プレイストセンの終わりの沿岸海域でメタンのレベルが上昇した分子化石記録
Kai-Uwe Hinrichs1, Laura R Hmelo, Sean P Sylva
1Department of Geology and Geophysics, Woods Hole Oceanographic Institution (WHOI), Woods Hole, MA 02543, USA.
Science (New York, N.Y.)
|February 22, 2003
まとめ
温暖化期間中に海底の堆積物からメタン水素の放出は,メタノトロフィック活動と関連している. サンタバーバラ盆地の沈殿物の証拠は,濃度のメタン排出と海洋の酸素レベルへの影響を明らかにしています.
科学分野:
- 地質化学 地質化学
- 海洋学 海洋学とは
- 古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは,古代気候学 (paleoclimatology) とは
背景:
- 海底の堆積物に貯蔵されているメタン水素は,温室効果ガス排出の潜在的な源である.
- 水素からエピソディックメタンの放出は,急速な気候変動の期間中に発生すると仮定されています.
- サンタバーバラ盆地 (Santa Barbara Basin) は,過去の海洋学および気候現象を研究するための重要な場所です.
研究 の 目的:
- 過去の気候温暖化間隔におけるメタンの放出イベントを調査する.
- メタンの放出に関連した微生物活性の種類と強度を特定する.
- メタンの循環が海洋の酸素予算に与える影響を理解するために.
主な方法:
- サンタバーバラ盆地からの堆積物コアにおける分子化石 (バイオマーカー) の分析.
- 堆積層の年代測定は,過去の気候間隔と相関する.
- 有酸素および無酸素メタノトロフィーを示すバイオマーカーの定量化.
主要な成果:
- 最後の氷河期の暖かい期間の堆積物には,有酸素および無酸素メタノトロフのバイオマーカーが含まれています.
- これらのバイオマーカーの高い濃度は,メタンに富んだ水域におけるメタノトロフィックの有意な活性を示している.
- 44,100年前の堆積物における無酸素メタノトロフィーの証拠は,特に濃度のメタン排出を示しています.
結論:
- 過去の急速な気候温暖化の間隔は,海底水素からメタンが大量に放出されることと関連していました.
- 有酸素および無酸素の両方のメタノトロフィック活動は,放出されたメタンを消費する上で重要な役割を果たします.
- サンタバーバラのような盆地におけるメタン循環は,水柱の酸素レベルに大きな影響を与える可能性があります.
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