まとめ
ナミビア沖のベンゲラ上流系は,ミオセンの初期後半,約1000万年前に始まった可能性が高い. このイニシエーションは,冷たい栄養豊富な水をもたらし,近代的なシステムを確立しました.
科学分野:
- 海洋地質学 海洋地質学
- パレオセアノグラフィー
- 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:
- ベンゲラ上流水系は,大西洋の海洋生態系の重要な構成要素です.
- その始まりを理解することは,過去の海洋学的な条件と気候の動態についての洞察を提供します.
研究 の 目的:
- 北ナミビア沖のベンゲラ上流システム開始のタイミングを決定する.
- システムの確立に関連した古海洋学的条件を再構築する.
主な方法:
- サイト362/362A.からの深海掘削プロジェクトコアの分析.
- 沈殿物の蓄積速度を調べる.
- ダイアトムの豊富さと微生物化石の温度偏好 (プランクトンのフォラミニファー,石灰質ナノプランクトン,シリコフラゲラート) の研究.
- 有機炭素含量と石灰岩骨格に含まれるリン酸化物による生産性の評価.
主要な成果:
- 堆積物学と古生物学のデータは,ミオセンの初期後半に大規模な,持続的な上流が始まることを示している.
- 現代のベンゲラ上流系は,現在より約1000万年前に遡ります.
- 証拠は,表面に冷たい栄養豊富な水の到来を示しています.
結論:
- ミオセンの初期後半は,現代のベンゲラ上流系統の始まりを示しています.
- この出来事は,ナミビア北部沖の海洋環境を大幅に変化させた.
- この発見は,主要な海洋学的システムの長期的な進化を理解するのに役立ちます.
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