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oai:kitami-it.repo.nii.ac.jp:00007573 2026-02-17T00:45:49Z 1:86

オホーツク海天然ガスハイドレートの同位体組成とその結晶特性 Isotopic Composition and Crystallographic Properties of Gas Hydrate in the Sea of Okhotsk 八久保, 晶弘 Hachikubo , Akihiro 八久保 Hachikubo 晶弘 Akihiro 坂上, 寛敏 南, 尚嗣 Minami, Hirotsugu 南 Minami 尚嗣 Hirotsugu 布川, 裕 庄子, 仁 open access ガスハイドレート 安定同位体 解離熱 ラマン分光法 水和数 gas hydrate stable isotope dissociation heat Raman spectroscopy hydration number New hydrate-bearing seepage structures off Sakhalin in the Sea of Okhotsk were investigated from 2003 to 2006 within the framework of the CHAOS project. We obtained samples of natural gas hydrate and measured the molecular and isotopic compositions of hydrate-bound gas. Methane δ13C and δD were in the range of －67 to －63‰ and －207 to －193‰, respectively. These results indicate a microbial origin produced by CO2 reduction according to Whiticar's diagram. Because ethane δ13C showed a thermogenic origin, hydrate-bound gas contains a small amount of thermogenic gas. The hydration numbers of the samples were estimated as 6.19 ± 0.02 using the Raman spectra of the C?H stretching mode and a thermodynamic calculation. Heat flow calorimetry revealed that the values for dissociation heat of the samples were 18.1 ± 0.3 kJ mol－1（ from hydrate phase to gas and ice phases） and 55.4±0.4 kJ mol－1（ from hydrate phase to gas and water phases）, which agree well with the values in of literature. 東京地学協会 2009-03 jpn journal article VoR https://kitami-it.repo.nii.ac.jp/records/7573 http://doi.org/10.5026/jgeography.118.207 地學雜誌 118 1 207 221 https://kitami-it.repo.nii.ac.jp/record/7573/files/(2009)JGeog_1.pdf application/pdf 1.4 MB 2016-11-22