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dc.contributor.authorSerov, Pavel
dc.contributor.authorPortnov, Aleksei D
dc.contributor.authorMienert, Jurgen
dc.contributor.authorSemenov, Peter
dc.contributor.authorIlatovskaya, Polonia
dc.date.accessioned2019-06-11T13:10:19Z
dc.date.available2019-06-11T13:10:19Z
dc.date.issued2015-07-16
dc.description.abstractThe Holocene marine transgression starting at ~19 ka flooded the Arctic shelves driving extensive thawing of terrestrial permafrost. It thereby promoted methanogenesis within sediments, the dissociation of gas hydrates, and the release of formerly trapped gas, with the accumulation in pressure of released methane eventually triggering blowouts through weakened zones in the overlying and thinned permafrost. Here we present a range of geophysical and chemical scenarios for the formation of pingo‐like formations (PLFs) leading to potential blowouts. Specifically, we report on methane anomalies from the South Kara Sea shelf focusing on two PLFs imaged from high‐resolution seismic records. A variety of geochemical methods are applied to study concentrations and types of gas, its character, and genesis. PLF 1 demonstrates ubiquitously low‐methane concentrations (14.2–55.3 ppm) that are likely due to partly unfrozen sediments with an ice‐saturated internal core reaching close to the seafloor. In contrast, PLF 2 reveals anomalously high‐methane concentrations of >120,000 ppm where frozen sediments are completely absent. The methane in all recovered samples is of microbial and not of thermogenic origin from deep hydrocarbon sources. However, the relatively low organic matter content (0.52–1.69%) of seafloor sediments restricts extensive in situ methane production. As a consequence, we hypothesize that the high‐methane concentrations at PLF 2 are due to microbial methane production and migration from a deeper source.en_US
dc.description.sponsorshipFederal Subsoil Resources Management Agency of Russiaen_US
dc.descriptionSource at <a href=https://doi.org/10.1002/2015JF003467>https://doi.org/10.1002/2015JF003467</a>.en_US
dc.identifier.citationSerov, P., Portnov, A., Mienert, J., Semenov, P. & Ilatovskaya, P. (2015). Methane release from pingo-like features across the South Kara Sea shelf, an area of thawing offshore permafrost. <i>Journal of Geophysical Research - Earth Surface, 120</i>(8), 1515-1529. https://doi.org/10.1002/2015JF003467en_US
dc.identifier.cristinIDFRIDAID 1258497
dc.identifier.doi10.1002/2015JF003467
dc.identifier.issn2169-9003
dc.identifier.issn2169-9011
dc.identifier.urihttps://hdl.handle.net/10037/15528
dc.language.isoengen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.isbasedonAll data used in this paper as well as detailed description of geochemical and geophysical methods are available upon request from the authors.en_US
dc.relation.ispartofSerov, P. (2019). Cryosphere-controlled methane release throughout the last glacial cycle. (Doctoral thesis). <a href=https://hdl.handle.net/10037/15559>https://hdl.handle.net/10037/15559</a>.
dc.relation.journalJournal of Geophysical Research - Earth Surface
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::Mineralogy, petrology, geochemistry: 462en_US
dc.subjectVDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Mineralogi, petrologi, geokjemi: 462en_US
dc.titleMethane release from pingo-like features across the South Kara Sea shelf, an area of thawing offshore permafrosten_US
dc.typeJournal articleen_US
dc.typeTidsskriftartikkelen_US
dc.typePeer revieweden_US


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