深海における炭酸イオンの氷河期からホロセーン期への再分布
1Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA. broecker@ldeo.columbia.edu
まとめ
氷河期の海は,炭酸イオン濃度グラデーションが顕著であった. 今日とは異なり,太平洋の深い水域では,濃度が深さとともに上昇し,大西洋の水域では減少し,より大きな海洋学的なコントラストを示しました.
科学分野:
- パレオセアノグラフィー
- マリン・ジオケミストリー 海洋地化学
- 海洋学 海洋学 海洋学
背景:
- 過去の海洋状態を理解することは,将来の気候変動を予測するために極めて重要です.
- 炭酸イオン濃度は,海洋化学と海洋生物に影響を与える重要な要因です.
研究 の 目的:
- 最後の氷河期における赤道深海の炭酸イオン濃度の分布を再構築する.
- 氷河時代の深海炭酸塩化学と現代の条件を比較するために.
主な方法:
- 氷河期とホロセンの標本間のフォラミニフェラ殻重量差の分析.
- セアラ・ライズ (西大西洋) とオントン・ジャワ高原 (西太平洋) の堆積物核のサンプリング.
- カーボネートイオン濃度の垂直水深グラデーションの再構築.
主要な成果:
- 炭酸イオン濃度の有意な垂直グラデーションは,氷河時代の深い海に存在していた.
- 赤道太平洋では,カーボネートイオン濃度が氷河期間の深さとともに増加した.
- 大西洋では,炭素酸イオン濃度が氷河期間の深さと共に減少した.
結論:
- 氷河時代の深海炭酸塩化学は,今日の海洋と大きく異なっていた.
- 氷河期における北大西洋と太平洋の深い水域の間には,炭酸イオン濃度の大きなコントラストが存在していた.
- これらの発見は,過去の氷河期における海洋循環と炭素循環における重要な変化を強調しています.
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