北極流域の堆積物における鉛の汚染によって明らかになった大西洋の水流経路
C Gobeil1, R W Macdonald, J N Smith
1Institut Maurice-Lamontagne, Mont-Joli, QC, G5H 3Z4, Canada., Institute of Ocean Sciences, Sidney, BC, V8L 4B2, Canada. GobeilC@dfo-mpo.gc.ca
Science (New York, N.Y.)
|August 18, 2001
まとめ
北極海の沈殿物は,50年以上にわたる鉛汚染パターンを明らかにしています. ユーラシア流域は北大西洋とつながっているが,カナダとユーラシア流域は分離し,安定した海流を示している.
科学分野:
- 環境科学 環境科学
- 海洋学 海洋学 海洋学
- 地質化学 地質化学
背景:
- 北極海の堆積物中の汚染鉛は,海洋の現在の動態についての洞察を提供します.
- 過去の海洋循環を理解することは,将来の環境変化を予測するために不可欠です.
研究 の 目的:
- 北極海の現在の組織と過去50年間の安定性を再構築する.
- 北極の堆積物における汚染物質鉛の経路と源を調査する.
主な方法:
- 堆積物における鉛濃度の分析.
- 安定した鉛同位体比の測定.
- 鉛-210の年代測定 堆積物核の年代測定 堆積物核の年代測定
主要な成果:
- 沈殿体鉛の分布は,20世紀を通して,ユーラシア盆地と北大西洋の間の強いつながりを示しています.
- ユーラシア盆地の大西洋水域境界流は,鉛輸送の重要な経路として特定されています.
- ラプテフ海から汚染された鉛は,北極横断の漂流で地表水に影響を与えます.
- カナダとユーラシア流域は,歴史的に独立して運営されてきた.
結論:
- 北極海の海流は過去50年間に比較的安定しており,汚染物質の分布に影響を与える明確な経路がある.
- ユーラシア流域は北大西洋の影響力の主要な経路として機能し,カナダ流域は主に孤立しています.
- 鉛の同位体は,過去の海洋学条件と北極の汚染源を解読するための効果的なトレーサとして機能します.
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