Characterizing the Distribution of Methane Sources and Cycling in the Deep Sea via in Situ Stable Isotope Analysis

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• 作者：Scott D. Wankel ; Yi-wen Huang ; Manish Gupta ; Robert Provencal ; J. Brian Leen ; Andrew Fahrland ; Charles Vidoudez ; Peter R. Girguis
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2013
• 出版时间：February 5, 2013
• 年：2013
• 卷：47
• 期：3
• 页码：1478-1486
• 全文大小：390K
• 年卷期：v.47,no.3(February 5, 2013)
• ISSN：1520-5851

文摘

The capacity to make in situ geo-referenced measurements of methane concentration and stable isotopic composition (未¹³C_CH4) would greatly improve our understanding of the distribution and type of methane sources in the environment, allow refined determination of the extent to which microbial production and consumption contributes to methane cycling, and enable the testing of hypotheses about the sensitivity of methane cycling to changes in environmental conditions. In particular, characterizing biogeochemical methane cycling dynamics in the deep ocean is hampered by a number of challenges, especially in environments where high methane concentrations preclude intact recovery of undisturbed samples. To that end, we have developed an in situ analyzer capable of 未¹³C_CH4 measurements in the deep ocean. Here we present data from laboratory and field studies in which we characterize the instrument鈥檚 analytical capabilities and performance and provide the first in situ stable isotope based characterization of the influence of anaerobic methane oxidation on methane flux from seep sediments. These data illustrate how in situ measurements can permit finer-scale analyses of variations in AOM activity, and facilitate advances in using 未¹³C_CH4 and other isotopic systems to interrogate biogeochemical cycles in the deep sea and other remote or challenging environments.