まとめ
大西洋の海底への地質物質の流れは,最後の氷河期には今日よりも高かった. 流動は脱氷期とホロケーン時代に減少し,深水の循環が沈殿物の輸送に潜在的に影響した.
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
- 地質化学 地質化学
背景:
- 沈殿物の海への流出における過去の変化を理解することは,海洋学的条件の再構築に不可欠です.
- 陸生流は,大陸の気象,侵食,輸送プロセスに関する洞察を提供します.
研究 の 目的:
- 異なる水深を横切って,赤道的な大西洋の海底に流れる原産物の流れを定量化するために.
- 最後の氷河期からホロセーン期までの地原産の入力における時間的な変化を再構築する.
主な方法:
- 過剰なトリウム-230 (230Th) 流量に対する地原流の正常化.
- 赤道大西洋の2箇所から,水深が異なる場所から採取した堆積物核の分析.
主要な成果:
- 地質性流は,最後の氷河期には,現在の流よりも著しく高かった.
- 流は脱氷期に減少し,ホロセンの半ばに最小値に達した.
- 水深が2,800メートル未満の水の流れの増加は,15,000年から5,000年前に観察されました.
結論:
- 最後の氷河期には,大西洋の海底への土着の投入が大幅に増加しました.
- 沈殿物輸送のダイナミクスは,潜在的に深水の循環の強化と関連しており,ホロセーン期の流動パターンに影響を与えました.
- 堆積物の再懸浮と横流輸送は,観測された深度依存的流量増加に役割を果たした可能性がある.
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