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dc.contributor.authorCook, Mea S.  Concept link
dc.contributor.authorKeigwin, Lloyd D.  Concept link
dc.contributor.authorBirgel, Daniel  Concept link
dc.contributor.authorHinrichs, Kai-Uwe  Concept link
dc.date.accessioned2011-05-31T18:31:45Z
dc.date.available2011-11-11T09:28:47Z
dc.date.issued2011-05-11
dc.identifier.citationPaleoceanography 26 (2011): PA2210en_US
dc.identifier.urihttps://hdl.handle.net/1912/4627
dc.descriptionAuthor Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 26 (2011): PA2210, doi:10.1029/2010PA001993.en_US
dc.description.abstractThere is controversy over the role of marine methane hydrates in atmospheric methane concentrations and climate change during the last glacial period. In this study of two sediment cores from the southeast Bering Sea (700 m and 1467 m water depth), we identify multiple episodes during the last glacial period of intense methane flux reaching the seafloor. Within the uncertainty of the radiocarbon age model, the episodes are contemporaneous in the two cores and have similar timing and duration as Dansgaard-Oeschger events. The episodes are marked by horizons of sediment containing 13C-depleted authigenic carbonate minerals; 13C-depleted archaeal and bacterial lipids, which resemble those found in ANME-1 type anaerobic methane oxidizing microbial consortia; and changes in the abundance and species distribution of benthic foraminifera. The similar timing and isotopic composition of the authigenic carbonates in the two cores is consistent with a region-wide increase in the upward flux of methane bearing fluids. This study is the first observation outside Santa Barbara Basin of pervasive, repeated methane flux in glacial sediments. However, contrary to the “Clathrate Gun Hypothesis” (Kennett et al., 2003), these coring sites are too deep for methane hydrate destabilization to be the cause, implying that a much larger part of the ocean's sedimentary methane may participate in climate or carbon cycle feedback at millennial timescales. We speculate that pulses of methane in these opal-rich sediments could be caused by the sudden release of overpressure in pore fluids that builds up gradually with silica diagenesis. The release could be triggered by seismic shaking on the Aleutian subduction zone caused by hydrostatic pressure increase associated with sea level rise at the start of interstadials.en_US
dc.description.sponsorshipSupport for this project was from the National Science Foundation Office of Polar Programs, United States Department of Energy, Oak Foundation, and MARUM at University of Bremen.en_US
dc.format.mimetypeapplication/pdf
dc.format.mimetypeapplication/postscript
dc.format.mimetypetext/plain
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2010PA001993
dc.subjectDansgaard-Oeschger eventsen_US
dc.subjectAnaerobic methane oxidationen_US
dc.subjectBiomarkersen_US
dc.titleRepeated pulses of vertical methane flux recorded in glacial sediments from the southeast Bering Seaen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2010PA001993


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