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norskInstitutt for geovitenskap: Recent submissions
Now showing items 801-820 of 1025
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Sedimentary environment and seismic anomalies of the upper Brygge and Kai formations on the northern part of the Mid-Norwegian Continental Shelf
(Master thesis; Mastergradsoppgave, 2017-05-15)The sedimentary environment and seismic anomalies of the upper Brygge and Kai formations on the northern part of the Mid-Norwegian Continental Shelf is analysed from 3D seismic data and the exploration well 6604/2-1. This was done in order to give a better understanding of the paleo-climatic development in the period before the establishment of the large-scale ice sheets of the Northern Hemisphere, ... -
Geomorfologisk analyse og skredkartlegging av Setså-området i Saltdal kommune, Nordland
(Master thesis; Mastergradsoppgave, 2017-05-14)Det norske fjord- og dallandskapet består høye fjell og bratte dalsider som er preget av skredaktivitet. Økende krav til framkommelighet langs vegnettet fører til at infrastrukturen er i stadig utvikling, og i mange tilfeller må vegbanen flyttes til mer skredsikre områder. Statens vegvesen er i gang med arbeidet for å flytte dagens Europaveg 6 gjennom Setså, Saltdal kommune, Nordland bort fra de ... -
Geomorfologisk og strukturgeologisk undersøkelse av ustabile skråninger og skredavsetninger i fjellområdet mellom Tromsøysundet og Ullsfjorden i Tromsf
(Master thesis; Mastergradsoppgave, 2017-05-15)Fjellskred er den naturkatastrofen i landet som kan gi høyest konsekvenser, og Troms fylke har flere registrerte ustabile fjellsider enn noe annet sted i landet. Dette gjør også at mange skred og ustabile fjellsider kan studeres innenfor et relativt lite geografisk område. Hensikten med denne oppgaven er å finne sammenhenger i parameterer i berggrunn og topografi som er med å initiere bevegelse i ... -
Integrated characterization of igneous intrusions in Central Spitsbergen
(Master thesis; Mastergradsoppgave, 2017-05-15)Igneous intrusions have a strong influence on petroleum systems, groundwater aquifers, and CO2 storage reservoirs, particularly because they can act as either barriers to, or carriers for fluid flow. This depends on several syn- and post emplacement processes, including fracture development in the intrusion and the host rocks, contact metamorphism of the host rocks, and hydrothermal activity. ... -
Thermal conditions and kinematics associated with final emplacement of the Lyngen nappe
(Master thesis; Mastergradsoppgave, 2017-05-15)The tectonic boundary of between the Lyngen magmatic complex and the underlaying Nordmannvik have been examined for kinematic indicators. This boundary is characterised by an amphibole facies garnet-mica-kyanite gneiss overlain by a greenschist facies amphibolite/meta-gabbro succession separated by heavily foliated and lineated garnet-mica schist, phyllites and quartzites. Two main populations of ... -
Microstructural changes during melt-assisted modification of quartzofeldspatic rocks. An example from the Eger Complex, North-Western Bohemian Massif
(Master thesis; Mastergradsoppgave, 2017-05-15)The Eger Complex is situated in the Saxothuringian domain at the western margin of Bohemian Massif (Czech Republic). Migmatitic orthogneisses associated with granofelses and high-pressure felsic granulites make up the majority of the complex, which is interpreted as an upper crystalline nappe exhumed from underneath the fore-arc Teplá-Barrandian domain during the Variscan orogeny. Studies conducted ... -
Drill cutting release in Ingøydjupet, SW Barents Sea from a well drilled in 1987, and its impact on benthic foraminifera
(Master thesis; Mastergradsoppgave, 2017-05-15)In the nearby areas of the SW Barents Sea, large hydrocarbon reserves have been identified. During drilling procedures, drill cuttings are produced and some are released to sea. The disposal of drill cuttings may cause environmental degradation to the marine environment. Increasing petroleum activities, therefore requires further knowledge of ocean current transportation of fine sediment particles ... -
Connection between chemical zonation and crystallographic preferred orientation as an indicator for the fabric development in eclogites. Example from the Saxothuringian eclogites, Bohemian massif, Czech Republic
(Master thesis; Mastergradsoppgave, 2017-05-15)The presence of eclogites is one of the strongest evidences for high pressure metamorphism, and for the presence of a paleo subduction zone. Deformation of eclogites can yield important information about the kinematics of subduction zones. The main mechanism for fabric development in eclogites is still a matter of debate among various research groups and has split the field in two. Most previous ... -
Shallow gas accumulations and fluid flow in the vicinity of the Goliat field, SW Barents Sea
(Master thesis; Mastergradsoppgave, 2017-05-15)This thesis focuses on the Goliat area located in the Hammerfest Basin, SW Barents Sea. The overall aim of this study is to increase the understanding of fluid flow processes between deeper thermogenic sources, and shallow gas accumulations. Indications of an active fluid flow system has been observed throughout the southwestern Barents Sea. Much of the fluid flow from deep hydrocarbon reservoirs ... -
Shallow stratigraphic cores NW of Bjørnøya, results and implications
(Master thesis; Mastergradsoppgave, 2017-05-15)Two shallow boreholes, 7418/01-U-01 and 7517/12-U-01, were in 1994 drilled by IKU / SINTEF on behalf of the Norwegian Petroleum Directorate (NPD) northwest of Bjørnøya in the western Barents Sea. These were part of a program totalling nine boreholes at six different locations between Bjørnøya and Svalbard. This area is not opened for petroleum activity, and the shallow boreholes were aimed at ... -
Carbonate concretions in an ice-contact delta, Skarmunken, Ullsfjord, northern Norway
(Master thesis; Mastergradsoppgave, 2017-03-10)At Skarmunken, a small village south of Ullsfjord, northern Troms, Norway, an outcrop containing carbonate concretions have been investigated. From sedimentary logging, five facies (facies A-E) have been classified by their grading and composition. Depositional data from logs, maximum pebble size (MPS) and earlier investigations suggests an ice-contact delta. TOC/TS data have revealed a dominantly ... -
Sources and turnover of organic carbon and methane in fjord and shelf sediments off Northern Norway
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-10-22)To better understand the present and past carbon cycling and transformation processes in methane-influenced fjord and shelf areas of northern Norway, we compared two sediment cores from the Hola trough and from Ullsfjorden. We investigated (1) the organic matter composition and sedimentological characteristics to study the sources of organic carbon (C<sub>org</sub>) and the factors influencing ... -
Paleo-methane emissions recorded in foraminifera near the landward limit of the gas hydrate stability zone offshore western Svalbard
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-02-26)We present stable isotope and geochemical data from four sediment cores from west of Prins Karls Forland (ca. 340 m water depth), offshore western Svalbard, recovered from close to sites of active methane seepage, as well as from shallower water depths where methane seepage is not presently observed. Our analyses provide insight into the record of methane seepage in an area where ongoing ocean ... -
A late-Holocene multi-proxy record from the northern Norwegian margin: Temperature and salinity variability
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-11-01)To elucidate the natural variability of Atlantic and Coastal water, a late-Holocene multi-proxy analysis is performed on a marine sediment core from the northern Norwegian margin. This includes planktic foraminiferal fauna and their preservation indicators, stable isotopes (δ18Oc, δ13C), sub-surface temperature (SSTMg/Ca) and salinity (SSS) records based on paired Mg/Ca and δ18Oc measurements of ... -
The influence of a model subglacial lake on ice dynamics and internal layering
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016-04-05)As ice flows over a subglacial lake, the drop in bed resistance leads to an increase in ice velocities and a draw down of isochrones and cold ice. The ice surface flattens as it adjusts to the lack of resisting forces at the base. The rapid transition in velocity induces changes in ice viscosity and releases deformation energy that can raise the temperature locally. Recent studies of Antarctic ... -
Gas hydrate and free gas detection using seismic quality factor estimates from high-resolution P-cable 3D seismic data
(Journal article; Tidsskriftartikkel; Peer reviewed, 2015-09-23)We have estimated the seismic attenuation in gas hydrate and free-gas-bearing sediments from high-resolution P-cable 3D seismic data from the Vestnesa Ridge on the Arctic continental margin of Svalbard. P-cable data have a broad bandwidth (20–300 Hz), which is extremely advantageous in estimating seismic attenuation in a medium. The seismic quality factor (Q), the inverse of seismic attenuation, ... -
Submarginal drumlin formation and late Holocene history of Fláajökull, southeast Iceland
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016)Fláajökull is a non-surging outlet glacier draining the south-eastern part of the Vatnajökull, southeast Iceland. Fláajökull was stationary or advanced slightly between 1966 and 1995 and formed a prominent end moraine. Glacial retreat since then has revealed a cluster of 15 drumlins. This study focuses on the morphology and sedimentology of the drumlins. They are 100–600 m long, 40–130 m wide, and ... -
Production of fluorescent dissolved organic matter in Arctic Ocean sediments
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016)Little is known about the production of fluorescent dissolved organic matter (FDOM) in the anoxic oceanic sediments. In this study, sediment pore waters were sampled from four different sites in the Chukchi-East Siberian Seas area to examine the bulk dissolved organic carbon (DOC) and their optical properties. The production of FDOM, coupled with the increase of nutrients, was observed above the ... -
Arctic megaslide at presumed rest
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016)Slope failure like in the Hinlopen/Yermak Megaslide is one of the major geohazards in a changing Arctic environment. We analysed hydroacoustic and 2D high-resolution seismic data from the apparently intact continental slope immediately north of the Hinlopen/Yermak Megaslide for signs of past and future instabilities. Our new bathymetry and seismic data show clear evidence for incipient slope ... -
Freshwater ostracods (Crustacea) and environmental variability of polygon ponds in the tundra of the Indigirka Lowland, north-east Siberia
(Journal article; Tidsskriftartikkel; Peer reviewed, 2016)Freshwater ostracods (Crustacea, Ostracoda) are valuable biological indicators. In Arctic environments, their habitat conditions are barely known and the abundance and diversity of ostracods is documented only in scattered records with incomplete ecological characterization. To determine the taxonomic range of ostracod assemblages and their habitat conditions in polygon ponds in the Indigirka Lowland, ...
