Viser treff 406-425 av 711

    • Mineralogical distribution and genetic aspects of cobalt at the active Fåvne and Loki’s Castle seafloor massive sulfide deposits, Arctic Mid-Ocean Ridges 

      Sahlström, Fredrik; Strmic Palinkas, Sabina; Dundas, Siv Hjorth; Sendula, Eszter; Cheng, Yanbo; Wold, Marie; Pedersen, Rolf Birger Svarstad (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-16)
      The demand for responsibly sourced cobalt has increased dramatically as a result of the global transition to ‘fossil-free’ electromobility. However, the distribution, mineralogical expressions and mechanisms of concentration of Co in different types of hydrothermal ore deposits remain poorly constrained, inhibiting resource assessments and exploration. Here we report Co and other metal concentrations ...
    • A Miocene age for the Molo Formation, Norwegian Sea shelf off Vestfjorden, based on marine palynology 

      Grøsfjeld, Kari; Dybkjær, Karen; Eidvin, Tor; Riis, Fridtjof; Rasmussen, Erik Skovbjerg; Knies, Jochen (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-10)
      Seven side-wall core samples from the lower part of the Molo Formation in exploration well 6610/3–1 off Vestfjorden/Lofoten have been reanalysed for marine palynomorphs. Description of new species from other studies and access to reference successions from nearby sites with an independent chronostratigraphy have enabled a more reliable depositional age constraint for the Molo Formation in its ...
    • Miocene Seep-Carbonates of the Northern Apennines (Emilia to Umbria, Italy): An Overview 

      Conti, Stefano; Argentino, Claudio; Fioroni, Chiara; Salocchi, Aura Cecilia; Fontana, Daniela (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-28)
      The natural emission of methane-rich fluids from the seafloor, known as cold seepage, is a widespread process at modern continental margins. The studies on present-day cold seepages provide high-resolution datasets regarding the fluid plumbing system, biogeochemical processes in the sediment, seafloor seepage distribution and ecosystems. However, the long-term (hundreds of thousands to millions of ...
    • The Miocene-Pliocene boundary and the Messinian Salinity Crisis in the easternmost Mediterranean: Insights from the Hatay Graben (Southern Turkey) 

      Boulton, Sarah J.; Smart, Christopher W.; Consolaro, Chiara; Snider, Avalon (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-12-02)
      The Hatay Graben is one of three easternmost basins in the Mediterranean that preserve sediments that span the Miocene–Pliocene boundary, including gypsums from the Messinian Salinity Crisis (MSC). Here we integrate existing data and present new sedimentological and micropalaeontological data to investigate the palaeoenvironments of late Miocene to early Pliocene deposits and place this important ...
    • MIS 3 age of the Veiki moraine in N Sweden – Dating the landform record of an intermediate-sized ice sheet in Scandinavia 

      Alexanderson, Helena; Hättestrand, Martina; Lindqvist, Mimmi A.; Sigfúsdóttir, Thorbjörg (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-07-14)
      The Veiki moraine in northern Sweden, a geomorphologically distinct landscape of ice-walled lake plains, has been interpreted to represent the former margin of an intermediate-sized pre–Last Glacial Maximum (LGM) Fennoscandian ice sheet, but its age is debated as either marine isotope stage (MIS) 5c or MIS 3. We have applied optically stimulated luminescence (OSL) and radiocarbon dating to four sites ...
    • Mississippian rocks and WNW–ESE-striking faults in Spitsbergen 

      Koehl, Jean-Baptiste P. (Conference object; Konferansebidrag, 2019-06-18)
    • Modeling the evolution of climate-sensitive Arctic subsea permafrost in regions of extensive gas expulsion at the West Yamal shelf 

      Portnov, Aleksei D; Mienert, Jurgen; Serov, Pavel (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-10-01)
      Thawing subsea permafrost controls methane release from the Russian Arctic shelf having a considerable impact on the climate-sensitive Arctic environment. Expulsions of methane from shallow Russian Arctic shelf areas may continue to rise in response to intense degradation of relict subsea permafrost. Here we show modeling of the permafrost evolution from the Late Pleistocene to present time at the ...
    • Modelling persistent methane seepage offshore western Svalbard since early Pleistocene 

      Knies, Jochen; Daszinnies, Matthias Christian; Plaza-Faverola, Andreia; Chand, Shyam; Sylta, Øyvind; Bünz, Stefan; Johnson, Joel E; Mattingsdal, Rune; Mienert, Jurgen (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-01-31)
      Recent observations of extensive methane release into the oceans and atmosphere have raised concern as to whether rising temperatures across the Arctic could drive rapid destabilization of gas hydrate reservoirs. Here, we report modelling results from hydrate-modulated methane seepage from Vestnesa Ridge, offshore western Svalbard, suggesting that continuous leakage has occurred from the seafloor ...
    • Modelling the Eurasian Ice Sheet 

      Patton, Henry Jared (Conference object; Konferansebidrag, 2024-03-15)
    • Modification of bedrock surfaces by glacial abrasion and quarrying: Evidence from North Wales 

      Glasser, Neil F.; Roman, Matej; Holt, Tom O.; Žebre, Manja; Patton, Henry; Hubbard, Alun Lloyd (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-30)
      Abrasion and quarrying are significant processes of subglacial erosion for ice masses in direct contact with hard substrates, yet their relative efficacy and spatio-temporal variability is unclear. Here, we investigate the glacial impact of these processes on a 70 m by 60 m bedrock surface at Moel Ysgyfarnogod in the Rhinog Mountains, Wales, using a combination of high-resolution digital photographs, ...
    • Monitoring marine mammals using unmanned aerial vehicles: quantifying detection certainty 

      Aniceto, Ana Sofia; Biuw, Martin; Lindstrøm, Ulf; Solbø, Stian; Broms, Fredrik Björn; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-03-08)
      Unmanned aerial vehicles (UAVs) are increasingly being recognized as potentially useful for detection of marine mammals in their natural habitats, but an important consideration is the associated uncertainties in animal detection. We present a study based on field trials using UAVs to carry out image‐based monitoring of cetaceans in two fjords in northern Norway. We conducted 12 missions to assess ...
    • Monitoring Of CO2 Leakage Using High-Resolution 3D Seismic Data – Examples From Snøhvit, Vestnesa Ridge And The Western Barents Sea 

      Bellwald, Benjamin; Waage, Malin; Planke, S; Lebedeva-Ivanova, Nina; Polteau, S; Tasianas, Alexandros; Bünz, Stefan; Plaza-Faverola, Andreia; Berndt, Christian; Stokke, H.H.; Millett, John; Myklebust, R. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-11-21)
      Injection of CO2 in subsurface reservoirs may cause overburden deformation and CO2 leakage. The aim of this study is to apply technologies for detection and monitoring of CO2 leakage and deformation above the injection reservoirs. The examples of this study include data from the Vestnesa Ridge natural seep site, the Snøhvit gas field and CO2 storage site region, and the Gemini North gas reservoir. ...
    • Morphological evidence for marine ice stream shutdown, central Barents Sea 

      Kurjanski, Bartosz; Rea, Brice R.; Spagnolo, Matteo; Winsborrow, Monica; Cornwell, David G.; Andreassen, Karin; Howell, John (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-05-02)
      Marine-based ice streams are responsible for a significant proportion of the ice mass loss from the present-day Greenland Ice Sheet, East Antarctic Ice Sheet (EAIS) and West Antarctic Ice Sheet (WAIS) but the processes controlling their initiation, evolution and shutdown remain elusive, hindering our understanding of how existing ice masses will respond to predicted future warming. The exposed beds ...
    • Multi-elemental chemostratigraphy of Triassic mudstones in eastern Svalbard: implications for source rock formation in front of the World’s largest delta plain 

      Wesenlund, Fredrik; Grundvåg, Sten-Andreas; Engelschiøn, Victoria Sjøholt; Thieβen, Olaf; Pedersen, Jon Halvard (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-03)
      The Triassic Boreal Ocean was a shallow epicontinental basin and the sink of the World's largest delta plain known to date. Nutrient and freshwater supply from this delta have been regarded as important causes for high productivity and water mass stratification, forming Middle Triassic oil-prone source rocks. Recent studies attribute upwelling and a productivity-induced oxygen minimum zone as ...
    • Multi-proxy approach to unravel methane emission history of an Arctic cold seep 

      Yao, Haoyi; Niemann, Helge; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-13)
      Arctic Ocean sediments contain large amounts of methane in the form of free gas and gas hydrate. This highly dynamic methane reservoir is susceptible to be modified by bottom water warming. The warming may lead to gas hydrate destabilization releasing elevated methane fluxes to the seafloor and seawater. Reconstructing past methane dynamics can be achieved by using specific proxies left in the ...
    • A multi-source-to-sink system in a dynamic plate tectonic setting: the Cenozoic of the Barents Sea, Norwegian Arctic 

      Lasabuda, Amando P. E.; Chiarella, Domenico; Sømme, Tor Oftedal; Hanssen, Alfred; Laberg, Jan Sverre; Rydningen, Tom Arne; Patton, Henry (Conference object; Konferansebidrag, 2022)
      <p>When multiple source areas are located on a continuously moving plate margin relative to a sink, the signal propagation in the source-to-sink system may vary significantly in time and space. How fast and severe the impact of tectonics and climate is on sediment erosiontransfer-deposition in this dynamic setting is still not well understood. Similarly, how do we quantify the relative sediment ...
    • Multiple sulfur isotopes in methane seep carbonates track unsteady sulfur cycling during anaerobic methane oxidation 

      Cremiere, Antoine; Pellerin, André; Wing, Boswell A.; Lepland, Aivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-19)
      The anaerobic oxidation of methane coupled with sulfate reduction (AOM-SR) is a major microbially-mediated methane consuming process in marine sediments including methane seeps. The AOM-SR can lead to the formation of methane-derived authigenic carbonates which entrap sulfide minerals (pyrite) and carbonate-associated sulfate (CAS). We studied the sulfur isotope compositions of the pyrite and CAS ...
    • Multiple sulphur isotope records tracking basinal and global processes in the 1.98 Ga Zaonega Formation, NW Russia 

      Paiste, Kärt; Lepland, Aivo; Zerkle, A.L.; Kirsimäe, Kalle; Izon, G.; Patel, N.K.; McLean, F.; Kreitsmann, T.; Mänd, Kaarel; Bui, T.H.; Romashkin, Alexander E.; Rychanchik, Dimitry V.; Prave, Anthony R (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-09-19)
      The exceptionally organic-rich rocks of the 1.98 Ga Zaonega Formation deposited in the Onega Basin, NW Russia, have refined our understanding of Earth System evolution during the Paleoproterozoic rise in atmospheric oxygen. These rocks were formed in vent- or seep influenced settings contemporaneous with voluminous mafic volcanism and contain strongly <sup>13</sup>C-depleted organic matter. ...
    • Multiproxy investigation of the last 2,000 years BP marine paleoenvironmental record along the western Spitsbergen margin 

      Torricella, Fiorenza; Gamboa Sojo, Viviana Maria; Gariboldi, Karen; Douss, Nessim; Musco, Maria Elena; Caricchi, Chiara; Lucchi, Renata Giulia; Carbonara, Katia; Morigi, Caterina (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-01)
      A reconstruction of the last 2,000 years BP of environmental and oceanographic changes on the western margin of Spitsbergen was performed using a multidisciplinary approach including the fossil assemblages of diatoms, planktic and benthic foraminifera and calcareous nannofossils and the use of geochemistry (X-ray fluorescence spectroscopy, X-ray diffraction). We identified two warm periods ...
    • Multiproxy paleoceanographic study from the western Barents Sea reveals dramatic Younger Dryas onset followed by oscillatory warming trend 

      Łącka, Magdalena; Michalska, Danuta; Pawłowska, Joanna; Szymańska, Natalia; Szczuciński, Witold; Forwick, Matthias; Zajączkowski, Marek (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-09-24)
      The Younger Dryas (YD) is recognized as a cool period that began and ended abruptly during a time of general warming at the end of the last glacial. New multi-proxy data from a sediment gravity core from Storfjordrenna (western Barents Sea, 253 m water depth) reveals that the onset of the YD occurred as a single short-lived dramatic environment deterioration, whereas the subsequent warming was ...