著者
庄子 仁 Jin Young K. Obzhirov Anatoly SALOMATIN Alexander BARANOV Boris GLADYSH Vyacheslav 八久保 晶弘 南 尚嗣 山下 総 高橋 信夫
出版者
Tokyo Geographical Society
雑誌
地學雜誌 (ISSN:0022135X)
巻号頁・発行日
vol.118, no.1, pp.175-193, 2009-03-25
参考文献数
35
被引用文献数
5 10

Methane hydrates exist beneath the sea bottom near cold seeps NE off the Sakhalin in the Sea of Okhotsk. Multidisciplinary field operations were performed at a study area (approximately 16 × 20 km<sup>2</sup>) to investigate seepage characteristics and understand gas hydrate formation mechanisms. A continuous profiling survey was conducted to obtain a distribution map of seepage structures on the floor by using a deep-tow, side-scan-sonar equipment. The distribution map reveals that the dense area of seepage structures coincides with a sea-floor area of deformed sediments caused possibly by repeated sediment slumping and debris flows in the past. We speculate that this deformation may have created shallow faults that are suitable to conduits for the migration and discharge of gas and fluid.<br> Three seepage structures were selected to study about their fluid-seep conditions around the sea floor level. Hieroglyph seepage structure is located at the northern end of the dense area of the structures. Kitami and Chaos structures are located about 2 and 7 km respectively apart from the Hieroglyph structure within the dense area. Large plumes on echograms and higher methane contents in the water column confirm gas seepage activities at the three structures. There observed at least two and four plumes at the Hieroglyph and Chaos structures, respectively. Each gas chimney image in seismic reflection profiles was traced to connect each BSR and seepage structure. Both pull-up and disturbed structures of BSR around the gas chimney images were interpreted as to be indications of significant heat flows caused by ascending fluid at both Kitami and Chaos structures. On the other hand, almost no pull-up/disturbance of BSR was observed at the Hieroglyph structure, suggesting little water seepage.<br> The seep activity may vary with time off the Sakhalin. The Hieroglyph structure is located at the edge of a dense area of the seepage structures. It might serve as an indicator for the long-term activity of the fluid seepage system off the Sakhalin.
著者
庄子 仁 Young K. JIN Anatoly OBZHIROV Alexander SALOMATIN Boris BARANOV Vyacheslav GLADYSH 八久保 晶弘 南 尚嗣 山下 聡 高橋 信夫
出版者
公益社団法人 東京地学協会
雑誌
地学雑誌 (ISSN:0022135X)
巻号頁・発行日
vol.118, no.1, pp.175-193, 2009-02-25 (Released:2010-04-05)
参考文献数
35
被引用文献数
10 10

Methane hydrates exist beneath the sea bottom near cold seeps NE off the Sakhalin in the Sea of Okhotsk. Multidisciplinary field operations were performed at a study area (approximately 16 × 20 km2) to investigate seepage characteristics and understand gas hydrate formation mechanisms. A continuous profiling survey was conducted to obtain a distribution map of seepage structures on the floor by using a deep-tow, side-scan-sonar equipment. The distribution map reveals that the dense area of seepage structures coincides with a sea-floor area of deformed sediments caused possibly by repeated sediment slumping and debris flows in the past. We speculate that this deformation may have created shallow faults that are suitable to conduits for the migration and discharge of gas and fluid. Three seepage structures were selected to study about their fluid-seep conditions around the sea floor level. Hieroglyph seepage structure is located at the northern end of the dense area of the structures. Kitami and Chaos structures are located about 2 and 7 km respectively apart from the Hieroglyph structure within the dense area. Large plumes on echograms and higher methane contents in the water column confirm gas seepage activities at the three structures. There observed at least two and four plumes at the Hieroglyph and Chaos structures, respectively. Each gas chimney image in seismic reflection profiles was traced to connect each BSR and seepage structure. Both pull-up and disturbed structures of BSR around the gas chimney images were interpreted as to be indications of significant heat flows caused by ascending fluid at both Kitami and Chaos structures. On the other hand, almost no pull-up/disturbance of BSR was observed at the Hieroglyph structure, suggesting little water seepage. The seep activity may vary with time off the Sakhalin. The Hieroglyph structure is located at the edge of a dense area of the seepage structures. It might serve as an indicator for the long-term activity of the fluid seepage system off the Sakhalin.
著者
若濱 五郎 成瀬 廉二 庄子 仁 藤井 理行 中澤 高清 高橋 修平 前 晋爾
出版者
北海道大学
雑誌
総合研究(A)
巻号頁・発行日
1988

本研究は、南極クィ-ンモ-ドランド氷床、グリ-ンランド氷床、北極氷冠、およびアジア内陸地域の氷河等にて堀削し採取された氷コアの解析を行い、諸特性を相互に比較検討することを目的として進められた。特に、最終氷期以降の大気環境変動の過程ならびに氷床・氷河の変動におよぼす氷の動力学的特性を明らかにすることに重点をおいた。研究成果の概要を、以下の1〜4の大項目に分けて述べる。1,氷の物理的性質の解析:氷床氷中の氷板、気泡、クラスレ-ト水和物の生成過程、ならびに多結晶氷の変形機構や再結晶について新しい知見が得られるとともに、氷コアの構造解析の新手法が開発された。2,氷の含有化学物質の分析:氷床氷中の酸素同位体、トリチウム、二酸化炭素、メタン、固体微粒子、主要化学成分、火山灰等の分析結果から、最終氷期以降あるいは近年500年間の大気環境変動過程について多くの情報が集積された。特に、両極地の比較検討も行われた。3,雪の堆積環境に関する解析と数値実験:南極地域にて観測された気象・雪氷デ-タ等の解析、および数値シミュレ-ションを行うことにより、中・低緯度から極地氷床への物質・水蒸気の輸送過程ならびに雪の堆積・削はく現象と分布について研究された。4,氷河・氷床の流動と変動機構に関する解析と数値実験:南極東クィ-ンモ-ドランド氷床の平衡性、白瀬氷河の変動、山脈周辺の氷床の動力学的特性、深層氷の年令推定法などについて考察された。1990年9月、札幌において本総合研究の全体研究集会を開催し、各研究結果の総合的討論を行った。この成果は、総合報告書(B5版、312ペ-ジ)として1991年3月に出版された。同報告書では、将来の氷床コア研究の展望と諸課題も論じられている。