海洋堆積物におけるメタン水素の安定性の低下は,相境界の粗さによるものです
W T Wood1, J F Gettrust, N R Chapman
1US Naval Research Laboratory, Stennis Space Center, Mississippi 39529, USA. warren.wood@nrlssc.navy.mil
Nature
|December 13, 2002
まとめ
海底の安定性とエネルギーに不可欠な海洋メタン水素堆積物は,流体が脱出する粗な基礎を示しています. これは,水素が多ければ不安定に近いことを示唆し,グローバルな変化モデルに影響を与えます.
科学分野:
- 地質学 地質学 地質学
- マリン・ジオサイエンス マリン・ジオサイエンス
- 地質物理学 地質物理学とは地質物理学です.
背景:
- メタン水酸化物の埋蔵は,海底の安定性と地球規模の変化に影響を与える巨大な炭素貯蔵庫です.
- 地震画像は通常,メタン水素安定ゾーンの底辺を平滑で平行な反射器として識別します.
- これらの堆積物は,潜在的なエネルギー資源を表しています.
研究 の 目的:
- 水素安定地帯の底辺の横向的な変動を調査する.
- 海底液の排出がメタン水素の分布と安定性に与える影響を理解する.
主な方法:
- 海底沈殿物の高解像度の地震断面の分析.
- カナダのバンクーバー島沖のカスカディア・マージンにおける海底沈殿物の観測.
主要な成果:
- 水素安定性ゾーンの底辺の横向きの変動が観察されました.
- 水素安定性ゾーンにガスが豊富な垂直の侵入を特定し,上向きの流体流と関連付けました.
- 海底液の排出により,水素安定地帯の粗な基礎が形成され,表面積が増加することが判明した.
結論:
- 水素安定ゾーンの底辺は,常に滑らかではなく,液体の排出によって大きく変化することがあります.
- 基底付近のメタン水合物の表面積の増加は,圧力変化 (例えば,海平面の低下) による解離の可能性が大きいことを意味します.
- この発見は,メタンの放出,海底の安定性,気候変動の理解に意味を持つ.
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