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dc.contributor.authorPlaza-Faverola, Andreia
dc.contributor.authorKeiding, Marie
dc.date.accessioned2019-02-26T14:16:43Z
dc.date.available2019-02-26T14:16:43Z
dc.date.issued2019-01-15
dc.description.abstractMethane seepage occurs across the western Svalbard margin at water depths ranging from < 300 m, landward from the shelf break, to > 1000 m in regions just a few kilometres from the mid-ocean ridges in the Fram Strait. The mechanisms controlling seepage remain elusive. The Vestnesa sedimentary ridge, located on oceanic crust at a depth of 1000–1700 m, hosts a perennial gas hydrate and associated free gas system. The restriction of the occurrence of acoustic flares to the eastern segment of the sedimentary ridge, despite the presence of pockmarks along the entire ridge, indicates a spatial variation in seepage activity. This variation coincides with a change in the faulting pattern as well as in the characteristics of the fluid flow features. Due to the position of the Vestnesa Ridge with respect to the Molloy and Knipovich mid-ocean ridges, it has been suggested that seepage along the ridge has a tectonic control. We modelled the tectonic stress regime due to oblique spreading along the Molloy and Knipovich ridges to investigate whether spatial variations in the tectonic regime along the Vestnesa Ridge are plausible. The model predicts a zone of tensile stress that extends northward from the Knipovich Ridge and encompasses the zone of acoustic flares on the eastern Vestnesa Ridge. In this zone the orientation of the maximum principal stress is parallel to pre-existing faults. The model predicts a strike-slip stress regime in regions with pockmarks where acoustic flares have not been documented. If a certain degree of coupling is assumed between deep crustal and near-surface deformation, it is possible that ridge-push forces have influenced seepage activity in the region by interacting with the pore-pressure regime at the base of the gas hydrate stability zone. More abundant seepage on the eastern Vestnesa Ridge at present may be facilitated by the dilation of faults and fractures favourably oriented with respect to the stress field. A modified state of stress in the past, due to more significant glacial stress for instance, may explain vigorous seepage activity along the entire Vestnesa Ridge. The contribution of other mechanisms to the state of stress (i.e. sedimentary loading and lithospheric flexure) remain to be investigated. Our study provides a first-order assessment of how tectonic stresses may be influencing the kinematics of near-surface faults and associated seepage activity offshore of the western Svalbard margin.en_US
dc.descriptionSource at <a href= https://doi.org/10.5194/se-10-79-2019> https://doi.org/10.5194/se-10-79-2019 </a>.en_US
dc.identifier.citationPlaza-Faverola, A. & Keiding, M. (2019). Correlation between tectonic stress regimes and methane seepage on the western Svalbard margin. Solid Earth, 10(1), 79-94. https://doi.org/10.5194/se-10-79-2019en_US
dc.identifier.cristinIDFRIDAID 1658051
dc.identifier.doi10.5194/se-10-79-2019
dc.identifier.issn1869-9510
dc.identifier.issn1869-9529
dc.identifier.urihttps://hdl.handle.net/10037/14776
dc.language.isoengen_US
dc.publisherEuropean Geosciences Union (EGU)en_US
dc.relation.isbasedonPlaza-Faverola, Andreia; Keiding, Marie, 2019, "Replication Data for: Correlation between tectonic stress regimes and methane seepage on the west-Svalbard margin", <a href=https://doi.org/10.18710/QXQCUI>https://doi.org/10.18710/QXQCUI</a>, DataverseNO, V1en
dc.relation.journalSolid Earth (SE)
dc.relation.projectIDinfo:eu-repo/grantAgreement/RCN/SFF/223259/Norway/Centre for Arctic Gas Hydrate, Environment and Climate/CAGE/.en_US
dc.rights.accessRightsopenAccessen_US
dc.subjectVDP::Mathematics and natural science: 400::Geosciences: 450::Tectonics: 463en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Tektonikk: 463en_US
dc.subjectVDP::Mathematics and natural science: 400::Geosciences: 450::Quaternary geology, glaciology: 465en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Kvartærgeologi, glasiologi: 465en_US
dc.titleCorrelation between tectonic stress regimes and methane seepage on the western Svalbard marginen_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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