings in herbs and shrubs: life span, age determination and stem anatomy. For Snow

  3. Plio-Pleistocene evolution of water mass exchange and erosional input at the Atlantic-Arctic gateway

    Science.gov (United States)

    Teschner, Claudia; Frank, Martin; Haley, Brian A.; Knies, Jochen

    2016-05-01

    Water mass exchange between the Arctic Ocean and the Norwegian-Greenland Seas has played an important role for the Atlantic thermohaline circulation and Northern Hemisphere climate. We reconstruct past water mass mixing and erosional inputs from the radiogenic isotope compositions of neodymium (Nd), lead (Pb), and strontium (Sr) at Ocean Drilling Program site 911 (leg 151) from 906 m water depth on Yermak Plateau in the Fram Strait over the past 5.2 Myr. The isotopic compositions of past bottom waters were extracted from authigenic oxyhydroxide coatings of the bulk sediments. Neodymium isotope signatures obtained from surface sediments agree well with present-day deepwater ɛNd signature of -11.0 ± 0.2. Prior to 2.7 Ma the Nd and Pb isotope compositions of the bottom waters only show small variations indicative of a consistent influence of Atlantic waters. Since the major intensification of the Northern Hemisphere Glaciation at 2.7 Ma the seawater Nd isotope composition has varied more pronouncedly due to changes in weathering inputs related to the waxing and waning of the ice sheets on Svalbard, the Barents Sea, and the Eurasian shelf, due to changes in water mass exchange and due to the increasing supply of ice-rafted debris (IRD) originating from the Arctic Ocean. The seawater Pb isotope record also exhibits a higher short-term variability after 2.7 Ma, but there is also a trend toward more radiogenic values, which reflects a combination of changes in input sources and enhanced incongruent weathering inputs of Pb released from freshly eroded old continental rocks.

  4. Observations of enhanced thinning in the upper reaches of Svalbard glaciers

    Directory of Open Access Journals (Sweden)

    T. D. James

    2012-11-01

    Full Text Available Changes in the volume and extent of land ice of the Svalbard archipelago have been the subject of considerable research since their sensitivity to changes in climate was first noted. However, the measurement of these changes is often necessarily based on point or profile measurements which may not be representative if extrapolated to a whole catchment or region. Combining high-resolution elevation data from contemporary laser-altimetry surveys and archived aerial photography makes it possible to measure historical changes across a glacier's surface without the need for extrapolation. Here we present a high spatial resolution time-series for six Arctic glaciers in the Svalbard archipelago spanning 1961 to 2005. We find high variability in thinning rates between sites with prevalent elevation changes at all sites averaging −0.59 ± 0.04 m a−1 between 1961–2005. Prior to 1990, ice surface elevation was changing at an average rate of −0.52 ± 0.09 m a−1 which decreased to −0.76 ± 0.10 m a−1 after 1990. Setting the elevation changes against the glaciers' altitude distribution reveals that significant increases in thinning rates are occurring most notably in the glaciers' upper reaches. We find that these changes are coincident with a decrease in winter precipitation at the Longyearbyen meteorological station and could reflect a decrease in albedo or dynamic response to lower accumulation. Further work is required to understand fully the causes of this increase in thinning rates in the glaciers' upper reaches. If on-going and occurring elsewhere in the archipelago, these changes will have a significant effect on the region's future mass balance. Our results highlight the importance of understanding the climatological context of geodetic mass balance measurements and demonstrate the difficulty of using index glaciers to represent regional changes in areas of strong climatological gradients.

  5. Regional passive seismic monitoring reveals dynamic glacier activity on Spitsbergen, Svalbard

    Directory of Open Access Journals (Sweden)

    Andreas Köhler

    2015-12-01

    Full Text Available Dynamic glacier activity is increasingly observed through passive seismic monitoring. We analysed near-regional-scale seismicity on the Arctic archipelago of Svalbard to identify seismic icequake signals and to study their spatial–temporal distribution within the 14-year period from 2000 until 2013. This is the first study that uses seismic data recorded on permanent broadband stations to detect and locate icequakes in different regions of Spitsbergen, the main island of the archipelago. A temporary local seismic network and direct observations of glacier calving and surging were used to identify icequake sources. We observed a high number of icequakes with clear spectral peaks between 1 and 8 Hz in different parts of Spitsbergen. Spatial clusters of icequakes could be associated with individual grounded tidewater glaciers and exhibited clear seasonal variability each year with more signals observed during the melt season. Locations at the termini of glaciers, and correlation with visual calving observations in situ at Kronebreen, a glacier in the Kongsfjorden region, show that these icequakes were caused dominantly by calving. Indirect evidence for glacier surging through increased calving seismicity was found in 2003 at Tunabreen, a glacier in central Spitsbergen. Another type of icequake was observed in the area of the Nathorstbreen glacier system. Seismic events occurred upstream of the glacier within a short time period between January and May 2009 during the initial phase of a major glacier surge. This study is the first step towards the generation and implementation of an operational seismic monitoring strategy for glacier dynamics in Svalbard.

  6. Over 400 previously undocumented Svalbard surge-type glaciers identified

    Science.gov (United States)

    Farnsworth, Wesley R.; Ingólfsson, Ólafur; Retelle, Michael; Schomacker, Anders

    2016-07-01

    Identifying glaciers that exhibit surge-type behavior is important when using evidence of ice front fluctuations as a proxy for reconstructing past climate oscillations. This study identifies previously undocumented surge-type glaciers in Svalbard, based on the presence of crevasse squeeze ridges in glacier forelands. Crevasse squeeze ridges are landforms suggested to be unique to surging glacier land systems. Estimates vary greatly as to the actual percentage of surge-type glaciers in Svalbard, and consequently their distribution pattern is poorly understood. A detailed survey of recent (2008-2012), high-resolution aerial imagery from TopoSvalbard, provided by the Norwegian Polar Institute, allowed for a survey of all the glacier forelands in Svalbard. Before our study, 277 individual glaciers in Svalbard have been documented to exhibit surge behavior. By using crevasse squeeze ridges as indicators of surge behavior, we have identified 431 additional glaciers that have surged. We suggest that this is a modest value as the unique surge landforms were not visible in approximately one-third of the forelands with documented surge histories. Limits to the crevasse squeeze ridge technique are presented and potential controlling factors for crevasse squeeze ridge formation/preservation are discussed.

  7. Comparative study of vertical suspension fluxes from the water column, rates of sedimentation, and absolute masses of the bottom sediments in the White Sea basin of the Arctic Ocean

    Science.gov (United States)

    Lisitzin, A. P.; Novigatsky, A. N.; Aliev, R. A.; Shevchenko, V. P.; Klyuvitkin, A. A.; Kravchishina, M. D.

    2015-12-01

    A new approach using dispersed organic matter of the water column in sedimentation traps in comparison with the surface layer of the bottom sediments is applied for the study of marine sedimentation. This approach provides the opportunity for an in situ (by fluxes of sedimentary matter in the water column) study of modern sedimentation in the surface layers of the bottom sediments and tracing the changes in the environment and climate at a new technological level. This also allows us to choose the reverse task: to reconstruct the fluxes of the matter and chemical elements in ancient seas by the rates (or absolute masses) of sedimentation.

  8. Arctic Newcomers

    DEFF Research Database (Denmark)

    Tonami, Aki

    2013-01-01

    Interest in the Arctic region and its economic potential in Japan, South Korea and Singapore was slow to develop but is now rapidly growing. All three countries have in recent years accelerated their engagement with Arctic states, laying the institutional frameworks needed to better understand an...

  9. Arctic methane

    NARCIS (Netherlands)

    Dyupina, E.; Amstel, van A.R.

    2013-01-01

    What are the risks of a runaway greenhouse effect from methane release from hydrates in the Arctic? In January 2013, a dramatic increase of methane concentration up to 2000 ppb has been measured over the Arctic north of Norway in the Barents Sea. The global average being 1750 ppb. It has been sugges

  10. Soil Physical and Environmental Conditions Controlling Patterned-Ground Variability at a Continuous Permafrost Site, Svalbard

    DEFF Research Database (Denmark)

    Watanabe, Tatsuya; Matsuoka, Norikazu; Christiansen, Hanne Hvidtfeldt

    2017-01-01

    This study examines soil physical and environmental conditions controlling patterned-ground variability on an alluvial fan in a continuous permafrost landscape, at Adventdalen, Svalbard. On-site monitoring of ground temperature, soil moisture and snow depth, laboratory analyses of soil physical...... properties and principal component analysis indicate that the distribution of patterned ground depends primarily on soil texture, soil moisture and the winter ground thermal regime associated with snow cover. Mudboils and composite patterns (mudboils surrounded by small polygons) occupy well-drained areas...... composed of clay-rich aeolian sediments. Compared to mudboils, composite patterns show a sharper contrast in soil texture between barren centres and vegetated rims. Hummocks filled with organic materials develop on poorly drained lowlands associated with a shallow water table. Ice-wedge polygons...

  11. Isotopic and Geochemical Investigation of Two Distinct Mars Analog Environments Using Evolved Gas Techniques in Svalbard, Norway

    Science.gov (United States)

    Stern, Jennifer Claire; Mcadam, Amy Catherine; Ten Kate, Inge L.; Bish, David L.; Blake, David F.; Morris, Richard V.; Bowden, Roxane; Fogel, Marilyn L.; Glamoclija, Mihaela; Mahaffy, Paul R.; Steele, Andrew; Amundsen, Hans E. F.

    2013-01-01

    The 2010 Arctic Mars Analog Svalbard Expedition (AMASE) investigated two distinct geologic settings on Svalbard, using methodologies and techniques to be deployed on Mars Science Laboratory (MSL). AMASErelated research comprises both analyses conducted during the expedition and further analyses of collected samples using laboratory facilities at a variety of institutions. The Sample Analysis at Mars (SAM) instrument suite on MSL includes pyrolysis ovens, a gas-processing manifold, a quadrupole mass spectrometer (QMS), several gas chromatography columns, and a Tunable Laser Spectrometer (TLS). An integral part of SAM development is the deployment of SAM-like instrumentation in the field. During AMASE 2010, two parts of SAM participated as stand-alone instruments. A Hiden Evolved Gas Analysis- Mass Spectrometer (EGA-QMS) system represented the EGA-QMS component of SAM, and a Picarro Cavity Ring Down Spectrometer (EGA-CRDS), represented the EGA-TLS component of SAM. A field analog of CheMin, the XRD/XRF on MSL, was also deployed as part of this field campaign. Carbon isotopic measurements of CO2 evolved during thermal decomposition of carbonates were used together with EGA-QMS geochemical data, mineral composition information and contextual observations made during sample collection to distinguish carbonates formation associated with chemosynthetic activity at a fossil methane seep from abiotic processes forming carbonates associated with subglacial basaltic eruptions. Carbon and oxygen isotopes of the basalt-hosted carbonates suggest cryogenic carbonate formation, though more research is necessary to clarify the history of these rocks.

  12. Advection of Atlantic Water to the Western and Northern Svalbard Shelves Through the Last 17.5 ka cal yr BP

    Science.gov (United States)

    Slubowska, M. A.; Rasmussen, T. L.; Koc, N.; Kristensen, D. K.; Nilsen, F.; Solheim, A.

    2005-12-01

    We have studied the distribution of benthic foraminifera species together with planktonic and benthic foraminifera abundances, stable oxygen isotopes and lithology in two cores: JM02-440 from the western (77° 22' N, 12° 48' E, 240 m water depth) and NP94-51 from the northern (80° 21' N and 16 ° 17' E, 400 m water depth) shelf of Svalbard. The purpose of the study was to reconstruct the changes in flow and character of the relatively warm Atlantic Water through the last 17.5 ka cal yr BP. The results from these two sites were compared with previously published records from the eastern Nordic Seas in order to follow the history of the advection of Atlantic Water as it moved northwards along the Norwegian coast and into the Arctic Ocean. Our results indicate that synchronous oceanographic changes occurred at the western and northern Svalbard shelves. The benthic foraminifera and oxygen isotope records indicate almost continuous presence of the Atlantic Water at the shelf areas since the deglaciation. The Bolling-Allerod period stands out as the warmest period in our records with the highest bottom waters temperatures indicating strong inflow of Atlantic Water. However, the warm Atlantic Water was isolated below cold and probably sea ice covered surface waters in contrast to the surface waters along the Norwegian coast, which experienced enhanced temperatures. During the Younger Dryas a freshening of the bottom waters occurred and the Polar Front was located in a proximal position to both sites. The strong inflow of saline, but chilled Atlantic Water happened during the Early Holocene. A distinct cooling and freshening of the bottom water masses occurred during the Mid- and Late Holocene, and was accompanied by glacier re-advances leading to the present-day conditions. During the last millennium, the inflow of Atlantic Water appears to increase, but the conditions turned unstable. The development of the paleoceanographic conditions at the western and northern

  13. Pan-Arctic observations in GRENE Arctic Climate Change Research Project and its successor

    Science.gov (United States)

    Yamanouchi, Takashi

    2016-04-01

    We started a Japanese initiative - "Arctic Climate Change Research Project" - within the framework of the Green Network of Excellence (GRENE) Program, funded by the Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT), in 2011. This Project targeted understanding and forecasting "Rapid Change of the Arctic Climate System and its Global Influences." Four strategic research targets are set by the Ministry: 1. Understanding the mechanism of warming amplification in the Arctic; 2. Understanding the Arctic climate system for global climate and future change; 3. Evaluation of the impacts of Arctic change on the weather and climate in Japan, marine ecosystems and fisheries; 4. Projection of sea ice distribution and Arctic sea routes. Through a network of universities and institutions in Japan, this 5-year Project involves more than 300 scientists from 39 institutions and universities. The National Institute of Polar Research (NIPR) works as the core institute and The Japan Agency for Marine- Earth Science and Technology (JAMSTEC) joins as the supporting institute. There are 7 bottom up research themes approved: the atmosphere, terrestrial ecosystems, cryosphere, greenhouse gases, marine ecology and fisheries, sea ice and Arctic sea routes and climate modeling, among 22 applications. The Project will realize multi-disciplinal study of the Arctic region and connect to the projection of future Arctic and global climatic change by modeling. The project has been running since the beginning of 2011 and in those 5 years pan-Arctic observations have been carried out in many locations, such as Svalbard, Russian Siberia, Alaska, Canada, Greenland and the Arctic Ocean. In particular, 95 GHz cloud profiling radar in high precision was established at Ny-Ålesund, Svalbard, and intensive atmospheric observations were carried out in 2014 and 2015. In addition, the Arctic Ocean cruises by R/V "Mirai" (belonging to JAMSTEC) and other icebreakers belonging to other

  14. Arctic Watch

    Science.gov (United States)

    Orcutt, John; Baggeroer, Arthur; Mikhalevsky, Peter; Munk, Walter; Sagen, Hanne; Vernon, Frank; Worcester, Peter

    2015-04-01

    The dramatic reduction of sea ice in the Arctic Ocean will increase human activities in the coming years. This will be driven by increased demand for energy and the marine resources of an Arctic Ocean more accessible to ships. Oil and gas exploration, fisheries, mineral extraction, marine transportation, research and development, tourism and search and rescue will increase the pressure on the vulnerable Arctic environment. Synoptic in-situ year-round observational technologies are needed to monitor and forecast changes in the Arctic atmosphere-ice-ocean system at daily, seasonal, annual and decadal scales to inform and enable sustainable development and enforcement of international Arctic agreements and treaties, while protecting this critical environment. This paper will discuss multipurpose acoustic networks, including subsea cable components, in the Arctic. These networks provide communication, power, underwater and under-ice navigation, passive monitoring of ambient sound (ice, seismic, biologic and anthropogenic), and acoustic remote sensing (tomography and thermometry), supporting and complementing data collection from platforms, moorings and autonomous vehicles. This paper supports the development and implementation of regional to basin-wide acoustic networks as an integral component of a multidisciplinary, in situ Arctic Ocean Observatory.

  15. Kelp and seaweed feeding by High-Arctic wild reindeer under extreme winter conditions

    OpenAIRE

    2012-01-01

    One challenge in current Arctic ecological research is to understand and predict how wildlife may respond to increased frequencies of ‘‘extreme’’ weather events. Heavy rain-on-snow (ROS) is one such extreme phenomenon associated with winter warming that is not well studied but has potentially profound ecosystem effects through changes in snow-pack properties and ice formation. Here, we document how ice-locked pastures following substantial amounts of ROS forced coastal Svalbard reindeer (Rang...

  16. Impact of Volcanic Eruptions on the Occurrence of PAHs Compounds in the Aquatic Ecosystem of the Southern Part of West Spitsbergen (Hornsund Fjord, Svalbard

    Directory of Open Access Journals (Sweden)

    Katarzyna Kozak

    2017-01-01

    Full Text Available The paper presents changes in concentration levels of dioxin-like compounds that can be observed over the course of four study seasons in water samples collected from the Arctic watershed of Svalbard. The conducted analysis involved anthropogenic and natural factors that may affect the concentration of PAHs in the study samples of water. An attempt is made to indicate the emission source of the compounds being deposited and to identify the extent to which the substances under analysis actually affect the Arctic ecosystems. Moreover, the work employs the following: diagnostic ratios PAHs, air masses backward trajectory analysis, Lidar observations and land relief analysis in order to provide a multi-level interpretation of the obtained data. Natural environment constitutes a complex system of subtle correlations that need to be perceived as a dynamic medium, in which multi-faceted processes take place.

  17. Tourism and Arctic Observation Systems: exploring the relationships

    Directory of Open Access Journals (Sweden)

    Suzanne de la Barre

    2016-03-01

    Full Text Available The Arctic is affected by global environmental change and also by diverse interests from many economic sectors and industries. Over the last decade, various actors have attempted to explore the options for setting up integrated and comprehensive trans-boundary systems for monitoring and observing these impacts. These Arctic Observation Systems (AOS contribute to the planning, implementation, monitoring and evaluation of environmental change and responsible social and economic development in the Arctic. The aim of this article is to identify the two-way relationship between AOS and tourism. On the one hand, tourism activities account for diverse changes across a broad spectrum of impact fields. On the other hand, due to its multiple and diverse agents and far-reaching activities, tourism is also well-positioned to collect observational data and participate as an actor in monitoring activities. To accomplish our goals, we provide an inventory of tourism-embedded issues and concerns of interest to AOS from a range of destinations in the circumpolar Arctic region, including Alaska, Arctic Canada, Iceland, Svalbard, the mainland European Arctic and Russia. The article also draws comparisons with the situation in Antarctica. On the basis of a collective analysis provided by members of the International Polar Tourism Research Network from across the polar regions, we conclude that the potential role for tourism in the development and implementation of AOS is significant and has been overlooked.

  18. Experimentally determined temperature thresholds for Arctic plankton community metabolism

    Directory of Open Access Journals (Sweden)

    J. M. Holding

    2013-01-01

    Full Text Available Climate warming is especially severe in the Arctic, where the average temperature is increasing 0.4 °C per decade, two to three times higher than the global average rate. Furthermore, the Arctic has lost more than half of its summer ice extent since 1980 and predictions suggest that the Arctic will be ice free in the summer as early as 2050, which could increase the rate of warming. Predictions based on the metabolic theory of ecology assume that temperature increase will enhance metabolic rates and thus both the rate of primary production and respiration will increase. However, these predictions do not consider the specific metabolic balance of the communities. We tested, experimentally, the response of Arctic plankton communities to seawater temperature spanning from 1 °C to 10 °C. Two types of communities were tested, open-ocean Arctic communities from water collected in the Barents Sea and Atlantic influenced fjord communities from water collected in the Svalbard fjord system. Metabolic rates did indeed increase as suggested by metabolic theory, however these results suggest an experimental temperature threshold of 5 °C, beyond which the metabolism of plankton communities shifts from autotrophic to heterotrophic. This threshold is also validated by field measurements across a range of temperatures which suggested a temperature 5.4 °C beyond which Arctic plankton communities switch to heterotrophy. Barents Sea communities showed a much clearer threshold response to temperature manipulations than fjord communities.

  19. The Arctic lithosphere: an overview

    Science.gov (United States)

    Drachev, S.; Pease, V.; Stephenson, R.

    2012-04-01

    relationship between segmentation of the Gakkel Ridge and ultra-slow spreading processes? • Has the axial geometry of the Gakkel Ridge changed since rifting? If not, why? • What structures connect seafloor spreading on the Gakkel Ridge to continental extension on the Laptev Shelf? • Where are the continuations of pre-Eocene orogens in the Arctic? • How do these crustal-scale discontinuities influence Arctic tectonic evolution? • How has this tectonic evolution affected the sedimentation history of the Arctic basins?

  20. Application of a minimal glacier model to Hansbreen, Svalbard

    NARCIS (Netherlands)

    Oerlemans, J.; Jania, J.; Kolondra, Leszek

    2011-01-01

    Hansbreen is a well studied tidewater glacier in the southwestern part of Svalbard, currently about 16 km long. Since the end of the 19th century it has been retreating over a distance of 2.7 km. In this paper the global dynamics of Hansbreen are studied with a minimal glacier model, in which the ic

  1. Laser Ablation Split Stream (LASS) U-Pb & Lu-Hf Isotope Analysis of Detrital Zircons from the Old Red Sandstone, NW Svalbard: Implications for Northern Caledonian Paleogeography

    Science.gov (United States)

    Beranek, L. P.; Gee, D. G.; Fisher, C. M.

    2015-12-01

    The Svalbard archipelago consists of three Caledonian provinces that were assembled by thrusting and transcurrent faulting during the Silurian and Devonian in a location directly northeast of the Greenland Caledonides. Syn- to post-orogenic alluvial strata, referred to as the Old Red Sandstones, filled pull-apart basins adjacent to the transcurrent faults and comprise cover assemblages that help constrain the timing of the Caledonian orogeny. To further investigate the tectonic history and paleogeography of the Raudfjorden-Liefdefjorden-Woodfjorden area of Spitsbergen, NW Svalbard, we analyzed rock samples of the Old Red Sandstones and underlying Precambrian basement complexes for detrital zircon analysis. Laboratory studies of the Old Red Sandstones include the novel Laser Ablation Split Stream (LASS) technique, which allows for simultaneous U-Pb & Lu-Hf isotope analysis of zircon crystals. Lower Devonian Red Bay Group strata contain a range of early Neoproterozoic to Neoarchean detrital zircons with prominent age peaks c. 960, 1050, 1370, 1450, 1650, and 2700 Ma; subordinate Ordovician (c. 460-490 Ma) and Cryogenian (c. 650 Ma) detrital zircons occur in a subset of the samples. Underlying Precambrian metasedimentary rocks are composed of similar earliest Neoproterozoic to Neoarchean age populations, which argues for much of the Red Bay Group to be derived from local basement rocks during thrusting and other faulting. The U-Pb ages and Hf isotope compositions of Paleozoic to Neoarchean detrital zircons are consistent with Arctic crustal evolution, and support the hypothesis that northwestern and northeastern provinces of the Svalbard Caledonides are extruded fragments of the northeast Greenland allochthons. The new Hf isotope results further allow paleogeographic and stratigraphic comparisons with rock assemblages proximal to the North Atlantic Caledonides during the Silurian-Devonian, including the Pearya terrane of Ellesmere Island, Alexander terrane of NW

  2. Walrus Odobenus rosmarus research in Svalbard, Norway, 2000-2010

    Directory of Open Access Journals (Sweden)

    Christian Lydersen

    2013-08-01

    Full Text Available Herein we report results from studies on walruses in Svalbard conducted in 2000-2010. Data from newly developed satellite relay data loggers (SRDLs revealed seasonal differences in habitat use of adult male walruses. During winter, they moved into areas of >90% ice concentration, traveling as far as 600 km from ice-free water. Breeding areas deep into the pack ice were identified based on timing of the occupancy and diving behaviour. When the breeding season was over, walruses with SRDLs that were still transmitting locations returned to the coast, showing high site fidelity to the previous year’s summering area. Haul-out data from the SRDLs provided correction factors for an aerial survey of walruses that covered all known haul-out sites within the Svalbard Archipelago. This survey estimated 2,629 (95 % CI; 2,318 – 2,998 walruses to be in Svalbard during August 2006. Blubber biopsies from adult male walruses analyzed for fatty acids (FAs showed vertical stratification similar to that observed in many other marine mammals. However, differences between layers were less pronounced, possibly because the thick dermis of walruses provides an insulating shield, affecting the FA composition of the outer blubber. The FA composition of the inner blubber most closely resembled the lipids in Mya truncata and Buccinum spp., which are considered the most important walrus prey in Svalbard. A study investigating the use of skin biopsies for assessing levels of organochlorines (OCs in walruses found a significant relationship between OC levels in skin and blubber. Another contaminant study found a significant decrease in levels of PCBs and DDE in walruses in Svalbard from 1993 to 2002-04. Large inter-individual variation in OC levels was found, although all of the study animals were adult males from roughly the same location. In FA analyses of the inner blubber this variation appeared to be diet-related, with high OC levels having FA compositions in the

  3. Reconstructing Methane Emission Events in the Arctic Ocean: Observations from the Past to Present

    Science.gov (United States)

    Panieri, G.; Mienert, J.; Fornari, D. J.; Torres, M. E.; Lepland, A.

    2015-12-01

    Methane hydrates are ice-like crystals that are present along continental margins, occurring in the pore space of deep sediments or as massive blocks near the seafloor. They form in high pressure and low temperature environments constrained by thermodynamic stability, and supply of methane. In the Arctic, gas hydrates are abundant, and the methane released by their destabilization can affect local to global carbon budgets and cycles, ocean acidification, and benthic community survival. With the aim to locate in space and time the periodicity of methane venting, CAGE is engaged in a vast research program in the Arctic, a component of which comprises the analyses of numerous sediment cores and correlative geophysical and geochemical data from different areas. Here we present results from combined analyses of biogenic carbonate archives along the western Svalbard Margin, which reveal past methane venting events in this region. The reconstruction of paleo-methane discharge is complicated by precipitation of secondary carbonate on foraminifera shells, driven by an increase in alkalinity during anaerobic oxidation of methane (AOM). The biogeochemical processes involved in methane cycling and processes that drive methane migration affect the depth where AOM occurs, with relevance to secondary carbonate formation. Our results show the value and complexity of separating primary vs. secondary signals in bioarchives with relevance to understanding fluid-burial history in methane seep provinces. Results from our core analyses are integrated with observations made during the CAGE15-2 cruise in May 2015, when we deployed a towed vehicle equipped with camera, multicore and water sampling capabilities. The instrument design was based on the Woods Hole Oceanographic Institution (WHOI) MISO TowCam sled equipped with a deep-sea digital camera and CTD real-time system. Sediment sampling was visually-guided using this system. In one of the pockmarks along the Vestnesa Ridge where high

  4. Methane Emissions from the Arctic Ocean to the Atmosphere

    Science.gov (United States)

    Platt, Stephen; Hermansen, Ova; Schmidbauer, Norbert; Pisso, Ignacio; Silyakova, Anna; Ferré, Benedicte; Lowry, Dave; Percival, Carl; Mienert, Jürgen; Myhre, Cathrine Lund

    2015-04-01

    The release of methane (CH4) presently stored in vast hydrate deposits under the seafloor is a potential climate tipping point and a major uncertainty in the global methane budget. Significant methane hydrate deposits are located in shallow waters in the Arctic where they may destabilise, releasing methane to the atmosphere due to ocean warming. To address this issue the Methane Emissions from Arctic Ocean to Atmosphere (MOCA, http://moca.nilu.no/) project was established in cooperation with the CAGE Centre of Excellence (http:cage.uit.no/). State-of-the-art oceanographic and atmospheric measurement techniques were applied over a large area of the Arctic including northern Norway, the Barents Sea, and areas of shallow water around Svalbard during summer 2014. Oceanographic measurements included the deployment of 63 measurement stations (temperature, salinity, density, oxygen, fluorescence, turbidity, etc.), water column sampling (CH4, nitrate, phosphate, silicates), and echo sounding (revealing locations where streams of gas bubbles are vented). Atmospheric on-line measurements were performed aboard the research vessel Helmer Hanssen (CH4, CO2, CO, meteorological parameters) and during a flight campaign (CH4, etc.). Air samples were collected for isotopic analysis (13C, 2H) and quantification of other hydrocarbons (ethane, propane, etc.). Finally, atmospheric measurements are compared with long term data sets from the nearby Zeppelin Mountain monitoring station (Ny Ålesund, Svalbard). Back-trajectory analysis and FLEXPART modelling are used to rule out non-local sources. Here we present an overview of all of these activities and the first results from MOCA in cooperation with CAGE - Centre for Arctic Gas Hydrate, and Climate at UiT, The Arctic University of Norway. We demonstrate that there are hotspots of activity where hydrocarbons are being emitted from the ocean, while in some areas emissions are surprisingly well contained by local biological and hydrological

  5. Adaptive harvest management for the Svalbard population of pink-footed geese: briefing summary

    Science.gov (United States)

    Johnson, Fred A.

    2013-01-01

    The African-Eurasian Waterbird Agreement (AEWA; http://www.unep-aewa.org/) calls for means to manage populations which cause conflicts with certain human economic activities. The Svalbard population of the pink-footed goose has been selected as the first test case for such an international species management plan to be developed. This document describes progress to date on the development of an adaptive harvest management (AHM) strategy for maintaining pink-footed goose abundance near their target level by providing for sustainable harvasts in Norway and Denmark. This briefing supplements material provided in the Progress Summary distributed to the International Working Group on February 1, 2013. We emphasize that peer review is an essential aspect of the process of developing and implementing an AHM program for pink-footed geese, and we will continue to solicit reviews by the International Working Group and their staff, as well as scientists not engaged in this effort. We wish to make the Working Group aware the the following two manuscripts have been submitted recently to refereed journals and are available upon request from the senior authors: Jensen, G.H., J. Madsen, F.A. Johnson, and M. Tamstorf. Snow conditions as an estimator of the breeding output in high-Arctic pink-footed geese Anser brachyrhynchus. Polar Biology: In review. Johnson, F.A., G.H. Jensen, J. Madsen, and B.K. Williams. Uncertainity, robustness, and the value of information in managing an expanding Arctic goose population. Ecological Modeling: In review. In addition to these manuscripts, the Progress Summary (February 1, 2013), and this Briefing Summary (April 23, 2013) an annual report will be produced in August 2013 and every summer thereafter. Additional manuscripts for journal publication are also anticipated.

  6. Winter temperature affects the prevalence of ticks in an Arctic seabird.

    Directory of Open Access Journals (Sweden)

    Sébastien Descamps

    Full Text Available The Arctic is rapidly warming and host-parasite relationships may be modified by such environmental changes. Here, I showed that the average winter temperature in Svalbard, Arctic Norway, explained almost 90% of the average prevalence of ticks in an Arctic seabird, the Brünnich's guillemot Uria lomvia. An increase of 1°C in the average winter temperature at the nesting colony site was associated with a 5% increase in the number of birds infected by these ectoparasites in the subsequent breeding season. Guillemots were generally infested by only a few ticks (≤5 and I found no direct effect of tick presence on their body condition and breeding success. However, the strong effect of average winter temperature described here clearly indicates that tick-seabird relationships in the Arctic may be strongly affected by ongoing climate warming.

  7. Metagenomics of the Svalbard reindeer rumen microbiome reveals abundance of polysaccharide utilization loci.

    Directory of Open Access Journals (Sweden)

    Phillip B Pope

    Full Text Available Lignocellulosic biomass remains a largely untapped source of renewable energy predominantly due to its recalcitrance and an incomplete understanding of how this is overcome in nature. We present here a compositional and comparative analysis of metagenomic data pertaining to a natural biomass-converting ecosystem adapted to austere arctic nutritional conditions, namely the rumen microbiome of Svalbard reindeer (Rangifer tarandus platyrhynchus. Community analysis showed that deeply-branched cellulolytic lineages affiliated to the Bacteroidetes and Firmicutes are dominant, whilst sequence binning methods facilitated the assemblage of metagenomic sequence for a dominant and novel Bacteroidales clade (SRM-1. Analysis of unassembled metagenomic sequence as well as metabolic reconstruction of SRM-1 revealed the presence of multiple polysaccharide utilization loci-like systems (PULs as well as members of more than 20 glycoside hydrolase and other carbohydrate-active enzyme families targeting various polysaccharides including cellulose, xylan and pectin. Functional screening of cloned metagenome fragments revealed high cellulolytic activity and an abundance of PULs that are rich in endoglucanases (GH5 but devoid of other common enzymes thought to be involved in cellulose degradation. Combining these results with known and partly re-evaluated metagenomic data strongly indicates that much like the human distal gut, the digestive system of herbivores harbours high numbers of deeply branched and as-yet uncultured members of the Bacteroidetes that depend on PUL-like systems for plant biomass degradation.

  8. Observations of widespread accelerated thinning in the upper reaches of Svalbard glaciers

    Directory of Open Access Journals (Sweden)

    T. D. James

    2012-03-01

    Full Text Available The measured rise in eustatic sea level over the 20th century was dominated by mass loss from the world's mountain glaciers and ice caps, and predictions suggest that these fresh water reservoirs will remain significant into the 21st century. However, estimates of this mass transfer to the ocean are based on a limited number of observations extrapolated to represent not only regional changes but often changes across individual glaciers. Combining high resolution elevation data from contemporary laser-altimetry surveys and archived aerial photography makes it possible to measure historical changes across a glacier's entire surface. Here we present a high spatial resolution time-series for six Arctic glaciers in the Svalbard Archipelago spanning 1961 to 2005. We find increasing thinning rates before and after 1990 with elevation losses occurring most notably in the glaciers' upper reaches. In the absence of a clear meteorological driver, we recommend further investigation into a possible albedo amplification of prevailing meteorological trends to explain these higher elevation changes, which could have important consequences on the region's mass balance due to the sensitivity of its hypsometric distribution. However, the strong influence of decadal-scale variability, while explaining lower rates of mass loss reported in earlier studies, highlights that caution must be exercised when interpreting thinning rates when averaged over long periods.

  9. Shell growth and environmental control of methanophyllic Thyasirid bivalves from Svalbard cold seeps

    Science.gov (United States)

    Carroll, Michael; Åström, Emmelie; Ambrose, William; Locke, William; Oliver, Graham; Hong, Wei-Li; Carroll, JoLynn

    2016-04-01

    The analysis of molluscan shell material (sclerochronology) can provide information about an organism's age, growth history, and environmental conditions during its lifetime. Bivalve molluscs are common members of hydrothermal vents and methane cold seeps communities where, supported by chemosynthetic symbionts, they can reach high density and biomass. But little is known about methane-associated bivalve populations inhabiting high-Arctic cold seeps, and sclerochronological analysis of methane-influenced bivalves is rare. We measured growth rates and elemental and isotopic shell signatures in a newly discovered species of bivalve (Thyasiridae) from cold seeps at 350-390m depth southwest of Svalbard. First discovered in 2014, recently described shells of Thyasira capitanea sp.nov. were found at 2 independent seep systems in Storfjordrenna. Mean shell carbon isotopic ratios from inorganic δ13C (mean = -4.8‰) and organic δ13C (mean = -26.9‰) fractions clearly indicate a methane influenced habitat and food source for these organisms. Shell mineral ratios (Li/Ca, Mg/Ca, Mn/Ca, Fe/Ca, Sr/Ca, Ba/Ca, Pb/Ca) sampled along the axis of growth with laser-ablated ICP-MS exhibit variability through time and between sites, suggesting that concentrations of these elements that may be affected by methane emissions. The mineralogical data also elucidates the internal pattern of shell deposition and growth checks, and combined with the isotopic and growth rate data, enables us to interpret the temporal history of methane release from these locations.

  10. Spatial and temporal trends in perfluoroalkyl substances (PFASs) in ringed seals (Pusa hispida) from Svalbard.

    Science.gov (United States)

    Routti, Heli; Gabrielsen, Geir Wing; Herzke, Dorte; Kovacs, Kit M; Lydersen, Christian

    2016-07-01

    This study investigates concentrations of perfluoroalkyl carboxylates (PFCAs), perfluoroalkyl sulfonates (PFSAs) and perfluoroalkane sulfonamides (FASA) in plasma from ringed seals sampled in the period 1990-2010 (n = 71) in Svalbard, Norway. Perfluorooctane sulfonate was dominant among the perfluoroalkyl substances. PFCAs were dominated by perfluoroundecanoate followed by perfluorononanoate. C4C8 PFCAs and perfluorooctane sulfonamide (FOSA) were detected in ≤42% of the samples. PFSA and PFCA concentrations were higher in seals sampled from Kongsfjorden, a fjord influenced by strong inflows of Atlantic Water compared to seals from fjords dominated by Arctic Water (e.g. Billefjorden). Sex, age and body condition of the seals did not influence PFAS concentrations. Due to the confounding effect of year and sampling area, temporal trends were assessed only in seals sampled from Kongsfjorden (5 years, n = 51). PFHxS and PFOS concentrations did not show significant linear trends during the whole study period, but a decrease was observed since 2004. Concentrations of all of the detected PFCAs (C9C13 PFCAs) increased until 2004 after which they have declined or stabilized.

  11. Rock avalanche and rock glacier: A compound landform study from Hornsund, Svalbard

    Science.gov (United States)

    Hartvich, Filip; Blahut, Jan; Stemberk, Josef

    2017-01-01

    On the northern coast of the Hornsund fjord at SW Svalbard, numerous rock block accumulations flank the foot of Rotjesfjellet ridge. Whereas these accumulations are widely described as rock glaciers, this study shows that other factors also influence formation of these landforms. In this study, morphometric profiling and terrain analyses, lichenometry, optical granulometry, Schmidt hammer measurements, geophysical measurements using electric resistivity tomography, geodetic measurements using terrestrial LiDAR and rockfall modelling were used to clarify the formation of one unusual block accumulation. The morphometric analysis of a detailed (0.5 m) DEM and relief profiles showed distinctly different morphology of one of four studied block accumulations. The electric resistivity tomography revealed an ice core in the accumulation, the Schmidt hammer sampling helped to establish relatively younger age of the lobe-like left part of accumulation and finally, the lichenometry was employed to place the event on the approximate position on the timescale. In conclusion, the unusual block accumulation is a result of two consequent processes: first, a typical foothill rock glacier has developed, and consequently a large rock avalanche occurred, adding material and deforming the NW part of the accumulation. Based on the results of lichenometry, the rock avalanche was estimated to be 250 ± 50 years old. The study thus presents one of the few reported slope deformation events from the recently deglaciated Arctic areas.

  12. Marine Arctic science capability making big strides

    Science.gov (United States)

    Johnson, Leonard; Brass, Garrett

    The profound influence of the Arctic Ocean on global environment, the rapid variability of Arctic processes, and the unresolved geology of the ocean floor have led to growing scientific interest in this region. Ongoing studies are investigating recent historical processes and modern processes such as changes in ocean circulation and ice cover patterns. Sediments beneath the Arctic Ocean record long- and short-term waxing and waning of the cryosphere in the Northern Hemisphere and its linkages to bottom water renewal and faunal adaptation. Underlying basement rocks reflect the tectonic history of the ocean basin, including its ridges and plateaus, which are unsampled and of unknown composition and origin. The vulnerability of Arctic populations to environmental problems makes the need to understand the region even more compelling (see, for example, Arctic Monitoring and Assessment Programme, 1997; also see Web site http://www.grida.no/amap).

  13. Hollow rhodoliths increase Svalbard's shelf biodiversity

    Science.gov (United States)

    Teichert, Sebastian

    2014-11-01

    Rhodoliths are coralline red algal assemblages that commonly occur in marine habitats from the tropics to polar latitudes. They form rigid structures of high-magnesium calcite and have a good fossil record. Here I show that rhodoliths are ecosystem engineers in a high Arctic environment that increase local biodiversity by providing habitat. Gouged by boring mussels, originally solid rhodoliths become hollow ecospheres intensely colonised by benthic organisms. In the examined shelf areas, biodiversity in rhodolith-bearing habitats is significantly greater than in habitats without rhodoliths and hollow rhodoliths yield a greater biodiversity than solid ones. This biodiversity, however, is threatened because hollow rhodoliths take a long time to form and are susceptible to global change and anthropogenic impacts such as trawl net fisheries that can destroy hollow rhodoliths. Rhodoliths and other forms of coralline red algae play a key role in a plurality of environments and need improved management and protection plans.

  14. Methane from the East Siberian Arctic shelf

    DEFF Research Database (Denmark)

    Petrenko...[], Vasilii V.; Etheridge, David M.

    2010-01-01

    that the release of Arctic CH4 was implied in previous climate shifts as well as in the recently renewed rise in atmospheric CH4. These claims are not supported by all the literature they cite. Their reference 5 (1) presents measurements of emissions only of carbon dioxide, not CH4. Their reference 8 (2), a study......In their Report “Extensive methane venting to the atmosphere from sediments of the East Siberian Arctic Shelf” (5 March, p. 1246), N. Shakhova et al. write that methane (CH4) release resulting from thawing Arctic permafrost “is a likely positive feedback to climate warming.” They add...

  15. Opening of the Arctic-North Atlantic Gateway

    Science.gov (United States)

    Engen, O.; Faleide, J. I.; Eldholm, O.; Breivik, A.

    2003-12-01

    The ˜150 km wide Fram Strait between Svalbard and Greenland is the only deep-water connection between the Arctic and the world oceans. It is essential for the thermohaline `engine' of the North Atlantic circulation system, pulling warm surface water north along the European coasts while returning cold, saline bottom water from the Arctic. Moreover, it contains a series of short, ultra-slow spreading segments and right-lateral transform faults, connecting the Gakkel Ridge to the rest of the Mid-Atlantic Ridge system. While the ridges to the north and south started spreading near the Paleocene-Eocene transition ( ˜55 Ma), the plate boundary between Svalbard and Greenland underwent shear and a transpressive orogeny. Only after the earliest Oligocene ( ˜33 Ma), when the Greenland plate became attached to North America and the rotation pole moved, the entire plate boundary became divergent. However, the final opening of the Fram Strait gateway was delayed for several reasons: First, basement terraces on the western Svalbard margin were downfaulted post-Eocene, witnessing a pre-breakup crustal thinning period that may have lasted for 15-20 m.y. Second, transform segments formed continental bridges for several m.y. after breakup on the ridge segments; the deep-water passage was not established before continental outliers were separated by young oceanic crust across all transform faults. Third, the Hovgaard microcontinent, which was split off the western Barents Sea-Svalbard margin, may have restricted water circulation for some time. By integrating gravity, bathymetry, magnetic and reflection seismic data we locate the positions of present and extinct spreading axes, as well as the continent-ocean transition (COT) on the Svalbard side. The COT correlates with a steep gradient in the Bouguer gravity anomaly, which is taken as a proxy COT on the sparsely surveyed Greenland side. By testing different rotation poles we arrive at a regionally consistent plate kinematic

  16. (Caesium 137 in meat from reindeer and grouse from Svalbard 1980 (author's transl))

    Energy Technology Data Exchange (ETDEWEB)

    Kjos-Hanssen, B.; Rennesund, J.S.

    Concentration of Caesium 137 in meat from Spitsbergen (Svalbard) and mainland Norway reindeer has been measured. It appears that the concentration values for Spitsbergen are of the order of 1 per cent of corresponding values for the mainland. It is suggested that low precipitation rates and a different reindeer diet contributes to the low Cs 137 concentration values in Svalbard. The concentration of Cs 137 in Svalbard grouse did not exceed the detection limit of the measurements (infinity 10 pCi/kg).

  17. Temperature thresholds for Arctic plankton community metabolism: an experimental assessment

    Directory of Open Access Journals (Sweden)

    J. M. Holding

    2011-11-01

    Full Text Available Climate warming is especially severe in the Arctic, where the average temperature is increasing 0.4 °C per decade, two to three times higher than the global average rate. Furthermore, the Arctic has lost more than half its summer ice extent since 1980 and predictions suggest that the Arctic will be ice free in the summer as early as 2050, which could increase rate of warming. Predictions based on the metabolic theory of ecology assume that temperature increase will enhance metabolic rates and thus both the rate of primary production and respiration will increase. However, these predictions do not consider the specific metabolic balance of the communities. We tested experimentally the response of Arctic plankton communities to seawater temperature spanning from 1 °C to 10 °C. Two types of communities were tested, open-ocean Arctic communities from water collected in the Barents Sea and Atlantic influenced fjord communities from water collected in the Svalbard fjord system. Metabolic rates did indeed increase as suggested by metabolic theory, however these results suggest a temperature threshold of 5 °C, beyond which the metabolism of plankton communities shifts from autotrophic to heterotrophic. Barents Sea communities showed a much clearer threshold response to temperature manipulations than fjord communities.

  18. Congruent responses to weather variability in high arctic herbivores.

    Science.gov (United States)

    Stien, Audun; Ims, Rolf A; Albon, Steve D; Fuglei, Eva; Irvine, R Justin; Ropstad, Erik; Halvorsen, Odd; Langvatn, Rolf; Loe, Leif Egil; Veiberg, Vebjørn; Yoccoz, Nigel G

    2012-12-23

    Assessing the role of weather in the dynamics of wildlife populations is a pressing task in the face of rapid environmental change. Rodents and ruminants are abundant herbivore species in most Arctic ecosystems, many of which are experiencing particularly rapid climate change. Their different life-history characteristics, with the exception of their trophic position, suggest that they should show different responses to environmental variation. Here we show that the only mammalian herbivores on the Arctic islands of Svalbard, reindeer (Rangifer tarandus) and sibling voles (Microtus levis), exhibit strong synchrony in population parameters. This synchrony is due to rain-on-snow events that cause ground ice and demonstrates that climate impacts can be similarly integrated and expressed in species with highly contrasting life histories. The finding suggests that responses of wildlife populations to climate variability and change might be more consistent in Polar regions than elsewhere owing to the strength of the climate impact and the simplicity of the ecosystem.

  19. Geomorphological and sedimentological record of accelerated deglaciation of small mountain glacier, Ragnarbreen, Svalbard

    Science.gov (United States)

    Ewertowski, Marek

    2010-05-01

    Most of the Svalbrad glaciers have been in retreat since the end of the Little Ice Age (LIA). Hence, they give a good opportunity to study the geomorphological and sedimentological record of deglaciation. The aim of the study is to describe main landsystem elements of Ragnar glacier and relate them to different stages of the glacier recession. The Ragnar glacier is located in the Svalbard archipelago, in the central part of the West Spitsbergen Isle, in the north branch of Billefjorden. Ragnar is a small (~ 6 km2), outlet glacier, which current clean ice edge has retreated ca. 1500 m from the position related to the maximum LIA extent. Fieldworks of the study comprised detailed geomorphological mapping and sedimentary works. Four main elements of the landsystem of the Ragnar glacier can be distinguished: 1) Clean glacier surface. Currently, the ice surface of Ragnar glacier is almost completely debris-free and with only several supraglacial streams. 2) Ice-marginal lake. The lake started to form after 1980 year. Since that time, its length has reached 1000 m. Distant (from the ice-edge) part of the lake is shallow (changes in distribution of the sediments and landforms. They also add some premises that in the first stage of deglaciation debris flow and other mass wasting processes are most common. In the later phase glaciolacustrine and glaciofluvial deposition also plays important role in transformation of landforms and sediments.

  20. Multidecadal climate and seasonal snow conditions in Svalbard

    Science.gov (United States)

    Pelt, W. J. J.; Kohler, J.; Liston, G. E.; Hagen, J. O.; Luks, B.; Reijmer, C. H.; Pohjola, V. A.

    2016-11-01

    Svalbard climate is undergoing amplified change with respect to the global mean. Changing climate conditions directly affect the evolution of the seasonal snowpack, through its impact on accumulation, melt, and moisture exchange. We analyze long-term trends and spatial patterns of seasonal snow conditions in Svalbard between 1961 and 2012. Downscaled regional climate model output is used to drive a snow modeling system (SnowModel), with coupled modules simulating the surface energy balance and snowpack evolution. The precipitation forcing is calibrated and validated against snow depth data on a set of glaciers around Svalbard. Climate trends reveal seasonally inhomogeneous warming and a weakly positive precipitation trend, with strongest changes in the north. In response to autumn warming the date of snow onset increased (2 days decade-1), whereas in spring/summer opposing effects cause a nonsignificant trend in the snow disappearance date. Maximum snow water equivalent (SWE) in winter/spring shows a modest increase (+0.01 meters water equivalent (mwe) decade-1), while the end-of-summer minimum snow area fraction declined strongly (from 48% to 36%). The equilibrium line altitude is highest in relatively dry inland regions, and time series show a clear positive trend (25 m decade-1) as a result of summer warming. Finally, rain-on-snow in the core winter season, affecting ground ice formation and limiting access of grazing animals to food supplies, peaks during specific years (1994, 1996, 2000, and 2012) and is found to be concentrated in the lower lying coastal regions in southwestern Svalbard.

  1. Effect of wind on Svalbard reindeer fur insulation

    Directory of Open Access Journals (Sweden)

    Christine Cuyler

    2002-06-01

    Full Text Available The heat transfer through Svalbard reindeer (Rangifer tarandus platyrhynchus fur samples was studied with respect to wind velocity, season and animal age. A total of 33 dorsal fur sections were investigated using a wind tunnel. Insulation varied with season (calving, summer, autumn and winter. At zero wind velocity, fur insulation was significantly different between seasons for both calf and adult fur samples. At the same time, there was no significant difference between calf and adult insulation for the summer, autumn and winter seasons. Calf fur insulated as well as adult fur. Winter insulation of Svalbard reindeer was approximately 3 times that of summer. Increasing wind veloci¬ty increased heat loss, however, the increase was not dramatic. When wind coefficients (slope of the heat transfer regression lines were compared, between season and between calf and adult, no significant differences were reported. All fur samples showed similar increases in heat transfer for wind velocities between 0 and 10 m.s-1. The conductance of winter fur of Svalbard reindeer was almost half that of caribou fur. Also, conductance was not as greatly influenced by wind as caribou fur

  2. Arctic Shipping

    DEFF Research Database (Denmark)

    Hansen, Carsten Ørts; Grønsedt, Peter; Lindstrøm Graversen, Christian

    , the latter aiming at developing key concepts and building up a basic industry knowledge base for further development of CBS Maritime research and teaching. This report attempts to map the opportunities and challenges for the maritime industry in an increasingly accessible Arctic Ocean...

  3. Genomes of two new ammonia-oxidizing archaea enriched from deep marine sediments.

    Directory of Open Access Journals (Sweden)

    Soo-Je Park

    Full Text Available Ammonia-oxidizing archaea (AOA are ubiquitous and abundant and contribute significantly to the carbon and nitrogen cycles in the ocean. In this study, we assembled AOA draft genomes from two deep marine sediments from Donghae, South Korea, and Svalbard, Arctic region, by sequencing the enriched metagenomes. Three major microorganism clusters belonging to Thaumarchaeota, Epsilonproteobacteria, and Gammaproteobacteria were deduced from their 16S rRNA genes, GC contents, and oligonucleotide frequencies. Three archaeal genomes were identified, two of which were distinct and were designated Ca. "Nitrosopumilus koreensis" AR1 and "Nitrosopumilus sediminis" AR2. AR1 and AR2 exhibited average nucleotide identities of 85.2% and 79.5% to N. maritimus, respectively. The AR1 and AR2 genomes contained genes pertaining to energy metabolism and carbon fixation as conserved in other AOA, but, conversely, had fewer heme-containing proteins and more copper-containing proteins than other AOA. Most of the distinctive AR1 and AR2 genes were located in genomic islands (GIs that were not present in other AOA genomes or in a reference water-column metagenome from the Sargasso Sea. A putative gene cluster involved in urea utilization was found in the AR2 genome, but not the AR1 genome, suggesting niche specialization in marine AOA. Co-cultured bacterial genome analysis suggested that bacterial sulfur and nitrogen metabolism could be involved in interactions with AOA. Our results provide fundamental information concerning the metabolic potential of deep marine sedimentary AOA.

  4. Genomes of two new ammonia-oxidizing archaea enriched from deep marine sediments.

    Science.gov (United States)

    Park, Soo-Je; Ghai, Rohit; Martín-Cuadrado, Ana-Belén; Rodríguez-Valera, Francisco; Chung, Won-Hyong; Kwon, KaeKyoung; Lee, Jung-Hyun; Madsen, Eugene L; Rhee, Sung-Keun

    2014-01-01

    Ammonia-oxidizing archaea (AOA) are ubiquitous and abundant and contribute significantly to the carbon and nitrogen cycles in the ocean. In this study, we assembled AOA draft genomes from two deep marine sediments from Donghae, South Korea, and Svalbard, Arctic region, by sequencing the enriched metagenomes. Three major microorganism clusters belonging to Thaumarchaeota, Epsilonproteobacteria, and Gammaproteobacteria were deduced from their 16S rRNA genes, GC contents, and oligonucleotide frequencies. Three archaeal genomes were identified, two of which were distinct and were designated Ca. "Nitrosopumilus koreensis" AR1 and "Nitrosopumilus sediminis" AR2. AR1 and AR2 exhibited average nucleotide identities of 85.2% and 79.5% to N. maritimus, respectively. The AR1 and AR2 genomes contained genes pertaining to energy metabolism and carbon fixation as conserved in other AOA, but, conversely, had fewer heme-containing proteins and more copper-containing proteins than other AOA. Most of the distinctive AR1 and AR2 genes were located in genomic islands (GIs) that were not present in other AOA genomes or in a reference water-column metagenome from the Sargasso Sea. A putative gene cluster involved in urea utilization was found in the AR2 genome, but not the AR1 genome, suggesting niche specialization in marine AOA. Co-cultured bacterial genome analysis suggested that bacterial sulfur and nitrogen metabolism could be involved in interactions with AOA. Our results provide fundamental information concerning the metabolic potential of deep marine sedimentary AOA.

  5. High sedimentation rates in the Early Triassic after latest Permian mass extinction: Carbonate production is main factor in non-Arctic regions

    Science.gov (United States)

    Horacek, Micha; Brandner, Rainer

    2016-04-01

    A substantial change in sedimentation rates towards higher values has been documented from the Late Permian to the Lower Triassic. Although it is assumed and also has been shown that the deposition of siliciclastic material increased in the Lower Triassic due to stronger erosion because of loss of land cover and increased chemical and physical weathering with extreme climate warming, the main sediment production occurred by marine carbonate production. Still, carbonate production might have been significantly influenced by weathering and erosion in the hinterland, as the transport of dust by storms into the ocean water probably was a main nutrient source for microbial carbonate producers, because "normal" nutrient supply by ocean circulation, i. e. upwelling was strongly reduced due to the elevated temperatures resulting in water-column stratification . Sediment accumulation was also clearly influenced by the paleo-geographic and latitudinal position, with lower carbonate production and sedimentation rates in moderate latitudes. The existence of a "boundary clay" and microbial carbonate mounds and layers in the immediate aftermath of the latest Permian mass extinction points towards a development from a short-timed acid ocean water - resulting in a carbonate production gap and the deposition of the boundary clay towards the deposition of the microbial mounds and layers due to the microbial production of micro-environments with higher alkalinity allowing the production of carbonate. After the return of the ocean water to normal alkalinity planktic production of carbonate resulted in a very high sedimentation rate, especially taking into account the absence of carbonate producing eukaryotic algae and animals.

  6. Arctic root-associated fungal community composition reflects environmental filtering.

    Science.gov (United States)

    Blaalid, Rakel; Davey, Marie L; Kauserud, Håvard; Carlsen, Tor; Halvorsen, Rune; Høiland, Klaus; Eidesen, Pernille B

    2014-02-01

    There is growing evidence that root-associated fungi have important roles in Arctic ecosystems. Here, we assess the diversity of fungal communities associated with roots of the ectomycorrhizal perennial herb Bistorta vivipara on the Arctic archipelago of Svalbard and investigate whether spatial separation and bioclimatic variation are important structuring factors of fungal community composition. We sampled 160 plants of B. vivipara from 32 localities across Svalbard. DNA was extracted from entire root systems, and 454 pyrosequencing of ITS1 amplicons was used to profile the fungal communities. The fungal communities were predominantly composed of Basidiomycota (55% of reads) and Ascomycota (35%), with the orders Thelephorales (24%), Agaricales (13.8%), Pezizales (12.6%) and Sebacinales (11.3%) accounting for most of the reads. Plants from the same site or region had more similar fungal communities to one another than plants from other sites or regions, and sites clustered together along a weak latitudinal gradient. Furthermore, a decrease in per-plant OTU richness with increasing latitude was observed. However, no statistically significant spatial autocorrelation between sites was detected, suggesting that environmental filtering, not dispersal limitation, causes the observed patterns. Our analyses suggest that while latitudinal patterns in community composition and richness might reflect bioclimatic influences at global spatial scales, at the smaller spatial scale of the Svalbard archipelago, these changes more likely reflect varied bedrock composition and associated edaphic factors. The need for further studies focusing on identifying those specific bioclimatic and edaphic factors structuring root-associated fungal community composition at both global and local scales is emphasized.

  7. Three Years of High Resolution Year-Round Monitoring of Ice-Wedge Thermal Contraction Cracking in Svalbard

    Science.gov (United States)

    Christiansen, H. H.

    2006-12-01

    Most likely ice-wedges are the most widespread periglacial landform in lowlands with continuous permafrost. With a changing climate it is important to understand better the geomorphological processes controlling ice- wedge growth and decay, as they might cause large changes to the surface of the landscape, particularly if the active layer thickness increases causing melting of the most ice-rich permafrost top layer. As most settlements on permafrost are located in lowland areas, ice-wedge formation can also influence the infrastructure. Understanding the processes of ice-wedge growth and their thaw transformation into ice-wedge casts are essential when using contemporary ice wedges as analogues of Pleistocene thermal contraction cracking in palaeoenvironmental reconstructions. As ice-wedges are largely controlled by winter conditions, improved understanding of the factors controlling their growth will enable better palaeoclimatic reconstructions both directly from ice-wedges, but also from ice-wedge casts, than just mean winter temperatures. Detailed studies of ice-wedge dynamics, including quantification of movement, have only been done in very few places in the Arctic. In high arctic Svalbard at 78°N climate at sea level locates these islands close to the southern limit of the continuous permafrost zone, with MAAT of as much as -4 to -6°C. However, thermal contraction cracking is demonstrated to be widespread in the Adventdalen study area in Svalbard. The year-round field access from the University Centre in Svalbard, UNIS, has enabled the collection of different continuous or high frequency ice-wedge process monitoring data since 2002 to improve the understanding of the geomorphological activity of this landform. In all the winters the air temperature was below -30°C for shorter or longer periods. During all the winters, the temperature in the top permafrost was below -15°C both in the ice-wedge top for shorter or longer periods. The snow cover was

  8. Airborne observations of changes of ice sheet and sea ice in the Arctic using CryoVEx campaign data

    DEFF Research Database (Denmark)

    Hvidegaard, Sine Munk; Skourup, Henriette; Forsberg, René

    DTU Space have collected surface elevation observations of the Arctic sea ice and land ice since 1998 using laser scanning and radar altimetry from a small fixed‐wing Twin‐Otter aircraft. The observations provide unique datasets for studying ongoing changes, and support the analysis of satellite......‐launch validation studies, with several aircraft and international in‐situ ground teams participating, both in Greenland, Arctic Canada, and Svalbard. The methods and campaigns are outlined together with examples of results.The campaigns focused on five main validation sites: Devon ice cap (Canada), Austfonna ice...

  9. Arctic Diatoms

    DEFF Research Database (Denmark)

    Tammilehto, Anna

    are often dominated by diatoms. They are single-celled, eukaryotic algae, which play an essential role in ocean carbon and silica cycles. Many species of the diatom genus Pseudo-nitzschia Peragallo produce a neurotoxin, domoic acid (DA), which can be transferred to higher levels in food webs causing amnesic...... as vectors for DA to higher levels in the arctic marine food web, posing a possible risk also to humans. DA production in P. seriata was, for the first time, found to be induced by chemical cues from C. finmarchicus, C. hyperboreus and copepodite stages C3 and C4, suggesting that DA may be related to defense...... against grazing. This thesis also quantified population genetic composition and changes of the diatom Fragilariopsis cylindrus spring bloom using microsatellite markers. Diatom-dominated spring blooms in the Arctic are the key event of the year, providing the food web with fundamental pulses of organic...

  10. Arctic Ocean

    Science.gov (United States)

    Parkinson, Claire L.; Zukor, Dorothy J. (Technical Monitor)

    2000-01-01

    The Arctic Ocean is the smallest of the Earth's four major oceans, covering 14x10(exp 6) sq km located entirely within the Arctic Circle (66 deg 33 min N). It is a major player in the climate of the north polar region and has a variable sea ice cover that tends to increase its sensitivity to climate change. Its temperature, salinity, and ice cover have all undergone changes in the past several decades, although it is uncertain whether these predominantly reflect long-term trends, oscillations within the system, or natural variability. Major changes include a warming and expansion of the Atlantic layer, at depths of 200-900 m, a warming of the upper ocean in the Beaufort Sea, a considerable thinning (perhaps as high as 40%) of the sea ice cover, a lesser and uneven retreat of the ice cover (averaging approximately 3% per decade), and a mixed pattern of salinity increases and decreases.

  11. High-Resolution Seismic Definition of the Distribution of Gas in the West Svalbard Margin

    Science.gov (United States)

    Minshull, T. A.; Westbrook, G. K.; Marin-Moreno, H.; Marsset, B.; Ker, S.; Sarkar, S.; Vardy, M. E.; Henstock, T.

    2014-12-01

    The widespread presence of gas beneath the seabed west of Svalbard is shown by negative-polarity high-amplitude reflectors (nephars), imaged in high-resolution near-surface and deep-towed seismic reflection data. The principal controls on the presence of gas are the gas hydrate stability zone (GHSZ), from which free gas is generally excluded, and stratigraphic control of permeable layers. A widespread bottom-simulating reflector (BSR) beneath the lower-mid continental slope indicates gas at the base of the GHSZ. The depth of the base of the GHSZ predicted by a numerical model that takes in to account variation in ocean temperature over the past two thousand years, is consistent with the depth of the BSR, even at its shallowest depth, where a steady-state model places base of the GHSZ shallower than the BSR. Similarly, farther up slope, where the BSR loses it coherency, the depths of the shallowest nephars are compatible with the predicted depth of the base of the GHSZ from the time-dependent model, but are about three times deeper than the predicted steady-state depth of the BSR. This approach to defining the limits of the GHSZ is not precise, as it depends upon the presence of gas. In the shallow sediment sequence, which has a high proportion of glacigenic sediments, gas is restricted to a smaller number of permeable units than in the contourite-dominated sequence farther down the continental slope. Where the seabed is shallower than the GHSZ, numerous plumes of methane gas ascend from the seabed, and gas, which has migrated up slope through dipping permeable layers, locally ponds beneath a thin veneer of unconformable glacial and post-glacial sediments on the continental shelf.

  12. Exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish.

    Science.gov (United States)

    Letcher, Robert J; Bustnes, Jan Ove; Dietz, Rune; Jenssen, Bjørn M; Jørgensen, Even H; Sonne, Christian; Verreault, Jonathan; Vijayan, Mathilakath M; Gabrielsen, Geir W

    2010-07-01

    based on correlations between biomarker endpoints (e.g., biochemical processes related to the immune and endocrine system, pathological changes in tissues and reproduction and development) and tissue residue levels of OHCs (e.g., PCBs, DDTs, CHLs, PBDEs and in a few cases perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonates (PFSAs)). Some exceptions include semi-field studies on comparative contaminant effects of control and exposed cohorts of captive Greenland sled dogs, and performance studies mimicking environmentally relevant PCB concentrations in Arctic charr. Recent tissue concentrations in several arctic marine mammal species and populations exceed a general threshold level of concern of 1 part-per-million (ppm), but a clear evidence of a POP/OHC-related stress in these populations remains to be confirmed. There remains minimal evidence that OHCs are having widespread effects on the health of Arctic organisms, with the possible exception of East Greenland and Svalbard polar bears and Svalbard glaucous gulls. However, the true (if any real) effects of POPs in Arctic wildlife have to be put into the context of other environmental, ecological and physiological stressors (both anthropogenic and natural) that render an overall complex picture. For instance, seasonal changes in food intake and corresponding cycles of fattening and emaciation seen in Arctic animals can modify contaminant tissue distribution and toxicokinetics (contaminant deposition, metabolism and depuration). Also, other factors, including impact of climate change (seasonal ice and temperature changes, and connection to food web changes, nutrition, etc. in exposed biota), disease, species invasion and the connection to disease resistance will impact toxicant exposure. Overall, further research and better understanding of POP/OHC impact on animal performance in Arctic biota are recommended. Regardless, it could be argued that Arctic wildlife and fish at the highest potential risk of

  13. Evidence of in situ microbial activity and sulphidogenesis in perennially sub-0 °C and hypersaline sediments of a high Arctic permafrost spring.

    Science.gov (United States)

    Lamarche-Gagnon, Guillaume; Comery, Raven; Greer, Charles W; Whyte, Lyle G

    2015-01-01

    The lost hammer (LH) spring perennially discharges subzero hypersaline reducing brines through thick layers of permafrost and is the only known terrestrial methane seep in frozen settings on Earth. The present study aimed to identify active microbial communities that populate the sediments of the spring outlet, and verify whether such communities vary seasonally and spatially. Microcosm experiments revealed that the biological reduction of sulfur compounds (SR) with hydrogen (e.g., sulfate reduction) was potentially carried out under combined hypersaline and subzero conditions, down to -20 °C, the coldest temperature ever recorded for SR. Pyrosequencing analyses of both 16S rRNA (i.e., cDNA) and 16S rRNA genes (i.e., DNA) of sediments retrieved in late winter and summer indicated fairly stable bacterial and archaeal communities at the phylum level. Potentially active bacterial and archaeal communities were dominated by clades related to the T78 Chloroflexi group and Halobacteria species, respectively. The present study indicated that SR, hydrogenotrophy (possibly coupled to autotrophy), and short-chain alkane degradation (other than methane), most likely represent important, previously unaccounted for, metabolic processes carried out by LH microbial communities. Overall, the obtained findings provided additional evidence that the LH system hosts active communities of anaerobic, halophilic, and cryophilic microorganisms despite the extreme conditions in situ.

  14. Arctic geodynamics: Continental shelf and deep ocean geophysics. ERS-1 satellite altimetry: A first look

    Science.gov (United States)

    Anderson, Allen Joel; Sandwell, David T.; Marquart, Gabriele; Scherneck, Hans-Georg

    1993-01-01

    An overall review of the Arctic Geodynamics project is presented. A composite gravity field model of the region based upon altimetry data from ERS-1, Geosat, and Seasat is made. ERS-1 altimetry covers unique Arctic and Antarctic latitudes above 72 deg. Both areas contain large continental shelf areas, passive margins, as well as recently formed deep ocean areas. Until ERS-1 it was not possible to study these areas with satellite altimetry. Gravity field solutions for the Barents sea, portions of the Arctic ocean, and the Norwegian sea north of Iceland are shown. The gravity anomalies around Svalbard (Spitsbergen) and Bear island are particularly large, indicating large isostatic anomalies which remain from the recent breakup of Greenland from Scandinavian. Recently released gravity data from the Armed Forces Topographic Service of Russia cover a portion of the Barents and Kara seas. A comparison of this data with the ERS-1 produced gravity field is shown.

  15. Food and soil-borne Penicillia in Arctic environments: Chemical diversity

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian

    Penicillia are very common inhabitants of cold environments, including arctic soil, plants, animals, and foods. We have investigated the mycobiota of Greenland inland ice and soil, and found a very unique and pronounced diversity among the Penicillia. Nearly all species were new to science....... The species found in inland ice were both of the soil-borne type, and Penicillia that grow and sporulate well at 25°C. The latter group of Penicillia have been found earlier in refrigerated foods, including P. nordicum, and in glacier ice and melting water from Svalbard (se Sonjak et al., this conference......). This “food-borne group” of arctic fungi also contained some new species, but not as many as in arctic soil. The chemical diversity of the Penicillium species was remarkably high and in most cases even larger than the chemical diversity of Penicillia in the tropics. Several new secondary metabolites were...

  16. Microbial nitrogen cycling in Arctic snowpacks

    Science.gov (United States)

    Larose, Catherine; Dommergue, Aurélien; Vogel, Timothy M.

    2013-09-01

    Arctic snowpacks are often considered as chemical reactors for a variety of chemicals deposited through wet and dry events, but are overlooked as potential sites for microbial metabolism of reactive nitrogen species. The fate of deposited species is critical since warming leads to the transfer of contaminants to snowmelt-fed ecosystems. Here, we examined the role of microorganisms and the potential pathways involved in nitrogen cycling in the snow. Next generation sequencing data were used to follow functional gene abundances and a 16S rRNA (ribosomal ribonucleic acid) gene microarray was used to follow shifts in microbial community structure during a two-month spring-time field study at a high Arctic site, Svalbard, Norway (79° N). We showed that despite the low temperatures and limited water supply, microbial communities inhabiting the snow cover demonstrated dynamic shifts in their functional potential to follow several different pathways of the nitrogen cycle. In addition, microbial specific phylogenetic probes tracked different nitrogen species over time. For example, probes for Roseomonas tracked nitrate concentrations closely and probes for Caulobacter tracked ammonium concentrations after a delay of one week. Nitrogen cycling was also shown to be a dominant process at the base of the snowpack.

  17. Tracing the origin of Arctic driftwood

    Science.gov (United States)

    Hellmann, Lena; Tegel, Willy; Eggertsson, Ã.`Lafur; Schweingruber, Fritz Hans; Blanchette, Robert; Kirdyanov, Alexander; GäRtner, Holger; Büntgen, Ulf

    2013-03-01

    Arctic environments, where surface temperatures increase and sea ice cover and permafrost depth decrease, are very sensitive to even slight climatic variations. Placing recent environmental change of the high-northern latitudes in a long-term context is, however, complicated by too short meteorological observations and too few proxy records. Driftwood may represent a unique cross-disciplinary archive at the interface of marine and terrestrial processes. Here, we introduce 1445 driftwood remains from coastal East Greenland and Svalbard. Macroscopy and microscopy were applied for wood anatomical classification; a multi-species subset was used for detecting fungi; and information on boreal vegetation patterns, circumpolar river systems, and ocean current dynamics was reviewed and evaluated. Four conifer (Pinus, Larix, Picea, and Abies) and three deciduous (Populus, Salix, and Betula) genera were differentiated. Species-specific identification also separated Pinus sylvestris and Pinus sibirica, which account for ~40% of all driftwood and predominantly originate from western and central Siberia. Larch and spruce from Siberia or North America represents ~26% and ~18% of all materials, respectively. Fungal colonization caused different levels of driftwood staining and/or decay. Our results demonstrate the importance of combining wood anatomical knowledge with insight on boreal forest composition for successfully tracing the origin of Arctic driftwood. To ultimately reconstruct spatiotemporal variations in ocean currents, and to better quantify postglacial uplift rates, we recommend consideration of dendrochronologically dated material from many more circumpolar sites.

  18. Arctic Social Sciences: Opportunities in Arctic Research.

    Science.gov (United States)

    Arctic Research Consortium of the United States, Fairbanks, AK.

    The U.S. Congress passed the Arctic Research and Policy Act in 1984 and designated the National Science Foundation (NSF) the lead agency in implementing arctic research policy. In 1989, the parameters of arctic social science research were outlined, emphasizing three themes: human-environment interactions, community viability, and rapid social…

  19. At-sea observations of the spring migration and pair bonding of ivory gulls (Pagophila eburnea around Svalbard and East Greenland

    Directory of Open Access Journals (Sweden)

    Henrik Kylin

    2011-03-01

    Full Text Available Because of logistical constraints little previous information exists on ivory gulls (Pagophila eburnea in the waters around Svalbard and the east coast of Greenland in late winter/early spring. The Swedish Arctic Ocean 2002 expedition investigated these areas at that time of year and in this paper I report on the observations of ivory gulls made during the expedition. The ivory gull was essentially absent from open waters but was the most common seabird in areas with pack ice, showing behavioural differences depending on local conditions. Generally, the number of ivory gulls was low when there was little plankton in the water. Ivory gulls followed the ship depending on the availability of food items in the wake and also depending on competition from other species, particularly glaucous gulls (Larus hyperboreus. Although ivory gulls were present in most of Fram Strait and the northern part of the East Greenland Current during 6 and 19 May, sightings were few and correlated to the amount of plankton in the water. Aggregations of several hundred were seen on the ice where copulation and other social interaction took place. A previously undescribed pair bonding behaviour during which females seemed to select between two competing males was observed north of Svalbard on 30 April–1 May. Off Scoresby Sound on 25 May, more than 700 birds were seen migrating north, while farther south along the Greenland coast on 30 May there was little indication of migration although many ivory gulls were seen.

  20. Biomonitoring tools and risk assessment in the Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Camus, L. [Akvaplan-niva, Polar Environmental Centre, Tromso (Norway); Univercity Centre at Svalbard, (Norway); Nahrgang, J.; Olsen, G.H. [Akvaplan-niva, Polar Environmental Centre, Tromso (Norway)

    2009-07-01

    With the expansion of oil and gas exploration and production activities in the Arctic, there is a need for reliable risk assessment and environmental monitoring tools adapted for the Arctic environment. Probabilistic approaches for risk assessment are used by offshore operators in the Norwegian sector of the North Sea. However, these methods are based on toxicity data on temperate species because there is insufficient data to run these models on Arctic species. Therefore, this study was conducted to perform toxicity tests with Arctic species and calculate their sensitivity distribution curve. The study was based on the Norwegian Water Column Monitoring programme. It involved a 3 year project to characterize the biological response of polar cold to oil exposure. Waterborne and dietary exposure to crude oil in polar cod collected in Svalbard was monitored. Many biological indexes ranging from molecular to biochemical, cellular and physiological levels were measured at various time points for biomonitoring the impact of oil in pack ice ecosystems. 29 refs., 3 tabs.

  1. Climate-driven regime shifts in Arctic marine benthos.

    Science.gov (United States)

    Kortsch, Susanne; Primicerio, Raul; Beuchel, Frank; Renaud, Paul E; Rodrigues, João; Lønne, Ole Jørgen; Gulliksen, Bjørn

    2012-08-28

    Climate warming can trigger abrupt ecosystem changes in the Arctic. Despite the considerable interest in characterizing and understanding the ecological impact of rapid climate warming in the Arctic, few long time series exist that allow addressing these research goals. During a 30-y period (1980-2010) of gradually increasing seawater temperature and decreasing sea ice cover in Svalbard, we document rapid and extensive structural changes in the rocky-bottom communities of two Arctic fjords. The most striking component of the benthic reorganization was an abrupt fivefold increase in macroalgal cover in 1995 in Kongsfjord and an eightfold increase in 2000 in Smeerenburgfjord. Simultaneous changes in the abundance of benthic invertebrates suggest that the macroalgae played a key structuring role in these communities. The abrupt, substantial, and persistent nature of the changes observed is indicative of a climate-driven ecological regime shift. The ecological processes thought to drive the observed regime shifts are likely to promote the borealization of these Arctic marine communities in the coming years.

  2.  Winter time burst of CO2 from the High Arctic soils of Svalbard

    DEFF Research Database (Denmark)

    Friborg, Thomas; Hansen, Birger; Elberling, Bo;

    of relatively few measurements which appear to give small and constant emission rates. Further, most studies of the processes behind winter time emission of CO2 conclude that the flux during this time of year can be linked to the respiratory release of CO2 from soil micro organisms, which is temperature...

  3. The physical environment of Kongsfjorden–Krossfjorden, an Arctic fjord system in Svalbard

    OpenAIRE

    2002-01-01

    Kongsfjorden-Krossfjorden and the adjacent West Spitsbergen Shelf meet at the common mouth of the two fjord arms. This paper presents our most up-to-date information about the physical environment of this fjord system and identifies important gaps in knowledge. Particular attention is given to the steep physical gradients along the main fjord axis, as well as to seasonal environmental changes. Physical processes on different scales control the large-scale circulation and small-scale (irrevers...

  4. The first magnetotelluric image of the lithospheric-scale geological architecture in central Svalbard, Arctic Norway

    Directory of Open Access Journals (Sweden)

    Thomas I. Beka

    2015-12-01

    Full Text Available Magnetotelluric data, collected from 30 stations on Spitsbergen as part of a reconnaissance geothermal resource assessment along a profile with 0.5–3-km spacing in 0.003–1000-s period range, were used to develop a lithospheric-scale two-dimensional (2D resistivity model, heretofore unavailable for the region. Inverting the determinant of the impedance tensor in 2D, we found the smoothest model fitting the data within a specified tolerance level. We justified the model by perturbing it, performing sensitivity analysis and re-running the inversion with a different algorithm and starting models. From our final model, we constructed a crustal-scale stratigraphic framework, using it to estimate the depth of major geological features and to locate structural deformations. The 2D resistivity model indicates a shallow low resistive (1000 Ωm east of the Billefjorden Fault Zone. Underneath, a (possibly Devonian basin is imaged as a thick conductive anomaly stretching >15 km downwards. Beneath a deformed Paleozoic–Mesozoic successions, an uplifted pre-Devonian shallow basement (>3000 Ωm is revealed. We estimated a thin lithosphere, in the range of ca. 55–100 km thick, that could explain the area's elevated surface heat flow (ca. 60–90 mW/m2, consistent with the calculated depth of thermal lithosphere heat-base boundaries for a partially melting mantle. The model indicates a possible replenishment pathway of upward heat transport from the shallow convective mantle to the composite crustal conductive units. This is encouraging for low-enthalpy geothermal development.

  5. Ice-cored moraine degradation mapped and quantified using an unmanned aerial vehicle: A case study from a polythermal glacier in Svalbard

    Science.gov (United States)

    Tonkin, T. N.; Midgley, N. G.; Cook, S. J.; Graham, D. J.

    2016-04-01

    Ice-cored lateral-frontal moraines are common at the margins of receding high-Arctic valley glaciers, but the preservation potential of these features within the landform record is unclear. Recent climatic amelioration provides an opportunity to study the morphological evolution of these landforms as they de-ice. This is important because high-Arctic glacial landsystems have been used as analogues for formerly glaciated areas in the mid-latitudes. This study uses SfM (Structure-from-Motion) photogrammetry and a combination of archive aerial and UAV (unmanned aerial vehicle) derived imagery to investigate the degradation of an ice-cored lateral-frontal moraine at Austre Lovénbreen, Svalbard. Across the study area as a whole, over an 11-year period, the average depth of surface lowering was - 1.75 ± 0.89 m. The frontal sections of the moraine showed low or undetectable rates of change. Spatially variable rates of surface lowering are associated with differences in the quantity of buried ice within the structure of the moraine. Morphological change was dominated by surface lowering, with limited field evidence of degradation via back-wastage. This permits the moraine a greater degree of stability than previously observed at other sites in Svalbard. It is unclear whether the end point will be a fully stabilised ice-cored moraine, in equilibrium with its environment, or an ice-free lateral-frontal moraine complex. Controls on geomorphological change (e.g. topography and climate) and the preservation potential of the lateral-frontal moraine are discussed. The methods used by this research also demonstrate the potential value of SfM photogrammetry and unmanned aerial vehicles for monitoring environmental change and are likely to have wider applications in other geoscientific sub-disciplines.

  6. Arctic Browning: vegetation damage and implications for carbon balance.

    Science.gov (United States)

    Treharne, Rachael; Bjerke, Jarle; Emberson, Lisa; Tømmervik, Hans; Phoenix, Gareth

    2016-04-01

    'Arctic browning' is the loss of biomass and canopy in Arctic ecosystems. This process is often driven by climatic and biological extreme events - notably extreme winter warm periods, winter frost-drought and severe outbreaks of defoliating insects. Evidence suggests that browning is becoming increasingly frequent and severe at the pan-arctic scale, a view supported by observations from more intensely observed regions, with major and unprecedented vegetation damage reported at landscape (>1000km2) and regional (Nordic Arctic Region) scales in recent years. Critically, the damage caused by these extreme events is in direct opposition to 'Arctic greening', the well-established increase in productivity and shrub abundance observed at high latitudes in response to long-term warming. This opposition creates uncertainty as to future anticipated vegetation change in the Arctic, with implications for Arctic carbon balance. As high latitude ecosystems store around twice as much carbon as the atmosphere, and vegetation impacts are key to determining rates of loss or gain of ecosystem carbon stocks, Arctic browning has the potential to influence the role of these ecosystems in global climate. There is therefore a clear need for a quantitative understanding of the impacts of browning events on key ecosystem carbon fluxes. To address this, field sites were chosen in central and northern Norway and in Svalbard, in areas known to have been affected by either climatic extremes or insect outbreak and subsequent browning in the past four years. Sites were chosen along a latitudinal gradient to capture both conditions already causing vegetation browning throughout the Norwegian Arctic, and conditions currently common at lower latitudes which are likely to become more damaging further North as climate change progresses. At each site the response of Net Ecosystem CO2 Exchange to light was measured using a LiCor LI6400 Portable Photosynthesis system and a custom vegetation chamber with

  7. Digestion of energy and nutrients in Svalbard reindeer

    Directory of Open Access Journals (Sweden)

    Hans Staaland

    1988-06-01

    Full Text Available Feeding trials with 5 male Svalbard reindeer, Rangifer tarandus platyrhynchus Vrolik were conducted at the Man and the Biosphere (MAB Research Station in Adventdalen, Svalbard. Five different diets were used, 1: commercial reindeer food, (RF-71, 2: a mixture of locally harvested grasses and sedges (mainly Dupontia pelligera and Eriphorum scheusczeri, 3: a pure moss (Pleurozium scheberi diet, 4: a lichen diet using the dominant Svalbard species Cetraria delisei, and 5: a mixed diet of RF-71, moss (P. schreberi and lichens (mainly Cladonia alpestris and Cladonia rangiferina. When fed the RF-71 diet the digestibility by Svalbard and Norwegian reindeer were similar with respect to dry matter (DM 75 v 74% and crude protein (CP 74 v 70% as were the availabilities of P (72 v 76% a and Ca (18 v 36% in the diet. The mixture of grasses and sedges was highly digestible with respect to DM ((66,5% but had low availabilities of Ca (12%, Mg (10% and P (-11%. DM digestibility of the lichen C delisei was low (33% however this lichen could constitute a good source of Ca. Moss palatability was very low (174-252 g or 9-13g/kg 0 75 intake daily. DM, CP and energy digestibilities, respectively 48, 53 and 49%, and the availabilities of P (66% and Ca (20% were indicative that they could add to the energy and protein intake while contributing significantly to nutrient balance of Svalbard reindeer when present in a mixed diet.Fordøyelse av energi og næringsstoffer hos Svalbard-rein.Abstract in Norwegian / Sammendrag: Ved MAB-stasjonen i Adventdalen på Svalbard ble det utført foringsforsøk med fem voksne bukker av Svalbardrein, Rangifer tarandus platyrhynchus Vrolik. Det ble nyttet fem forskjellige forty per, 1: pelletert reinfor, RF71, 2: en blanding av gras og siv høstet i Adventdalen (vesentlig Dupontia pelligera og Eriophorum scheuchzeri, 3: en ren mosediett (Pleurozium schreberi, 4: lav av den vanlige Svalbard -arten, Cetraria delisei, 5: en blandet diett av RF

  8. Selected anthropogenic and natural radioisotopes in the Barents Sea and off the western coast of Svalbard.

    Science.gov (United States)

    Leppänen, Ari-Pekka; Kasatkina, Nadezhda; Vaaramaa, Kaisa; Matishov, Gennady G; Solatie, Dina

    2013-12-01

    The Murmansk Marine Biological Institute (MMBI) performed high-latitude expeditions to the Barents Sea during 2007-2009 where a scientist from the Radiation and Nuclear Safety Authority (STUK) participated. The aim of the expeditions was to study and map the current radiological situation throughout the Barents Sea. In the expeditions, samples of seawater, sediment and biota were collected for radioactivity studies. The (90)Sr and (137)Cs isotopes were analysed from the seawater samples and no spatial distribution in the concentrations of (90)Sr and (137)Cs was found. The sediment samples were analysed for γ-emitting isotopes. In the statistical analysis performed only the (90)Sr was found to have no spatial distribution. In the (137)Cs concentrations two areas containing higher concentrations were observed: one in the western part of Svalbard and another in Franz Victoria Trough near the Franz Josef Land archipelago. The increase in the western coast of Svalbard suggests an Atlantic influence while in the Franz Victoria Trough source regions are possibly more complex. Since (137)Cs in marine sediments mainly originates from terrestrial sources, finding higher concentrations in the northern part of the Barents Sea may also suggest a contribution of (137)Cs carried by the ocean currents and by sea ice from the outside Barents Sea. In addition to γ spectrometric measurements, the sediment samples were radiochemically analysed for (210)Pb. It was found that the unsupported fraction of (210)Pb showed significant spatial variation. The fraction of unsupported (210)Pb was reduced to 40-70% near Bear Island, Edge Island and in the Franz Josef Land archipelago. In these regions the sea is typically covered with sea ice during winter. The relatively low fraction of unsupported (210)Pb is possibly caused by blocking of wet and dry deposition of (210)Pb onto the sea by winter sea ice. In biota samples, only small traces, at the level of 0.2 Bq/kg w.w. of (137)Cs, were found

  9. Modern seasonal variability of central Arctic Ocean sea-ice cover: Reconstruction based on biomarker ("IP25" and "PIP25") data from sediment trap samples

    Science.gov (United States)

    Fahl, K.; Stein, R.

    2012-04-01

    During the Polarstern 1995 Expedition, a long-term mooring system with two cone-shaped multi-sampling traps was deployed at the dominantly ice-covered western slope of the southern Lomonosov Ridge (81°04.5'N, 138°54.0'E, 1712 m water depth). One trap was installed at 150 m below the sea surface, the other at 150 m above the bottom at 1550 m depth; material was collected in 20 time intervals between September 1995 and August 1996. For background data see Fahl and Nöthig (2007). Here, we present new biomarker data recording the seasonal variability of sea-ice cover. This type of data representing modern seasonal variability of the sea-ice biomarker proxies, was not available so far from the central Arctic Ocean but may help significantly the interpretation of these proxies to be used in sedimentary records for reconstruction of paleo-sea-ice distributions. In this study, we have focused on the novel sea ice proxy "IP25", a direct proxy for sea ice coverage (Belt et al., 2007). Furthermore, we used the phytoplankton-IP25 index ("PIP25" Index), a further development of the IP25 index, based on the coupling of the environmental information carried by IP25 (sea ice) and brassicasterol (open-water phytoplankton productivity) (Müller et al., 2011). The interval November 1995 to June 1996 is characterized by the absence of the sea-ice proxy IP25 (except very minor values for January and April), suggesting a predominantly permanent sea-ice cover at the trap location. During July/August 1996, maximum fluxes of the diatom-specific fatty acids and brassicasterol as well as maximum contents of biogenic opal (Fahl and Nöthig, 2007) indicate increased primary productivity. The marine organic matter (here POC, brassicasterol, and fatty acids) and the IP25 values decrease systematically from 150 to 1550m depth, indicating the typical biogeochemical degradation with increasing water depth. Due to the coincidence of maximum abundances of sea-ice proxies and open-ocean primary

  10. Arctic and subarctic environmental analyses utilizing ERTS-1 imagery. [permafrost sediment transport, snow cover, ice conditions, and water runoff in Alaska

    Science.gov (United States)

    Anderson, D. M.; Mckim, H. L.; Haugen, R. K.; Gatto, L. W.; Slaughter, C. W.; Marlar, T. L. (Principal Investigator)

    1973-01-01

    The author has identified the following significant results. Physiognomic landscape features were used as geologic and vegetative indicators in preparation of a surficial geology, vegetation, and permafrost map at a scale of 1:1 million using ERTS-1 band 7 imagery. The detail from this map compared favorably with USGS maps at 1:250,000 scale. Physical boundaries mapped from ERTS-1 imagery in combination with ground truth obtained from existing small maps and other sources resulted in improved and more detailed maps of permafrost terrain and vegetation for the same area. ERTS-1 imagery provides for the first time, a means of monitoring the following regional estuarine processes: daily and periodic surface water circulation patterns; changes in the relative sediment load of rivers discharging into the inlet; and, several local patterns not recognized before, such as a clockwise back eddy offshore from Clam Gulch and a counterclockwise current north of the Forelands. Comparison of ERTS-1 and Mariner imagery has revealed that the thermokarst depressions found on the Alaskan North Slope and polygonal patterns on the Yukon River Delta are possible analogs to some Martian terrain features.

  11. Arctic Ocean Scientific Drilling: The Next Frontier

    Directory of Open Access Journals (Sweden)

    Ruediger Stein

    2010-04-01

    Full Text Available The modern Arctic Ocean appears to be changing faster than any other region on Earth. To understand the potential extent of high latitude climate change, it is necessary to sample the history stored in the sediments filling the basins and covering the ridges of the Arctic Ocean. These sediments have been imaged with seismic reflection data, but except for the superficial record, which has been piston cored, they have been sampled only on the Lomonosov Ridge in 2004 during the Arctic Coring Expedition (ACEX-IODP Leg 302; Backman et al., 2006 and in 1993 in the ice-free waters in the Fram Strait/Yermak Plateau area (ODP Leg 151; Thiede et al., 1996.Although major progress in Arctic Ocean research has been made during the last few decades, the short- and long-term paleoceanographic and paleoclimatic history as well as its plate-tectonic evolution are poorly known compared to the other oceans. Despite the importance of the Arctic in the climate system, the database we have from this area is still very weak. Large segments of geologic time have not been sampled in sedimentary sections. The question of regional variations cannot be addressed.

  12. PAST Gateways (Palaeo-Arctic Spatial and Temporal Gateways): Introduction and overview

    Science.gov (United States)

    Ó Cofaigh, Colm; Briner, Jason P.; Kirchner, Nina; Lucchi, Renata G.; Meyer, Hanno; Kaufman, Darrell S.

    2016-09-01

    This special issue relates to the Second International Conference of the PAST Gateways (Palaeo-Arctic Spatial and Temporal Gateways) network which was held in Trieste, Italy in 2014. Twenty five papers are included and they address topics under four main themes: (1) The growth and decay of Arctic ice sheets; (2) Arctic sea ice and palaeoceanography; (3) Terrestrial Arctic environments and permafrost change; and (4) Holocene Arctic environmental change. Geographically the focus is circum-Arctic; the special issue includes detailed regional studies from Greenland, Scandinavia, Russia, and Arctic North America and the adjoining seas, as well as a series of synthesis-type, review papers on Fennoscandian Ice Sheet deglaciation and Holocene Arctic palaeo-climate change. The methodologies employed are diverse and include marine sediment core and geophysical investigations, terrestrial glacial geology and geomorphology, isotopic analysis of ground ice, palaeo-ecological analysis of lacustrine and terrestrial sedimentary archives, geochronology and numerical ice sheet modeling.

  13. Quantifying Methane Emissions from the Arctic Ocean Seabed to the Atmosphere

    Science.gov (United States)

    Platt, Stephen; Pisso, Ignacio; Schmidbauer, Norbert; Hermansen, Ove; Silyakova, Anna; Ferré, Benedicte; Vadakkepuliyambatta, Sunil; Myhre, Gunnar; Mienert, Jürgen; Stohl, Andreas; Myhre, Cathrine Lund

    2016-04-01

    Large quantities of methane are stored under the seafloor in the shallow waters of the Arctic Ocean. Some of this is in the form of hydrates which may be vulnerable to deomposition due to surface warming. The Methane Emissions from Arctic Ocean to Atmosphere MOCA, (http://moca.nilu.no/) project was established in collaboration with the Centre for Arctic Gas Hydrate, Environment and Climate (CAGE, https://cage.uit.no/). In summer 2014, and summer and autumn 2015 we deployed oceanographic CTD (Conductivity, Temperature, Depth) stations and performed state-of-the-art atmospheric measurements of CH4, CO2, CO, and other meteorological parameters aboard the research vessel Helmer Hanssen west of Prins Karl's Forland, Svalbard. Air samples were collected for isotopic analysis (13C, 2H) and quantification of other hydrocarbons (ethane, propane, etc.). Atmospheric measurements are also available from the nearby Zeppelin Observatory at a mountain close to Ny-Ålesund, Svalbard. We will present data from these measurements that show an upper constraint of the methane flux in measurement area in 2014 too low to influence the annual CH4 budget. This is further supported by top-down constraints (maximum release consistent with observations at the Helmer Hansen and Zeppelin Observatory) determined using FLEXPART foot print sensitivities and the OsloCTM3 model. The low flux estimates despite the presence of active seeps in the area (numerous gas flares were observed using echo sounding) were apparently due to the presence of a stable ocean pycnocline at ~50 m.

  14. Norwegian contributions to Arctic environmental sciences from the 1880s to the third International Polar Year

    Institute of Scientific and Technical Information of China (English)

    Roger G. Barry

    2016-01-01

    This paper reviews the major contributions made by Norwegian scientists to Arctic environmental sciences since the 1880s. The review begins with the ifrst International Polar Year (IPY) in 1882–83. It then considers the 1890s to 1920s with the scientiifc expeditions focusing on ocean and sea ice conditions of Nansen, Amundsen and H. Sverdrup, and the mapping of the Queen Elizabeth Islands by Otto Sverdrup and colleagues. The period from 1911 to the mid-1920s also witnessed annual expeditions to Svalbard led by Adolf Hoel. The 1930s to 1945 period encompassed the Second International Polar Year when Arctic weather stations were established or maintained. The time interval post-World War II to 2000 witnessed major advances made possible by technical and organizational innovations. The establishment of the Norwegian Polar Institute in 1948 led to extensive research on the glaciers and snow cover in the Svalbard archipelago and to oceanographic and sea ice research in the Barents Sea and Arctic Ocean. Remote sensing methods began to be widely used from the 1980s. The new millennium saw the undertaking of the third IPY and a shift to multinational projects. New ifelds such as ocean–ice–atmosphere variability became active and there was much attention to high-latitudeclimate change in the context of global warming.

  15. Recent mass balance of Arctic glaciers derived from repeat-track ICESat altimetry (Invited)

    Science.gov (United States)

    Moholdt, G.; Nuth, C.; Hagen, J. M.; Wolken, G. J.; Gardner, A.

    2010-12-01

    The Arctic region is more affected by climate change than the lower latitudes. Glaciers and ice caps are sensitive indicators of climate change, and there is a high demand for more accurate quantifications of glacier changes in the Arctic. ICESat laser altimetry has been a popular tool for assessing recent elevation changes of the Greenland ice sheet. Other high Arctic glaciers have an equally dense coverage of ICESat tracks, but the quantity and quality of elevation comparisons are degraded due to smaller glacier sizes and steeper slopes. A methodological study at the Svalbard archipelago in the Norwegian Arctic has shown that it is feasible to obtain reasonable elevation change estimates from repeat-track ICESat altimetry (Moholdt et al., 2010). The best results were achieved using all available ICESat data in a joint analysis where surface slope and elevation change were estimated for homogeneous planes that were fitted to the data along each track. The good performance of the plane method implies that it can also be used in other Arctic regions of similar characteristics where accurate DEMs are typically not available. We present 2003-2009 elevation change rates for the Norwegian Arctic (Svalbard), the Russian Arctic (Novaya Zemlya, Severnaya Zemlya and Franz Josefs Land) and the Canadian Arctic (Queen Elizabeth Islands and Baffin Island). The glaciers and ice caps of these regions cover a total area of ~230 000 km2 which is about 30% of the world-wide glacier cover outside of the Greenland and Antarctic ice sheets. Most regions experience strong thinning at low elevations, while the pattern at higher elevations varies from slight thinning to slight thickening. There are also examples of local anomalous elevation changes due to unstable glacier dynamics, e.g. glacier surging. Hypsometric calculations are performed to calculate regional volume changes on a bi-annual time scale and over the entire ICESat period (2003-2009). Short-term variations in firn layer

  16. Arctic Expedition of the Frozen Five: an Alternative way of Education and Outreach During the International Polar Year

    Science.gov (United States)

    Senger, K.; Björkman, M.; Garny, H.; Girard, L.; Lichteneger, J.

    2006-12-01

    In March 2007, a group of international students of the geosciences will embark on a two month expedition across the wilderness of Svalbard. The journey will involve traversing up to 1000 km of high Arctic glaciers between 76° an 80°N, reaching both the southernmost and northernmost capes of Spitsbergen, Svalbard's largest island. We expect to be frequently camping at -30°C, as well as having a high probability of encountering polar bears, crevasses and arctic storms during the expedition. Through this expedition, we wish to promote the multi-disciplinary approach required in successful Arctic science. Our team, young and energetic, has already demonstrated a strong research interest in the Arctic and is ready to share their passion with the general public. Presentations by the various team members focus on the enhanced climate change and related processes witnessed at high latitudes. The concept of alternative energy, including solar power and kites used while en route, is given a high priority throughout. Here we present the education and outreach framework of the project, as well as introducing the research background of the team. We highlight current progress on the integration of this expedition in high schools around the world. The Frozen Five expedition runs in close collaboration with New Zealand's Youth Steering Committee, a major IPY project, aiming to network young polar researchers and promote the study of the polar regions to potential scientists.

  17. Spatial and temporal analysis of Holocene coastal development: applications to erosion assessment and cultural heritage mitigation on Svalbard

    OpenAIRE

    2013-01-01

    High geomorphic and climatic variability in Arctic coastlines makes evaluating future coastal erosion in a changing climate a challenge. Predictions must, among other things, incorporate modifications to sediment supply and accommodation space, changes in the permafrost regime, climate variability including rising air and sea temperatures, stronger winds, less sea ice, and increased precipitation. This thesis explores processes and climate variables associated with coastal development through...

  18. The response of polar glaciers to Late Holocene climate change reconstructed from terrestrial geomorphological evidence on Svalbard

    Science.gov (United States)

    Lukas, Sven; Benn, Douglas I.; Temminghoff, Maria; Boston, Clare M.; Irvine-Fynn, Tris; Porter, Philip R.; Barrand, Nick E.; Nicholson, Lindsey I.; Ross, Fionna H.; Humlum, Ole

    2010-05-01

    Arctic ice masses are likely to experience some of the most dramatic changes in the context of projected atmospheric warming. Understanding how quickly and in what form these changes will manifest themselves is important in order to be able to predict future impacts, through feedback mechanisms, on the climate at different spatial scales, ranging from local to global. In addition to this, it is also important to consider various temporal scales to obtain a longer-term perspective beyond historical and instrumental records. In order to assess modes of glacier response against this background we present results from four terrestrial glaciers on Svalbard, three of which are located in a semi-arid climate and one in a maritime setting with a humid climate. We have employed a multi-disciplinary approach comprising geomorphological mapping, sedimentological logging and analyses, process observations, differences between digital elevation models constructed for different years and DC resistivity surveys of glacier snouts and forelands to arrive at a holistic process understanding of glacier response to Late Holocene climate change and to tease apart climatic controls on their response. Our results show that the presence of debris overlying buried ice blocks and continuous glacier ice bodies in a continuous permafrost environment complicates the relationship between climatic warming and glacier response. Processes in foreland evolution are intimately linked to debris thickness and distribution on the one hand and to the evolution and reorganisation of the sub-, en- and proglacial drainage system which controls where material evacuation and thus debris-cover thinning and removal takes place. In our contribution, we will discuss the processes in detail and will develop a conceptual model that will allow the response of arctic glaciers to be placed into a wider framework that incorporates neoglacial and current times.

  19. The 1994 Arctic Ocean Section. The First Major Scientific Crossing of the Arctic Ocean,

    Science.gov (United States)

    1996-09-01

    chlorofluorocarbons (CFCs), helium, oxygen, CO2 system components, AMS 14C, tritium, 18O, nutrients, salinity, trace metals, radionuclides and organic contaminants...spatial and temporal extremes in the rate of biological sequestration of atmospheric CO2 , ranging from oligotrophic conditions in the central Arctic to...paleoceanographic or paleoatmospheric circulation patterns and contribute to better paleoclimate reconstructions. Surface sediments collected along

  20. The influence of climate during and after a glacial surge - A comparison of the last two surges of Fridtjovbreen, Svalbard

    Science.gov (United States)

    Lønne, Ida

    2014-02-01

    Glacial surges are periods of fast flow, often limited in space and time, and driven by internal conditions which are not fully explained. The quantity and variety of documented case-studies and settings demonstrate that the critical variables are difficult to isolate. In an alternative approach, two surges from the same basin were compared at Fridtjovhamna; one of the few known sites where this is possible. Fridtjovbreen is a polythermal glacier that has been through two recent surges: the last event (1991-2002) occurred during an unusually warm period in the high Arctic, whereas the previous surge culminated in 1861, around the Little Ice Age when many Svalbard-glaciers had their maximum Holocene extent. Based on a multi-disciplinary study, processes and landforms from the two episodes were compared with respect to ice-front movement rates, formation and decay of ice-cored moraines and glacial meltwater drainage patterns. The study demonstrates that moraines and meltwater traces from the oldest surge, locally well preserved, provide excellent opportunities for reconstructing the behavior of the ice-mass. The last surge, however, took place during a period with ablation rates never seen at this latitude, and 10 years after the maximum extent, the deglaciated areas onshore hardly show traces from the event.

  1. Turbulent high-latitude oceanic intrusions—details of non-smooth apparent isopycnal transport West of Svalbard

    Science.gov (United States)

    van Haren, Hans; Greinert, Jens

    2016-07-01

    Filament intrusions are observed in high-resolution temperature (T) measurements from a 100-m and several month-long mooring in the Fram Strait in around 400-m water depth at the continental slope West of Svalbard (Spitsbergen, Norway). In this dynamic environment, a wide variety of intrusive layers are observed with thicknesses between 5 and 80 m with warmer water between cooler waters above and below. The layers typically last from several hours up to 1 day, exceeding the local buoyancy period but not lasting as long as intrusive layers in the open ocean. The intrusions are a result of an intermingling of Arctic and North-Atlantic waters and generated in the basins interior and locally via internal wave steepening upon the sloping bottom. Freely propagating semidiurnal lunar internal tides cannot exist without background vorticity at these high latitudes. Strongly nonlinear turbulent bores are not observed at the tidal periodicity, but wave fronts occur at the sub-inertial frequency of dominant baroclinic instability. The fronts are in part associated with near-buoyancy frequency internal waves (breaking). The details of the moored T observations and their spectral content demonstrate the non-smooth, relatively turbulent development including convective overturning and shear-induced instabilities when intrusions disperse in presumably salinity-compensated isopycnal layers.

  2. 800 year ice-core record of nitrogen deposition in Svalbard linked to ocean productivity and biogenic emissions

    Directory of Open Access Journals (Sweden)

    I. A. Wendl

    2014-09-01

    Full Text Available We present the records of the two nitrogen species nitrate (NO3− and ammonium (NH4+ analysed in a new ice core from Lomonosovfonna, Svalbard, in the Eurasian Arctic covering the period 1222–2009. We investigate the emission sources and the influence of melt on the records. During the 20th century both records are influenced by anthropogenic pollution from Eurasia. In pre-industrial times NO3− is highly correlated with methane-sulfonate (MSA on decadal time-scales, which we explain by a fertilising effect. Enhanced atmospheric NO3− concentrations and the corresponding nitrogen input to the ocean trigger the growth of dimethyl-sulfide-(DMS-producing phytoplankton. Increased DMS production results in elevated fluxes to the atmosphere where it is oxidised to MSA. Eurasia was presumably the main source area also for pre-industrial NO3−, but a more exact source apportionment could not be performed based on our data. This is different for NH4+, where biogenic ammonia (NH3 emissions from Siberian boreal forests were identified as the dominant source of pre-industrial NH4+. Changes in melt at the Lomonosovfonna glacier are excluded as major driving force for the decadal variations of the investigated compounds.

  3. The influence of supraglacial debris cover variability on de-icing processes - examples from Svalbard

    Science.gov (United States)

    Lukas, Sven; Benn, Douglas I.; Boston, Clare M.; Hawkins, Jack; Lehane, Niall E.; Lovell, Harold; Rooke, Michael

    2014-05-01

    Extensive supraglacial debris covers are widespread near the margins of many cold-based and polythermal surging and non-surging glaciers in Svalbard. Despite their importance for current glacier dynamics and a detailed understanding of how they will affect the de-icing of ice-marginal areas, little work has been carried out to shed light on the sedimentary processes operating in these debris covers. We here present data from five different forelands in Svalbard. In all five cases, surfaces within the debris cover can be regarded as stable where debris cover thickness exceeds that of the active layer; vegetation development and absence of buried ice exposures at the surface support this conclusion, although test pits and geophysical investigations have revealed the presence of buried ice at greater depths (> 1-3 m). These findings imply that even seemingly stable surfaces at present will be subject to change by de-icing in the future. Factors and processes that contribute towards a switch from temporarily stable to unstable conditions have been identified as: 1. The proximity to englacial or supraglacial meltwater channels. These channels enlarge due to thermo-erosion, which can lead to the eventual collapse of tunnel roofs and the sudden generation of linear instabilities in the system. Along such channels, ablation is enhanced compared to adjacent debris-covered ice, and continued thermo-erosion continuously exposes new areas of buried ice at the surface. This works in conjunction with 2. Debris flows that occur on all sloping ground and transfer material from stable to less stable (sloping) locations within the debris cover and eventually into supraglacial channels, from where material is then removed from the system. Several generations of debris flows have been identified in all five debris covers, strongly suggesting that these processes are episodic and that the loci of these processes switch. This in turn indicates that transfer of material by debris flows

  4. Temporal trends of Persistent Organic Pollutants (POPs) in arctic air: 20 years of monitoring under the Arctic Monitoring and Assessment Programme (AMAP).

    Science.gov (United States)

    Hung, Hayley; Katsoyiannis, Athanasios A; Brorström-Lundén, Eva; Olafsdottir, Kristin; Aas, Wenche; Breivik, Knut; Bohlin-Nizzetto, Pernilla; Sigurdsson, Arni; Hakola, Hannele; Bossi, Rossana; Skov, Henrik; Sverko, Ed; Barresi, Enzo; Fellin, Phil; Wilson, Simon

    2016-10-01

    Temporal trends of Persistent Organic Pollutants (POPs) measured in Arctic air are essential in understanding long-range transport to remote regions and to evaluate the effectiveness of national and international chemical control initiatives, such as the Stockholm Convention (SC) on POPs. Long-term air monitoring of POPs is conducted under the Arctic Monitoring and Assessment Programme (AMAP) at four Arctic stations: Alert, Canada; Stórhöfði, Iceland; Zeppelin, Svalbard; and Pallas, Finland, since the 1990s using high volume air samplers. Temporal trends observed for POPs in Arctic air are summarized in this study. Most POPs listed for control under the SC, e.g. polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs) and chlordanes, are declining slowly in Arctic air, reflecting the reduction of primary emissions during the last two decades and increasing importance of secondary emissions. Slow declining trends also signifies their persistence and slow degradation under the Arctic environment, such that they are still detectable after being banned for decades in many countries. Some POPs, e.g. hexachlorobenzene (HCB) and lighter PCBs, showed increasing trends at specific locations, which may be attributable to warming in the region and continued primary emissions at source. Polybrominated diphenyl ethers (PBDEs) do not decline in air at Canada's Alert station but are declining in European Arctic air, which may be due to influence of local sources at Alert and the much higher historical usage of PBDEs in North America. Arctic air samples are screened for chemicals of emerging concern to provide information regarding their environmental persistence (P) and long-range transport potential (LRTP), which are important criteria for classification as a POP under SC. The AMAP network provides consistent and comparable air monitoring data of POPs for trend development and acts as a bridge between national monitoring programs and SC's Global Monitoring

  5. N-ICE2015: Multi-disciplinary study of the young sea ice system north of Svalbard from winter to summer.

    Science.gov (United States)

    Steen, Harald; Granskog, Mats; Assmy, Philipp; Duarte, Pedro; Hudson, Stephen; Gerland, Sebastian; Spreen, Gunnar; Smedsrud, Lars H.

    2016-04-01

    The Arctic Ocean is shifting to a new regime with a thinner and smaller sea-ice area cover. Until now, winter sea ice extent has changed less than during summer, as the heat loss to the atmosphere during autumn and winter is large enough form an ice cover in most regions. The insulating snow cover also heavily influences the winter ice growth. Consequently, the older, thicker multi-year sea ice has been replace by a younger and thinner sea. These large changes in the sea ice cover may have dramatic consequences for ecosystems, energy fluxes and ultimately atmospheric circulation and the Northern Hemisphere climate. To study the effects of the changing Arctic the Norwegian Polar Institute, together with national and international partners, launched from January 11 to June 24, 2015 the Norwegian Young Sea ICE cruise 2015 (N-ICE2015). N-ICE2015 was a multi-disciplinary cruise aimed at simultaneously studying the effect of the Arctic Ocean changes in the sea ice, the atmosphere, in radiation, in ecosystems. as well as water chemistry. R/V Lance was frozen into the drift ice north of Svalbard at about N83 E25 and drifted passively southwards with the ice until she was broken loose. When she was loose, R/V Lance was brought back north to a similar starting position. While fast in the ice, she served as a living and working platform for 100 scientist and engineers from 11 countries. One aim of N-ICE2015 is to present a comprehensive data-set on the first year ice dominated system available for the scientific community describing the state and changes of the Arctic sea ice system from freezing to melt. Analyzing the data is progressing and some first results will be presented.

  6. Investigating cytoskeletal function in chloroplast protrusion formation in the arctic-alpine plant Oxyria digyna.

    Science.gov (United States)

    Holzinger, A; Wasteneys, G O; Lütz, C

    2007-05-01

    Arctic and alpine plants like Oxyria digyna have to face enhanced environmental stress. This study compared leaves from Oxyria digyna collected in the Arctic at Svalbard (78 degrees N) and in the Austrian Alps (47 degrees N) at cellular, subcellular, and ultrastructural levels. Oxyria digyna plants collected in Svalbard had significantly thicker leaves than the samples collected in the Austrian Alps. This difference was generated by increased thickness of the palisade and spongy mesophyll layers in the arctic plants, while epidermal cells had no significant size differences between the two habitats. A characteristic feature of arctic, alpine, and cultivated samples was the occurrence of broad stroma-filled chloroplast protrusions, 2 - 5 microm broad and up to 5 microm long. Chloroplast protrusions were in close spatial contact with other organelles including mitochondria and microbodies. Mitochondria were also present in invaginations of the chloroplasts. A dense network of cortical microtubules found in the mesophyll cells suggested a potential role for microtubules in the formation and function of chloroplast protrusions. No direct interactions between microtubules and chloroplasts, however, were observed and disruption of the microtubule arrays with the anti-microtubule agent oryzalin at 5 - 10 microM did not alter the appearance or dynamics of chloroplast protrusions. These observations suggest that, in contrast to studies on stromule formation in Nicotiana, microtubules are not involved in the formation and morphology of chloroplast protrusions in Oxyria digyna. The actin microfilament-disrupting drug latrunculin B (5 - 10 microM for 2 h) arrested cytoplasmic streaming and altered the cytoplasmic integrity of mesophyll cells. However, at the ultrastructural level, stroma-containing, thylakoid-free areas were still visible, mostly at the concave sides of the chloroplasts. As chloroplast protrusions were frequently found to be mitochondria-associated in Oxyria

  7. Mesozooplankton community development at elevated CO2 concentrations: results from a mesocosm experiment in an Arctic fjord

    Directory of Open Access Journals (Sweden)

    B. Niehoff

    2013-03-01

    Full Text Available The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world ocean. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated CO2 are still lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 μatm to 1420 μatm. Vertical net hauls were taken weekly over about one month with an Apstein net (55 μm mesh size in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analysed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (Cirripedia, Polychaeta, Bivalvia, Gastropoda, and Decapoda dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms and the pCO2 had no significant effect on the overall community structure. Also, we did not find significant relationships between the pCO2 level and the abundance of single taxa. Changes in heterogeneous communities are, however, difficult to detect, and the exposure to elevated pCO2 was relatively short. We therefore suggest that future mesocosm experiments should be run for longer periods.

  8. The red-sky enigma over Svalbard in December 2002

    Directory of Open Access Journals (Sweden)

    F. Sigernes

    2005-07-01

    Full Text Available On 6 December 2002, during winter darkness, an extraordinary event occurred in the sky, as viewed from Longyearbyen (78° N, 15° E, Svalbard, Norway. At 07:30 UT the southeast sky was surprisingly lit up in a deep red colour. The light increased in intensity and spread out across the sky, and at 10:00 UT the illumination was observed to reach the zenith. The event died out at about 12:30 UT. Spectral measurements from the Auroral Station in Adventdalen confirm that the light was scattered sunlight. Even though the Sun was between 11.8 and 14.6deg below the horizon during the event, the measured intensities of scattered light on the southern horizon from the scanning photometers coincided with the rise and setting of the Sun. Calculations of actual heights, including refraction and atmospheric screening, indicate that the event most likely was scattered solar light from a target below the horizon. This is also confirmed by the OSIRIS instrument on board the Odin satellite. The deduced height profile indicates that the scattering target is located 18–23km up in the stratosphere at a latitude close to 73–75° N, southeast of Longyearbyen. The temperatures in this region were found to be low enough for Polar Stratospheric Clouds (PSC to be formed. The target was also identified as PSC by the LIDAR systems at the Koldewey Station in Ny-Ålesund (79° N, 12° E. The event was most likely caused by solar illuminated type II Polar Stratospheric Clouds that scattered light towards Svalbard. Two types of scenarios are presented to explain how light is scattered.

    Keywords. Atmospheric composition and structure (Transmissions and scattering of radiation; Middle atmospherecomposition and chemistry; Instruments and techniques – History of geophysics (Atmospheric Sciences; The red-sky phenomena

  9. Is the "Atlantification" of the Arctic Ocean extending?

    Science.gov (United States)

    Ivanov, V.; Alexeev, V. A.; Koldunov, N. V.; Repina, I.; Sandø, A. B.; Smedsrud, L. H.; Smirnov, A.

    2015-12-01

    We present recent observation and modelling results, which suggest that retreat of the sea-ice edge in the Atlantic sector of the Arctic Ocean over several recent years may be an indication of the growing influence of Atlantic Water on the hydrographic regime ("Atlantification"). The 'memory' of ice-depleted conditions in summer is transferred to the fall season, through excess heat content in the upper mixed layer, which in turn transfers to mid-winter via thinner and younger ice. This thinner ice is more fragile and mobile, thus facilitating the formation of polynyas and leads. When openings in ice cover form along the Atlantic Water pathway, weak density stratification at the mixed layer base supports the development of thermohaline convection, which further entrains warm and salty water from deeper layers. Convection-induced upward heat flux from the Atlantic layer retards ice formation, either keeping ice thickness low or blocking ice formation entirely. The joint analysis of observations and modelling data is performed north-east of Svalbard where the top hundred meters of Atlantic inflow through the Fram Strait cools and freshens rapidly. Complementary research methods, including statistical analyses of observations and numerical modelling, support our basic "Atlantification" concept. A general conclusion from the analysis performed is that the recently observed retreat of sea ice northeast of Svalbard in winter may be explained by the positive feedback between summer ice decay and the growing influence of oceanic heat on a seasonal time scale.

  10. Barry Lopez's Relational Arctic

    OpenAIRE

    Kjeldaas, Sigfrid

    2014-01-01

    "Arctic dreams: imagination and desire in a Northern landscape"(1986) can be read as American nature writer Barry Lopez’s attempt to evoke a more profound and ecologically sound understanding of the North American Arctic. This article investigates how Arctic Dreams uses insights from Jacob von Uexküll’s Umwelt theory, in combination with what Tim Ingold describes as a particular form of animism associated with circumpolar indigenous hunter cultures, to portray the Arctic natur...

  11. Arctic microbial community dynamics influenced by elevated CO2 levels

    Directory of Open Access Journals (Sweden)

    K. Schulz

    2012-09-01

    Full Text Available The Arctic Ocean ecosystem is particular vulnerable for ocean acidification (OA related alterations due to the relatively high CO2 solubility and low carbonate saturation states of its cold surface waters. Thus far, however, there is only little known about the consequences of OA on the base of the food web. In a mesocosm CO2-enrichment experiment (overall CO2 levels ranged from ∼180 to 1100 μatm in the Kongsfjord off Svalbard, we studied the consequences of OA on a natural pelagic microbial community. The most prominent finding of our study is the profound effect of OA on the composition and growth of the Arctic phytoplankton community, i.e. the picoeukaryotic photoautotrophs and to a lesser extent the nanophytoplankton prospered. A shift towards the smallest phytoplankton as a result of OA will have direct consequences for the structure and functioning of the pelagic food web and thus for the biogeochemical cycles. Furthermore, the dominant pico- and nanophytoplankton groups were found prone to viral lysis, thereby shunting the carbon accumulation in living organisms into the dissolved pools of organic carbon and subsequently affecting the efficiency of the biological pump in these Arctic waters.

  12. Environmental factors structuring Arctic megabenthos - a case study from a shelf and two fjords

    Directory of Open Access Journals (Sweden)

    Kirstin eMeyer

    2015-04-01

    Full Text Available From photographic samples, we describe the benthic megafaunal communities in two north Svalbard fjords and on the adjacent continental shelf. We analyze the fauna in relation to abiotic factors of depth, bottom water temperature, percent cover of hard substratum, heterogeneity of stone size, and bottom-water turbidity to explore how these factors might affect the fauna and how they are related to the functional traits (size, morphology, mobility, colonial/solitary, and feeding type of the megabenthos. Depth and bottom water temperature were consistently the strongest correlates with faunal composition and functional traits of the constituent species. A greater proportion of the variability in the functional traits of the megabenthos could be explained by abiotic factors rather than faunal composition, indicating that the abiotic factors of depth and temperature were strongly related to the functional traits of the megabenthos. On a local scale, stone size heterogeneity explained most variation in the functional traits of the megabenthos in one fjord. The results of this case study show a significant relationship between bottom water temperature and the functioning of north Svalbard megabenthic communities. Warming temperatures in the Arctic will likely decrease the variety of functional traits represented in Svalbard megabentos, resulting in scavenger-dominated communities. A reduction in megabenthic biomass may also result, reducing energy availability to higher trophic levels.

  13. Phosphate solubilizing ability of two Arctic Aspergillus niger strains

    Directory of Open Access Journals (Sweden)

    Shiv Mohan Singh,

    2011-06-01

    Full Text Available Many filamentous fungi were isolated from the soils of Ny-Ålesund, Spitsbergen, Svalbard, and were screened in vitro for their phosphate solubilizing ability. Two strains of Aspergillus niger showed good tricalcium phosphate (TCP solubilizing ability in Pikovskaya's medium. The TCP solubilization index was calculated at varying levels of pH and temperatures. The ability of Aspergillus niger strain-1 to solubilize and release inorganic-P was 285 µg ml–1, while Aspergillus niger strain-2 solubilized 262 µg ml–1 from 0.5% TCP after seven days. This is the first report of TCP solubilization by Arctic strains that may serve as very good phosphate solubilizers in the form of biofertilizer.

  14. Sedimentological characteristics of ice-wedge polygon terrain in Adventdalen (Svalbard) - environmental and climatic implications for the late Holocene

    Science.gov (United States)

    Oliva, M.; Vieira, G.; Pina, P.; Pereira, P.; Neves, M.; Freitas, M. C.

    2014-09-01

    Ice wedges are widespread periglacial features in the landscape of Adventdalen, Svalbard. The networks of ice wedges have created areas with well-developed polygonal terrains in the lowest fluvial terraces in this valley. We have examined the sedimentological characteristics of the northern and southern banks of the Advent river for palaeoenvironmental purposes. The base of two sedimentary sections reported radiocarbon dates of 3.3 and 3.9 ka BP, respectively. The northern site is constituted by three very different lithostratigraphical units, which suggests that their formation should be related to different environmental and climate conditions. By contrast, the southern section shows a rather homogeneous composition, with no significant variations in grain size and organic matter content. In both cases the uppermost sediments are constituted by a thick aeolian deposit. According to our data, warmer climate conditions may have prevailed during the mid Holocene until 3.3 ka BP with widespread peat formation in the valley bottom. Subsequently, a period with alternating soil formation and aeolian sedimentation took place from 3 to 2.5 ka BP, probably due to increasing climatic severity. During the last millennium a long-term cooling trend has favoured aeolian deposition in the lowest part of Adventdalen.

  15. Sedimentological characteristics of ice-wedge polygon terrain in Adventdalen (Svalbard. Environmental and climatic implications for the Late Holocene

    Directory of Open Access Journals (Sweden)

    M. Oliva

    2014-05-01

    Full Text Available Ice-wedges are widespread periglacial features in the landscape of Adventalen, Svalbard. The networks of ice-wedges have created areas with well-developed polygonal terrains in the lowest fluvial terraces in this valley. We have examined the sedimentological characteristics of the northern and southern banks of the Advent river for palaeoenvironmental purposes. The base of two sedimentary sections reported radiocarbon dates of 3.3 and 3.9 ka cal BP, respectively. The northern site is constituted by three very different lithostratigraphical units, which suggests that their formation should be related to different environmental and climate conditions. By contrast, the southern section shows a rather homogeneous composition, with no significant variations in grain size and organic matter content. In both cases the uppermost sediments are constituted by a thick aeolian deposit. According to our data, warmer climate conditions may have prevailed during the Mid Holocene until 3.3 ka cal BP with widespread peat formation in the valley bottom. Subsequently, a period with alternating soil formation and aeolian sedimentation took place from 3 to 2.5 ka cal BP, probably due to increasing climatic severity. During the last millennium a long-term cooling trend has favoured aeolian deposition in the lowest Adventalen valley.

  16. Sedimentological characteristics of ice-wedge polygon terrain in Adventdalen (Svalbard). Environmental and climatic implications for the Late Holocene

    Science.gov (United States)

    Oliva, M.; Vieira, G.; Pina, P.; Pereira, P.; Neves, M.; Freitas, M. C.

    2014-05-01

    Ice-wedges are widespread periglacial features in the landscape of Adventalen, Svalbard. The networks of ice-wedges have created areas with well-developed polygonal terrains in the lowest fluvial terraces in this valley. We have examined the sedimentological characteristics of the northern and southern banks of the Advent river for palaeoenvironmental purposes. The base of two sedimentary sections reported radiocarbon dates of 3.3 and 3.9 ka cal BP, respectively. The northern site is constituted by three very different lithostratigraphical units, which suggests that their formation should be related to different environmental and climate conditions. By contrast, the southern section shows a rather homogeneous composition, with no significant variations in grain size and organic matter content. In both cases the uppermost sediments are constituted by a thick aeolian deposit. According to our data, warmer climate conditions may have prevailed during the Mid Holocene until 3.3 ka cal BP with widespread peat formation in the valley bottom. Subsequently, a period with alternating soil formation and aeolian sedimentation took place from 3 to 2.5 ka cal BP, probably due to increasing climatic severity. During the last millennium a long-term cooling trend has favoured aeolian deposition in the lowest Adventalen valley.

  17. Aerosol absorption coefficient and Equivalent Black Carbon by parallel operation of AE31 and AE33 aethalometers at the Zeppelin station, Ny Ålesund, Svalbard

    Science.gov (United States)

    Eleftheriadis, Konstantinos; Kalogridis, Athina-Cerise; Vratolis, Sterios; Fiebig, Markus

    2016-04-01

    Light absorbing carbon in atmospheric aerosol plays a critical role in radiative forcing and climate change. Despite the long term measurements across the Arctic, comparing data obtained by a variety of methods across stations requires caution. A method for extracting the aerosol absorption coefficient from data obtained over the decades by filter based instrument is still under development. An IASOA Aerosol working group has been initiated to address this and other cross-site aerosol comparison opportunities. Continuous ambient measurements of EBC/light attenuation by means of a Magee Sci. AE-31 aethalometer operating at the Zeppelinfjellet station (474 m asl; 78°54'N, 11°53'E), Ny Ålesund, Svalbard, have been available since 2001 (Eleftheriadis et al, 2009), while a new aethalometer model (AE33, Drinovec et al, 2014) has been installed to operate in parallel from the same inlet since June 2015. Measurements are recorded by a Labview routine collecting all available parameters reported by the two instrument via RS232 protocol. Data are reported at 1 and 10 minute intervals as averages for EBC (μg m-3) and aerosol absorption coefficients (Mm-1) by means of routine designed to report Near Real Time NRT data at the EBAS WDCA database (ebas.nilu.no) Results for the first 6 month period are reported here in an attempt to evaluate comparative performance of the two instruments in terms of their response with respect to the variable aerosol load of light absorbing carbon during the warm and cold seasons found in the high arctic. The application of available conversion schemes for obtaining the absorption coefficient by the two instruments is found to demonstrate a marked difference in their output. During clean periods of low aerosol load (EBC agreement with regression slope for the 880 nm signal between the two at ~ 0.9 compared to a slope at ~ 0.6 during the period of higher absorbing carbon loads (400Arctic: Measurements at Zeppelin station, Ny-Ålesund, Svalbard

  18. Mud aprons in front of Svalbard surge moraines: Evidence of subglacial deforming layers or proglacial glaciotectonics?

    Science.gov (United States)

    Kristensen, Lene; Benn, Douglas I.; Hormes, Anne; Ottesen, Dag

    2009-10-01

    Large debris-flow units commonly occur on the distal sides of subaqueous end moraines deposited by surges of Svalbard tidewater glaciers, but have rarely been described in terrestrial settings. Some researchers have argued that these kinds of debris flows reflect processes unique to the subaqueous environment, such as the extrusion of subglacial deforming layers or extensive failure of oversteepened moraine fronts. In this paper, we describe terrestrial and subaqueous parts of a single late Holocene moraine system deposited by a major surge of the tidewater glacier Paulabreen in west Spitsbergen. The ice-marginal landforms on land closely resemble the corresponding landforms on the seabed as evidenced by geomorphic mapping and geophysical profiles from both environments. Both onland and offshore, extensive areas of hummocky moraine occur on the proximal side of the maximum glacier position, and large mud aprons (interpreted as debris flows) occur on the distal side. We show that the debris-flow sediments were pushed in front of the advancing glacier as a continuously failing, mobile push moraine. We propose that the mud aprons are end members of a proglacial landforms continuum that has thrust-block moraines as the opposite end member. Two clusters of dates (~ 8000 YBP and ~ 700 YBP) have previously been interpreted to indicate two separate surges responsible for the moraine formation. New dates suggest that the early cluster indicates a local extinction of the abounded species Chlamys islandica. Other changes corresponding to the widespread 8.2 ka event within the fjord, may suggest that the extinction of the C. islandica corresponds to that time.

  19. A minimal, statistical model for the surface albedo of Vestfonna ice cap, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Möller

    2012-09-01

    Full Text Available The ice cap Vestfonna is located in northeastern Svalbard and forms one of the largest ice bodies of the Eurasian Arctic. Its surface albedo plays a key role in the understanding and modelling of its energy and mass balance. The principle governing factors for albedo evolution, i.e. precipitation and air temperature and therewith snow depth and melt duration, were found to vary almost exclusively with terrain elevation throughout the ice cap. Hence, surface albedo can be expected to develop a comparable pattern. A new statistical model is presented that estimates this mean altitudinal albedo profile of the ice cap on the basis of a minimal set of meteorological variables on a monthly resolution. Model calculations are based on a sigmoid function of the artificial quantity rain-snow ratio and a linear function of cumulative snowfall and cumulative positive degree days. Surface albedo fields of the MODIS snow product MOD10A1 from the period March to October in the years 2001–2008 serve as a basis for both calibration and cross-validation of the model. The meteorological model input covers the period September 2000 until October 2008 and is based on ERA-Interim data of a grid point located close to the ice cap. The albedo model shows a good performance. The root mean square error between observed and modelled albedo values along the altitudinal profile is 0.057±0.028 (mean ± one standard deviation. The area weighted mean even reduces to a value of 0.054. Distinctly higher deviations (0.07–0.09 are only present throughout the very lowest and uppermost parts of the ice cap that are either small in area or hardly affected by surface melt. Thus, the new, minimal, statistical albedo model presented in this study is found to reproduce the albedo evolution on Vestfonna ice cap on a high level of accuracy and is thus suggested to be fully suitable for further application in broader energy or mass-balance studies of the ice cap.

  20. A minimal, statistical model for the surface albedo of Vestfonna ice cap, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Möller

    2012-03-01

    Full Text Available The ice cap Vestfonna is located in Northeastern Svalbard and forms one of the largest ice bodies of the Eurasian Arctic. Its surface albedo plays a key role in understanding and modelling of its energy and mass balance. The principle governing factors for albedo evolution, i.e. precipitation and air temperature and therewith snowdepth and melt duration, were found to vary almost exclusively with terrain elevation throughout the ice cap. Hence, surface albedo can be expected to develop a comparable pattern. A new statistical model is presented that estimates this mean altitudinal albedo profile of the ice cap on the basis of a minimal set of meteorological variables on a monthly resolution. Model calculations are based on a logistic function of the artificial quantity rain-snow ratio and a linear function of cumulative snowfall and cumulative positive degree days. Surface albedo fields of the MODIS snow product MOD10A1 of the period March to October of the years 2001–2008 serve as a basis for both calibration and cross-validation of the model. The meteorological model input covers the period September 2000 until October 2008 and is based on ERA-Interim data of a grid point located close to the ice cap. The albedo model shows a good performance. The root mean square error between observed and modelled albedo values along the altitudinal profile is 0.057 ± 0.028 (mean ± one standard deviation. The area weighted mean even reduces to a value of 0.053. Distinctly higher deviations (0.07–0.09 are only present throughout the very lowest and uppermost parts of the ice cap that are either small in area or hardly affected by surface melt. Thus, the new, minimal, statistical albedo model presented in this study is found to reproduce the albedo evolution on Vestfonna ice cap on a high level of accuracy and is thus suggested to be fully suitable for further application in broader energy or mass-balance studies of the ice cap.

  1. Islands of the Arctic

    Science.gov (United States)

    Overpeck, Jonathan

    2004-02-01

    Few environments on Earth are changing more dramatically than the Arctic. Sea ice retreat and thinning is unprecedented in the period of the satellite record. Surface air temperatures are the warmest in centuries. The biology of Arctic lakes is changing like never before in millennia. Everything is pointing to the meltdown predicted by climate model simulations for the next 100 years. At the same time, the Arctic remains one of the most pristine and beautiful places on Earth. For both those who know the Arctic and those who want to know it, this book is worth its modest price. There is much more to the Arctic than its islands, but there's little doubt that Greenland and the major northern archipelagos can serve as a great introduction to the environment and magnificence of the Arctic. The book uses the islands of the Arctic to give a good introduction to what the Arctic environment is all about. The first chapter sets the stage with an overview of the geography of the Arctic islands, and this is followed by chapters that cover many key aspects of the Arctic: the geology (origins), weather and climate, glaciers, ice sheets, sea ice, permafrost and other frozen ground issues, coasts, rivers, lakes, animals, people, and environmental impacts. The material is pitched at a level well suited for the interested layperson, but the book will also appeal to those who study the science of the Arctic.

  2. Approaching a Postcolonial Arctic

    DEFF Research Database (Denmark)

    Jensen, Lars

    2016-01-01

    This article explores different postcolonially configured approaches to the Arctic. It begins by considering the Arctic as a region, an entity, and how the customary political science informed approaches are delimited by their focus on understanding the Arctic as a region at the service...... of the contemporary neoliberal order. It moves on to explore how different parts of the Arctic are inscribed in a number of sub-Arctic nation-state binds, focusing mainly on Canada and Denmark. The article argues that the postcolonial can be understood as a prism or a methodology that asks pivotal questions to all...... approaches to the Arctic. Yet the postcolonial itself is characterised by limitations, not least in this context its lack of interest in the Arctic, and its bias towards conventional forms of representation in art. The article points to the need to develop a more integrated critique of colonial and neo...

  3. 西北冰洋阿尔法脊晚第四纪的陆源沉积物记录及其古环境意义%Late Quaternary Terrigenous Sedimentation in the Western Arctic Ocean as Exemplified by a Sedimentary Record from the Alpha Ridge

    Institute of Scientific and Technical Information of China (English)

    刘伟男; 王汝建; 陈建芳; 程振波; 陈志华; 孙烨忱

    2012-01-01

    通过西北冰洋阿尔法脊B84A孔中—晚第四纪以来的沉积物颜色旋回,Mn、Ca元素相对含量、颜色反射率、有孔虫丰度、冰筏碎屑(IRD)含量、粒度组分及其敏感性分析的综合研究,建立了B84A孔的地层年代框架,其沉积物被划分为MIS 12~MIS 1的沉积序列。阿尔法脊B84A孔可以识别出12个IRD事件,它们大多出现在冰消期,并认为其源区为加拿大北极群岛地区。这些IRD事件反映了加拿大北极冰盖的崩塌和气候变化。阿尔法脊B84A孔沉积物的环境敏感组分分别为细组分(4~9μm)和粗组分(19~53μm),两者的变化趋势相反,主要由海冰和洋流进行搬运,指示了洋流的强度变化。B84A孔的平均沉积速率约为0.4 cm/ka,与阿尔法脊周围地区沉积速率相近。相比于近岸的高沉积速率,其限制因素主要为大面积海冰覆盖造成的较低的生产力和由于长距离搬运造成的较低的陆源输入量。%Terrigenous components in sediment core B84A from the Alpha Ridge,western Arctic Ocean,have been investigated to reconstruct the Mid to Late Quaternary variations in sedimentation,source regions,and related climate changes.The core stratigraphy,evaluated by a combination of variations in Mn content,color cycles,foraminiferal abundance,and lithological correlation,extends back to estimated Marine Isotope Stage(MIS) 12.Twelve ice rafted detritus(IRD,〉250 μm) events were identified and interpreted to mostly occur during the deglacial periods.The Canadian Arctic covered by ice sheets during glacial periods is suggested to be the major source region.The IRD events likely indicate the collapses of ice sheets,possibly in relation to abrupt climate changes.Grain size analysis of B84A indicates sedimentologically sensitive components in core B84A in the silt subfractions 4~9 μm and 19~53 μm,which are inferred to be mainly transported by currents and sea ice

  4. Pan-Arctic modelling of net ecosystem exchange of CO2.

    Science.gov (United States)

    Shaver, G R; Rastetter, E B; Salmon, V; Street, L E; van de Weg, M J; Rocha, A; van Wijk, M T; Williams, M

    2013-08-19

    Net ecosystem exchange (NEE) of C varies greatly among Arctic ecosystems. Here, we show that approximately 75 per cent of this variation can be accounted for in a single regression model that predicts NEE as a function of leaf area index (LAI), air temperature and photosynthetically active radiation (PAR). The model was developed in concert with a survey of the light response of NEE in Arctic and subarctic tundras in Alaska, Greenland, Svalbard and Sweden. Model parametrizations based on data collected in one part of the Arctic can be used to predict NEE in other parts of the Arctic with accuracy similar to that of predictions based on data collected in the same site where NEE is predicted. The principal requirement for the dataset is that it should contain a sufficiently wide range of measurements of NEE at both high and low values of LAI, air temperature and PAR, to properly constrain the estimates of model parameters. Canopy N content can also be substituted for leaf area in predicting NEE, with equal or greater accuracy, but substitution of soil temperature for air temperature does not improve predictions. Overall, the results suggest a remarkable convergence in regulation of NEE in diverse ecosystem types throughout the Arctic.

  5. Deep Arctic Ocean warming during the last glacial cycle

    Science.gov (United States)

    Cronin, T. M.; Dwyer, G.S.; Farmer, J.; Bauch, H.A.; Spielhagen, R.F.; Jakobsson, M.; Nilsson, J.; Briggs, W.M.; Stepanova, A.

    2012-01-01

    In the Arctic Ocean, the cold and relatively fresh water beneath the sea ice is separated from the underlying warmer and saltier Atlantic Layer by a halocline. Ongoing sea ice loss and warming in the Arctic Ocean have demonstrated the instability of the halocline, with implications for further sea ice loss. The stability of the halocline through past climate variations is unclear. Here we estimate intermediate water temperatures over the past 50,000 years from the Mg/Ca and Sr/Ca values of ostracods from 31 Arctic sediment cores. From about 50 to 11 kyr ago, the central Arctic Basin from 1,000 to 2,500 m was occupied by a water mass we call Glacial Arctic Intermediate Water. This water mass was 1–2 °C warmer than modern Arctic Intermediate Water, with temperatures peaking during or just before millennial-scale Heinrich cold events and the Younger Dryas cold interval. We use numerical modelling to show that the intermediate depth warming could result from the expected decrease in the flux of fresh water to the Arctic Ocean during glacial conditions, which would cause the halocline to deepen and push the warm Atlantic Layer into intermediate depths. Although not modelled, the reduced formation of cold, deep waters due to the exposure of the Arctic continental shelf could also contribute to the intermediate depth warming.

  6. High Arctic plant phenology is determined by snowmelt patterns but duration of phenological periods is fixed

    DEFF Research Database (Denmark)

    Semenchuk, Philipp R.; Gillespie, Mark A K; Rumpf, Sabine B.;

    2016-01-01

    The duration of specific periods within a plant's life cycle are critical for plant growth and performance. In the High Arctic, the start of many of these phenological periods is determined by snowmelt date, which may change in a changing climate. It has been suggested that the end of these periods...... controls phenology and phenological period duration in High Arctic Svalbard using a melt timing gradient from natural and experimentally altered snow depths. We investigated the response of early- and late-season phenophases from both vegetative and reproductive phenological periods of eight common species....... We found that all phenophases follow snowmelt patterns, irrespective of timing of occurrence, vegetative or reproductive nature. Three of four phenological period durations based on these phenophases were fixed for most species, defining the studied species as periodic. Periodicity can thus...

  7. Regional variation of sediment load of Asian rivers flowing into the ocean

    Institute of Scientific and Technical Information of China (English)

    刘曙光; 丁坚; 华棣; 杨洪林; 李从先; 杨守业

    2001-01-01

    Study of Asian major rivers discharge to the ocean reveals variations of their water discharges and sediment loads, and local characteristic of river sediment concentrations. On the basis of this, the Asian rivers can be divided into three regions: Eurasia Arctic, East Asia, Southeast and South Asia Region. The Eurasia Arctic Region is characteristic of the lowest sediment concentration and load, while the East Asia Region is of the highest sediment concentration and higher sediment load, and the Southeast and South Asia Region yields higher sediment concentration and highest sediment load.

  8. Remote sensing of aerosols in the Arctic for an evaluation of global climate model simulations.

    Science.gov (United States)

    Glantz, Paul; Bourassa, Adam; Herber, Andreas; Iversen, Trond; Karlsson, Johannes; Kirkevåg, Alf; Maturilli, Marion; Seland, Øyvind; Stebel, Kerstin; Struthers, Hamish; Tesche, Matthias; Thomason, Larry

    2014-07-16

    In this study Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua retrievals of aerosol optical thickness (AOT) at 555 nm are compared to Sun photometer measurements from Svalbard for a period of 9 years. For the 642 daily coincident measurements that were obtained, MODIS AOT generally varies within the predicted uncertainty of the retrieval over ocean (ΔAOT = ±0.03 ± 0.05 · AOT). The results from the remote sensing have been used to examine the accuracy in estimates of aerosol optical properties in the Arctic, generated by global climate models and from in situ measurements at the Zeppelin station, Svalbard. AOT simulated with the Norwegian Earth System Model/Community Atmosphere Model version 4 Oslo global climate model does not reproduce the observed seasonal variability of the Arctic aerosol. The model overestimates clear-sky AOT by nearly a factor of 2 for the background summer season, while tending to underestimate the values in the spring season. Furthermore, large differences in all-sky AOT of up to 1 order of magnitude are found for the Coupled Model Intercomparison Project phase 5 model ensemble for the spring and summer seasons. Large differences between satellite/ground-based remote sensing of AOT and AOT estimated from dry and humidified scattering coefficients are found for the subarctic marine boundary layer in summer.

  9. Disease transmission in an extreme environment: nematode parasites infect reindeer during the Arctic winter.

    Science.gov (United States)

    Carlsson, Anja M; Justin Irvine, R; Wilson, Kenneth; Piertney, Stuart B; Halvorsen, Odd; Coulson, Stephen J; Stien, Audun; Albon, Steve D

    2012-07-01

    Parasitic nematodes are found in almost all wild vertebrate populations but few studies have investigated these host-parasite relationships in the wild. For parasites with free-living stages, the external environment has a major influence on life-history traits, and development and survival is generally low at sub-zero temperatures. For reindeer that inhabit the high Arctic archipelago of Svalbard, parasite transmission is expected to occur in the summer, due to the extreme environmental conditions and the reduced food intake by the host in winter. Here we show experimentally that, contrary to most parasitic nematodes, Marshallagia marshalli of Svalbard reindeer is transmitted during the Arctic winter. Winter transmission was demonstrated by removing parasites in the autumn, using a novel delayed-release anthelmintic bolus, and estimating re-infection rates in reindeer sampled in October, February and April. Larval stages of nematodes were identified using molecular tools, whereas adult stages were identified using microscopy. The abundance of M. marshalli adult worms and L4s increased significantly from October to April, indicating that reindeer were being infected with L3s from the pasture throughout the winter. To our knowledge, this study is the first to experimentally demonstrate over-winter transmission of a gastro-intestinal nematode parasite in a wild animal. Potential mechanisms associated with this unusual transmission strategy are discussed in light of our knowledge of the life-history traits of this parasite.

  10. An imaging interferometry capability for the EISCAT Svalbard Radar

    Directory of Open Access Journals (Sweden)

    T. Grydeland

    2005-01-01

    Full Text Available Interferometric imaging (aperture synthesis imaging is a technique used by radio astronomers to achieve angular resolution that far surpasses what is possible with a single large aperture. A similar technique has been used for radar imaging studies of equatorial ionospheric phenomena at the Jicamarca Radio Observatory. We present plans for adding an interferometric imaging capability to the EISCAT Svalbard Radar (ESR, a capability which will contribute significantly to several areas of active research, including naturally and artificially enhanced ion-acoustic echoes and their detailed relation in space and time to optical phenomena, polar mesospheric summer echoes (PMSE, and meteor studies.

    Interferometry using the two antennas of the ESR has demonstrated the existence of extremely narrow, field-aligned scattering structures, but having only a single baseline is a severe limitation for such studies. Building additional IS-class antennas at the ESR is not a trivial task. However, the very high scattering levels in enhanced ion-acoustic echoes and PMSE means that a passive receiver antenna of more modest gain should still be capable of detecting these echoes.

    In this paper we present simulations of what an imaging interferometer will be capable of observing for different antenna configurations and brightness distributions, under ideal conditions, using two different image inversion algorithms. We also discuss different antenna and receiver technologies.

  11. Surge dynamics in the Nathorstbreen glacier system, Svalbard

    Directory of Open Access Journals (Sweden)

    M. Sund

    2013-10-01

    Full Text Available Nathorstbreen glacier system (NGS recently experienced the largest surge in Svalbard since 1936, and is examined using spatial and temporal observations from DEM differencing, time-series of surface velocities from satellite synthetic aperture radar (SAR and other sources. The upper basins with maximum accumulation during quiescence correspond to regions of initial lowering. Initial speed-up exceeds quiescent velocities by a factor of several tens of times. This suggests that polythermal glaciers surges are initiated in the temperate area before mass is displaced downglacier. Subsequent downglacier mass displacement coincides with areas of 100–200 times increased velocities (stage 2. After > 5 yr the joint NGS terminus advanced abruptly into tidewater during winter. The advance was followed by upglacier propagation of crevasses, indicating a re-action following from the already displaced mass and extending flow. NGS advanced ca. 15 km, while another ca. 3 km length was lost due to calving. Surface lowering of ca. 50 m was observed in some upglacier areas and during 5 yr the total area increased by 20%. Maximum measured flow rates were at least 25 m d−1, 2500 times quiescence, while average velocities were about 10 m d−1. The surges of Zawadzkibreen cycle with ca. 70 yr periods.

  12. Diversity and distribution of Tardigrada in Arctic cryoconite holes

    Directory of Open Access Journals (Sweden)

    Krzysztof Zawierucha

    2016-06-01

    Full Text Available Despite the fact that glaciers and ice sheets have been monitored for more than a century, knowledge on the glacial biota remains poor. Cryoconite holes are water-filled reservoirs on a glacier’s surface and one of the most extreme ecosystems for micro-invertebrates. Tardigrada, also known as water bears, are a common inhabitant of cryoconite holes. In this paper we present novel data on the morphology, diversity, distribution and role in food web of tardigrades on Arctic glaciers. From 33 sampled cryoconite holes of 6 glaciers on Spitsbergen, in 25 tardigrades were found and identified. Five taxa of Tardigrada (Eutardigrada were found in the samples, they are: Hypsibius dujardini, Hypsibius sp. A, Isohypsibius sp. A., Pilatobius recamieri, and one species of Ramazzottiidae. H. dujardini and P. recamieri were previously known from tundra in the Svalbard archipelago. Despite the number of studies on Arctic tundra ecosystems, Hypsibius sp. A, one species of Ramazzottiidae and Isohypsibius sp. A are known only from cryoconite holes. Tardigrade found in this study do not falsify the hypothesis that glaciers and ice sheets are a viable biome (characteristic for biome organisms assemblages - tardigrades. Diagnosis of Hypsibius sp. A, Isohypsibius sp. A, and species of Ramazzottiidae with discussion on the status of taxa, is provided. To check what analytes are associated with the presence of tardigrades in High Arctic glacier chemical analyses were carried out on samples taken from the Buchan Glacier. pH values and the chemical composition of anions and cations from cryoconite hole water from the Buchan Glacier are also presented. The current study on the Spitsbergen glaciers clearly indicates that tardigrade species richness in cryoconite holes is lower than tardigrade species richness in Arctic tundra ecosystems, but consists of unique cryoconite hole species. As cryoconite tardigrades may feed on bacteria as well as algae, they are primary

  13. Late Cretaceous seasonal ocean variability from the Arctic.

    Science.gov (United States)

    Davies, Andrew; Kemp, Alan E S; Pike, Jennifer

    2009-07-09

    The modern Arctic Ocean is regarded as a barometer of global change and amplifier of global warming and therefore records of past Arctic change are critical for palaeoclimate reconstruction. Little is known of the state of the Arctic Ocean in the greenhouse period of the Late Cretaceous epoch (65-99 million years ago), yet records from such times may yield important clues to Arctic Ocean behaviour in near-future warmer climates. Here we present a seasonally resolved Cretaceous sedimentary record from the Alpha ridge of the Arctic Ocean. This palaeo-sediment trap provides new insight into the workings of the Cretaceous marine biological carbon pump. Seasonal primary production was dominated by diatom algae but was not related to upwelling as was previously hypothesized. Rather, production occurred within a stratified water column, involving specially adapted species in blooms resembling those of the modern North Pacific subtropical gyre, or those indicated for the Mediterranean sapropels. With increased CO(2) levels and warming currently driving increased stratification in the global ocean, this style of production that is adapted to stratification may become more widespread. Our evidence for seasonal diatom production and flux testify to an ice-free summer, but thin accumulations of terrigenous sediment within the diatom ooze are consistent with the presence of intermittent sea ice in the winter, supporting a wide body of evidence for low temperatures in the Late Cretaceous Arctic Ocean, rather than recent suggestions of a 15 degrees C mean annual temperature at this time.

  14. Brief communication: ikaite (CaCO3*6H2O discovered in Arctic sea ice

    Directory of Open Access Journals (Sweden)

    M. A. Granskog

    2010-02-01

    Full Text Available We report for the first time on the discovery of calcium carbonate crystals as ikaite (CaCO3*6H2O in sea ice from the Arctic (Kongsfjorden, Svalbard. This finding demonstrates that the precipitation of calcium carbonate during the freezing of sea ice is not restricted to the Antarctic, where it was observed for the first time in 2008. This finding is an important step in the quest to quantify its impact on the sea ice driven carbon cycle and should in the future enable improvement parametrization sea ice carbon models.

  15. Arctic wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Peltola, E. [Kemijoki Oy (Finland); Holttinen, H.; Marjaniemi, M. [VTT Energy, Espoo (Finland); Tammelin, B. [Finnish Meteorological Institute, Helsinki (Finland)

    1998-12-31

    Arctic wind energy research was aimed at adapting existing wind technologies to suit the arctic climatic conditions in Lapland. Project research work included meteorological measurements, instrument development, development of a blade heating system for wind turbines, load measurements and modelling of ice induced loads on wind turbines, together with the development of operation and maintenance practices in arctic conditions. As a result the basis now exists for technically feasible and economically viable wind energy production in Lapland. New and marketable products, such as blade heating systems for wind turbines and meteorological sensors for arctic conditions, with substantial export potential, have also been developed. (orig.)

  16. Arctic tipping points

    OpenAIRE

    Smolkova, Valentina

    2015-01-01

    The Arctic is warming much faster than the entire planet, and this causes severe melting of sea ice. However, the climate of different regions of the Earth is interconnected, and changes in the amount of ice in the Arctic can dramatically affect the climate across the whole planet. Some scientists claim that a possible tipping point is the event of the ice-free Arctic Ocean in summer. Certain predictions point towards ice-free Arctic summers around the year 2050, whereas others pre- dict this...

  17. Results from Three Years of Ka-Band Propagation Characterization at Svalbard, Norway

    Science.gov (United States)

    Nessel, James; Zemba, Michael; Morse, Jacquelynne

    2015-01-01

    Over the next several years, NASA plans to launch several earth science missions which are expected to achieve data throughputs of 5-40 terabits per day transmitted from low earth orbiting spacecraft to ground stations. The current S-band and X-band frequency allocations in use by NASA, however, are incapable of supporting the data rates required to meet this demand. As such, NASA is in the planning stages to upgrade its existing Near Earth Network (NEN) polar ground stations to support Ka-band (25.5-27 GHz) operations. Consequently, it installed and operated a Ka-band radiometer at the Svalbard site. Svalbard was chosen as the appropriate site for two primary reasons: (1) Svalbard will be the first site to be upgraded to Ka-band operations within the NEN Polar Network enhancement plan, and (2) there exists a complete lack of Ka-band propagation data at this site (as opposed to the Fairbanks, AK NEN site, which has 5 years of characterization collected during the Advanced Communications Technology becomes imperative that characterization of propagation effects at these NEN sites is conducted to determine expected system Satellite (ACTS) campaign). processing and provide the Herein, we discuss the data three-year measurement results performance, particularly at low elevation angles ((is) less than 10 deg) from the ongoing Ka-band propagation characterization where spacecraft signal acquisition typically occurs. Since May 2011, NASA Glenn Research Center has installed and operated a Ka-band radiometer at the NEN site located in Svalbard, Norway. The Ka-band radiometer monitors the water vapor line, as well as 4 frequencies around 26.5 GHz at a fixed 10 deg elevation angle. Three-year data collection results indicate good campaign at Svalbard, Norway. Comparison of these results with the ITU models and existing ERA profile data indicates very good agreement when the 2010 rain maps and cloud statistics are used. Finally, the Svalbard data is used to derive the expected

  18. Proposal for a Joint NASA/KSAT Ka-band RF Propagation Terminal at Svalbard, Norway

    Science.gov (United States)

    Volosin, Jeffrey; Acosta, Roberto; Nessel, James; McCarthy, Kevin; Caroglanian, Armen

    2010-01-01

    This slide presentation discusses the placement of a Ka-band RF Propagation Terminal at Svalbard, Norway. The Near Earth Network (NEN) station would be managed by Kongsberg Satellite Services (KSAT) and would benefit NASA and KSAT. There are details of the proposed NASA/KSAT campaign, and the responsibilities each would agree to. There are several reasons for the placement, a primary reason is comparison with the Alaska site, Based on climatological similarities/differences with Alaska, Svalbard site expected to have good radiometer/beacon agreement approximately 99% of time.

  19. Novel and Unexpected Microbial Diversity in Acid Mine Drainage in Svalbard (78° N, Revealed by Culture-Independent Approaches

    Directory of Open Access Journals (Sweden)

    Antonio García-Moyano

    2015-10-01

    Full Text Available Svalbard, situated in the high Arctic, is an important past and present coal mining area. Dozens of abandoned waste rock piles can be found in the proximity of Longyearbyen. This environment offers a unique opportunity for studying the biological control over the weathering of sulphide rocks at low temperatures. Although the extension and impact of acid mine drainage (AMD in this area is known, the native microbial communities involved in this process are still scarcely studied and uncharacterized. Several abandoned mining areas were explored in the search for active AMD and a culture-independent approach was applied with samples from two different runoffs for the identification and quantification of the native microbial communities. The results obtained revealed two distinct microbial communities. One of the runoffs was more extreme with regards to pH and higher concentration of soluble iron and heavy metals. These conditions favored the development of algal-dominated microbial mats. Typical AMD microorganisms related to known iron-oxidizing bacteria (Acidithiobacillus ferrivorans, Acidobacteria and Actinobacteria dominated the bacterial community although some unexpected populations related to Chloroflexi were also significant. No microbial mats were found in the second area. The geochemistry here showed less extreme drainage, most likely in direct contact with the ore under the waste pile. Large deposits of secondary minerals were found and the presence of iron stalks was revealed by microscopy analysis. Although typical AMD microorganisms were also detected here, the microbial community was dominated by other populations, some of them new to this type of system (Saccharibacteria, Gallionellaceae. These were absent or lowered in numbers the farther from the spring source and they could represent native populations involved in the oxidation of sulphide rocks within the waste rock pile. This environment appears thus as a highly interesting

  20. Detection of Vehicle Tracks and Vegetation Damages Caused by use of Snowmobiles in the Longyearbyen Area on Svalbard using Unmanned Aircraft

    Science.gov (United States)

    Storvold, R.; Karlsen, S. R.; Solbø, S. A.; Johansen, B.; Johansen, K.; Høgda, K. A.; Tømmervik, H.; Zmarz, A.; Joly, D.

    2013-12-01

    The study area in the surroundings of Longyearbyen on Svalbard, Arctic Norway, located at 71.2°N and 16°E is characterized by dry Arctic climate with a snow season of more than eight months, annual precipitation of less than 200mm, and a mean July temperature of about 6°C. Longyearbyen is the main settlement on Svalbard, with about 2000 inhabitants. During the last two decades the number of snowmobiles have increased from a few hundred to a number almost equals the number of inhabitants, and snowmobile trips are today the one of the main leisure activities. In addition, thousands of tourist visits every spring, and many of these go on organized snowmobile trips. Due to the often thin snow cover, and use of snowmobile even during the spring snow melt in May and early June, the rapid growth in use of snowmobile has made some damage to the vegetation. Damage on the fragile vegetation caused by the skids and belts of the snowmobile can be observed in most parts of the Adventdalen valley, close to Longyearbyen. The main aim of this study is to explore the feasibility and accuracy of using data from Unmanned Aircraft Systems (UAS) to identify vehicle tracks and damages on vegetation caused by the use of snowmobiles. Use of UAS give the opportunity to carry out research in a manner that minimizes the environmental footprint of the research activities. Small unmanned aircraft, combining both fixed wing multi rotor types allow us to collect image data for vegetation mapping without having any personnel walking into the field disturbing the sensitive High Arctic ecosystems. UAS used here are inexpensive and simple to operate. They are being developed with the goal of providing airborne capabilities for scientists at an affordable cost. The aircraft were instrumented with a normal Canon Powershot S100 RGB compact camera and a modified Canon Powershot SX230 NDVI camera. The fixed wing aircraft was taking pictures from 100 meters altitude with ground resolution of 2.5 cm

  1. White Arctic vs. Blue Arctic: Making Choices

    Science.gov (United States)

    Pfirman, S. L.; Newton, R.; Schlosser, P.; Pomerance, R.; Tremblay, B.; Murray, M. S.; Gerrard, M.

    2015-12-01

    As the Arctic warms and shifts from icy white to watery blue and resource-rich, tension is arising between the desire to restore and sustain an ice-covered Arctic and stakeholder communities that hope to benefit from an open Arctic Ocean. If emissions of greenhouse gases to the atmosphere continue on their present trend, most of the summer sea ice cover is projected to be gone by mid-century, i.e., by the time that few if any interventions could be in place to restore it. There are many local as well as global reasons for ice restoration, including for example, preserving the Arctic's reflectivity, sustaining critical habitat, and maintaining cultural traditions. However, due to challenges in implementing interventions, it may take decades before summer sea ice would begin to return. This means that future generations would be faced with bringing sea ice back into regions where they have not experienced it before. While there is likely to be interest in taking action to restore ice for the local, regional, and global services it provides, there is also interest in the economic advancement that open access brings. Dealing with these emerging issues and new combinations of stakeholders needs new approaches - yet environmental change in the Arctic is proceeding quickly and will force the issues sooner rather than later. In this contribution we examine challenges, opportunities, and responsibilities related to exploring options for restoring Arctic sea ice and potential pathways for their implementation. Negotiating responses involves international strategic considerations including security and governance, meaning that along with local communities, state decision-makers, and commercial interests, national governments will have to play central roles. While these issues are currently playing out in the Arctic, similar tensions are also emerging in other regions.

  2. Application of a minimal glacier model to Hansbreen, Svalbard

    Directory of Open Access Journals (Sweden)

    J. Oerlemans

    2011-01-01

    Full Text Available Hansbreen is a well studied tidewater glacier in the southwestern part of Svalbard, currently about 16 km long. Since the end of the 19th century it has been retreating over a distance of 2.7 km. In this paper the global dynamics of Hansbreen are studied with a minimal glacier model, in which the ice mechanics are strongly parameterised and a simple law for iceberg calving is used. The model is calibrated by reconstructing a climate history in such a way that observed and simulated glacier length match. In addition, the calving law is tuned to reproduce the observed mean calving flux for the period 2000–2008.

    Equilibrium states are studied for a wide range of values of the equilibrium line altitude. The dynamics of the glacier are strongly nonlinear. The height-mass balance feedback and the water depth-calving flux feedback give rise to cusp catastrophes in the system.

    For the present climatic conditions Hansbreen cannot survive. Depending on the imposed climate change scenario, in AD 2100 Hansbreen is predicted to have a length between 10 and 12 km. The corresponding decrease in ice volume (relative to the volume in AD 2000 is 45 to 65%.

    Finally the late-Holocene history of Hansbreen is considered. We quote evidence from dated peat samples that Hansbreen did not exist during the Holocene Climatic Optimum. We speculate that at the end of the mid-Holocene Climatic Optimum Hansbreen could advance because the glacier bed was at least 50 m higher than today, and because the tributary glaciers on the western side may have supplied a significant amount of mass to the main stream. The excavation of the overdeepening and the formation of the shoal at the glacier terminus probably took place during the Little Ice Age.

  3. Slow recovery of High Arctic heath communities from nitrogen enrichment.

    Science.gov (United States)

    Street, Lorna E; Burns, Nancy R; Woodin, Sarah J

    2015-04-01

    Arctic ecosystems are strongly nutrient limited and exhibit dramatic responses to nitrogen (N) enrichment, the reversibility of which is unknown. This study uniquely assesses the potential for tundra heath to recover from N deposition and the influence of phosphorus (P) availability on recovery. We revisited an experiment in Svalbard, established in 1991, in which N was applied at rates representing atmospheric N deposition in Europe (10 and 50 kg N ha(-1)  yr(-1) ; 'low' and 'high', respectively) for 3-8 yr. We investigated whether significant effects on vegetation composition and ecosystem nutrient status persisted up to 18 yr post-treatment. Although the tundra heath is no longer N saturated, N treatment effects persist and are strongly P-dependent. Vegetation was more resilient to N where no P was added, although shrub cover is still reduced in low-N plots. Where P was also added (5 kg P ha(-1)  yr(-1) ), there are still effects of low N on community composition and nutrient dynamics. High N, with and without P, has many lasting impacts. Importantly, N + P has caused dramatically increased moss abundance, which influences nutrient dynamics. Our key finding is that Arctic ecosystems are slow to recover from even small N inputs, particularly where P is not limiting.

  4. On large outflows of Arctic sea ice into the Barents Sea

    Science.gov (United States)

    Kwok, Ron; Maslowski, Wieslaw; Laxon, Seymour W.

    2005-01-01

    Winter outflows of Arctic sea ice into the Barents Sea are estimated using a 10-year record of satellite ice motion and thickness. The mean winter volume export through the Svalbard/Franz Josef Land passage is 40 km3, and ranges from -280 km3 to 340 km3. A large outflow in 2003 is preconditioned by an unusually high concentration of thick perennial ice over the Nansen Basin at the end of the 2002 summer. With a deep atmospheric low situated over the eastern Barents Sea in winter, the result is an increased export of Arctic ice. The Oct-Mar ice area flux, at 110 x 10 to the third power km3, is not only unusual in magnitude but also remarkable in that >70% of the area is multiyear ice; the ice volume flux at340 km3 is almost one-fifth of the ice flux through the Fram Strait. Another large outflow of Arctic sea ice through this passage, comparable to that in 2003, is found in 1996. This southward flux of sea ice represents one of two major sources of freshwater in the Barents Sea; the other is the eastward flux of water via the Norwegian Coastal Current. The possible consequences of variable freshwater input on the Barents Sea hydrography and its impact on transformation of Atlantic Water en route to the Arctic Ocean are examined with a 25-year coupled ice-ocean model.

  5. Predictions replaced by facts: a keystone species' behavioural responses to declining arctic sea-ice.

    Science.gov (United States)

    Hamilton, Charmain D; Lydersen, Christian; Ims, Rolf A; Kovacs, Kit M

    2015-11-01

    Since the first documentation of climate-warming induced declines in arctic sea-ice, predictions have been made regarding the expected negative consequences for endemic marine mammals. But, several decades later, little hard evidence exists regarding the responses of these animals to the ongoing environmental changes. Herein, we report the first empirical evidence of a dramatic shift in movement patterns and foraging behaviour of the arctic endemic ringed seal (Pusa hispida), before and after a major collapse in sea-ice in Svalbard, Norway. Among other changes to the ice-regime, this collapse shifted the summer position of the marginal ice zone from over the continental shelf, northward to the deep Arctic Ocean Basin. Following this change, which is thought to be a 'tipping point', subadult ringed seals swam greater distances, showed less area-restricted search behaviour, dived for longer periods, exhibited shorter surface intervals, rested less on sea-ice and did less diving directly beneath the ice during post-moulting foraging excursions. In combination, these behavioural changes suggest increased foraging effort and thus also likely increases in the energetic costs of finding food. Continued declines in sea-ice are likely to result in distributional changes, range reductions and population declines in this keystone arctic species.

  6. Ice-Free Arctic Ocean?

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    The current warming trends in the Arctic may shove the Arctic system into a seasonally ice-free state not seen for more than one million years, according to a new report. The melting is accelerating, and researchers were unable to identify any natural processes that might slow the deicing of the Arctic. "What really makes the Arctic different…

  7. Arctic Sea Level Reconstruction

    DEFF Research Database (Denmark)

    Svendsen, Peter Limkilde

    method.For oceanographic purposes, the altimetric record over the Arctic Ocean is inferiorin quality to that of moderate latitudes, but nonetheless an invaluable set of observations. During this project, newly processed Arctic altimetry from the ERS-1/-2 and Envisat missions has become available......Reconstruction of historical Arctic sea level is very difficult due to the limited coverage and quality of tide gauge and altimetry data in the area. This thesis addresses many of these issues, and discusses strategies to help achieve a stable and plausible reconstruction of Arctic sea level from...... 1950 to today.The primary record of historical sea level, on the order of several decades to a few centuries, is tide gauges. Tide gauge records from around the world are collected in the Permanent Service for Mean Sea Level (PSMSL) database, and includes data along the Arctic coasts. A reasonable...

  8. The Caledonian suture in the high Arctic? New data from the Chukchi Borderland, Amerasia Basin

    Science.gov (United States)

    O'Brien, T.; Brumley, K. J.; Miller, E. L.; Mayer, L. A.

    2013-12-01

    The Chukchi Borderland (CB) is a bathymetric high in the Arctic Ocean that is extended by N