Viser treff 943-962 av 982

    • U-Pb zircon provenance of metamorphosed clastic sediments in the Brusque Metamorphic Complex, Dom Feliciano Belt, southeastern Brazil 

      Eiesland, Ragnhild (Master thesis; Mastergradsoppgave, 2018-05-15)
      The Brusque Metamorphic Complex is situated in the northern part of the Dom Feliciano Belt in the state of Santa Catarina, southeastern Brazil. The complex is composed of Neoproterozoic sequences of volcanic and sedimentary rocks, which were folded and metamorphosed at greenschist to low-amphibolite facies conditions. U-Pb dating of detrital zircon grains in five samples of clastic metasedimentary ...
    • U-Th chronology and formation controls of methane-derived authigenic carbonates from the Hola trough seep area, northern Norway 

      Sauer, Simone; Knies, Jochen; Lepland, Aivo; Sahy, Diana; Martma, Tõnu; Noble, Stephen R.; Schönenbergerb, Jasmin; Klug, Martin; Schubert, Carsten J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-10-20)
      We investigated methane-derived authigenic carbonate (MDAC) crusts and nodules from a cold seep site on the northern Norwegian continental shelf in ca. 220 m water depth to determine the timing and mode of their formation. Gas bubbling observed during remotely operated vehicle (ROV)-assisted sampling of MDAC crusts revealed ongoing seep activity. Authigenic carbonates were present as crusts on the ...
    • UAV photogrammetry and structure from motion to assess calving dynamics at Store Glacier, a large outlet draining the Greenland ice sheet 

      Ryan, Johnny C.; Hubbard, Alun Lloyd; Box, Jason E.; Todd, Joe; Christoffersen, Poul; Carr, J. Rachel; Holt, Tom O.; Snooke, Neal A. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-01-06)
      This study presents the application of a costeffective, unmanned aerial vehicle (UAV) to investigate calving dynamics at a major marine-terminating outlet glacier draining the western sector of the Greenland ice sheet. The UAV was flown over Store Glacier on three sorties during summer 2013 and acquired over 2000 overlapping, geotagged images of the calving front at an ∼ 40 cm ground sampling ...
    • Uncovering hidden structures: previously undescribed pseudopodia and ectoplasmic structures in planktonic foraminifera 

      Greco, Mattia; Westgård, Adele; Sykes, Freya Elizabeth; Mohamed, Mohamed Mahmoud Ezat Ahmed; Meilland, Julie (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-07-05)
      The trophic strategies of cold-water planktonic foraminifera are not well understood due to the challenge of culturing them in polar conditions. Here, we identify previously unknown ectoplasmic and cytoplasmic projections in three species of planktonic foraminifera thriving in polar and subpolar marine environments: Globigerina bulloides, Neogloboquadrina incompta and Neogloboquadrina pachyderma. ...
    • Underexplored continental shelf gateways: timing, mechanisms and role of SW Barents Sea Gateway, Norwegian Arctic 

      Lasabuda, Amando P. E.; Hanssen, Alfred; Laberg, Jan Sverre; Rydningen, Tom Arne; Patton, Henry; Faleide, Jan Inge; Abdelmalak, Mohamed Mansour; Kjølhamar, Bent (Conference object; Konferansebidrag, 2022)
      Ocean gateways connecting ocean basins are crucial for water and heat circulation, which influence global temperature, climate evolution and sediment distribution. While deep-water gateways have been a major research focus by the community, very little attention has been drawn to shallower gateways located on the continental shelves, where such circulation also takes place. In this study, we investigate ...
    • Undersjøiske daler og oljereservoar 

      Vorren, Tore Ola; Laberg, Jan Sverre (Chronicle; Kronikk, 2010-10-02)
    • Undersjøiske kjempeskred og flodbølger 

      Vorren, Tore Ola; Laberg, Jan Sverre (Chronicle; Kronikk, 2010-09-25)
    • Undersøkelse av ustabilt fjellparti ved Adjet, Storfjord, Troms. Betydningen av ulike kategorier av glideplan i berggrunnen og mekanismer for utglidning 

      Bakkhaug, Iselin (Master thesis; Mastergradsoppgave, 2015-05-15)
      Strukturelle element i berggrunnen kan ha stor betydning for utvikling av ustabile fjellparti og fjellskred. I dette studiet vil det fokuseres på hvilken rolle strukturelle element i berggrunnen har hatt å si for skredhendelsene og deformasjonen i området og hvordan disse har preget det geologiske bildet. Det ustabile fjellpartiet er lokalisert på fjellet Adjet ved tettstedet Skibotn i Storfjord ...
    • Unravelling key controls on the rift climax to post-rift fill of marine rift basins: insights from 3D seismic analysis of the Lower Cretaceous of the Hammerfest Basin, SW Barents Sea 

      Marin Restrepo, Dora Luz; Escalona Varela, Alejandro; Grundvåg, Sten-Andreas; Olaussen, Snorre; Sandvik, Sara; Śliwińska, Kasia K. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-19)
      In this study, we investigate key factors controlling the rift climax to post‐rift marine basin fill. We use two‐ and three‐dimensional seismic data in combination with sedimentological core descriptions from the Hammerfest Basin, south‐western Barents Sea to characterize and analyse the tectonostratigraphy and seismic facies of the Lower Cretaceous succession. Based on our biostratigraphic analyses, ...
    • An updated Weichselian chronostratigraphic framework of the Kongsfjorden Trough Mouth Fan and its implications for the glacial history of Svalbard 

      Wiberg, Daniel Hesjedal; Haflidason, Haflidi; Laberg, Jan Sverre (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-02)
      The Arctic is a climate-sensitive area, responding rapidly to present changes, but for the past changes, the recordis still incomplete. Forinstance, theWeichselian glacial historyof the Svalbard–Barents Sea Ice Sheet (SBIS) haslargely been reconstructed based on studies of the fragmentary Spitsbergen terrestrial and shelf records. However, the sediments removed from the land and shelf areas during ...
    • Upper cretaceous-paleogene stratigraphy and development of the Mímir High, Vøring transform margin, Norwegian Sea 

      Polteau, Stephane; Planke, Sverre; Zastrozhnov, Dmitrii; Abdelmalak, Mohamed Mansour; Lebedeva-Ivanova, Nina; Eckhoff Planke, Ellen; Svensen, Henrik; Mazzini, Adriano; Gernigon, Laurent; Myklebust, Reidun; Kjølhamar, Bent; Pedersen, Rolf B.; Sandstå, Nils Rune; Bünz, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-19)
      Transform margins represent strike-slip type of plate boundaries that form during continental breakup and initial ocean opening. They are often characterized by margin-parallel highs with exposed pre- and syn-rift sequences. The Vøring Transform Margin, offshore mid-Norway, initiated in the earliest Eocene during the opening of the NE Atlantic. Here, 2D seismic reflection data reveal a transform ...
    • The upper Paleozoic regional development of the Ottar basin from seismic 2D interpretation 

      Finnesand, Sebastian Sandvik (Master thesis; Mastergradsoppgave, 2018-05-15)
      The Ottar basin is not yet formally defined, but is a known structural element situated under the Bjarmeland Platform in the southwestern Barents Sea, buried beneath thick, flay-lying Mesozoic strata. This thesis focuses on delineating the informal upper Paleozoic Ottar basin. The delineation presented, is based on lateral/vertical variations in lithology and the surrounding tectonic setting of the ...
    • Upper Triassic to lower Cretaceous tectonostratigraphic development of the Barents Sea South East 

      Kristiansen, Ådne Frostad (Master thesis; Mastergradsoppgave, 2020-05-27)
      The aim of this study is to investigate the tectonic- and evolutionary differences between major structural elements of the Barents Sea South East (BSSE) during the uppermost Triassic to lower Cretaceous. The study area comprises the following structural elements: the Bjarmeland- and Finnmark platforms, the Nordkapp- and Tiddlybanken basins, the Signalhorn-, Haapet- and Veslekari domes and the ...
    • Use of 2D-seismic data and available wells to investigate the source potential of the Palaeozoic interval in the Loppa High area, SW Barents Sea 

      Hetland, Asbjørn (Master thesis; Mastergradsoppgave, 2018-05-15)
      While most established plays in the Barents Sea have occurred in the Mesozoic, the Alta and Gohta discoveries prove a new carbonate play concept, with a source rock that does not stem from the Jurassic. Based on depositional environment and TOC values from the Palaeozoic interval a source rock with Top Ørn as its bottom and Top Røye as its top was interpreted. Basin modelling carried out on this ...
    • The Use of Foraminiferal Geochemistry to Investigate Methane Seepage at the Svyatogor Ridge, Arctic Ocean 

      Akinselure, Abidemi Alex (Master thesis; Mastergradsoppgave, 2022-05-12)
      Methane is a greenhouse gas contributing to contemporaneous global warming, and seepage is one of the ways through which it migrates from the deep sedimentary basins, all the way up to the hydro- and atmosphere. The study of methane seepage is still young as scientists are yet to discover most seep sites as well as seep associated biological species. A record of past methane seepage can be derived ...
    • Using thermal UAV imagery to model distributed debris thicknesses and sub-debris melt rates on debris-covered glaciers 

      Bisset, Rosie R.; Nienow, Peter W.; Goldberg, Daniel N.; Wigmore, Oliver; Loayza-Muro, Raúl A.; Wadham, Jemma Louise; Macdonald, Moya L.; Bingham, Robert G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-14)
      Supraglacial debris cover regulates the melt rates of many glaciers in mountainous regions around the world, thereby modifying the availability and quality of downstream water resources. However, the influence of supraglacial debris is often poorly represented within glaciological models, due to the absence of a technique to provide high-precision, spatially continuous measurements of debris thickness. ...
    • Variability in transport of terrigenous material on the shelves and the deep Arctic Ocean during the Holocene 

      Wegner, C.; Bennet, K.; Vernal, Anne de; Forwick, Matthias; Fritz, M.; Heikkilä, Maija; Łącka, Magdalena; Lantuit, Hugues; Laska, Michał; Moskalik, Mateusz; O’Regan, Matt; Pawłowska, J; Promińska, Agnieszka; Rachold, Volker; Vonk, Jorien E.; Werner, Kirstin (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-09)
      Arctic coastal zones serve as a sensitive filter for terrigenous matter input onto the shelves via river discharge and coastal erosion. This material is further distributed across the Arctic by ocean currents and sea ice. The coastal regions are particularly vulnerable to changes related to recent climate change. We compiled a pan-Arctic review that looks into the changing Holocene sources, transport ...
    • 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 ...
    • Variability of Marine Methane Bubble Emissions on the Clayoquot Slope, Offshore Vancouver Island, Between 2017 and 2021 

      Marcon, Yann; Römer, Miriam; Scherwath, Martin; Riedel, Michael; Dølven, Knut Ola; Heesemann, Martin (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-17)
      Seabed methane gas emissions occur worldwide at cold seeps located along most continental margins. Fluxes of methane gas released from the seabed in the form of bubbles can be extremely variable even over short time intervals. Some factors controlling the variability are still poorly understood. Here, we report on the results of continuous long-term sonar monitoring of bubble emissions at a depth ...
    • Variability of present and past PAH concentrations in sediments of the SW Barents Sea 

      Junttila, Juho; Carroll, JoLynn; Dijkstra, Noortje (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-09)
      The concentration and distribution of polyaromatic hydrocarbons (PAHs) in surface and subsurface sediment samples from Tromsøflaket and Ingøydjupet, southwestern Barents Sea, were investigated in order to provide insight into the levels and origins of PAHs in a region with petroleum activities. PAH profiles in sediments were evaluated in context with sediment grain size and total organic carbon ...