Now showing items 36-55 of 698

    • Baseline undersøkelse av studiekvalitet og undervisningskultur på Institutt for geovitenskap ved UiT Norges arktiske universitet 

      Martens, Iver; Malm, Rie Hjørnegaard (Research report; Forskningsrapport, 2019-04)
      Institutt for geovitenskap ved UiT Norges arktiske universitet ønsker å gjøre en innsats for å forbedre undervisningen ved instituttet. Instituttet tilbyr utdanninger på bachelor-, master- og doktorgradsnivå, med 12 bachelorkurs, 28 masterkurs og 9 kurs på doktorgradsnivå. Dette prosjektet fokuserer på undervisningskvaliteten på bachelor- og master utdanningen. Vi håper rapporten kan bidra til ...
    • BedMachine v3: Complete bed topography and ocean bathymetry mapping of Greenland from multi-beam echo sounding combined with mass conservation 

      Morlighem, Mathieu; Williams, Chris N.; Rignot, Eric J.M.; An, Lu; Arndt, Jan Erik; Bamber, Jonathan L.; Catania, Ginny A.; Chauché, Nolwenn; Dowdeswell, Julian A.; Dorschel, Boris; Fenty, Ian; Hogan, Kelly A.; Howat, Ian M.; Hubbard, Alun Lloyd; Jakobsson, Martin; Jordan, Thomas M.; Kjeldsen, Kristian Kjellerup; Millan, Romain; Mayer, Larry; Mouginot, Jérémie; Noël, Brice P.Y.; O'Cofaigh, Colm; Palmer, Steven; Rysgaard, Søren; Seroussi, Hélène; Siegert, Martin J.; Slabon, Patricia; Straneo, Fiamma; van den Broeke, Michiel R.; Weinrebe, Wilhelm Reimer; Wood, Michael; Zinglersen, Karl Brix (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-09-18)
      Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts and undercuts Greenland's marine‐terminating glaciers. Here we present a new compilation of Greenland bed topography that assimilates seafloor bathymetry and ice thickness ...
    • Benthic foraminifera as bio-indicators of chemical and physical stressors in Hammerfest harbor (Northern Norway) 

      Dijkstra, Noortje; Junttila, Juho; Skirbekk, Kari; Carroll, JoLynn; Husum, Katrine; Hald, Morten (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-01)
      We investigated benthic foraminiferal assemblages in contaminated sediments in a subarctic harbor of northern Norway to assess their utility as indicators of anthropogenic impacts. Sediments in the harbor are repositories for POPs and heavy metals supplied through discharges from industry and shipping activities. Sediment contaminant concentrations are at moderate to poor ecological quality ...
    • Benthic Foraminifera in Arctic Methane Hydrate Bearing Sediments 

      Dessandier, Pierre-Antoine; Borrelli, Chiara; Kalenitchenko, Dimitri; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-10)
      Benthic foraminifera have been widely used as proxy for paleo-methane emissions, mainly based on their stable isotopic signature. In cold seeps, the ecology of these organisms remains uncertain, in particular their ability to thrive during active phases of seepage. In this study, we evaluate the benthic foraminiferal response to methane seepage in Arctic sediments. We do so by examining living and ...
    • Benthic foraminiferal assemblages and environmental drivers along the Kveithola Trough (NW Barents Sea) 

      Caridi, Francesca; Sabbatini, Anna; Bensi, Manuel; Kovačević, Vedrana; Lucchi, Renata Giulia; Morigi, Caterina; Povea, Patricia; Negri, Alessandra (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-14)
      We describe the population density, biodiversity and vertical distribution in the sediment of benthic foraminifera, and their relationship to environmental parameters, in the Kveithola Trough (NW Barents Sea). Two staining methods, Cell Tracker Green (CTG) and Rose Bengal (RB), were used to distinguish between living and dead tests. CTG proved to be more effective than RB, and we therefore used this ...
    • Benthic foraminiferal growth seasons implied from Mg/Ca-temperature correlations for three Arctic species 

      Skirbekk, Kari; Hald, Morten; Thomas Jr., Marchitto; Junttila, Juho; Klitgaard Kristensen, Dorthe; Sørensen, Steffen Aagaard (Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-11-22)
      Core-top sediment samples from Kongsfjorden, Svalbard, and adjacent fjord and shelf areas were collected in order to investigate a potential relationship between Mg/Ca-ratios of Arctic benthic foraminifera and the ambient bottom water temperatures (BWT). The area is influenced by large seasonal variation in factors such as light and temperature, which is further strengthened by oceanographic shifts, ...
    • Benthic foraminiferal investigations in Middle to Late Quaternary sections of Kongsfjordhallet, north-west Svalbard 

      Chatterjee, Debolina; Ghosh, Anupam; Alexanderson, Helena (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-29)
      Stratigraphic sites in north-west Svalbard record at least six significant glacial advances in the last 200 Ky, and sediments deposited under locally high relative sea level during intervening interstadials or interglacials contain abundant benthic foraminifera. We present a biostratigraphic record from the Kongsfjordhallet site in the Kongsfjorden area that covers five high relative sea-level events ...
    • The benthic foraminiferal δ34S records fux and timing of paleo methane emissions 

      Borrelli, Chiara; Gabitov, R.I.; Liu, M.-C.; Hertwig, A.T.; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-28)
      In modern environments, pore water geochemistry and modelling simulations allow the study of methane (CH<sub>4</sub>) sources and sinks at any geographic location. However, reconstructing CH<sub>4</sub> dynamics in geological records is challenging. Here, we show that the benthic foraminiferal δ<sup>34</sup>S can be used to reconstruct the fux (i.e., difusive vs. advective) and timing of CH<sub>4</sub> ...
    • The Billefjorden Fault Zone north of Spitsbergen: a major terrane boundary? 

      Koehl, Jean-Baptiste P.; Allaart, Lis (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-13)
      The Billefjorden Fault Zone is a major terrane boundary in the Norwegian Arctic. The fault separates basement rocks of Svalbard’s north-eastern and north-western terranes that recorded discrete Precambrian tectonothermal histories and were accreted, intensely deformed and metamorphosed during the Caledonian Orogeny. Although the fault represents a major, crustal-scale tectonic boundary, its north-ward ...
    • Biocryomorphology: integrating microbial processes with ice surface hydrology, topography and roughness 

      Cook, J.; Edwards, A.; Hubbard, Alun Lloyd (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-02)
    • Biogeochemical Consequences of Nonvertical Methane Transport in Sediment Offshore Northwestern Svalbard 

      Treude, Tina; Krause, Stefan; Steinle, Lea; Burwicz, Ewa B.; Hamdan, L.J.; Niemann, Helge; Feseker, Tomas; Liebetrau, Volker; Krastel, Sebastian; Berndt, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-21)
      A site at the gas hydrate stability limit was investigated offshore northwestern Svalbard to study methane transport in sediment. The site was characterized by chemosynthetic communities (sulfur bacteria mats, tubeworms) and gas venting. Sediments were sampled with in situ porewater collectors and by gravity coring followed by analyses of porewater constituents, sediment and carbonate geochemistry, ...
    • Biogeochemical evidence of anaerobic methane oxidation on active submarine mud volcanoes on the continental slope of the Canadian Beaufort Sea 

      Lee, Dong-Hun; Kim, Jung-Hyun; Lee, Yung Mi; Stadnitskaia, Alina; Jin, Young Keun; Niemann, Helge; Kim, Young-Gyun; Shin, Kyung-Hoon (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-12-20)
      In this study, we report lipid biomarker patterns and phylogenetic identities of key microbial communities mediating anaerobic oxidation of methane (AOM) in active mud volcanoes (MVs) on the continental slope of the Canadian Beaufort Sea. The carbon isotopic compositions (δ13C) of sn-2- and sn-3-hydroxyarchaeol showed the highly 13C-depleted values (−114 ‰ to −82 ‰) associated with a steep depletion ...
    • Biogeochemical investigations of methane seepage at the ultraslow-spreading Arctic mid-ocean ridge: Svyatogor ridge, Fram Strait 

      Argentino, Claudio; Borrelli, Chiara; Akinselure, Abidemi; Correa-Diaz, Melyssa; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2024-02-13)
      The Arctic continental shelves are important reservoirs of methane stored in gas hydrates and deeper geological formations. However, little is known about methane dynamics in deeper oceanic settings such as mid-ocean ridges, mainly due to operational challenges related to their remoteness. This study investigates a recently discovered methane seepage environment at Svyatogor Ridge, a sediment-covered ...
    • Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea 

      Argentino, Claudio; Lee, Amicia; Fallati, Luca; Sahy, Diana; Birgel, Daniel; Peckmann, Jörn; Bünz, Stefan; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-10-25)
      The origin of modern seafloor methane emissions in the Barents Sea is tightly connected to the glacio-tectonic and oceanographic transformations following the last ice age. Those regional events induced geological structure re-activation and destabilization of gas hydrate reservoirs over large areas of the European continental margins, sustaining widespread fluid plumbing systems. Despite the ...
    • Biomarker and isotopic composition of seep carbonates record environmental conditions in two Arctic methane seeps 

      Yao, Haoyi; Panieri, Giuliana; Lehmann, Moritz F; Himmler, Tobias; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-12)
      Present-day activity of cold-seeps in the ocean is evident from direct observations of methane emanating from the seafloor, the presence of chemosynthetic organisms, or the quantification of gas concentrations in the water column and pore water solutes. Verifying past cold seep activity and biogeochemical characteristics is more challenging but may be reconstructed from proxy records of authigenic ...
    • Bivalve beds reveal rapid changes in ocean oxygenation in the Boreal Middle Triassic – a case study from Svalbard, Norway 

      Engelschiøn, Victoria Sjøholt; Bernhardsen, Sofie; Wesenlund, Fredrik; Hammer, Øyvind; Hurum, Jørn Harald; Mørk, Atle (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-17)
      A fossil-rich interval in the organic-rich marine black mudstone of the Middle Triassic Botneheia Formation on eastern Svalbard was logged in high-resolution on an extremely well exposed section with emphasis on bivalve beds, taphonomic features, trace fossils and oxygenation proxies. The size distribution, fragmentation, articulation and orientation of three bivalve beds of the epifaunal flat ...
    • Bivalve shell horizons in seafloor pockmarks of the last glacial-interglacial transition suggest a thousand years of methane emissions in the Arctic Ocean 

      Ambrose, William; Panieri, Giuliana; Schneider, Andrea; Plaza-Faverola, Andreia; Carroll, Michael Leslie; Åström, Emmelie; Locke, W.L.; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-05)
      We studied discrete bivalve shell horizons in two gravity cores from seafloor pockmarks on the Vestnesa Ridge (1200 m water depth) and western Svalbard (798000 N, 068550 W) to provide insight into the temporal and spatial dynamics of seabed methane seeps. The shell beds, dominated by two genera of the family Vesicomyidae: Phreagena s.l. and Isorropodon sp., were 20–30 cm thick and centered at ...
    • Bottom water acidification and warming on the western Eurasian Arctic shelves: Dynamical downscaling projections 

      Wallhead, P. J.; Bellerby, R.G.J.; Silyakova, A.; Slagstad, D.; Polukhin, A. A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-25)
      The impacts of oceanic CO2 uptake and global warming on the surface ocean environment have received substantial attention, but few studies have focused on shelf bottom water, despite its importance as habitat for benthic organisms and demersal fisheries such as cod. We used a downscaling ocean biogeochemical model to project bottom water acidification and warming on the western Eurasian Arctic ...
    • Bottom-simulating reflector dynamics at Arctic thermogenic gas provinces: An example from Vestnesa Ridge, offshore west Svalbard 

      Plaza-Faverola, Andreia; Vadakkepuliyambatta, Sunil; Hong, Wei-Li; Mienert, Jurgen; Bünz, Stefan; Chand, Shyam; Greinert, Jens (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06)
    • Brine formation in relation to climate changes and ice retreat during the last 15,000 years in Storfjorden, Svalbard, 76–78°N 

      Rasmussen, Tine Lander; Thomsen, Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-10-06)
      Storfjorden, Svalbard, is an area of intense brine formation. The brine is cold, dense, rich in oxygen and CO2, and has reduced pH. Storfjorden is unique because it contains well-preserved agglutinated foraminifera dating back to the beginning of the last deglaciation. We have investigated the distribution of calcareous and agglutinated benthic foraminifera, benthic oxygen and carbon isotopes, ...