最後の脱氷期における同期的な放射性炭素と気候の変化
K A Hughen1, J R Southon, S J Lehman
1Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA. khughen@whoi.edu
まとめ
放射性炭素年代測定は,脱氷期における大気中の炭素14の変動を明らかにし,これは若いドライアスの冷却イベントと一致しています. これらの変化は,おそらく深海の換気における急激な変化の結果である.
科学分野:
- 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
- ラジオメトリック・デッティング
- 海洋学 海洋学 海洋学
背景:
- 炭素14 (14C) タイムスケールは,特に過去の気候イベントの際に,校正を必要とします.
- 前回の大気14Cの変化の再構築では,脱氷期間の高解像度が欠けていました.
研究 の 目的:
- カリアコ盆地からの高解像度データを使用して14Cのタイムスケールを校正する.
- 大気中の14Cの変動と,脱氷期における急激な気候変動との関係を調査する.
主な方法:
- カリアコ盆地の堆積物核からの放射性炭素データの分析.
- 14Cのデータとベリリウム10 (10Be) のデータと古気候記録の比較.
主要な成果:
- 脱氷期 (15,000〜10,000年前) の高解像度14C校正.
- 再構築された大気中の14Cの変化は,以前に推定されたよりも大きかった.
- 最も重要な14Cの放出は,若いドライアスの冷却イベントと同時に行われた.
結論:
- 深海の換気における急激なシフトは,同時に起こる気候と14°Cの変化の主な原動力として提案されている.
- この発見は,海洋プロセスと大気組成と,地球の歴史における重要な時期における気候の変化を直接結びつけている.
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