クレータ紀初期における海洋脱酸素化の気候の値
Kohen W Bauer1,2, N Ryan McKenzie3, Chris T L Cheung4
1Department of Earth Science, The University of Hong Kong, Pok Fu Lam, Hong Kong. kohenbauer@gmail.com.
Nature
|September 4, 2024
まとめ
海洋無酸素現象 (OAEs) は,火山による二酸化炭素 (CO2) 排出量と気候の限界値と関連しています. この値を超えると 海洋の酸素の減少が長くなり 回復が遅い気候フィードバックメカニズムにより遅れたのです
科学分野:
- 古代気候学
- 地化学
- 海洋学
背景:
- 海洋無酸素現象 (OAEs) は温暖化と生物学的危機に関連した世界的な脱酸素化を表しています.
- 火山による二酸化炭素 (CO2) 排出は,気候温暖化によるOAEの疑わしい要因である.
- 初期の白亜紀のOAE1aは重要なOAEですが,その原動力や動態は不明です.
研究 の 目的:
- OAE1aを駆動するプロセスのタイミングとダイナミクスを解明する.
- OAE1a中の気候強制と海洋酸素化の因果関係を調査する.
- 地球システムのダイナミクスに OAE1a の長期的な影響を理解する.
主な方法:
- OAE1aの海洋化学と気候記録の分析
- 火山による二酸化炭素排出量,気候の限界値,海洋の脱酸素化との相互作用をモデル化しています.
- シリケート気象フィードバックと軌道強制の役割を調査する.
主要な成果:
- OAE1a中の急速な脱酸素は,火山によるCO2排出と気候の値を超えることと相関しています.
- シリケート気象フィードバックの緩やかな回復は 100万年以上にわたって再酸化を遅らせました
- OAE1aの後,残留熱と軌道強制は,さらに100万年周期的な脱酸素化を誘導した.
結論:
- OAE1a中の海洋の脱酸素化は,重要な気候の値を超えた火山のCO2排出によって引き起こされた.
- OAE1aからの地球システムの回復は,気候の遅いフィードバックのために長引きました.
- 火山活動,気象,そして海洋の酸素含有量との間には,気候の限界によって規制される緊密な結合が存在します.
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