Elucidation of source and flux of methane in marine environments

阐明海洋环境中甲烷的来源和通量

• 批准号: 11308020
• 负责人: GAMO Toshitaka
• 金额: $ 26.48万
• 依托单位: HOKKAIDO UNIVERSITY (2000-2001)The University of Tokyo (1999)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11308020/
• 关键词: Submarine hydrothermal activity; Submarine cold seepage; Methane; Carbon isotope ratio; Microbiological activity; Plate boundaries; Gas hydrate; Continuous flow mass spectrometry; 海底熱水系; 沖縄トラフ; 日本海東縁; 南海トラフ; 炭素同位体比; 海底熱水活動; マリアナトラフ; 水曜海山

This study aimed at elucidating the behavior of methane in the oceanic environment, especially in oceanic waters and pore fluids in sedimentary layers. Concentration and stable carbon isotope ratios (^<13>C/^<12>C) of methane were precisely measured by using an isotope-ratio-monitoring gas chromatography/mass spectrometry system newly constructed in this study. Submarine hydrothermally active areas at spreading centers and arc volcanoes (Central Indian Ridge, Gulf of Aden, Mariana Trough, Okinawa Trough, Suiyo Seamount etc.) and cold seepage areas at plate subduction zones (Nankai Trough, Eastern Japan Sea etc.) were investigated in detail using research vessels and submersibles, in order to take fluid samples for methane analysis from these areas. The carbon isotope ratio of methane has enabled us to distinguish the following three different types of methane: magmatic methane, methane from thermocatalytic decomposition of organic matter, and biogenic methane. In addition, oxidative decomposition of methane was recognized in pore fluids as well as in seawater, by detecting the enrichment of ^<13>C of methane to occur during microbiological processes. Gas hydrate below seafloor was also discussed as an important source of methane from the sediment to seawater.

本研究旨在阐明甲烷在海洋环境中的行为，特别是在海洋沃茨和沉积层孔隙流体中。利用<13><12>本研究中新建立的同位素比值监测气相色谱/质谱系统，精确测定了甲烷的浓度和稳定碳同位素比值（^ C/^ C）。扩张中心海底热液活动区和弧火山（中印度洋海岭、亚丁湾、马里亚纳海槽、冲绳海槽、水予海山等）板块俯冲带（南海海槽、东日本海等）的冷渗区使用研究船和潜水器详细调查了这些地区的情况，以便从这些地区采集液体样本进行甲烷分析。甲烷的碳同位素比使我们能够区分以下三种不同类型的甲烷：岩浆甲烷、有机质热催化分解甲烷和生物甲烷。此外，通过检测微生物过程中甲烷的^ C富集，在孔隙流体和海水中识别出甲烷的氧化分解<13>。还讨论了海底以下的天然气水合物，认为它是从沉积物向海水输送甲烷的一个重要来源。

项目成果

池田 元美ほか編: "海と環境-海が変わると地球が変わる"講談社サイエンティフィク. 244 (2001)

池田元美等人编辑：“海洋与环境 - 当海洋发生变化时，地球也会发生变化”讲谈社科学杂志 244 (2001)。

U. Tsunogai, N. Yoshida, J. Ishibashi, T. Gamo: "Carbon isotopic distribution of methane in deep-sea hydrothermal plume, Myojin KnoII caldera, Izu-Bonin arc: Implications for microbial methane oxidation in ocean and applications to heat flux estimation"Ge

U. Tsunogai、N. Yoshida、J. Ishibashi、T. Gamo：“深海热液羽流、Myojin KnoII 破火山口、伊豆-博宁弧中甲烷的碳同位素分布：对海洋中微生物甲烷氧化的影响及其在热通量中的应用

Kei Okamura et al.: "Development of a deep-sea in situ Mn analyzer and its application for hydrotherma plume observation"Marine Chemistry. 76. 17-26 (2001)

Kei Okamura 等人：“深海原位锰分析仪的开发及其在热液羽流观测中的应用”海洋化学。

U.Tsunogai et al.: "Carbon isotope evidence of methane oxidation through surfate reduction in sediment beneath cold seep vents on the seafloor at Nankai"Mar. Geol.. (印刷中).

U. Tsunogai 等人：“南海海底冷泉喷口下沉积物中表面硫酸盐还原导致甲烷氧化的碳同位素证据”，地质学杂志，2017 年 3 月。

Urumu Tsunogai et al.: "Carbon isotopic evidense of methane oxidation through sulfate reduction in sediment beneath cold seep vents on the seafloor at Nankai Trough"Marine Geology. In press.

Urumu Tsunogai 等人：“南海海槽海底冷泉喷口下沉积物中硫酸盐还原导致甲烷氧化的碳同位素证据”海洋地质学。