Viser treff 138-157 av 711

    • Direct 40Ar/39Ar K‐feldspar dating of Late Permian–Early Triassic brittle faulting in Northern Norway 

      Davids, Corine; Benowitz, Jeff A.; Layer, Paul; Bergh, Steffen G (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-04-23)
      While the offshore post‐Caledonian extensional history of the north Norwegian passive margin is well constrained, the tectonic relationship between onshore and offshore regions is less clear because of limited age constraints on the timing of rifting onshore. <sup>40</sup>Ar/<sup>39</sup>Ar dating of K‐feldspar from hydrothermally altered fault rocks in a Precambrian gneiss complex in northern Norway ...
    • Direct measurements of meltwater runoff on the Greenland ice sheet surface 

      Smith, Laurence C.; Yang, Kang; Pitcher, Lincoln H.; Overstreet, Brandon T.; Chu, Vena W.; Rennermalm, Åsa K.; Ryan, Jonathan C.; Cooper, Matthew G.; Gleason, Colin J.; Tedesco, Marco; Jeyaratnam, Jeyavinoth; van As, Dirk; van den Broeke, Michiel R.; van de Berg, Willem Jan; Noël, Brice; Langen, Peter L.; Cullather, Richard I.; Zhao, Bin; Willis, Michael J.; Hubbard, Alun Lloyd; Box, Jason E.; Jenner, Brittany A.; Behar, Alberto E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-12-05)
      Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream ...
    • 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 ...
    • Dissolution precipitation creep as a process for the strain localisation in mafic rocks 

      Lee, Amicia; Stunitz, Holger; Soret, Mathieu; Battisti, Matheus Ariel (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-01-01)
      The lower crust is, on average, mafic in composition and composed of minerals that remain mechanically strong up to high temperatures. Here we show that dissolution-precipitation creep (as a type of diffusion creep) plays a major role in deformation of gabbro bodies at upper amphibolite facies conditions. The Kågen gabbro, N. Norway, is comprised of undeformed gabbro lenses enclosed by mylonitised ...
    • 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 ...
    • Distinct methane-dependent biogeochemical states in Arctic seafloor gas hydrate mounds 

      Klasek, Scott A.; Hong, Wei-Li; Torres, Marta E.; Ross, Stella; Hostetler, Katelyn; Portnov, Alexey; Gründger, Friederike; Colwell, Frederick S. (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-11-02)
      Archaea mediating anaerobic methane oxidation are key in preventing methane produced in marine sediments from reaching the hydrosphere; however, a complete understanding of how microbial communities in natural settings respond to changes in the flux of methane remains largely uncharacterized. We investigate microbial communities in gas hydrate-bearing seafloor mounds at Storfjordrenna, offshore ...
    • Distinct modes of meltwater drainage and landform development beneath the last Barents Sea ice sheet 

      Shackleton, Calvin; Patton, Henry; Winsborrow, Monica; Esteves, Mariana; Bjarnadòttir, Lilja Rùn; Andreassen, Karin Marie (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-04-18)
      The flow of glacial ice is impacted by basal meltwater drainage systems that fluctuate on a continuum from distributed, high-pressure environments to channelized, lower pressure networks. Understanding the long-term development of dominant drainage modes and impacts on ice flow and landform development is a crucial step in predicting palaeo and contemporary ice-mass response to changes in ...
    • Distribution and Abundances of Planktic Foraminifera and Shelled Pteropods During the Polar Night in the Sea-Ice Covered Northern Barents Sea 

      Zamelczyk, Katarzyna; Fransson, Agneta; Chierici, Melissa; Jones, Elizabeth Marie; Meilland, Julie; Anglada-Ortiz, Griselda; Hodal Lødemel, Helene (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-22)
      Planktic foraminfera and shelled pteropods are important calcifying groups of zooplankton in all oceans. Their calcium carbonate shells are sensitive to changes in ocean carbonate chemistry predisposing them as an important indicator of ocean acidification. Moreover, planktic foraminfera and shelled pteropods contribute significantly to food webs and vertical flux of calcium carbonate in polar pelagic ...
    • Distribution and characteristics of overdeepenings beneath the Greenland and Antarctic ice sheets: Implications for overdeepening origin and evolution 

      Patton, Henry; Swift, D.A.; Clark, C.D.; Livingstone, Stephen J.; Cook, S.J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09-15)
      Glacier bed overdeepenings are ubiquitous in glacier systems and likely exert significant influence on ice dynamics, subglacial hydrology, and ice stability. Understanding of overdeepening formation and evolution has been hampered by an absence of quantitative empirical studies of their distribution and morphology, with process insights having been drawn largely from theoretical or numerical studies. ...
    • Distribution of living benthic foraminifera in the northern Chukchi Sea 

      Racine, Calypso; Bonnin, Jérôme; Nam, Seung-Il; Giraudeau, Jacques; Biguenet, Maude; Dessandier, Pierre-Antoine; Kim, Jung‑Hyun (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-27)
      Living (Rose Bengal stained) benthic foraminifera were studied in the topmost sediments of five multi- and box cores collected on the continental shelf, upper and lower slopes, of the Chukchi Sea to provide background information on modern benthic foraminiferal distribution, useful for future studies. Sediment cores were collected during August–September 2015, when the area is seasonally ice-free. ...
    • Divergent drift of Adriatic-Dinaridic and Moesian carbonate platforms during the rifting phase witnessed by Triassic MVT Pb-Zn and SEDEX deposits; a metallogenic approach 

      Palinkaš, Ladislav A.; Damyanov, Zhelyazko K.; Šoštarić, Sibila Borojević; Strmic Palinkas, Sabina; Marinova, Irina (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-29)
      Early-intracontinental rifting of Pangea was a result of thermal doming in Uppermost Permian time giving rise to the formation of horst-graben structures, followed by slow subsidence, marine transgression and evaporite deposition. The consequences of incipient magmatism and a high heat flow are numerous geothermal fields and subterrestrial hydrothermal siderite-barite-polysulfide deposits (PALINKAŠ ...
    • Diverse gas composition controls the Moby-Dick gas hydrate system in the Gulf of Mexico 

      Portnov, Alexey; Cook, A.E.; Vadakkepuliyambatta, Sunil (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-08-12)
      In marine basins, gas hydrate systems are usually identified by a bottom simulating reflection (BSR) that parallels the seafloor and coincides with the base of the gas hydrate stability zone (GHSZ). We present a newly discovered gas hydrate system, Moby-Dick, located in the Ship Basin in the northern Gulf of Mexico. In the seismic data, we observe a channel-levee complex with a consistent phase ...
    • Does Arctic warming reduce preservation of organic matter in Barents Sea sediments? 

      Faust, Johan Christoph; Stevenson, Mark A.; Abbott, Geoffrey D.; Knies, Jochen; Tessin, Allyson; Mannion, Isobel; Ford, Ailbe; Hilton, Robert; Peakall, Jeffrey; März, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-31)
      Over the last few decades, the Barents Sea experienced substantial warming, an expansion of relatively warm Atlantic water and a reduction in sea ice cover. This environmental change forces the entire Barents Sea ecosystem to adapt and restructure and therefore changes in pelagic–benthic coupling, organic matter sedimentation and long-term carbon sequestration are expected. Here we combine new and ...
    • Dry and strong quartz during deformation of the lower crust in the presence of melt 

      Menegon, Luca; Nasipuri, Pritam; Stunitz, Holger; Behrens, Harald; Ravna, Erling J Krogh (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      Granulite facies migmatitic gneisses from the Seiland Igneous Province (northern Norway) were deformed during deep crustal shearing in the presence of melt, which formed by dehydration melting of biotite. Partial melting and deformation occurred during the intrusion of large gabbroic plutons at the base of the lower crust at 570 to 520 Ma in an intracontinental rift setting. The migmatitic gneisses ...
    • Dynamic and history of methane seepage in the SW Barents Sea: new insights from Leirdjupet Fault Complex 

      Argentino, Claudio; Waghorn, Kate Alyse; Vadakkepuliyambatta, Sunil; Polteau, Stephane; Bünz, Stefan; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-23)
      Methane emissions from Arctic continental margins are increasing due to the negative effect of global warming on ice sheet and permafrost stability, but dynamics and timescales of seafloor seepage still remain poorly constrained. Here, we examine sediment cores collected from an active seepage area located between 295 and 353 m water depth in the SW Barents Sea, at Leirdjupet Fault Complex. The ...
    • Dynamics of a retreating ice sheet: a LiDAR study in Värmland, SW Sweden 

      Goodship, Alastair; Alexanderson, Helena (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-11-11)
      Värmland in south western Sweden lies across the established zone of marine-terrestrial transition of the Scandinavian Ice Sheet (SIS) margin. The region lies inside the Younger Dryas maximum limit reached at 12.7 cal ka BP and the area of rapid final SIS retreat from 11.5 cal ka BP. LiDAR data across Värmland allows more detailed observation and analysis of glacial landforms formed during this stage ...
    • Early and middle Miocene ice sheet dynamics in the Ross Sea: Results from integrated core-log-seismic interpretation 

      Perez, Lara F; De Santis, Laura; Mckay, Robert M.; Larter, Robert D.; Ash, Jeanine A; Bart, Phil J.; Böhm, Gualtiero; Brancatelli, Giuseppe; Browne, Imogen; Colleoni, Florence; Dodd, Justin P.; Geletti, Riccardo; Harwood, David M.; Kuhn, Gerhard; Laberg, Jan Sverre; Leckie, R. Mark; Levy, Richard H.; Marschalek, James; Mateo, Zenon; Naish, Timothy R.; Sangiorgi, Francesca; Shevenell, Amelia E.; Sorlien, Christopher C.; van de Flierdt, Tina; IODP Expedition 374, Scientists (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-11)
      Oscillations in ice sheet extent during early and middle Miocene are intermittently preserved in the sedimentary record from the Antarctic continental shelf, with widespread erosion occurring during major ice sheet advances, and open marine deposition during times of ice sheet retreat. Data from seismic reflection surveys and drill sites from Deep Sea Drilling Project Leg 28 and International Ocean ...
    • Early and Middle Pleistocene environments, landforms and sediments in Scotland 

      Hall, Adrian M.; Merritt, Jon W.; Connell, E. Rodger; Hubbard, Alun Lloyd (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-10-04)
      This paper reviews the changing environments, developing landforms and terrestrial stratigraphy during the Early and Middle Pleistocene stages in Scotland. Cold stages after 2.7 Ma brought mountain ice caps and lowland permafrost, but larger ice sheets were short-lived. The late Early and Middle Pleistocene sedimentary record found offshore indicates more than 10 advances of ice sheets from ...
    • An Early Neogene—Early Quaternary Contourite Drift System on the SW Barents Sea Continental Margin, Norwegian Arctic 

      Rydningen, Tom Arne; Høgseth, Gert; Lasabuda, Amando Putra Ersaid; Laberg, Jan Sverre; Safronova, Polina; Forwick, Matthias (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-30)
      The onset and evolution of the middle to late Cenozoic “icehouse” world was influenced by the development of the global ocean circulation linking the Norwegian–Greenland Sea-Arctic Ocean to the Atlantic Ocean. The evolution of the early Neogene to early Quaternary Bjørnøyrenna Drift, located at the SW Barents Sea continental margin, shed new light on this important hydrological event. By analyzing ...
    • The Early to Middle Cenozoic Paleoenvironment and Erosion Estimates for the northwestern Barents Sea 

      Lasabuda, Amando Putra Ersaid; Laberg, Jan Sverre; Knutsen, Stig-Morten; Safronova, Polina (Conference object; Konferansebidrag, 2017)
      <p>The northwestern Barents Sea continental margin is a structurally complex area characterized by a series of basins and highs. It’s Cenozoic development was influenced by: 1) the formation of the Spitsbergen fold-andthrust belt towards the north and a pull-apart basin, the Vestbakken Volcanic Province, to the south, and 2) the subsequent rifting and opening of the Fram Strait, the deep-water gateway ...