Release of Methane from Bering Sea Sediments During the Last Glacial Period
Several lines of evidence suggest that during times of elevated methane flux the sulfate-methane transition zone (SMTZ) was positioned near the sediment-water interface. We studied two cores (from 700 m and 1457 m water depth) from the Umnak Plateau region. Anomalously low d13C and high d18O in bent...
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Woods Hole Oceanographic Institution
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ftunivnotexas:info:ark/67531/metadc929343 2023-05-15T15:43:35+02:00 Release of Methane from Bering Sea Sediments During the Last Glacial Period Cook, Mea Keigwin, Lloyd United States. Department of Energy. 2007-11-30 Text https://doi.org/10.2172/969330 https://digital.library.unt.edu/ark:/67531/metadc929343/ English eng Woods Hole Oceanographic Institution grantno: FC26-05NT42665 doi:10.2172/969330 osti: 969330 https://digital.library.unt.edu/ark:/67531/metadc929343/ ark: ark:/67531/metadc929343 Interstitials Sediments Bering Sea Oxidation Methane Stable Isotopes Climates Carbonates Water 03 Natural Gas Sediment-Water Interfaces Foraminifera Report 2007 ftunivnotexas https://doi.org/10.2172/969330 2019-05-25T22:08:07Z Several lines of evidence suggest that during times of elevated methane flux the sulfate-methane transition zone (SMTZ) was positioned near the sediment-water interface. We studied two cores (from 700 m and 1457 m water depth) from the Umnak Plateau region. Anomalously low d13C and high d18O in benthic and planktonic foraminifera in these cores are the consequence of diagenetic overgrowths of authigenic carbonates. There are multiple layers of authigenic-carbonate-rich sediment in these cores, and the stable isotope compositions of the carbonates are consistent with those formed during anaerobic oxidation of methane (AOM). The carbonate-rich layers are associated with biomarkers produced by methane-oxidizing archaea, archaeol and glyceryl dibiphytanyl glyceryl tetraether (GDGT). The d13C of the archaeol and certain GDGTs are isotopically depleted. These carbonate- and AOM-biomarker-rich layers were emplaced in the SMTZ during episodes when there was a high flux of methane or methane-rich fluids upward in the sediment column. The sediment methane in the Umnak Plateau region appears to have been very dynamic during the glacial period, and interacted with the ocean-atmosphere system at millennial time scales. The upper-most carbonate-rich layers are in radiocarbon-dated sediment deposited during interstitials 2 and 3, 28-20 ka, and may be associated with the climate warming during this time. Report Bering Sea Planktonic foraminifera University of North Texas: UNT Digital Library Bering Sea Umnak Plateau ENVELOPE(-170.250,-170.250,54.250,54.250) |
institution |
Open Polar |
collection |
University of North Texas: UNT Digital Library |
op_collection_id |
ftunivnotexas |
language |
English |
topic |
Interstitials Sediments Bering Sea Oxidation Methane Stable Isotopes Climates Carbonates Water 03 Natural Gas Sediment-Water Interfaces Foraminifera |
spellingShingle |
Interstitials Sediments Bering Sea Oxidation Methane Stable Isotopes Climates Carbonates Water 03 Natural Gas Sediment-Water Interfaces Foraminifera Cook, Mea Keigwin, Lloyd Release of Methane from Bering Sea Sediments During the Last Glacial Period |
topic_facet |
Interstitials Sediments Bering Sea Oxidation Methane Stable Isotopes Climates Carbonates Water 03 Natural Gas Sediment-Water Interfaces Foraminifera |
description |
Several lines of evidence suggest that during times of elevated methane flux the sulfate-methane transition zone (SMTZ) was positioned near the sediment-water interface. We studied two cores (from 700 m and 1457 m water depth) from the Umnak Plateau region. Anomalously low d13C and high d18O in benthic and planktonic foraminifera in these cores are the consequence of diagenetic overgrowths of authigenic carbonates. There are multiple layers of authigenic-carbonate-rich sediment in these cores, and the stable isotope compositions of the carbonates are consistent with those formed during anaerobic oxidation of methane (AOM). The carbonate-rich layers are associated with biomarkers produced by methane-oxidizing archaea, archaeol and glyceryl dibiphytanyl glyceryl tetraether (GDGT). The d13C of the archaeol and certain GDGTs are isotopically depleted. These carbonate- and AOM-biomarker-rich layers were emplaced in the SMTZ during episodes when there was a high flux of methane or methane-rich fluids upward in the sediment column. The sediment methane in the Umnak Plateau region appears to have been very dynamic during the glacial period, and interacted with the ocean-atmosphere system at millennial time scales. The upper-most carbonate-rich layers are in radiocarbon-dated sediment deposited during interstitials 2 and 3, 28-20 ka, and may be associated with the climate warming during this time. |
author2 |
United States. Department of Energy. |
format |
Report |
author |
Cook, Mea Keigwin, Lloyd |
author_facet |
Cook, Mea Keigwin, Lloyd |
author_sort |
Cook, Mea |
title |
Release of Methane from Bering Sea Sediments During the Last Glacial Period |
title_short |
Release of Methane from Bering Sea Sediments During the Last Glacial Period |
title_full |
Release of Methane from Bering Sea Sediments During the Last Glacial Period |
title_fullStr |
Release of Methane from Bering Sea Sediments During the Last Glacial Period |
title_full_unstemmed |
Release of Methane from Bering Sea Sediments During the Last Glacial Period |
title_sort |
release of methane from bering sea sediments during the last glacial period |
publisher |
Woods Hole Oceanographic Institution |
publishDate |
2007 |
url |
https://doi.org/10.2172/969330 https://digital.library.unt.edu/ark:/67531/metadc929343/ |
long_lat |
ENVELOPE(-170.250,-170.250,54.250,54.250) |
geographic |
Bering Sea Umnak Plateau |
geographic_facet |
Bering Sea Umnak Plateau |
genre |
Bering Sea Planktonic foraminifera |
genre_facet |
Bering Sea Planktonic foraminifera |
op_relation |
grantno: FC26-05NT42665 doi:10.2172/969330 osti: 969330 https://digital.library.unt.edu/ark:/67531/metadc929343/ ark: ark:/67531/metadc929343 |
op_doi |
https://doi.org/10.2172/969330 |
_version_ |
1766377766406586368 |