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dc.contributor.advisorBünz, Stefan
dc.contributor.authorAas, Cecilie
dc.date.accessioned2014-08-06T07:40:34Z
dc.date.available2014-08-06T07:40:34Z
dc.date.issued2014-07-17
dc.description.abstractAbstract: Numerous unburied seafloor pockmarks are related to current methane-leakage at Vestnesa Ridge (~79° N), west of Svalbard. About 50 km long and 1-3 km wide, Vestnesa Ridge is a 1-2 km thick sediment drift to the north of the active Molloy transform – on the eastern spreading segment. With its crest at 1200-1300 m depth, the ridge is located on young (<19.6 Ma) oceanic crust. The entire length of the crest is dominated by more than 100 pockmarks that are up to 700 m in diameter. The depressions in the seabed are caused by the vertical migration of gas through leakage structures; chimneys and pipes. The study area for this project is at the eastern end of Vestnesa Ridge, where the pockmarks are predominantly of a larger scale than those at the western end of the ridge. The distribution of pockmarks is associated to a wide-spread Bottom-Simulating-Reflector (BSR), which indicates the possible occurrence of gas hydrates by representing the base of the Gas-Hydrate-Stability-Zone (GHSZ). Gas hydrates act as a permeability barrier regarding fluid flow. Presumably, their occurrence in this area is controlling the distribution of gas-leakage. Beneath the GHSZ, free gas is shown by strongly negative reflections in the seismic – confirming this assumption. Chimneys are leakage-structures connecting the pockmarks to the BSR. The chimneys and their internal fluid flow are related to several faults spreading through the ridge. Faults are well known conduits for fluid flow. Mechanisms for fluid flow through chimney-structures, is however uncertain. Results from RMS-amplitude mapping in this project, indicate that the chimneys internal fluid flow is also strongly influenced by faults.en
dc.identifier.urihttps://hdl.handle.net/10037/6507
dc.identifier.urnURN:NBN:no-uit_munin_6110
dc.language.isoengen
dc.publisherUiT The Arctic University of Norwayen
dc.publisherUiT Norges arktiske universiteten
dc.rights.accessRightsopenAccess
dc.rights.holderCopyright 2014 The Author(s)
dc.rights.urihttps://creativecommons.org/licenses/by-nc-sa/3.0en_US
dc.rightsAttribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0)en_US
dc.subject.courseIDEOM-3901en
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Petroleumsgeologi og -geofysikk: 464en
dc.subjectVDP::Mathematics and natural science: 400::Geosciences: 450::Petroleum geology and petroleum geophysics: 464en
dc.titleFocused fluid flow through the gas-hydrate stability zone on the Vestnesa Ridge, offshore W-svalbarden
dc.typeMaster thesisen
dc.typeMastergradsoppgaveen


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Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0)
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