Recent additions

  • 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 ...
  • Anthropocene rockfalls travel farther than prehistoric predecessors 

    Vick, Louise Mary; Borella, Josh Walter; Quigley, Mark (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09-02)
    Human modification of natural landscapes has influenced surface processes in many settings on Earth. Quantitative data comparing the distribution and behavior of geologic phenomena before and after human arrival are sparse but urgently required to evaluate possible anthropogenic influences on geologic hazards. We conduct field and imagery-based mapping, statistical analysis, and numerical modeling ...
  • Long-lasting Cadomian magmatic activity along an active northern Gondwana margin: U–Pb zircon and Sr–Nd isotopic evidence from the Brunovistulian Domain, eastern Bohemian Massif 

    Soejono, Igor; Janousek, Vojtěch; Žáčková, Eliška; Sláma, Jiří; Konopásek, Jiří; Machek, Matěj; Hanžl, Pavel (Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-03)
    Cadomian magmatic complexes of the Brunovistulian Domain crop out at the eastern termination of the Bohemian Massif. However, the age, nature and geotectonic affinity of some of pre-Variscan (meta-)igneous rock complexes from this domain are still unknown. Geochronological and geochemical study of the granitic rocks across the Brunovistulian Domain reveals new information about the timing and nature ...
  • Identifying global vs. basinal controls on Paleoproterozoic organic carbon and sulfur isotope records 

    Paiste, Kärt; Lepland, Aivo; Zerkle, Aubrey L.; Kirsimae, Kalle; Kreitsmann, Timmu; Mänd, Kaarel; Romashkin, Alexander E.; Rychanchik, Dimitry V.; Prave, Anthony R (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-03)
    Paleoproterozoic sedimentary successions are important archives of the redox evolution of Earth’s atmosphere and oceans. Efforts to unravel the dynamics of our planet’s early oxygenation from this archive rely on various geochemical proxies, including stable carbon and sulfur isotopes. However, ancient metasedimentary rocks often experienced early- and late-stage (bio)geochemical processes making ...
  • 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, ...
  • Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification 

    Jelby, Mads Engholm; Grundvåg, Sten-Andreas; Helland-Hansen, William; Olaussen, Snorre; Stemmerik, Lars (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-10-03)
    The hydrodynamic mechanisms responsible for the genesis and facies variability of shallow‐marine sandstone storm deposits (tempestites) have been intensely debated, with particular focus on hummocky cross‐stratification. Despite being ubiquitously utilized as diagnostic elements of high‐energy storm events, the full formative process spectrum of tempestites and hummocky cross‐stratification is still ...
  • Innovative methods to monitor rock and mountain slope deformation 

    Hormes, Anne; Adams, Marc; Amabile, Anna Sara; Blauensteiner, Franz; Demmler, Christian; Fey, Christine; Ostermann, Marc; Rechberger, Christina; Sausgruber, Thomas; Vecchiotti, Filippo; Vick, Louise Mary; Zangerl, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-17)
    Displacement rates of mountain slope deformations that can affect entire valley mountain flanks are often measured spatially distributed in‐situ without spatial significance. The spatially explicit measurement and recording of time series of slope deformations is a challenge, as the unstable slopes are often disintegrated into several subdomains, which move with different deformation rates. The ...
  • Geochemical evidence for seabed fluid flow linked to the subsea permafrost outer border in the South Kara Sea 

    Semenov, Petr; Portnov, Aleksei D; Krylov, Alexey; Egorov, Alexander V; Vanshtein, Boris (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-04-16)
    Driven by rising bottom water temperatures, the thawing of subsea permafrost leads to an increase in fluid flow intensity in shallow marine sediments and results in the emission of methane into the water column. Limiting the release of permafrost-related gas hydrates and permafrost- sequestered methane into the global carbon cycle are of primary importance to the prevention of future Arctic Ocean ...
  • Late Quaternary glacier and sea-ice history of northern Wijdefjorden, Svalbard 

    Allaart, Lis; Müller, Juliane; Schomacker, Anders; Rydningen, Tom Arne; Håkansson, Lena; Kjellman, Sofia Elisabeth; Mollenhauer, Gesine; Forwick, Matthias (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-04-10)
    The deglaciation history and Holocene environmental evolution of northern Wijdefjorden, Svalbard, are reconstructed using sediment cores and acoustic data (multibeam swath bathymetry and sub‐bottom profiler data). Results reveal that the fjord mouth was deglaciated prior to 14.5±0.3 cal. ka BP and deglaciation occurred stepwise. Biomarker analyses show rapid variations in water temperature and sea ...
  • Global temperature calibration of the Long chain Diol Index in marine surface sediments 

    de Bar, Marijke W.; Weiss, Gabriella; Yildiz, Caglar; Rampen, Sebastiaan W.; Lattaud, Julie; Bale, Nicole J.; Mienis, Furu; Brummer, Geert-Jan A.; Schulz, Hartmut; Rush, Darci; Kim, Jung-Hyun; Donner, Barbara; Knies, Jochen; Lückge, Andreas; Stuut, Jan-Berend W.; Sinninghe Damsté, Jaap S.; Schouten, Stefan (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-07)
    The Long chain Diol Index (LDI) is a relatively new organic geochemical proxy for sea surface temperature (SST), based on the abundance of the C<sub>30</sub> 1,15-diol relative to the summed abundance of the C<sub>28</sub> 1,13-, C<sub>30</sub> 1,13- and C<sub>30</sub> 1,15-diols. Here we substantially extend and re-evaluate the initial core top calibration by combining the original dataset with 172 ...
  • Late Devonian–Carboniferous faulting and controlling structures and fabrics in NW Finnmark 

    Koehl, Jean-Baptiste P.; Bergh, Steffen G; Osmundsen, Per Terje; Redfield, Thomas Fitzmaurice; Indrevær, Kjetil; Lea, Halldis; Bergø, Espen (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-09-10)
    In the SW Barents Sea, Devonian–Carboniferous collapse led to the formation of major basins and faults, e.g., the Hammerfest Basin bounded by the Troms–Finnmark Fault Complex, and rhomboid- to sigma-shaped (half-)grabens on the Finnmark Platform. High-resolution aeromagnetic and bathymetry data from the shallow shelf show that analogue fault systems are present in coastal and onshore areas of NW ...
  • Microbial communities from Arctic marine sedimentsrespond slowly to methane addition duringex situenrichments 

    Klasek, Scott; Torres, Martha; Bartlett, Douglas H.; Tyler, Madeline; Hong, Wei-Li; Colwell, Frederick (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-12-15)
    Anaerobic methanotrophic archaea (ANME) consume methane in marine sediments, limiting its release to the water column, but their responses to changes in methane and sulfate supplies remain poorly constrained. To address how methane exposure may affect microbial communities and methane‐ and sulfur‐cycling gene abundances in Arctic marine sediments, we collected sediments from offshore Svalbard that ...
  • 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 ...
  • Is there a Climatic Control on Icelandic Volcanism? 

    Cooper, Claire L.; Savov, Ivan P.; Patton, Henry; Hubbard, Alun; Ivanovic, Ruza F.; Carrivick, Jonathan L.; Swindles, Graeme T. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-07)
    The evidence for periods of increased volcanic activity following deglaciation, such as following ice sheet retreat after the Last Glacial Maximum, has been examined in several formerly glaciated areas, including Iceland, Alaska, and the Andean Southern Volcanic Zone. Here we present new evidence supporting the theory that during episodes of cooling in the Holocene, Icelandic volcanic activity ...
  • Biogeochemical Consequences of Nonvertical Methane Transport in Sediment Offshore Northwestern Svalbard 

    Treude, Tina; Krause, Stefan; Steinle, Lea; Burwicz, Ewa B.; Hamdan, L.J.; Niemann, Helge; Feseker, Tomas; Liebetrau, Volker; Krastel, Sebastian; Berndt, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-21)
    A site at the gas hydrate stability limit was investigated offshore northwestern Svalbard to study methane transport in sediment. The site was characterized by chemosynthetic communities (sulfur bacteria mats, tubeworms) and gas venting. Sediments were sampled with in situ porewater collectors and by gravity coring followed by analyses of porewater constituents, sediment and carbonate geochemistry, ...
  • Structurally controlled rock slope deformation in northern Norway 

    Vick, Louise Mary; Böhme, Martina; Rouyet, Line; Bergh, Steffen G; Corner, Geoffrey D.; Lauknes, Tom Rune (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-11)
    Gravitational forcing of oversteepened rock mass leads to progressive failure, including rupture, creeping, sliding and eventual avalanching of the unstable mass. As the point of rupture initiation typically follows pre-existing structural discontinuities within the rock mass, understanding the structural setting of slopes is necessary for an accurate characterisation of the hazards and estimation ...
  • The role of deformation-reaction interactions to localize strain in polymineralic rocks: Insights from experimentally deformed plagioclase-pyroxene assemblages 

    Mansard, Nicolas; Stunitz, Holger; Raimbourg, Hugues; Précigout, Jacques (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-09)
    In order to study the mutual effect of deformation and mineral reactions, we have conducted shear experiments on fine-grained plagioclase-pyroxene assemblages in a Griggs-type solid-medium deformation apparatus. Experiments were performed at a constant shear strain rate of 10<sup>−5</sup> s<sup>−1</sup>, a confining pressure of 1 GPa and temperatures of 800, 850 and 900 °C. While the peak stress of ...
  • Deciphering late Devonian–early Carboniferous P–T–t path of mylonitized garnet-mica schists from Prins Karls Forland, Svalbard 

    Kośmińska, Karolina; Spear, Frank S.; Majka, Jarosław; Faehnrich, Karol; Manecki, Maciej; Piepjohn, Karsten; Dallmann, Winfried (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-03-03)
    Quartz‐in‐garnet inclusion barometry integrated with trace element thermometry and calculated phase relations is applied to mylonitized schists of the Pinkie unit cropping out on the island of Prins Karls Forland, western part of the Svalbard Archipelago. This approach combines conventional and novel techniques and allows deciphering of the pressure–temperature (<i>P–T</i>) evolution of mylonitic ...
  • Manganese/iron‐supported sulfate‐dependent anaerobic oxidation of methane by archaea in lake sediments 

    Su, Guangyi; Zopfi, Jakob; Yao, Haoyi; Steinle, Lea; Niemann, Helge; Lehmann, Moritz F (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-11-04)
    Anaerobic oxidation of methane (AOM) by methanotrophic archaea is an important sink of this greenhouse gas in marine sediments. However, evidence for AOM in freshwater habitats is rare, and little is known about the pathways, electron acceptors, and microbes involved. Here, we show that AOM occurs in anoxic sediments of a sulfate‐rich lake in southern Switzerland (Lake Cadagno). Combined AOM‐rate ...
  • Estimation of net apparent erosion in the SW Barents Sea by applying velocity inversion analysis 

    Ktenas, Dimitrios; Meisingset, Ivar; Henriksen, Erik; Nielsen, Jesper Kresten (Journal article; Tidsskriftartikkel; Peer reviewed, 2019)
    The SW Barents Sea was subjected to significant uplift and erosion during the Cenozoic, processes that are believed to have had a significant impact on hydrocarbon maturation and migration in the area. The current study uses compaction of shale- and sand-dominated layers to make a map of net apparent erosion throughout the SW Barents Sea. The map shows regional trends consistent with deep-seated ...

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