Fakultet for naturvitenskap og teknologi: Nye registreringer
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The Four Faces of Hyperelliptic curves
(Master thesis; Mastergradsoppgave, 2020-05-13)In this thesis we will look at elliptic and hyperelliptic curves. There are three abelian groups that are isomorphic to hyperelliptic curves. The Jacobian of hyperelliptic curves, the ideal class group and the form class group, will all be defined and given abelian group structure. We will give an algorithm for point addition and point doubling done exclusively in the jacobian of the curve. ... -
Identifying global vs. basinal controls on Paleoproterozoic organic carbon and sulfur isotope records
(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 ... -
The rock slope failures at Låvan and Dusnjarga, Northern Norway. A comprehensive Quaternary, morphological and structural analysis
(Master thesis; Mastergradsoppgave, 2020-05-15)Rock avalanches and subsequent displacement waves represented the deadliest natural disaster in Norway in the past century. The two deep-seated and unstable slopes Dusnjarga and Låvan in Troms county (Norway) are clearly defined by morphological deformation features. Due to the steep fjord setting, a potential catastrophic rock avalanche could pose a severe threat to people and infrastructure along ... -
Ice extent in sub-arctic fjords and coastal areas from 2001 to 2019 analyzed from MODIS imagery
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-03)Results examining variations in the ice extent along the Norwegian coastline based on the analysis of Moderate Resolution Imaging Spectroradiometer (MODIS) images from 2001 to 2019, February through May, are presented. A total of 386 fjords and coastal areas were outlined and grouped into ten regions to assess seasonal and long-term trends in ice extent. In addition, three fjords were examined to ... -
Modification of bedrock surfaces by glacial abrasion and quarrying: Evidence from North Wales
(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, ... -
Spatial trend analysis of gridded temperature data at varying spatial scales
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-28)Classical assessments of trends in gridded temperature data perform independent evaluations across the grid, thus, ignoring spatial correlations in the trend estimates. In particular, this affects assessments of trend significance as evaluation of the collective significance of individual tests is commonly neglected. In this article we build a space–time hierarchical Bayesian model for temperature ... -
Upper Triassic to lower Cretaceous tectonostratigraphic development of the Barents Sea South East
(Master thesis; Mastergradsoppgave, 2020-05-27)The aim of this study is to investigate the tectonic- and evolutionary differences between major structural elements of the Barents Sea South East (BSSE) during the uppermost Triassic to lower Cretaceous. The study area comprises the following structural elements: the Bjarmeland- and Finnmark platforms, the Nordkapp- and Tiddlybanken basins, the Signalhorn-, Haapet- and Veslekari domes and the ... -
Tempestite facies variability and storm‐depositional processes across a wide ramp: Towards a polygenetic model for hummocky cross‐stratification
(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 ... -
Glacial dynamics and fluid flow processes in Bjørnøyrenna and the Loppa High area, SW Barents Sea
(Master thesis; Mastergradsoppgave, 2020-05-15)During the Late Weichselian glaciation, the Bjørnøyrenna ice stream was the main outlet of the Barents Sea Ice Sheet. In this thesis, a 3D seismic dataset from the Loppa High, located in the main ice stream trunk, has been used to study the glacial sediment package, revealing details on pastglacial dynamics, fluid flow processes and gas hydrate formation. Three seismic horizons have been interpreted: ... -
Engineering geology of the Jettan rockslide, Kåfjorden
(Master thesis; Mastergradsoppgave, 2020-05-15)The unstable rock slope (URS) Jettan is located at Nordnesfjellet in Kåfjorden municipality in Troms and Finnmark County, 800 m above the fjord. The rockslide has an estimated volume of 6 Mm3, and moving at a rate of up to 50 mm a-1. Jettan is considered a “high risk object” within the Norwegian unstable mountain framework. This is due to the potential displacement wave impact to housings, infrastructure ... -
The escherichia coli alkA gene is activated to alleviate mutagenesis by an oxidized deoxynucleoside
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-25)The cellular methyl donor S-adenosylmethionine (SAM) and other endo/exogenous agents methylate DNA bases non-enzymatically into products interfering with replication and transcription. An important product is 3-methyladenine (m<sup>3</sup>A), which in <i>Escherichia coli</i> is removed by m<sup>3</sup>A-DNA glycosylase I (Tag) and II (AlkA). The <i>tag</i> gene is constitutively expressed, while ... -
Innovative methods to monitor rock and mountain slope deformation
(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 ... -
Rational selection of co-catalysts for the deaminative hydrogenation of amides
(Journal article; Tidsskriftartikkel; Peer reviewed, 2020-01-20)The catalytic hydrogenation of amides is an atom economical method to synthesize amines. Previously, it was serendipitously discovered that the combination of a secondary amide co-catalyst with (<sup>iPr</sup>PNP)Fe(H)(CO) (<sup>iPr</sup>PNP = N[CH<sub>2</sub>CH<sub>2</sub>(P<sup>i</sup>Pr<sub>2</sub>)]<sub>2</sub>−), results in a highly active base metal system for deaminative amide hydrogenation. ... -
Geochemical evidence for seabed fluid flow linked to the subsea permafrost outer border in the South Kara Sea
(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 ... -
The relationship between shallow anomalies and gas-flaring on the flank of the Nordkapp Basin in the SE Barents Sea
(Master thesis; Mastergradsoppgave, 2020-05-18)This study investigates the north-east-subbasin of the Nordkapp Basin in the Barents Sea. Main focus has been on mapping shallow seismic anomalies from 3D data, their potential association with faulting and sub-surface structures, and further to compare the occurrence of seismic anomalies to possible gas-flares above the seabed from water column data. The stratigraphic intervals from Triassic to ... -
Last Glacial Maximum – Holocene palaeoenvironment in Bessel Fjord and southwestern Dove Bugt, Northeast Greenland
(Master thesis; Mastergradsoppgave, 2020-05-14)Marine studies reconstructing ice sheet conditions on the Northeast Greenland shelf and adjacent fjords since the Last Glacial Maximum (LGM) are sparse. As a result, the timing and origin of the deglaciation of the ice sheet over marine areas is not well constrained. This thesis aims to improve our understanding of the LGM, deglaciation, and Holocene ice dynamics of the Greenland Ice Sheet (GrIS) ... -
Beneath the snow – Developing a wireless sensor node for remote locations in the Arctic
(Master thesis; Mastergradsoppgave, 2020-05-15)In this thesis we describe how we designed, built, deployed, and improved upon a robust hardware- and software solution, tailor-made to this scientific question. During the course of this project, we created three distinct versions and we have conducted two deployments of the sensor nodes in the Arctic tundra. The node is able to measure CO2 , temperature, and humidity, in addition to monitoring an ... -
Late Quaternary glacier and sea-ice history of northern Wijdefjorden, Svalbard
(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
(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 ... -
Analyse av strukturer og bevegelsesdata i det ustabile fjellskredområdet Gámmanjunni 3, Kåfjord kommune, Troms og Finnmark fylke. Med vekt på kontrollerende faktorer, skråningsprosesser, bevegelsesdynamikk og skredmodeller.
(Master thesis; Mastergradsoppgave, 2020-05-15)Gámanjunni 3 er et av de ustabile fjellpartiene i Norge med høyest bevegelseshastighet. Hovedmålet med studiet er å sammenstille gamle og nye feltdata, bevegelsesdata og geofysiske data fra tidligere studier ved Gámanjunni 3 til en helhetlig geologisk modell i 3D, og undersøke hvilke interne og eksterne faktorer som kontrollerer fjellpartiet. I tillegg skal det fokuseres på bevegelsesdynamikk, ...