Viser treff 461-480 av 1012

    • Reduced methane seepage from Arctic sediments during cold bottom-water conditions 

      Ferré, Benedicte; Jansson, Pär; Moser, Manuel; Serov, Pavel; Portnov, Aleksei D; Graves, Carolyn; Panieri, Giuliana; Gründger, Friederike; Berndt, Christian; Lehmann, Moritz F.; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-13)
      Large amounts of methane are trapped within gas hydrate in subseabed sediments in the Arctic Ocean, and bottom-water warming may induce the release of methane from the seafloor. Yet the effect of seasonal temperature variations on methane seepage activity remains unknown as surveys in Arctic seas are conducted mainly in summer. Here we compare the activity of cold seeps along the gas hydrate stability ...
    • Holocene environmental changes in Dicksonfjorden, west Spitsbergen, Svalbard 

      Joo, Young Ji; Forwick, Matthias; Park, Kwangkyu; Joe, Youngjin; Son, Yeong Ju; Nam, Seung-Il (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-26)
      Multi-proxy analyses of two sediment cores from Dicksonfjorden were performed to reconstruct Holocene environmental conditions in this northern branch of Isfjorden, the largest fjord system in Svalbard. Factors affecting the depositional processes include shifts in sources of sediments, ice rafting and regional glacio-isostatic rebound. Sediments were derived from Palaeozoic siliciclastics ...
    • Ice‐margin retreat and grounding‐zone dynamics during initial deglaciation of the Storfjordrenna Ice Stream, western Barents Sea 

      Shackleton, Calvin; Winsborrow, Monica; Andreassen, Karin; Lucchi, Renata Giulia; Bjarnadóttir, Lilja Rún (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-11)
      Processes occurring at the grounding zone of marine terminating ice streams are crucial to marginal stability, influencing ice discharge over the grounding‐line, and thereby regulating ice‐sheet mass balance. We present new marine geophysical data sets over a ~30×40 km area from a former ice‐stream grounding zone in Storfjordrenna, a large cross‐shelf trough in the western Barents Sea, south of ...
    • Evolution of contourite drifts in regions of slope failures at eastern Fram Strait 

      Osti, Giacomo; Waghorn, Kate Alyse; Waage, Malin; Plaza-Faverola, Andreia; Ferré, Benedicte (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-15)
      Geotechnical characteristics of contouritic deposition often lead to preconditioning slope instabilities and failures along glaciated and formerly glaciated continental margins.<br> However, internal depositional geometry is also an important factor in triggering instabilities. This work highlights the importance of the tectonic and oceanographic evolution of the Northwestern (NW) Svalbard margin ...
    • Physical controls of dynamics of methane venting from a shallow seep area west of Svalbard 

      Silyakova, Anna; Jansson, Pär; Serov, Pavel; Ferré, Benedicte; Pavlov, A.K; Hattermann, T.; Graves, C.A; Platt, S.M; Myhre, Cathrine Lund; Gründger, Friederike; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-06)
      We investigate methane seepage on the shallow shelf west of Svalbard during three consecutive years, using discrete sampling of the water column, echosounder-based gas flux estimates, water mass properties, and numerical dispersion modelling. The results reveal three distinct hydrographic conditions in spring and summer, showing that the methane content in the water column is controlled by a combination ...
    • 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 ...
    • Impact of drill cutting releases on benthic foraminifera at three exploration wells drilled between 1992 and 2012 in the SW Barents Sea, Norway 

      Dijkstra, Noortje; Junttila, Juho; Aagaard-Sørensen, Steffen (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-04)
      The aim of this study is to identify the environmental impact of drill cuttings (DC) released around three wells drilled in 1992, 2000 and 2012 in the SW Barents Sea. Foraminiferal assemblages are studied in cores taken along transects <250 m from wells. Well E-1992 shows no impact of DC on foraminifera indicating that low amounts of released DC limit environmental impact. Impact at wells G-2000 and ...
    • Sylfjellet: a new outcrop of the Paleogene Van Mijenfjorden Group in Svalbard 

      Jochmann, Malte Michel; Augland, Lars Eivind; Lenz, Olaf; Bieg, Gerd; Haugen, Turid; Grundvåg, Sten-Andreas; Jelby, Mads E.; Midtkandal, Ivar; Dolezych, Martina; Hjálmarsdóttir, Hanna Rósa (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-05)
      A hitherto unrecognized Paleogene outcrop has been discovered at Sylfjellet, a mountain located at the northern side of Isfjorden, Svalbard. The strata, which cover an area of 0.8 km2, have until now been assigned to the Lower Cretaceous succession of the Adventdalen Group. In this study, the Sylfjellet site was studied in detail to provide an updated structural and sedimentological description of ...
    • Postglacial paleoceanography of the western Barents Sea: Implications for alkenone-based sea surface temperatures and primary productivity 

      Lacka, Magdalena; Cao, Min; Rosell-Melé, Antoni; Pawlowska, Joanna; Kucharska, Małgorzata; Forwick, Matthias; Zajaczkowski, Marek (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-11)
      The increasing influence of Atlantic Water (AW) in the Barents Sea, a process known as “Atlantification”, is gradually decreasing sea ice cover in the region. Ongoing global climate warming is likely to be one of its drivers, but to further understand the role of natural variability and the biogeochemical impacts of the inflow of AW into the western Barents Sea, we reconstructed sea surface temperatures ...
    • Evolution of a rock slope failure at Skredkallen, Vannøya 

      Mikkelsen, Martin (Master thesis; Mastergradsoppgave, 2019-11-15)
      Rock slope failures are known major contributors to landscape evolution in alpine Norway, and also pose a threat to people and infrastructure in the present day. By examining the history of rock slope failures at active rockslide sites an understanding of recurrence intervals and triggering mechanisms can be achieved. The focus of this study is to form a complete picture of the evolution of an area ...
    • The marine sedimentary environments of Kongsfjorden, Svalbard: an archive of polar environmental change 

      Husum, Katrine; Howe, John A; Baltzer, Agnes; Forwick, Matthias; Jensen, Maria; Jernas, Patrycja; Korsun, Sergei; Miettinen, Arto; Mohan, Rahul; Morigi, Caterina; Myhre, Per Inge; Prins, Maarten A.; Skirbekk, Kari; Sternal, Beata; Boos, Michel; Dijkstra, Noortje; Troelstra, Simon R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-16)
      Kongsfjorden, a fjord in north-western Svalbard, is characterized by large environmental gradients driven by meltwater processes along the margins of tidewater glaciers and the inflow of relatively warm Atlantic Water, the main heat source for the European Arctic. These factors make Kongsfjorden a key area to investigate changes in the polar climate–ocean–glacier system and to examine the resulting ...
    • 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 ...
    • Late Weichselian and Holocene palaeoceanography of Storfjordrenna, southern Svalbard 

      Lacka, M.; Zajaczkowski, M.; Forwick, Matthias; Szczucinski, W. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-03-27)
      Multiproxy analyses (including benthic and planktonic foraminifera, δ<sup>18</sup>O and δ<sup>13</sup>C records, grain-size distribution, ice-rafted debris, XRF geochemistry and magnetic susceptibility) were performed on a <sup>14</sup>C-dated marine sediment core from Storfjordrenna, located off of southern Svalbard. The sediments in the core cover the termination of Bølling–Allerød, the Younger ...
    • Exploring the teaching environment in a higher education geoscience programme 

      Malm, Rie Hjørnegaard; Martens, Iver (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-03-19)
      This paper explores the teaching environment among the teaching staff in thegeoscience programme at UiT The Arctic University of Norway. The findings in this paper are based on a large baseline study conducted in 2018. This paper operationalises the teaching culture by analysing the teachers’ ideas, collaborations, and attitudes towards teaching. In-depth interviews ...
    • Geochemistry of rutile-bearing veins at Engebøfjellet, Naustdal, Norway. 

      Grane, Kristoffer (Master thesis; Mastergradsoppgave, 2018-11-15)
      The Engebøfjellet eclogite, located in Naustdal, Norway, contain quartz veins with large rutile (TiO2) phenocrystals. Trace element composition of rutile deposited in veins and in the eclogite matrix was analysed with the use of LA-ICP-MS. The Nb content decrease with increasing V in the rutile, and contents of these elements vary depending on depositional environment. One quartz vein associated ...
    • Image based quantitative comparisons indicate heightened megabenthos diversity and abundance at a site of weak hydrocarbon seepage in the southwestern Barents Sea 

      Sen, Arunima; Chitkara, Chestaa; Hong, Wei-Li; Lepland, Aivo; Cochrane, Sabine; Di Primio, Rolando; Brunstad, Harald (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-08)
      <p><i>Background - </i>High primary productivity in the midst of high toxicity defines hydrocarbon seeps; this feature usually results in significantly higher biomass, but in lower diversity communities at seeps rather than in the surrounding non-seep benthos. Qualitative estimates indicate that this dichotomy does not necessarily hold true in high latitude regions with respect to megafauna. Instead, ...
    • 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 ...
    • Sedimentology and palynology of the Lower Cretaceous succession of central Spitsbergen: integration of subsurface and outcrop data 

      Grundvåg, Sten-A; Jelby, Mads Engholm; Śliwińska, Kasia Kamila; Nøhr-Hansen, Henrik; Aadland, Tore; Sandvik, Sara Elvelund; Tennvassås, Ingrid; Engen, Thea; Olaussen, Snorre (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-06-27)
      The Lower Cretaceous succession in Svalbard is commonly considered as an important analogue to age-equivalent strata on the Barents Shelf which are sporadically targeted by exploration wells. In this study, the stratigraphic and genetic relationship between the Rurikfjellet (open marine), Helvetiafjellet (paralic) and Carolinefjellet (open marine) formations of the Lower Cretaceous succession in ...
    • Significance of substrate soil moisture content for rockfall hazard assessment 

      Vick, Louise Mary; Zimmer, Valerie; White, Christopher; Massey, Chris; Davies, Tim (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-27)
      Rockfall modelling is an important tool for hazard analysis in steep terrain. Calibrating terrain parameters ensures that the model results more accurately represent the site-specific hazard. Parameterizing rockfall models is challenging because rockfall runout is highly sensitive to initial conditions, rock shape, size and material properties, terrain morphology, and terrain material properties. ...
    • Conduit processes during the February 11, 2010 Vulcanian eruption of Soufriere Hills, Montserrat 

      Burgisser, Alain; Bechon, Tonin; Chevalier, Laure; Collombet, Marielle; Arbaret, Laurent; Forien, Melanie (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-29)
      We analyzed pumice from the February 11, 2010 Vulcanian explosion that immediately followed a large dome collapse at Soufrière Hills volcano. We obtained pre-explosive values of porosity, pressure, and depth by combining textural analyses and glass water content determinations. Our data suggest that the February 2010 explosion evacuated the upper 3 km of the conduit from the dense magma (≤10 vol% ...