Viser treff 141-160 av 755

    • Widespread natural methane and oil leakage from sub-marine Arctic reservoirs 

      Serov, Pavel; Mattingsdal, Rune; Winsborrow, Monica; Patton, Henry; Andreassen, Karin Marie (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-30)
      Parceling the anthropogenic and natural (geological) sources of fossil methane in the atmosphere remains problematic due to a lack of distinctive chemical markers for their discrimination. In this light, understanding the distribution and contribution of potential geological methane sources is important. Here we present empirical observations of hitherto undocumented, widespread and extensive methane ...
    • The effect of muscovite on the microstructural evolution and rheology of quartzite in general shear 

      Tokle, L.; Hirth, G.; Stunitz, Holger (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-13)
      We conducted general shear experiments on synthetic mixtures of quartz and muscovite aggregates at 800 °C and 1.5 GPa with 0.1 wt% H<sub>2</sub>O added in the Griggs apparatus to investigate the role of muscovite content on the microstructural evolution and rheological properties of quartz aggregates. Muscovite content varied between 0, 5, 10 and 25% muscovite. Mechanically, the sample strengths ...
    • The phylogeography and ecology of Oligobrachia frenulate species suggest a generalist chemosynthesis-based fauna in the arctic 

      Sen, Arunima; Andersen, Liselotte W.; Kjeldsen, Kasper U.; Michel, Loïc N.; Hong, Wei-Li; Choquet, Marvin; Rasmussen, Tine Lander (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-02)
      We used ancient DNA (aDNA) extraction methods to sequence museum voucher samples of Oligobrachia webbi, a frenulate siboglinid polychaete described from a northern Norwegian fjord over fifty years ago. Our sequencing results indicate a genetic match with the cryptic seep species, Oligobrachia haakonmosbiensis (99% pairwise identity for 574 bp mtCOI fragments). Due to its similarity with O. webbi, ...
    • Late Holocene pteropod distribution across the base of the south-eastern Mediterranean margin: the importance of the > 63 µm fraction 

      Beccari, Valentina; Almogi-Labin, Ahuva; Basso, Daniela; Panieri, Giuliana; Makovsky, Yizhaq; Hajdas, Irka; Spezzaferri, Silvia (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-17)
      Euthecosomata pteropods were analysed in core sediments collected in the framework of the 2016 EUROFLEETS2 SEMSEEP cruise, offshore of Israel, in the eastern Mediterranean Sea. The investigated cores were retrieved in a deep-sea coral area at 690 m depth, an actively methane-seeping pockmark area at 1038 m depth, and a deep-sea channel area at 1310 m water depth. We identified and documented the ...
    • 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 ...
    • Pleistocene depositional environments and links to cryosphere-ocean interactions on the eastern Ross Sea continental slope, Antarctica (IODP Hole U1525A) 

      King, Maxine V.; Gales, Jenny A.; Laberg, Jan Sverre; Mckay, Robert M.; De Santis, Laura; Kulhanek, Denise K.; Hosegood, Phil J.; Morris, Antony; IODP Expedition 374, Scientists (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-10-22)
      The repeated proximity of West Antarctic Ice Sheet (WAIS) ice to the eastern Ross Sea continental shelf break during past ice age cycles has been inferred to directly influence sedimentary processes occurring on the continental slope, such as turbidity current and debris flow activity; thus, the records of these processes can be used to study the past history of the WAIS. Ross Sea slope sediments ...
    • GEO-3144/8144 Teaching Cruise: Geologically controlled hydrocarbon seepage in Hopendjupet and the wider Barents Sea 

      Serov, Pavel; Patton, Henry; Mazzini, Adriano; Mattingsdal, Rune; Shephard, Grace; Cooke, Frances Ann; Martins de Aguiar, Victor Cesar; Holm, Villads Dyrved; Alessandrini, Giuliana; Meza Cala, Juan Camilo; Luerssen, Paula (Research report; Forskningsrapport, 2022-11-18)
      The CAGE22-6 cruise on-board R/V Helmer Hanssen hosted UiT´s Arctic Marine Geology and Geophysics (GEO-8144 and GEO-3144) field course for PhD and Master students, and was carried out in collaboration with NPD – the Norwegian Petroleum Directorate and the INTPART project HOTMUD based at Centre for Earth Evolution and Dynamics (CEED) the University of Oslo. The cruise was also a part of the UNESCO ...
    • Handwritten letters and photo albums linking geoscientists with school classes 

      Stiller-Reeve, Mathew Alexander; Argentino, Claudio; Waghorn, Kate Alyse; Vadakkepuliyambatta, Sunil; Kalenitchenko, Dimitri; Panieri, Giuliana (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-14)
      Was something lost as society moved away from “traditional” media such as handwritten letters and photography and into the digital age? Some of the authors remember this age fondly, and we wanted to see if this fondness could be translated into a science dialogue project with school classes. We designed and carried out a communication process with four classes at different schools across Europe. ...
    • Storm chasing: Tracking Holocene storminess in southern Sweden using mineral proxies from inland and coastal peat bogs 

      Kylander, Malin E.; Martínez-Cortizas, Antonio; Sjöström, Jenny K.; Gåling, Jenny; Gyllencreutz, Richard; Bindler, Richard; Alexanderson, Helena; Schenk, Frederik; Reinardy, Benedict T.I.; Chandler, Benjamin M.P.; Gallagher, Kerry (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-25)
      Severe extratropical winter storms are a recurrent feature of the European climate and cause widespread socioeconomic losses. Due to insufficient long-term data, it remains unclear whether storminess has shown a notable response to changes in external forcing over the past millennia, which impacts our ability to project future storminess in a changing climate. Reconstructing past storm variability ...
    • Non-linear response of glacier melting to Holocene warming in Svalbard recorded by sedimentary iron (oxyhydr)oxides 

      Jang, Kwangchul; Bayon, Germain; Vogt, Christoph; Forwick, Matthias; Ahn, Youngkyu; Kim, Jung-Hyun; Nam, Seung-Il (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-03-01)
      The recent acceleration of ice-sheet loss with its direct impact on sea-level rise and coastal ecosystems is of major environmental and societal concern. However, the effect of atmospheric temperature increases on long-term glacier retreat remains poorly defined due to limited historical observations and uncertainties in numerical ice-sheet models, which challenges climate change adaptation planning. ...
    • 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 ...
    • Pelagic calcium carbonate production and shallow dissolution in the North Pacific Ocean 

      Ziveri, Patrizia; Gray, William Robert; Anglada Ortiz, Griselda; Manno, Clara; Grelaud, Michael; Incarbona, Alessandro; Rae, James William Buchanan; Subhas, Adam V.; Pallacks, Sven; White, Angelicque; Adkins, Jess F.; Berelson, William (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-02-20)
      Planktonic calcifying organisms play a key role in regulating ocean carbonate chemistry and atmospheric CO<sub>2</sub>. Surprisingly, references to the absolute and relative contribution of these organisms to calcium carbonate production are lacking. Here we report quantification of pelagic calcium carbonate production in the North Pacific, providing new insights on the contribution of the three ...
    • Sedimentology of Neoproterozoic storm-influenced braid deltas, Varanger Peninsula, North Norway 

      Grundvåg, Sten-Andreas; Skorgenes, Julia (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-30)
      The oldest part of the upper Riphean (Cryogenian) sedimentary succession of the Varanger Peninsula, North Norway, includes a series of sandstone-dominated units of fluvio-deltaic to shallow-marine origin and thinner, intercalated mudstone-rich units. The sedimentology and stratigraphic understanding of the mudstone-rich units are less complete compared to their sandstone-dominated counterparts. In ...
    • Quaternary and Neogene Reservoirs of the Norwegian Continental Shelf and the Faroe-Shetland Basin 

      Bellwald, Benjamin; Planke, Sverre; Vadakkepuliyambatta, Sunil; Buenz, Stefan; Batchelor, Christine L.; Manton, Ben; Zastrozhnov, Dmitry; Walker, Faye; Myklebust, Reidun (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-06-01)
      Glaciogenic reservoirs host important hydrocarbon resources across the globe. Examples such as the Peon and Aviat discoveries in the North Sea show that Quaternary and Neogene reservoirs can be prospective in the region. In this study, we interpret 2D and 3D reflection seismic data combined with borehole information to document unconventional play models from the shallow subsurface of the Norwegian ...
    • The Svalbard Carboniferous to Cenozoic Composite Tectono-Stratigraphic Element 

      Olaussen, Snorre; Grundvåg, Sten-Andreas; Senger, Kim; Anell, Ingrid; Betlem, Peter; Birchall, Thomas; Braathen, Alvar; Dallmann, Winfried Kurt; Jochmann, Malte Michel; Johannessen, Erik P.; Lord, Gareth Steven; Mørk, Atle; Osmundsen, Per Terje; Smyrak-Sikora, Aleksandra; Stemmerik, Lars (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-26)
      The Svalbard Composite Tectono-Stratigraphic Element is located on the north-western corner of the Barents Shelf and comprises a Carboniferous to Pleistocene sedimentary succession. Due to Cenozoic uplift the succession is subaerially exposed in the Svalbard archipelago. The oldest parts of the succession consist of Carboniferous to Permian mixed siliciclastic, carbonate and evaporite and spiculitic ...
    • Introduction: Processes and Palaeo-Environmental Changes in the Arctic from Past to Present (PalaeoArc) special issue 

      Lyså, Astrid; Jennings, Anne; Morigi, Caterina; Stokes, Chris R.; Winsborrow, Monica (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-05)
      PalaeoArc (Processes and Palaeo-Environmental Changes in the Arctic: From Past to Present) is an international network research programme, the aim of which is to understand and explain the climatically induced environmental changes in the Arctic that have taken place throughout the Quaternary and continue in the present-day (see http://www.palaeoarc.no/). This network builds on and extends the ...
    • Plastic photodegradation under simulated marine conditions 

      Delre, Annalisa; Goudriaan, Maaike; Morales, Victor Hernando; Vaksmaa, Annika; Rachel Tintswalo, Ndhlovu; Marianne, Baas; Keijzer, Edwin; de Groot, Tim; Zeghal, Emna; Egger, Matthias; Röckmann, Thomas; Niemann, Helge (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-12)
      Ocean plastic pollution is a problem of increasing magnitude; yet, the amount of plastic at the sea surface is much lower than expected. Solar ultraviolet (UV) radiation can induce photodegradation, but its importance in determining the longevity of floating plastic remains unconstrained. Here, we measured photodegradation rates of different plastic types slightly larger than microplastics (virgin ...
    • Using thermal UAV imagery to model distributed debris thicknesses and sub-debris melt rates on debris-covered glaciers 

      Bisset, Rosie R.; Nienow, Peter W.; Goldberg, Daniel N.; Wigmore, Oliver; Loayza-Muro, Raúl A.; Wadham, Jemma Louise; Macdonald, Moya L.; Bingham, Robert G. (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-14)
      Supraglacial debris cover regulates the melt rates of many glaciers in mountainous regions around the world, thereby modifying the availability and quality of downstream water resources. However, the influence of supraglacial debris is often poorly represented within glaciological models, due to the absence of a technique to provide high-precision, spatially continuous measurements of debris thickness. ...
    • Glacial history and depositional environments in little Storfjorden and Hambergbukta of Arctic Svalbard since the younger dryas 

      Joe, Young Jin; Jang, Kwangchul; Forwick, Matthias; Laberg, Jan Sverre; Kong, Gee Soo; Kang, Moo-Hee; Yoon, Seok-Hoon; Nam, Seung-Il (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-11-21)
      Geophysical and lithological data provide crucial information for the understanding of glacial history in Arctic Svalbard. In this study, we reconstructed the glacier-induced depositional environments of Little Storfjorden and its tributary, Hambergbukta, over the last 13 ka to better understand the glacial history of southeastern Svalbard. The combined uses of swath-bathymetry, high-resolution ...
    • Factors controlling the net ecosystem production of cryoconite on Western Himalayan glaciers 

      Shamurailatpam, Monica S.; Telling, Jon; Wadham, Jemma Louise; Ramanathan, A. L.; Yates, Christopher A.; Raju, N. Janardhana (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-12-07)
      In situ experiments were conducted to determine the net ecosystem production (NEP) in cryoconite holes from the surface of two glaciers (Patsio glacier and Chhota Shigri glacier) in the Western Himalaya during the melt season from August to September 2019. The study aimed to gain an insight into the factors controlling microbial activity on glacier surfaces in this region. A wide range of parameters, ...