Fakultet for naturvitenskap og teknologi: Recent submissions
Now showing items 4021-4040 of 5327
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Two-stage exhumation of subducted Saxothuringian continental crust records underplating in the subduction channel and collisional forced folding (Krkonoše-Jizera Mts., Bohemian Massif)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-08)The Krkonoše-Jizera Massif in the northern part of the Variscan Bohemian Massif provides insight into the exhumation mechanisms for subducted continental crust. The studied region exposes a relatively large portion of a flat-lying subduction-related complex that extends approximately 50 km away from the paleosuture. wide extent of HP-LT metamorphism has been confirmed by new P-T estimates indicating ... -
Ice-sheet-driven methane storage and release in the Arctic
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-07)It is established that late-twentieth and twenty-first century ocean warming has forced dissociation of gas hydrates with concomitant seabed methane release. However, recent dating of methane expulsion sites suggests that gas release has been ongoing over many millennia. Here we synthesize observations of B1,900 fluid escape features—pockmarks and active gas flares—across a previously glaciated ... -
Evidence for ice-free summers in the late Miocene central Arctic Ocean
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-04)Although the permanently to seasonally ice-covered Arctic Ocean is a unique and sensitive component in the Earth’s climate system, the knowledge of its long-term climate history remains very limited due to the restricted number of pre-Quaternary sedimentary records. During Polarstern Expedition PS87/2014, we discovered multiple submarine landslides along Lomonosov Ridge. Removal of younger ... -
Deconvoluting complex structural histories archived in brittle fault zones
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-16)Brittle deformation can saturate the Earth’s crust with faults and fractures in an apparently chaotic fashion. The details of brittle deformational histories and implications on, for example, seismotectonics and landscape, can thus be difficult to untangle. Fortunately, brittle faults archive subtle details of the stress and physical/chemical conditions at the time of initial strain localization ... -
Constraints on oceanic methane emissions west of Svalbard from atmospheric in situ measurements and Lagrangian transport modeling
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-12-10) -
On the performance and energy efficiency of the PGAS programming model on multicore architectures
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-09-15) -
Electronic structure of small surfactants: a continuum solvation study
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-07-18)The e ect of surfaces and interfaces on the structure and properties of molecules is of a great interest in a number of biological and technological applications. Nevertheless, such an investigation is extremely challenging from an experimental point of view, due to the bidimensionality of the environment. In recent years, we have developed a framework to study molecules at surfaces ... -
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
(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 ... -
Oil spill characterization in the hybrid-polarity SAR domain using log-cumulants
(Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-10-18)Log-cumulants have proven to be an interesting tool for evaluating the statistical properties of potential oil spills in polarimetric Synthetic Aperture Radar (SAR) data within the common horizontal (H) and vertical (V) polarization basis. The use of first, second, and third order sample log-cumulants has shown potential for evaluating the texture and the statistical distributions, as well as ... -
Benthic foraminiferal growth seasons implied from Mg/Ca-temperature correlations for three Arctic species
(Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-11-22)Core-top sediment samples from Kongsfjorden, Svalbard, and adjacent fjord and shelf areas were collected in order to investigate a potential relationship between Mg/Ca-ratios of Arctic benthic foraminifera and the ambient bottom water temperatures (BWT). The area is influenced by large seasonal variation in factors such as light and temperature, which is further strengthened by oceanographic shifts, ... -
Paleoceanographic development during the last deglaciation and Holocene, over the Bear Island slide scar, SW Barents Sea
(Master thesis; Mastergradsoppgave, 2017-02-02)The investigated sediment core HH13-243 GC is located under the present flow of the warm and saline Atlantic Water (AW), but close to, glaciated continental margins. The core site is situated in an area that is sensitive to changes and reflects the paleoceanography of the northernmost Norwegian Sea and the Western Barents Sea. We investigated the changes in inflow of Atlantic water and the ... -
On RAM performance of production facilities operating under the Barents Sea harsh environmental conditions
(Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-05-19)Oil and gas (O&G) industry is expanding its activities into Arctic offshore, where is characterised with severe operating conditions and less-developed infrastructure. Such conditions affect the reliability, availability, and maintainability (RAM) of offshore O&G plants, operations, and activities through different scenarios. Plant RAM analysis provides key information for decision-making on, for ... -
Availability assessment of oil and gas processing plants operating under dynamic Arctic weather conditions
(Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-03-19)We consider the assessment of the availability of oil and gas processing facilities operating under Arctic conditions. The novelty of the work lies in modelling the time-dependent effects of environmental conditions on the components failure and repair rates. This is done by introducing weather-dependent multiplicative factors, which can be estimated by expert judgements given the scarce data available ... -
A Segmentation based CFAR detection algorithm using truncated statistics
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-01-18)Target detection in nonhomogeneous sea clutter environments is a complex and challenging task due to the capture effect from interfering outliers and the clutter edge effect from background intensity transitions. For synthetic aperture radar (SAR) measurements, those issues are commonly caused by multiple targets and meteorological and oceanographic phenomena, respectively. This paper proposes a ... -
Divergent drift of Adriatic-Dinaridic and Moesian carbonate platforms during the rifting phase witnessed by Triassic MVT Pb-Zn and SEDEX deposits; a metallogenic approach
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-29)Early-intracontinental rifting of Pangea was a result of thermal doming in Uppermost Permian time giving rise to the formation of horst-graben structures, followed by slow subsidence, marine transgression and evaporite deposition. The consequences of incipient magmatism and a high heat flow are numerous geothermal fields and subterrestrial hydrothermal siderite-barite-polysulfide deposits (PALINKAŠ ... -
The Ljubija geothermal field: A herald of the Pangea break-up (NW Bosnia and Herzegovina)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-29)The Ljubija ore deposits are the loci typici of siderite-barite-polysulphide deposits within the Inner Dinarides, Gemerides and Eastern Alps. Numerous sites of ore outcrops, smaller or larger ore bodies of mineralization, consisting of Fe carbonates, sulphides, barite and fluorite are scattered over an area of 150 square km. The half billion tons of iron ore resources occur as replacement in ... -
Porphyry Cu mineralization related to the small Tertiary volcanic intrusions in the Bučim ore deposit, Eastern Macedonia
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-29)The paper presents data about the geology, geochemistry, structure, genesis and specific features of the Bučim porphyry Cu deposit which is actively mined in Macedonia. The porphyry mineralization (0.3 % Cu, 0.3-0.5 ppm Au) is spatially and temporarily associated with Tertiary subvolcanic intrusions of latitic and latitic-andesitic composition. The intrusions occurred during Oligo-Miocene time ... -
Origin and K-Ar age of the phreatomagmatic breccia at the Trepča Pb-Zn-Ag skarn deposit, Kosovo: Implications for ore-forming processes
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-29)The Trepča Pb-Zn-Ag skarn deposit in Kosovo is spatially and temporarily related to the phreatomagmatic breccia of Oligocene age (~23Ma). The deposit shows features typical for skarn deposits worldwide, including a stage of isochemical metamorphism, a prograde stage of an anhydrous, low oxygen and low sulfur fugacity character, and a retrograde stage characterized by an increase in the water ... -
A Multisensor Comparison of Experimental Oil Spills in Polarimetric SAR for High Wind Conditions
(Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-06-23)In this paper, we present the experimental setup and data collection during the Norwegian Radar oil Spill Experiment 2015, followed by a comparison of a subset of the multisensory synthetic aperture radar (SAR) imagery collected during the experiment. Multipolarization SAR data acquired by Radarsat-2, TerraSAR-X, and the uninhabited aerial vehicle synthetic aperture radar (UAVSAR) less than 6 min ... -
Characterization and discrimination of evolving mineral and plant oil slicks based on L-band synthetic aperture radar (SAR)
(Peer reviewed; Journal article; Tidsskriftsartikkel, 2016-10-18)Evolution of the damping ratio for Bragg wavenumbers in the range 32-43 rad/m is evaluated for oil slicks of different composition released in the open ocean and allowed to develop naturally. The study uses quad-polarimetric L-band airborne synthetic aperture radar data acquired over three mineral oil emulsion releases of different, known oil-to-water ratio, and a near-coincident release of 2-ethylhexyl ...