• A 160,000-year-old history of tectonically controlled methane seepage in the Arctic 

      Himmler, Tobias; Sahy, Diana; Martma, Tõnu; Bohrmann, Gerhard; Plaza-Faverola, Andreia; Bünz, Stefan; Condon, Daniel J.; Knies, Jochen; Lepland, Aivo (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-08-07)
      The geological factors controlling gas release from Arctic deep-water gas reservoirs through seabed methane seeps are poorly constrained. This is partly due to limited data on the precise chronology of past methane emission episodes. Here, we use uranium-thorium dating of seep carbonates sampled from the seabed and from cores drilled at the Vestnesa Ridge, off West Svalbard (79°N, ~1200 m water ...
    • 3D Seismic Investigation of a Gas Hydrate and Fluid Flow System on an Active Mid‐Ocean Ridge; Svyatogor Ridge, Fram Strait 

      Waghorn, Kate Alyse; Bünz, Stefan; Plaza-Faverola, Andreia; Johnson, Joel E. (Journal article; Tidsskriftartikkel; Peer reviewed, 2018-05-12)
      Tectonic settings play a large role in the development of fluid flow pathways for gas migrating through sedimentary strata. Many gas hydrate systems worldwide are located on either passive continental margins, in large contourite deposits on the slopes of passive continental margins or on subduction margins. The Svyatogor Ridge, however, located at the northwestern flank of the Knipovich Ridge and ...
    • Abiotic methane from ultraslow-spreading ridges can charge Arctic gas hydrates 

      Johnson, Joel E; Mienert, Jurgen; Plaza-Faverola, Andreia; Vadakkepuliyambatta, Sunil; Knies, Jochen; Bünz, Stefan; Andreassen, Karin; Ferré, Benedicte (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05)
      Biotic gas generation from the degradation of organic carbon in marine sediments supplies and maintains gas hydrates throughout the world’s oceans. In nascent, ultraslow-spreading ocean basins, methane generation can also be abiotic, occurring during the high-temperature (>200 °C) serpentinization of ultramafic rocks. Here, we report on the evolution of a growing Arctic gas- and gas hydrate–charged ...
    • An Arctic natural oil seep investigated from space to the seafloor 

      Panieri, Giuliana; Argentino, Claudio; Ramalho, Sofia P.; Vulcano, Francesca; Savini, Alessandra; Fallati, Luca; Brekke, Trond; Galimberti, Giulia; Riva, Federica; Balsa, João; Eilertsen, Mari Heggernes; Stokke, Runar; Steen, Ida Helene; Sahy, Diana; Kalenitchenko, Dimitri Stanislas Desire; Bünz, Stefan; Mattingsdal, Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-19)
      Due to climate change, decreasing ice cover and increasing industrial activities, Arctic marine ecosystems are expected to face higher levels of anthropogenic stress. To sustain healthy and productive ocean ecosystems, it is imperative to build baseline data to assess future changes. Herein, a natural oil seep site offshore western Svalbard (Prins Karls Forland, PKF, 80–100 m water depth), discovered ...
    • Biogeochemistry and timing of methane-derived carbonate formation at Leirdjupet fault complex, SW Barents sea 

      Argentino, Claudio; Lee, Amicia; Fallati, Luca; Sahy, Diana; Birgel, Daniel; Peckmann, Jörn; Bünz, Stefan; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-10-25)
      The origin of modern seafloor methane emissions in the Barents Sea is tightly connected to the glacio-tectonic and oceanographic transformations following the last ice age. Those regional events induced geological structure re-activation and destabilization of gas hydrate reservoirs over large areas of the European continental margins, sustaining widespread fluid plumbing systems. Despite the ...
    • Bottom-simulating reflector dynamics at Arctic thermogenic gas provinces: An example from Vestnesa Ridge, offshore west Svalbard 

      Plaza-Faverola, Andreia; Vadakkepuliyambatta, Sunil; Hong, Wei-Li; Mienert, Jurgen; Bünz, Stefan; Chand, Shyam; Greinert, Jens (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-06)
    • Carbon isotope (d13C) excursions suggest times of major methane release during the last 14 ka in Fram Strait, the deep-water gateway to the Arctic 

      Consolaro, Chiara; Rasmussen, Tine Lander; Panieri, Giuliana; Mienert, Jurgen; Bünz, Stefan; Sztybor, Kamila (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Characterizing Håkon Mosby Mud Volcano (Barents Sea) cold seep systems by combining ROV-based acoustic data and underwater photogrammetry 

      Fallati, Luca; Panieri, Giuliana; Savini, Alessandra; Varzi, Andrea Giulia; Argentino, Claudio; Bünz, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-31)
      Cold-seep systems have a unique geo-ecological significance in the deep-sea environment. They impact the variability of present-day submarine sedimentary environments, affecting the evolution of the landscape over time and creating a variety of submarine landforms, one of which is Mud Volcanoes (MVs). MVs are submarine landforms form due extrusion of mud, fluids, and gas, mainly methane, from deeper ...
    • Constraints on Gas Hydrate Distribution and Morphology in Vestnesa Ridge, Western Svalbard Margin, Using Multicomponent Ocean‐Bottom Seismic Data 

      Singhroha, Sunny; Chand, Shyam; Bünz, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-26)
      Gas hydrates occur within sediments on the western Svalbard continental margin and the Vestnesa Ridge, a large sediment drift that extends in a west‐north‐west direction from the margin towards the mid‐ocean ridge. We acquired multi‐component ocean‐bottom seismic (OBS) data at ten locations on the crest area of the eastern segment of the Vestnesa Ridge, an area with active gas seepage. P and S‐wave ...
    • Controls on gas hydrate system evolution in a region of active fluid flow in the SW Barents Sea 

      Vadakkepuliyambatta, Sunil; Hornbach, Matthew; Bünz, Stefan; Phrampus, Benjamin (Journal article; Tidsskriftartikkel, 2015-09)
      The location and stability of gas hydrates in the SW Barents Sea is poorly constrained due to complex geological, geochemical, and geophysical conditions, including poor controls on regional heat flow and gas chemistry. Understanding the stability of gas hydrates in this region is important, as recent studies suggest destabilizing hydrates may lead to methane discharge into the ocean and possibly ...
    • Crustal processes sustain Arctic abiotic gas hydrate and fluid flow systems 

      Waghorn, Kate Alyse; Vadakkepuliyambatta, Sunil; Plaza-Faverola, Andreia; Johnson, Joel E; Bünz, Stefan; Waage, Malin (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-30)
      The Svyatogor Ridge and surroundings, located on the sediment-covered western flank of the Northern Knipovich Ridge, host extensive gas hydrate and related fluid flow systems. The fluid flow system here manifests in the upper sedimentary sequence as gas hydrates and free gas, indicated by bottom simulating reflections (BSRs) and amplitude anomalies. Using 2D seismic lines and bathymetric data, we ...
    • Dating submarine landslides using the transient response of gas hydrate stability 

      Portnov, Aleksei D; You, Kehua; Flemings, Peter B.; Cook, Ann E.; Heidari, Mahdi; Sawyer, Derek E.; Bünz, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-02)
      Submarine landslides are prevalent on the modern-day seafloor, yet an elusive problem is constraining the timing of past slope failure. We present a novel age-dating technique based on perturbations to underlying gas hydrate stability caused by slide-impacted seafloor changes. Using three-dimensional (3-D) seismic data, we mapped an irregular bottom simulating reflection (BSR) underneath a submarine ...
    • Detection of gas hydrates in faults using azimuthal seismic velocity analysis,Vestnesa Ridge, W-Svalbard Margin 

      Singhroha, Sunny; Bünz, Stefan; Plaza Faverola, Andreia Aletia; Chand, Shyam (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-24)
      Joint analysis of electrical resistivity and seismic velocity data is primarily used todetect the presence of gas hydrate-filled faultsand fractures. In this study, we present a novel approach to inferthe occurrence of structurally-controlled gas hydrateaccumulations using azimuthal seismic velocity analysis. We perform thisanalysis using ocean-bottom seismic (OBS) data at two sites on Vestnesa ...
    • Detectionof gas hydrates infaults using azimuthal seismic velocity analysis,Vestnesa Ridge, W-Svalbard Margin 

      Singhroha, Sunny; Bünz, Stefan; Plaza-Faverola, Andreia; Chand, Shyam (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-24)
      Joint analysis of electrical resistivity and seismic velocity data is primarily used to detect the presence of gas hydrate‐filled faults and fractures. In this study, we present a novel approach to infer the occurrence of structurally‐controlled gas hydrate accumulations using azimuthal seismic velocity analysis. We perform this analysis using ocean‐bottom seismic (OBS) data at two sites on Vestnesa ...
    • 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 ...
    • Enhanced CO2 uptake at a shallow Arctic Ocean seep field overwhelms the positive warming potential of emitted methane 

      Pohlman, John; Greinert, Jens; Ruppel, Carolyn; Silyakova, Anna; Vielstädte, Lisa; Casso, Michael; Mienert, Jürgen; Bünz, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-05-08)
      Continued warming of the Arctic Ocean in coming decades is projected to trigger the release of teragrams (1 Tg = 106 tons) of methane from thawing subsea permafrost on shallow continental shelves and dissociation of methane hydrate on upper continental slopes. On the shallow shelves (<100 m water depth), methane released from the seafloor may reach the atmosphere and potentially amplify global ...
    • Feasibility of using the P-Cable high-resolution 3D seismic system in detecting and monitoring CO2 leakage 

      Waage, Malin; Singhroha, Sunny; Bünz, Stefan; Planke, Sverre; Waghorn, Kate Alyse; Bellwald, Benjamin (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-01-23)
      The P-Cable technology is an acquisition principle for high-resolution and ultra-high-resolution 3D seismic data. Many 3D seismic datasets have been acquired over the last decade, but the application in time-lapse studies for monitoring of CO2 storage is a new and intriguing topic. High-resolution 3D (HR3D) seismic has the potential to detect and monitor CO2 leakage at carbon capture and storage ...
    • Gas hydrate and free gas detection using seismic quality factor estimates from high-resolution P-cable 3D seismic data 

      Singhroha, Sunny; Bünz, Stefan; Plaza-Faverola, Andreia; Chand, Shyam (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-23)
      We have estimated the seismic attenuation in gas hydrate and free-gas-bearing sediments from high-resolution P-cable 3D seismic data from the Vestnesa Ridge on the Arctic continental margin of Svalbard. P-cable data have a broad bandwidth (20–300 Hz), which is extremely advantageous in estimating seismic attenuation in a medium. The seismic quality factor (Q), the inverse of seismic attenuation, ...
    • Geological controls of giant crater development on the Arctic seafloor 

      Waage, Malin; Serov, Pavel; Andreassen, Karin; Waghorn, Kate Alyse; Bünz, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-21)
      Active methane seepage occurs congruent with a high density of up to 1 km-wide and 35 m deep seafloor craters (>100 craters within 700 km<sup>2</sup> area) within lithified sedimentary rocks in the northern Barents Sea. The crater origin has been hypothesized to be related to rapid gas hydrate dissociation and methane release around 15–12 ka BP, but the geological setting that enabled and possibly ...
    • Geological controls on fluid flow and gas hydrate pingo development on the Barents Sea margin 

      Waage, Malin; Portnov, Aleksei D; Serov, Pavel; Bünz, Stefan; Waghorn, Kate Alyse; Vadakkepuliyambatta, Sunil; Mienert, Jurgen; Andreassen, Karin (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-16)
      In 2014, the discovery of seafloor mounds leaking methane gas into the water column in the northwestern Barents Sea became the first to document the existence of non‐permafrost related gas hydrate pingos (GHP) on the Eurasian Arctic shelf. The discovered site is given attention because the gas hydrates occur close to the upper limit of the gas hydrate stability, thus may be vulnerable to climatic ...