Now showing items 481-500 of 1012

    • A High-Resolution Geomagnetic Relative Paleointensity Record From the Arctic Ocean Deep-Water Gateway Deposits During the Last 60 kyr 

      Caricchi, Chiara; Lucchi, Renata Giulia; Sagnotti, Leonardo; Macri, Patrizia; Di Roberto, Alessio; Del Carlo, Paola; Husum, Katrine; Laberg, Jan Sverre; Morigi, Caterina (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-16)
      We present a paleomagnetic and rock magnetic data set from two long sediment cores collected from Bellsund and Isfjorden contourite drifts located on the eastern side of the Fram Strait (western Spitsbergen margin). The data set gave the opportunity to define the behavior of the past geomagnetic field at high latitude and to constrain the palaeoclimatic events that occurred in a time framework ...
    • Cenozoic Erosion of the Barents Sea Shelf, Norwegian Arctic: A Review 

      Lasabuda, Amando Putra Ersaid; Laberg, Jan Sverre; Knutsen, Stig-Morten; Rydningen, Tom Arne (Conference object; Konferansebidrag, 2018-12)
      The circum North Atlantic-Arctic continental margin and adjacent land areas have experienced several episodes of uplift and erosion during the Cenozoic. A series of efforts quantifying this erosion for the Barents Sea shelf, where the Arctic shelf is at its widest and deepest have been done since the early 90’s using different methods. As the seismic and well database have expanded considerably, ...
    • Chemosynthesis influences food web and community structure in high-Arctic benthos 

      Åström, Emmelie; Carroll, Michael; Sen, Arunima; Niemann, Helge; Ambrose Jr., William G.; Lehmann, Moritz F; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-25)
      Cold seeps are locations where seafloor communities are influenced by the seepage of methane and other reduced compounds from the seabed. We examined macro-infaunal benthos through community analysis and trophic structure using stable isotope analysis at 3 seep locations in the Barents Sea. These seeps were characterized by high densities of the chemosymbiotic polychaetes Siboglinidae, clade Frenulata ...
    • Meter-Scale 3D Seismic Data for High-Resolution Site Characterization 

      Lebedeva-Ivanova, Nina; Polteau, Stephane; Zastrozhnov, Dmitry; Planke, Sverre; Waage, Malin; Bünz, Stefan; Bellwald, Benjamin; Vanneste, Maarten; Sauvin, Guillaume; Myklebust, R. (Conference object; Konferansebidrag, 2019-06-03)
      High-resolution 3D site characterization can deliver reliable quantitative property volumes of the subsurface when based on seismic data able to image meter-sized objects. Following the theoretical analysis of seismic wave propagation in the shallow sub-surface, we present case studies based on re-processing of 3D P-Cable seismic data. The case study of data re-processing from the Vestnesa Ridge ...
    • Devonian core complex exhumation and Cenozoic decollements as alternatives to the Ellesmerian Orogeny 

      Koehl, Jean-Baptiste P. (Conference object; Konferansebidrag, 2018-10)
      The Ellesmerian Orogeny (Piepjohn et al., 2000) is a short-lived contractional–transpressional event that occurred in the Late Devonian–Mississippian, i.e., after Devonian collapse of the Caledonides and prior to Carboniferous rifting. Thus far, this episode of contraction–transpression was required to explain the presence of undeformed Carboniferous–Permian sedimentary rocks on top of folded ...
    • WNW-ESE-striking Timanian faults in Svalbard 

      Koehl, Jean-Baptiste P. (Conference object; Konferansebidrag, 2019-10)
    • Mississippian rocks and WNW–ESE-striking faults in Spitsbergen 

      Koehl, Jean-Baptiste P. (Conference object; Konferansebidrag, 2019-06-18)
    • Impact of Timanian thrusts on the Phanerozoic tectonic history of Svalbard 

      Koehl, Jean-Baptiste P. (Conference object; Konferansebidrag, 2019-09-13)
      Despite more than a century of investigation, the relationship between basement rocks throughout the Svalbard Archipelago is still a mystery. Though these rocks display similar geochronological ages, they show significantly different metamorphic grades and structures. Thus far, Svalbard was believed to be composed of three terranes of rocks formed hundreds–thousands of kilometers apart and accreted ...
    • Dissolved Inorganic Geogenic Phosphorus Load to a Groundwater-Fed Lake: Implications of Terrestrial Phosphorus Cycling by Groundwater 

      Nisbeth, Catharina Simone; Kidmose, Jacob; Weckström, Kaarina; Reitzel, Kasper; Odgaard, Bent Vad; Bennike, Ole; Thorling, Lærke; McGowan, Suzanne; Schomacker, Anders; Kristensen, David Lajer Juul; Jessen, Søren (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-24)
      The general perception has long been that lake eutrophication is driven by anthropogenic sources of phosphorus (P) and that P is immobile in the subsurface and in aquifers. Combined investigation of the current water and P budgets of a 70 ha lake (Nørresø, Fyn, Denmark) in a clayey till-dominated landscape and of the lake’s Holocene trophic history demonstrates a potential significance of geogenic ...
    • Long-term fluid expulsion revealed by carbonate crusts and pockmarks connected to subsurface gas anomalies and palaeo-channels in the central North Sea 

      Chand, Shyam; Cremiere, Antoine; Lepland, Aivo; Thorsnes, Terje; Brunstad, Harald; Stoddart, Daniel (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-19)
      Gas seepage through the seafloor into the water column is inferred based on acoustic mapping, video observations and geochemical analyses at multiple locations in the Viking Graben and Utsira High areas of the central North Sea. Flares in the Viking Graben occur both inside and along the periphery of a submarine melt water channel where pockmarks (up to 500 m in diameter) and methane-derived carbonate ...
    • Changes in sea ice cover and ice sheet extent at the Yermak Plateau during the last 160 ka - Reconstructions from biomarker records 

      Kremer, A; Stein, R; Fahl, K.; Ji, Z; Yang, Z; Wiers, Steffen; Matthiessen, J; Forwick, Matthias; Löwemark, Ludvig; O'Regan, M; Chen, J; Snowball, Ian (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-02-15)
      The Yermak Plateau is located north of Svalbard at the entrance to the Arctic Ocean, i.e. in an area highly sensitive to climate change. A multi proxy approach was carried out on Core PS92/039-2 to study glacial-interglacial environmental changes at the northern Barents Sea margin during the last 160 ka. The main emphasis was on the reconstruction of sea ice cover, based on the sea ice proxy ...
    • Polyphase kinematic history of transpression along the Mecca Hills segment of the San Andreas fault, southern California 

      Bergh, Steffen G; Sylvester, Arthur G.; Damte, Alula; Indrevær, Kjetil (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-09)
      Miocene–Pliocene sedimentary rocks in the Mecca Hills, southern California, were uplifted and deformed by transpression along a restraining bend in the San Andreas fault trace between the Orocopia and San Bernardino Mountains in Pleistocene time. This paper presents field evidence for three stages of structural evolution of a complex, asymmetric wedge-like flower structure, expressed as: (1) ...
    • Excess water storage induced by viscous strain localization during high-pressure shear experiment 

      Précigout, Jacques; Stünitz, Holger; Villeneuve, Johan (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-05)
      Strain localization in viscously deformed rocks commonly results in fine-grained shear zones where massive fluid circulation is regularly observed. Recently attributed to strain-induced pumping, this phenomenon may have major implications for the distribution of ores deposits and rock rheology. However, although grain size reduction and/or creep cavitation have been proposed as important processes, ...
    • Methane-fuelled biofilms predominantly composed of methanotrophic ANME-1 in Arctic gas hydrate-related sediments 

      Gründger, Friederike; Carrier, Vincent; Svenning, Mette Marianne; Panieri, Giuliana; Vonnahme, Tobias R.; Klasek, Scott; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-05)
      Sedimentary biofilms comprising microbial communities mediating the anaerobic oxidation of methane are rare. Here, we describe two biofilm communities discovered in sediment cores recovered from Arctic cold seep sites (gas hydrate pingos) in the north-western Barents Sea, characterized by steady methane fluxes. We found macroscopically visible biofilms in pockets in the sediment matrix at the depth ...
    • Integrated Petrophysical and Seismic interpretation of Norne Field, Norway. 

      Khan, Adnan (Master thesis; Mastergradsoppgave, 2014-09-16)
      The aim of this thesis is to evaluate petrophysical properties and seismic interpretation of main reservoirs of Norne field in Mid Norwegian sea. Petrophysical evaluation helps in getting familiar with reservoir characterization using wireline logs data. The main concentration has been given to evaluate different reservoir properties i.e. porosity, shale volume, water saturation, hydrocarbon saturation, ...
    • The Permafrost Young Researchers Network (PYRN) is getting older – the past, present, and future of our evolving community 

      Tanski, George; Bergstedt, Helena; Bevington, Alexandre; Bonnaventure, Philip; Bouchard, Frédéric; Coch, Caroline; Dumais, Simon; Evgrafova, Alvetina; Frauenfeld, Oliver; Frederick, Jennifer; Fritz, Michael; Frolov, Denis; Harder, Silvie; Hartmeyer, Ingo; Heslop, Joanne; Högström, Elin; Johansson, Margareta; Kraev, Gleb; Kuznetsova, Elena; Lenz, Josefine; Lupachev, Alexey; Magnin, Florence; Martens, Jannik; Maslakov, Alexey; Morgenstern, Anne; Nieuwendam, Alexandre; Oliva, Marc; Radosavljevic, Boris; Ramage, Justine; Schneider, Andrea; Stanilovskaya, Julia; Strauss, Jens; Trochim, Erin; Vecellio, Daniel; Weber, Samuel; Lantuit, Hugues (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-02-07)
      A lasting legacy of the International Polar Year (IPY) 2007–2008 was the promotion of the Permafrost Young Researchers Network (PYRN), initially an IPY outreach and education activity by the International Permafrost Association (IPA). With the momentum of IPY, PYRN developed into a thriving network that still connects young permafrost scientists, engineers, and researchers from other disciplines. ...
    • Variability of Acoustically Evidenced Methane Bubble Emissions Offshore Western Svalbard 

      Veloso-Alarcon, Mario E.; Jansson, Pär; De Batist, Marc; Minshull, Timothy A.; Westbrook, Graham K.; Pälike, Heiko; Bünz, Stefan; Wright, Ian; Greinert, Jens (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-22)
      Large reservoirs of methane present in Arctic marine sediments are susceptible to rapid warming, promoting increasing methane emissions. Gas bubbles in the water column can be detected, and flow rates can be quantified using hydroacoustic survey methods, making it possible to monitor spatiotemporal variability. We present methane (CH<sub>4</sub>) bubble flow rates derived from hydroacoustic data ...
    • Discharge of Meteoric Water in the Eastern Norwegian Sea since the Last Glacial Period 

      Hong, Wei-Li; Lepland, Aivo; Himmler, Tobias; Kim, Ji‐Hoon; Chand, Shyam; Sahy, Diana; Solomon, Evan A.; Rae, James W. B.; Martma, Tõnu; Nam, Seung‐Il; Knies, Jochen (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-03)
      Submarine groundwater discharge could impact the transport of critical solutes to the ocean. However, its driver(s), significance over geological time scales, and geographical coverage are poorly understood. We characterize a submarine groundwater seep from the continental slope off northern Norway where substantial amount of meteoric water was detected. We reconstruct the seepage history from ...
    • A novel biomarker-based proxy for the spring phytoplankton bloom in Arctic and sub-arctic settings – HBI T25 

      Belt, Simon T.; Smik, Lukas; Köseoğlu, Denizcan; Knies, Jochen; Husum, Katrine (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-19)
      The spring phytoplankton bloom is a characteristic feature of mid-high latitudes in modern times, but can be challenging to identify in palaeo records. In the current study, we investigated the absolute and relative distributions of two diatom-derived tri-unsaturated highly branched isoprenoid (HBI) lipids, at least one of which has previously been suggested to be a possible proxy for the productive ...
    • Hydrate occurrence in Europe: A review of available evidence 

      Minshull, Timothy A.; Marin-Moreno, Hector; Betlem, Peter; Bialas, Joerg; Bünz, Stefan; Burwicz, Ewa; Cameselle, Alejandra L.; Cifci, Gunay; Giustiniani, Michela; Hillman, Jess I.T.; Hölz, Sebastian; Hopper, John R.; Ion, Gabriel; Leon, Ricardo; Magalhaes, Vitor; Makovsky, Yizhaq; Mata, Maria-Pilar; Max, Michael D.; Nielsen, Tove; Okay, Seda; Ostrovsky, Ilia; O'Neil, Nick; Pinheiro, Luis M.; Plaza-Faverola, Andreia; Rey, Daniel; Roy, Srikumar; Schwalenberg, Katrin; Senger, Kim; Vadakkepuliyambatta, Sunil; Vasilev, Atanas; Vázquez, Juan-Tomás (Journal article; Tidsskriftartikkel, 2019-08-16)
      Large national programs in the United States and several Asian countries have defined and characterised their marine methane hydrate occurrences in some detail, but European hydrate occurrence has received less attention. The European Union-funded project “Marine gas hydrate – an indigenous resource of natural gas for Europe” (MIGRATE) aimed to determine the European potential inventory of exploitable ...