Institutt for geovitenskap: Nye registreringer

Viser treff 881-900 av 1025

    • Geological modelling for investigating CO2 emissions in Florina Basin, Greece 

      Koukuzas, N.; Tasianas, Alexandros; Gemeni, V; Alexopoulos, D.; Vasilatos, Charalampos (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-10-15)
      This paper presents an investigation of naturally occurring CO2 emissions from the Florina natural analogue site in Greece. The main objective was to interpret previously collected depth sounding data, convert them into surfaces, and use them as input to develop, for the rst time, 3D geological models of the Florina basin. By also locating the extent of the aquifer, the location of the CO2 ...

    • Changing surface–atmosphere energy exchange and refreezing capacity of the lower accumulation area, West Greenland 

      Charalampidis, C.; Van As, D.; Box, J.E.; van den Broeke, M.R.; Colgan, W.T.; Doyle, S.H.; Hubbard, Alun Lloyd; MacFerrin, M.; Machguth, H.; Smeets, C.J.P.P. (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-18)
      We present 5 years (2009–2013) of automatic weather station measurements from the lower accumulation area (1840 m a.s.l. – above sea level) of the Greenland ice sheet in the Kangerlussuaq region. Here, the summers of 2010 and 2012 were both exceptionally warm, but only 2012 resulted in a strongly negative surface mass budget (SMB) and surface meltwater run-off. The observed run-off was ...

    • Bivalve shell horizons in seafloor pockmarks of the last glacial-interglacial transition suggest a thousand years of methane emissions in the Arctic Ocean 

      Ambrose, William; Panieri, Giuliana; Schneider, Andrea; Plaza-Faverola, Andreia; Carroll, Michael Leslie; Åström, Emmelie; Locke, W.L.; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-05)
      We studied discrete bivalve shell horizons in two gravity cores from seafloor pockmarks on the Vestnesa Ridge (1200 m water depth) and western Svalbard (798000 N, 068550 W) to provide insight into the temporal and spatial dynamics of seabed methane seeps. The shell beds, dominated by two genera of the family Vesicomyidae: Phreagena s.l. and Isorropodon sp., were 20–30 cm thick and centered at ...

    • Geophysical constraints on the dynamics and retreat of the Barents Sea ice sheet as a palaeobenchmark for models of marine icesheet deglaciation 

      Patton, Henry; Andreassen, Karin; Bjarnadóttir, Lilja Rún; Dowdeswell, J.A.; Winsborrow, Monica; Noormets, Riko; Polyak, Leonid; Auriac, A.; Hubbard, Alun Lloyd (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-11-14)
      Our understanding of processes relating to the retreat of marine-based ice sheets, such as the West Antarctic Ice Sheet and tidewater-terminating glaciers in Greenland today, is still limited. In particular, the role of ice-stream instabilities and oceanographic dynamics in driving their collapse are poorly constrained beyond observational timescales. Over numerous glaciations during the Quaternary, ...

    • Controls on gas hydrate system evolution in a region of active fluid flow in the SW Barents Sea 

      Vadakkepuliyambatta, Sunil; Hornbach, Matthew; Bünz, Stefan; Phrampus, Benjamin (Journal article; Tidsskriftartikkel, 2015-09)
      The location and stability of gas hydrates in the SW Barents Sea is poorly constrained due to complex geological, geochemical, and geophysical conditions, including poor controls on regional heat flow and gas chemistry. Understanding the stability of gas hydrates in this region is important, as recent studies suggest destabilizing hydrates may lead to methane discharge into the ocean and possibly ...

    • Seismic Modeling of Free Gas Occurrences and Bottom Simulation Reflection (BSR) Beneath Hydrate-bearing Sediments 

      Tesfamariam, Daniel Adhanom (Master thesis; Mastergradsoppgave, 2016-01-17)
      This master thesis study uses seismic modeling to better understand the seismic response of the free gas that accumulates beneath hydrate-bearing sediments. To this end, I developed 12 different geological models ranging from very simple geometries to anticline structures. Within these models, I varied the distribution of free gas in the layers beneath the BSR. Sediment properties were taken from ...

    • Late Triassic channel systems at the Loppa High, SW Barents Sea 

      Agafonova, Olga (Master thesis; Mastergradsoppgave, 2015-12-23)
      The study is based on the 3D seismic dataset (LN09M01). The study area is located in the southwest Barents Sea, south-western flank of the Loppa High. In the SW Barents Sea, the Middle to Late Triassic interval incorporates relatively thick and widespread fluvial system in the Snadd Formation, which is characterized by distinctive abundance of channel bodies of varying shape and extend. During ...

    • Correlation between changes in paleoceanography, paleoclimate and methane seepage on Vestnesa Ridge, eastern Fram Strait. 

      Myrvang, Karoline (Master thesis; Mastergradsoppgave, 2015-12-21)
      Two sediment cores HH14-002 GC and HH12-930 GC from Vestnesa Ridge in the eastern part of Fram Strain have been investigated to reconstruct the paleoclimate and paleoceanographic conditions during the last ~37,000 years, and to study possibly changes in emission of methane from the seabed through time. Core HH14-002 GC was taken from outside a pockmark, while core HH12-930 GC was taken from inside ...

    • Palaeoceanographic development in Leirdjupet Trough, western Barents Sea, during the Holocene: evidence from foraminiferal, isotopic and sedimentological records 

      Kovalenko, Boriss (Master thesis; Mastergradsoppgave, 2015-12-14)
      The gravity core HH14-012GC from Leirdjupet Trough has been investigated to detect changes in sedimentation and the variations in distribution patterns of marine microorganisms (Planktic and Benthic Foraminifera) and stable isotope values of their shells to reconstruct the variability of the inflow of Atlantic water to the study area. The results are compared to published paleodata records to ...

    • Til IBGs 20-års-jubileum 

      Labugt, Sylvia (Kronikk; Chronicle, 1992)

    • Morphodynamics of a sandy beach during a one-year cycle at Sandbukt, Breivika, Troms, northern Norway 

      Jóhannesson, Jóhannes Marteinn (Master thesis; Mastergradsoppgave, 2015-12-11)
      Six cross-shore beach profiles were monitored in a monthly interval at Sandbukt Beach at Breivikeidet, from October 2014 to October 2015, in order to study impact of storms on the beach profile and understand monthly, seasonal, and annual changes in the beach profile. Change in beach volume showed erosion and decrease in beach width on the southern part of the beach during the winter season, while ...

    • Sedimentære avsetningsmiljøer og deglasiasjonshistorie i Kaldfjorden, Kvaløya, Troms Fylke 

      Hermansen, Hermann Olaussen (Master thesis; Mastergradsoppgave, 2015-11-15)
      Multi-proxy analyser av tre sedimentkjerner som inkluderer litostratigrafi, fysiske egenskaper og XRF kjerne skanning, har sammen med analyser av høyoppløselig seismisk data blitt integrert for å kunne rekonstruere deglasiasjonshistorien og paleo miljøet i Kaldfjorden på Kvaløya, Troms fylke. I Kaldfjorden er stor-skala batymetrien delt inn i fire hoved-basseng med en sedimentmektighet på opptil ...

    • Sedimentære avsetningsmiljøer og deglasiasjonshistorie i Ersfjorden, Kvaløya, Troms fylke. 

      Olsen, Joakim Andre (Master thesis; Mastergradsoppgave, 2015-11-15)
      «Multi-proxy» analyser av tre sedimentkjerneprøver (inkludert litostratigrafi, fysiske egenskaper, kornfordelingsanalyse og XRF skanning) og analyse av høyoppløselige seismiske data ble korrelert for å belyse sedimentasjonsprosesser og rekonstruere deglasiasjonshistorie, samt postglasialt sedimentasjonsmiljø under sen Weichsel og Holocen i Ersfjorden på Kvaløya, nordvest i Troms fylke. Tre ...

    • Effects of mortality changes on biomass and production in Calanus spp. populations 

      Skardhamar, Jofrid; Reigstad, Marit; Carroll, Jolynn; Eiane, Ketil; Wexels Riser, Christian; Slagstad, Dag (Journal article; Tidsskriftartikkel; Peer reviewed, 2011-04-28)
      Calanus species are the main link between primary producers and higher trophic-level organisms in the Barents Sea. The natural mortality rate is an essential parameter for determining the standing stock of Calanus, but it is also one of the most uncertain parameters in present knowledge. The level of human activity, and the associated risk of pollution, is increasing in the Barents Sea, and knowledge ...

    • Land sokkel korrelasjon av sprø mesozoiske og paleozoiske forkastninger i et profil over Vestfjordbassenget, Vestvågøya og Ribbebassenget. 

      Lundekvam, Petter Andreas (Master thesis; Mastergradsoppgave, 2015-08-19)
      Denne studien har studert geomorfologi og sprø forkastninger i et profil som strekker seg fra Vestfjordbassenget, over Vestvågøya/Lofotryggen og Ribbebassenget. Det flate slettelandskapet sentralt på Vestvågøya skiller seg ut fra landskapet ellers i Lofoten, som stor sett består av alpint fjellandskap. Slettelandskapet er omgitt av alpine asymmetriske fjell langs kysten i NØ og NV. Fjellenes brattside ...

    • Analyse av mesozoiske forkastninger og asymmetriske landskap i et profil over Lofotryggen ved Leknes, Vestvågøy. Implikasjoner for dannelsen av roterte forkastningsblokker, riftrelaterte bassenger og nedforkastningen av Leknesgruppen 

      Haraldsvik, Kristian Liland (Master thesis; Mastergradsoppgave, 2015-07-15)
      Dette studiet fokuserer på asymmetriske landskap og deres relasjon til sprø forkastninger, bassenger og roterte forkastningsblokker i et profil over Lofotryggen ved Leknes. Det anvendte datasettet består av sammensatte data fra feltarbeid og landskapsobservasjoner, batymatriske kart og seismiske profiler fra kontinentalsokkelen i Lofoten og Vesterålen. Lofotryggen er definert av to prominente NØ-SV ...

    • Study of the Late Cenozoic depositional environment and seismic anomalies on the Trøndelag Platform using 3D seismic data 

      Jensen, André Frantzen (Master thesis; Mastergradsoppgave, 2015-06-04)
      This thesis has focused on the depositional environment during the development of the Naust Formation in order to improve our understanding of the glacial history of the mid-Norwegian continental shelf, using 3D-seismic data from the Trænabanken and Sklinnadjupet area along with regional 2D-lines. Seismic anomalies have also been investigated to increase our understanding of fluid migration affecting ...

    • Geomorphological study of the rock-slope failure at Adjet, Storfjord, Troms 

      Nopper, Hannah (Master thesis; Mastergradsoppgave, 2015-06-06)
      Norway is known for its steep mountains and many fjords. This landscape provides the potential for large rock-slope failures (RSFs) which, in turn, can cause other catastrophic hazards, e.g. tsunamis. In Troms County, northern Norway, many RSFs are found east and west of the Lyngen peninsula, within an area of discontinuous permafrost. The RSF at Adjet is located southeast of the Lyngen peninsula. ...

    • High-resolution study of selected Dansgaard- Oeschger events and Heinrich event 4 42,189–33,393 cal. years BP. Gravity core JM11-FI-15GC from Fugløy Ridge, northeastern Faeroe Islands Margin 

      Jónsdóttir, Björg (Master thesis; Mastergradsoppgave, 2015-05-15)
      The focus of this thesis was selected Dansgaard-Oeschger (D-O) events and Heinrich event 4 (H4). A gravity core, JM11-FI-15GC, from Fugløy Ridge was used for the investigation. The location of the core site is important due the fact that the Faeroe- Shetland Channel is a key area in understanding the changes in circulation during the last glacial period. In total there were eighteen D-O climatic ...

    • Structural and geochemical mapping of a Fe-mineralized quartz-mica rich unit in the Ringvassøya Greenstone Belt, West Troms Basement Complex 

      Elvenes, Hallgeir (Master thesis; Mastergradsoppgave, 2015-05-28)
      Ringvassøy is one of a chain of large coastal islands representing the Archaean to Paleoproterozoic West Troms Basement Complex (WTBC), west of the Caledonides. On Ringvassøy, a basement of mainly tonalitic gneiss is overlain by the Ringvassøy Greenstone Belt (RGB), which is metamorphosed up to middle amphibolite facies. Tonalitic gneiss in the west and southeast of the island has U–Pb zircon ages ...