Now showing items 197-216 of 315

    • OBS Data Analysis to Quantify Gas Hydrate and Free Gas in the South Shetland Margin (Antarctica) 

      Song, Sha; Tinivella, Umberta; Giustiniani, Michela; Singhroha, Sunny; Bünz, Stefan; Cassiani, Giorgio (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-25)
      The presence of a gas hydrate reservoir and free gas layer along the South Shetland margin (offshore Antarctic Peninsula) has been well documented in recent years. In order to better characterize gas hydrate reservoirs, with a particular focus on the quantification of gas hydrate and free gas and the petrophysical properties of the subsurface, we performed travel time inversion of ocean-bottom ...
    • Ocean temperature variability for the past 60 years on the Norwegian-Svalbard margin influences gas hydrate stability on human time scales 

      Ferré, Benedicte; Mienert, Jurgen; Feseker, Tomas (Journal article; Tidsskriftartikkel; Peer reviewed, 2012-10-23)
      The potential impact of future climate change on methane release from oceanic gas hydrates is the subject of much debate. We analyzed World Ocean Database quality controlled data on the Norwegian‐Svalbard continental margin from the past 60 years to evaluate the potential effect of ocean temperature variations on continental margin gas hydrate reservoirs. Bottom water temperatures in the Norwegian‐Svalbard ...
    • On Palaeozoic-Mesozoic brittle normal faults along the SW Barents Sea margin: fault processes and implications for basement permeability and margin evolution 

      Indrevær, Kjetil; Stunitz, Holger; Bergh, Steffen G (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • On the causes of Arctic sea ice in the warm Early Pliocene 

      Clotten, Caroline; Stein, Rüdiger; Fahl, Kirsten; Schreck, Michael; Risebrobakken, Bjørg; De Schepper, Stijn (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-30)
      Scattered and indirect evidence suggests that sea ice occurred as far south as the Iceland Sea during the Early Pliocene, when the global climate was warmer than present. However, conclusive evidence as well as potential mechanisms governing sea ice occurrence outside the Arctic Ocean during a time with elevated greenhouse gas concentrations are still elusive. Here we present a suite of organic ...
    • The onset of flysch sedimentation in the Kaoko Belt (NW Namibia) – Implications for the pre-collisional evolution of the Kaoko–Dom Feliciano–Gariep orogen 

      Konopásek, Jiří; Hoffmann, Karl Heinz; Sláma, Jiří; Košler, Jan (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-17)
      <p>Detrital zircon provenance study of a metamorphosed sedimentary succession in the eastern part of the Kaoko Belt in Namibia has revealed two distinct sources for the Neoproterozoic sedimentation along the southwestern Congo Craton margin. The lower part of the succession shows detrital zircon ages consistent with erosion of Paleoproterozoic basement of the Congo Craton with an inferred Mesoproterozoic ...
    • Optimising the use of marine tephrochronology in the North Atlantic: a detailed investigation of the Faroe Marine Ash Zones II, III and IV 

      Griggs, Adam J.; Davies, Siwan M.; Abbott, Peter M.; Rasmussen, Tine Lander; Palmer, A. P. (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Organic Matter Sources in North Atlantic Fjord Sediments 

      Faust, Johan Christoph; Knies, Jochen (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-31)
      To better constrain the global carbon cycle fundamental knowledge of the role of carbon cycling on continental margins is crucial. Fjords are particularly important shelf areas for carbon burial due to relatively high sedimentation rates and high organic matter fluxes. As terrigenous organic matter is more resistant to remineralization than marine organic matter, a comprehensive knowledge of the ...
    • Origin and K-Ar age of the phreatomagmatic breccia at the Trepča Pb-Zn-Ag skarn deposit, Kosovo: Implications for ore-forming processes 

      Strmic Palinkas, Sabina; Palinkaš, Ladislav A.; Mandić, Magda; Roller-Lutz, Zvjezdana; Pécskay, Zoltan; Maliqi, Gani; Bermanec, Vladimir (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-29)
      The Trepča Pb-Zn-Ag skarn deposit in Kosovo is spatially and temporarily related to the phreatomagmatic breccia of Oligocene age (~23Ma). The deposit shows features typical for skarn deposits worldwide, including a stage of isochemical metamorphism, a prograde stage of an anhydrous, low oxygen and low sulfur fugacity character, and a retrograde stage characterized by an increase in the water ...
    • The Origin of Gas Seeps in the Northern Adriatic Sea 

      Donda, Federica; Tinivella, Umberta; Gordini, Emiliano; Panieri, Giuliana; Volpi, Valentina; Civile, Dario; Forlin, Edy; Facchin, Lorenzo; Burca, Mihai; Cova, Andrea; Ferrante, Giulia M. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06)
      A multidisciplinary approach has been used for the first time to study the widespread occurrence of hydrocarbon seeps in the northern Adriatic Sea. Geological, geophysical and geochemical analyses were performed to identify and characterize the gas-charged fluids occurring throughout the Plio-Quaternary succession, and to date the shallow gas seeping at three leakage sites. The analysis of CHIRP, ...
    • Palaeoceanographic and environmental changes in the eastern Fram Strait during the last 14,000 years based on benthic and planktonic foraminifera 

      Consolaro, Chiara; Rasmussen, Tine Lander; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-14)
      Benthic and planktonic foraminifera, stable isotopes and other geochemical and sedimentological parameters have been investigated in a sediment core from Vestnesa Ridge (79°N, NW Svalbard margin, 1300 m water depth) in order to reconstruct the palaeoceanographic and palaeoenvironmental evolution of the eastern Fram Strait during the last 14,000 years. Our multiproxy data and, in particular, our ...
    • Palaeoceanographic reconstruction of surface-ocean changes in the southern Norwegian Sea for the last ~130,000 years based on diatoms and with comparison to foraminiferal records 

      Hoff, Ulrike; Rasmussen, Tine Lander; Meyer, Hanno; Koc, Nalan; Hansen, Jesper (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-28)
      Fossil marine diatom assemblages in a sediment core from the central northern Faroe slope in the Norwegian Sea were used to reconstruct palaeoceanographic changes in the surface water mixed layer from the last ~130,000 years (Marine Isotope Stage (MIS) 6/5 transition to MIS 1 (including the Eemian and Holocene interglacials) and to compare the results with previously published results on planktic ...
    • Palaeoceanography of the Barents Sea continental margin, north of Nordaustlandet, Svalbard, during the last 74 ka 

      Chauhan, Teena; Rasmussen, Tine Lander; Noormets, Riko (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-07-17)
      We investigated gravity core HH11‐09GC from 488 m water depth at the northern Svalbard margin in order to reconstruct changes in Atlantic Water (AW) inflow to the Arctic Ocean. The study was based on the distribution patterns of benthic and planktic foraminifera, benthic and planktic oxygen and carbon isotopes, lithology and physical properties of the sediments. The core contains sediments from ...
    • Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard 

      Panieri, Giuliana; Graves, Carolyn; James, Rachel (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-26)
      We present stable isotope and geochemical data from four sediment cores from west of Prins Karls Forland (ca. 340 m water depth), offshore western Svalbard, recovered from close to sites of active methane seepage, as well as from shallower water depths where methane seepage is not presently observed. Our analyses provide insight into the record of methane seepage in an area where ongoing ocean ...
    • Paleoceanographic development in Storfjorden, Svalbard, during the deglaciation and Holocene: evidence from benthic foraminiferal records 

      Rasmussen, Tine Lander; Thomsen, Erik (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-08-07)
      Brines can have a profound influence on the relative abundance of calcareous and agglutinated foraminiferal faunas. Here we investigated the distribution of benthic foraminiferal species in four cores from a brine‐enriched environment in Storfjorden, Svalbard. Stratigraphically, the cores comprise the last 15 000 years. The purpose of the study was to reconstruct changes in the palaeoecology and ...
    • Particle sources and downward fluxes in the eastern Fram strait under the influence of the west Spitsbergen current 

      Sanchez-Vidal, Anna; Veres, Oriol; Langone, Leonardo; Ferré, Benedicte; Calafat, Antoni; Canals, Miquel; Durrieu de Madron, Xavier; Heussner, Serge; Mienert, Jurgen; Grimalt, Joan O.; Pusceddu, Antonio; Danovaro, Roberto (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-06-10)
      <p>The carbon cycle of the Arctic Ocean is tightly regulated by land–atmosphere–cryosphere–ocean interactions. Characterizing these environmental exchanges and feedbacks is critical to facilitate projections of the carbon cycle under changing climate conditions. The environmental drivers of sinking particles including organic carbon (OC) to the deep-sea floor are investigated with four moorings ...
    • 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. ...
    • Petroleum, coal and research drilling onshore Svalbard: a historical perspective 

      Senger, Kim; Brugmans, Peter; Grundvåg, Sten-Andreas; Jochmann, Malte Michel; Nøttvedt, Arvid; Olaussen, Snorre; Skotte, Asbjørn; Smyrak-Sikora, Aleksandra (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-07-05)
      The beginning of the Norwegian oil industry is often attributed to the first exploration drilling in the North Sea in 1966, the first discovery in 1967 and the discovery of the supergiant Ekofisk field in 1969. However, petroleum exploration already started onshore Svalbard in 1960 with three mapping groups from Caltex and exploration efforts by the Dutch company Bataaffse (Shell) and the Norwegian ...
    • Physical Conditions of Fast Glacier Flow: 1. Measurements From Boreholes Drilled to the Bed of Store Glacier, West Greenland 

      Doyle, S. H.; Hubbard, B.; Christoffersen, P.; Young, T.J.; Hofstede, C; Bougamont, M.; Box, J.E.; Hubbard, A.L. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-21)
      Marine‐terminating outlet glaciers of the Greenland Ice Sheet make significant contributions to global sea level rise, yet the conditions that facilitate their fast flow remain poorly constrained owing to a paucity of data. We drilled and instrumented seven boreholes on Store Glacier, Greenland, to monitor subglacial water pressure, temperature, electrical conductivity, and turbidity along with ...
    • Physical Conditions of Fast Glacier Flow: 2. Variable Extent of Anisotropic Ice and Soft Basal Sediment From Seismic Reflection Data Acquired on Store Glacier, West Greenland 

      Hofstede, C.; Christoffersen, P.; Hubbard, B.; Doyle, S.H.; Young, T.J.; Diez, A.; Eisen, O.; Hubbard, Alun Lloyd (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-09)
      Outlet glaciers of the Greenland Ice Sheet transport ice from the interior to the ocean and contribute directly to sea level rise because discharge and ablation often exceed the accumulation. To develop a better understanding of these fast‐flowing glaciers, we investigate the basal conditions of Store Glacier, a large outlet glacier flowing into Uummannaq Fjord in west Greenland. We use two crossing ...
    • Physical Conditions of Fast Glacier Flow: 3.Seasonally-Evolving Ice Deformation onStore Glacier, West Greenland 

      Young, Tun Jan; Christoffersen, Poul; Doyle, Samuel H.; Nicholls, Keith W.; Stewart, C.L.; Hubbard, Bryn; Hubbard, Alun Lloyd; Lok, Lai B.; Brennan, Paul V.; Benn, Douglas I; Luckman, Adrian; Bougamont, Marion H. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-08)
      Temporal variations in ice sheet flow directly impact the internal structure within ice sheetsthrough englacial deformation. Large-scale changes in the vertical stratigraphy within ice sheets havebeen previously conducted on centennial to millennial timescales; however, intra-annual changes inthe morphology of internal layers have yet to be explored. Over a period of 2 years, we use autonomousphas ...