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| Titel |
Gas Hydrate Mounds in the Eastern Slope of the Chukchi Basin, Arctic Ocean: Indicators of Methane-rich Focused Fluid Flow |
| VerfasserIn |
Young-Gyun Kim, Hyoung-Jun Kim, Sookwan Kim, Imgyo Lee, Ji-Hoon Kim, Dong-Hun Lee, Seung-Goo Kang, Young Keun Jin |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250148045
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| Publikation (Nr.) |
 EGU/EGU2017-12273.pdf |
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| Zusammenfassung |
| While the origin and distribution vary across geological conditions, there have been
numerous reports on the occurrence of natural gas hydrate in the continental margins over the
world ocean. However, in situ gas hydrate in the Chukchi Basin has not yet been found
despite a favorable condition for its occurrence. Here we document, for the first time, the
discovery of mound morphologies containing gas hydrate as well as methane-derived
authigenic carbonate (MDAC) in the Chukchi Basin obtained during the IBRV Araon
Expedition ARA07C in 2016. We analyzed high-resolution multibeam and sub-bottom
profiler images, and radioactive isotopes (δ13CCH4, δDCH4) of gases from both the retrieved
cores and dissociated hydrate to unravel the origin of the mounds. The mounds were found
solitarily along certain water depth intervals and characterized by a circular shape, sizing up
to tens of meters in width and a few meters in height. Acoustic turbidity is common below
thin hemipelagic sediment layer, indicative of shallow accumulation of gas. The
isotopic signatures suggest that thermogenic methane may migrate to the shallow
depth although its migration pathway cannot be clarified. Our findings bring new
insight on the occurrence of gas hydrate mounds in the Chukchi Basin, and their
development linked to methane-rich focused fluid flow from deep. We will further
investigate microbial characterization from the MDAC with analyses of the lipid
marker and 16s rRNA to demonstrate methane flux variation with geological time. |
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