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  • Methane bubbles in the Arctic Ocean. Quantification, variability analysis and modelling of free and dissolved methane from the seafloor to the atmosphere 

    Jansson, Pär (Doctoral thesis; Doktorgradsavhandling, 2018-11-09)
    Intensive but heterogeneous and transient seepage of methane (CH4) bubbles from the seafloor exist west of Prins Karls Forland (PKF), offshore western Svalbard. The powerful greenhouse gas CH4, has 32 times higher warming potential than carbon dioxide (CO2) and if seepage of CH4 from the seafloor reaches the atmosphere, it will contribute to the warming climate. Warming of the oceans may in turn, ...
  • Holocene glacier history of Svalbard: Retracing the style of (de-)glaciation 

    Farnsworth, Wesley Randall (Doctoral thesis; Doktorgradsavhandling, 2018-12-06)
    Through the Holocene, Svalbard glaciers have exhibited at least two phases of re-advance, one during the Early Holocene and another throughout the entire Late Holocene. No geomorphological features have been identified corresponding to glacier re-advances between 9.0 – 4.5 ka BP. The Early Holocene glacier re-advances identified across Svalbard and they correspond to a diverse range of glacier sizes. ...
  • Advancing Segmentation and Unsupervised Learning Within the Field of Deep Learning 

    Kampffmeyer, Michael Christian (Doctoral thesis; Doktorgradsavhandling, 2018-10-19)
    Due to the large improvements that deep learning based models have brought to a variety of tasks, they have in recent years received large amounts of attention. However, these improvements are to a large extent achieved in supervised settings, where labels are available, and initially focused on traditional computer vision tasks such as visual object recognition. Specific application domains that ...
  • Reconstructing the Paleoproterozoic sulfur cycle: Insights from the multiple sulfur isotope record of the Zaonega Formation, Karelia, Russia 

    Paiste, Kärt (Doctoral thesis; Doktorgradsavhandling, 2018-11-08)
    Earth’s oxygen-rich atmosphere and its capacity to sustain complex life is the most paramount feature that distinguishes Earth from all other planets. The irreversible oxygenation of atmosphere occurred about half way through Earth’s history at ~2.3 Ga (the Great Oxidation Event – GOE) when for the first-time photosynthetic oxygen production surpassed the consumption by chemical reactions allowing ...
  • Unmanned aerial vehicles for marine mammal surveys in arctic and sub-arctic regions 

    Aniceto, Ana Sofia Albuquerque Lima (Doctoral thesis; Doktorgradsavhandling, 2018-06-19)
    New tools and methods are needed to monitor marine resources so that industrial activities can be conducted without (or at least minimizing) adverse impacts on species of concern. UAVs can be used as a complementary or alternative tool to current methods for monitoring and research of marine mammals. This study highlights current knowledge gaps and the need for further empirical testing of these ...
  • Advancing relativistic electronic structure methods for solids and in the time domain 

    Kadek, Marius (Doctoral thesis; Doktorgradsavhandling, 2018-08-28)
    Effects arising from the special theory of relativity significantly influence the electronic structure and properties of molecules and solid-state materials containing heavy elements. At the same time, the inclusion of the relativistic effects in theoretical and computational models increases their methodological complexity and the computational cost. In the solid state, additional challenges ...
  • KAIRA - The Kilpisjärvi Atmospheric Imaging Receiver Array 

    McKay, Derek (Doctoral thesis; Doktorgradsavhandling, 2018-08-24)
    The Kilpisjärvi Atmospheric Imaging Receiver Array (KAIRA) is a phased-array radio detector located in Arctic Finland, where auroral electron precipitation is common. This unique deployment of a modern radio telescope in an unconventional location has resulted in a novel and powerful instrument capable of carrying out a large variety of remote-sensing, geoscience experiments. This work presents a ...
  • Octaiodoporphyrin and Octaiodocorrole: Isolation of a Cis Porphyrin Tautomer 

    Thomassen, Ivar Kristian (Doctoral thesis; Doktorgradsavhandling, 2018-09-28)
    Iodinated aromatics are excellent starting materials for further elaboration via transition-metal-catalyzed cross-coupling reactions. Considering the diverse applications of porphyrins and corroles - as photosensitizers in photodynamic therapy, dye sensitized solar cells, near-infrared dyes, gas sensors, nonlinear optical materials, and catalysts - the synthetic potential of β-polyiodinated or ...
  • Statistical properties of intermittent fluctuations in the boundary of fusion plasmas 

    Theodorsen, Audun (Doctoral thesis; Doktorgradsavhandling, 2018-06-14)
    Fluctuation-induced plasma–wall interactions is a major concern for the next generation, high duty-cycle magnetic confinement fusion devices. The turbulence is generated in the outboard midplane transition region between the confined core plasma and the scrape-off layer where magnetic field lines intersect material walls. Here, filaments of hot and dense plasma, elongated in the field direction, ...
  • Multi-frequency radar remote sensing of sea ice. Modelling and interpretation of polarimetric multi-frequency radar signatures of sea ice 

    Grahn, Jakob (Doctoral thesis; Doktorgradsavhandling, 2018-06-08)
    This thesis deals with polarimetric multi-frequency radar signatures of sea ice. It presents a thorough background on the topic and three case studies. The first study presents a global sensitivity analysis of the fully polarimetric radar backscatter response from snow covered sea ice. The analysis is global in the sense that it takes into account the observed ranges of sea ice properties that ...
  • Mid/Late Devonian-Carboniferous extensional faulting in Finnmark and the SW Barents Sea 

    Koehl, Jean-Baptiste Philippe (Doctoral thesis; Doktorgradsavhandling, 2018-05-24)
    In northern Norway, late/post-Caledonian extension initiated along inverted, brittle-ductile thrusts, e.g. Sørøya-Ingøya shear zone, which truncated existing, margin-oblique, late Neoproterozoic, Timanian faults and margin-parallel, latest Mesoproterozoic-mid Neoproterozoic faults related to the opening of the Asgard Sea and Iapetus Ocean. Inverted thrusts were active through the Devonian and early ...
  • Synthesis and inhibitor design of carbapenemase inhibitors 

    Akhter, Sundus (Doctoral thesis; Doktorgradsavhandling, 2018-05-24)
    The efficiency of bacteria in acquiring resistance for their survival ensures a never-ending war against resistance. The only tactic to curtail the resistance crisis is to keep pace with it, e.g. by continuous development of new antibiotics with activity against resistant bacteria or revival of existing agents by inhibiting the mechanisms of resistance. β-lactams are the largest and most widely used ...
  • Cenozoic tectonosedimentary development and erosion estimates for the Barents Sea continental margin, Norwegian Arctic 

    Lasabuda, Amando Putra Ersaid (Doctoral thesis; Doktorgradsavhandling, 2018-04-26)
    The Barents Sea shelf has been experienced extensive uplift and erosion in the Cenozoic. However, the pre-glacial erosion has been so far less constrained in comparison to the glacial erosion. This paper aims to better understand the early–middle Cenozoic erosion in the western Barents Sea and the late Cenozoic erosion in the northern Barents Sea by using the mass-balance approach. The study utilizes ...
  • Late Weichselian ice-sheet dynamics and deglaciation history of the northern Svalbard margin 

    Fransner, Oscar (Doctoral thesis; Doktorgradsavhandling, 2018-05-04)
    This thesis presents new results from marine geological and geophysical studies based on sediment gravity cores, airgun, subbottom acoustic and high-resolution swath bathymetric data from fjords, the continental shelf and slope north of Nordaustlandet, Svalbard. From these records, the glacial landform assemblages as well as the glacial and postglacial sedimentary environments were interpreted. Where ...
  • Benthic communities at high-Arctic cold seeps: Faunal response to methane seepage in Svalbard 

    Åström, Emmelie (Doctoral thesis; Doktorgradsavhandling, 2018-03-20)
    Cold seeps are chemosynthetic habitats found in both deep sea and shallow ocean-shelves worldwide, including the polar regions. At seeps, hydrocarbons, sulfide, and other reduced compounds emerge from the seafloor, providing energy to fuel chemoautotrophic production. Microbial assemblages, supported by the oxidation and reduction of gases and fluids, form the base of a food web composing unique and ...
  • Diagenetically altered benthic foraminifera reveal paleo-methane seepage 

    Schneider, Andrea (Doctoral thesis; Doktorgradsavhandling, 2018-05-02)
    Methane is a powerful greenhouse gas and its atmospheric concentrations varied throughout the geological history. Large amounts of methane are stored in seafloor sediments and society is apprehensive that some of this methane may enter the water column and atmosphere. Vestnesa Ridge, located offshore north-western Svalbard, is one of the northernmost known active methane seeps. This PhD project ...
  • Investigation of Sea Ice Using Multiple Synthetic Aperture Radar Acquisitions 

    Yitayew, Temesgen Gebrie (Doctoral thesis; Doktorgradsavhandling, 2018-02-23)
    The thesis investigates imaging in the vertical direction of different types of ice in the arctic using synthetic aperture radar (SAR) tomography and SAR interferometry. In the first part, the magnitude and the positions of the dominant scattering contributions within snow covered fjord and lake ice layers are effectively identified by using a very high resolution ground-based tomographic SAR system. ...
  • Mountain building processes in the northern Norwegian Caledonides - Examining Caledonian continental collision using a combination of structural mapping, phase equilibrium modelling and geochronology 

    Faber, Carly (Doctoral thesis; Doktorgradsavhandling, 2018-01-17)
    Studying orogenesis allows us to better understand the construction of continental crust and the lower crustal processes that occur in modern orogenic belts (e.g. the Himalaya). The Scandinavian Caledonides formed when Laurentia and Baltica collided during the Silurian/Devonian, and allow for direct study of mid- to lower crustal metamorphism in a continental collision zone. This work focuses on the ...
  • Long-range memory in Earth's climate response - analysis of paleoclimatic records and climate model simulations 

    Nilsen, Tine (Doctoral thesis; Doktorgradsavhandling, 2018-01-22)
    The memory properties in paleoclimate temperature records based on model simulations and proxy-reconstructions have been investigated, to find out if these records exhibit long-range memory in a similar manner as many instrumental temperature records. On time scales from years to centuries and even millennia, long-range memory is identified in the paleoclimate records using a toolbox of statistical ...
  • Applying Multivariate Analysis to Developing Electrodialytic Remediation of Harbour Sediments from Arctic Locations 

    Pedersen, Kristine Bondo (Doctoral thesis; Doktorgradsavhandling, 2015-03-13)
    Electrodialytic remediation (EDR) is a method for removing pollutants from different materials achieved by acidification and transport processes induced by application of an electric field of low intensity. In the thesis, EDR was shown to be a reliable technology for removal of heavy metals, PAH, PCB and TBT from harbour sediments. The final concentrations of heavy metals met the background criteria ...

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