Blar i forfatter "Cremiere, Antoine"

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    • Diagenetic alteration of benthic foraminifera from a methane seep site on Vestnesa Ridge (NW Svalbard) 

      Schneider, Andrea; Cremiere, Antoine; Panieri, Giuliana; Lepland, Aivo; Knies, Jochen (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-03-08)
      Anomalously low δ<sup>13</sup>C values in foraminiferal calcite tests are due to diagenetic alteration in methane seep sites. Our study applies diagenetically altered fossil benthic foraminiferal tests as geochemical tracers in reconstructing natural past methane seepage episodes at Vestnesa Ridge offshore NW Svalbard. We combine examinations of the test wall microstructure, mineralogical and stable ...

    • Long-term fluid expulsion revealed by carbonate crusts and pockmarks connected to subsurface gas anomalies and palaeo-channels in the central North Sea 

      Chand, Shyam; Cremiere, Antoine; Lepland, Aivo; Thorsnes, Terje; Brunstad, Harald; Stoddart, Daniel (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-19)
      Gas seepage through the seafloor into the water column is inferred based on acoustic mapping, video observations and geochemical analyses at multiple locations in the Viking Graben and Utsira High areas of the central North Sea. Flares in the Viking Graben occur both inside and along the periphery of a submarine melt water channel where pockmarks (up to 500 m in diameter) and methane-derived carbonate ...

    • Methane transport and sources in an Arctic deep-water cold seep offshore NW Svalbard (Vestnesa Ridge, 79°N) 

      Sauer, Simone; Hong, Wei-Li; Yao, Haoyi; Lepland, Aivo; Klug, Martin; Eichinger, Florian; Himmler, Tobias; Cremiere, Antoine; Panieri, Giuliana; Schubert, Carsten J.; Knies, Jochen (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-29)
      We investigate the uppermost 60 cm of sediment in active pockmarks of a deep-water methane seep site from Vestnesa Ridge offshore NW Svalbard. Using video guided core sampling with a remotely operated vehicle we collected push cores directly from bacterial mats within two active pockmarks, Lunde and Lomvi. Pore water analyses show very shallow sulphate methane transition zones and transport-reaction ...

    • 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 ...

    • Putative fossils of chemotrophic microbes preserved in seep carbonates from Vestnesa Ridge, off northwest Svalbard, Norway 

      Himmler, Tobias; Cremiere, Antoine; Birgel, Daniel; Wirth, Richard; Orphan, Victoria J.; Kirsimae, Kalle; Knies, Jochen; Peckmann, Jörn; Lepland, Aivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-20)
      The microbial key players at methane seeps are methanotrophic archaea and sulfate-reducing bacteria. They form spherical aggregates and jointly mediate the sulfate-dependent anaerobic oxidation of methane (SD–AOM: CH4 + SO42– → HCO3– + HS– + H2O), thereby inducing the precipitation of authigenic seep carbonates. While seep carbonates constitute valuable archives for molecular fossils of SD–AOM-mediating ...

    • Seepage from an arctic shallow marine gas hydrate reservoir is insensitive to momentary ocean warming 

      Hong, Wei-Li; Torres, Marta E.; Carroll, JoLynn; Cremiere, Antoine; Panieri, Giuliana; Yao, Haoyi; Serov, Pavel (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06-07)
      Arctic gas hydrate reservoirs located in shallow water and proximal to the sediment-water interface are thought to be sensitive to bottom water warming that may trigger gas hydrate dissociation and the release of methane. Here, we evaluate bottom water temperature as a potential driver for hydrate dissociation and methane release from a recently discovered, gas-hydrate-bearing system south of ...

    • Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway 

      Sauer, Simone; Hong, Wei-Li; Knies, Jochen; Lepland, Aivo; Forwick, Matthias; Klug, Martin; Eichinger, Florian; Baranwal, Soma; Cremiere, Antoine; Chand, Shyam; Schubert, Carsten J. (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-22)
      To better understand the present and past carbon cycling and transformation processes in methane-influenced fjord and shelf areas of northern Norway, we compared two sediment cores from the Hola trough and from Ullsfjorden. We investigated (1) the organic matter composition and sedimentological characteristics to study the sources of organic carbon (C<sub>org</sub>) and the factors influencing ...

    • Timescales of methane seepage on the Norwegian margin following collapse of the Scandinavian Ice Sheet 

      Cremiere, Antoine; Lepland, Aivo; Chand, Shyam; Sahy, Diana; Condon, Daniel J.; Noble, Stephen R.; Martma, Tõnu; Thorsnes, Terje; Sauer, Simone; Brunstad, Harald (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-05-11)
      Gas hydrates stored on continental shelves are susceptible to dissociation triggered by environmental changes. Knowledge of the timescales of gas hydrate dissociation and subsequent methane release are critical in understanding the impact of marine gas hydrates on the ocean–atmosphere system. Here we report a methane efflux chronology from five sites, at depths of 220–400 m, in the southwest Barents ...