北大西洋深水形成的早期橄纪启动
R Davies1, J Cartwright, J Pike
1ExxonMobil International Limited, St Catherine's House, 2 Kingsway, PO Box 393, London WC2B 6WF, UK.
Nature
|April 20, 2001
概括
北极和北大西洋之间的深水流比以前认为的更早,大约3500万年前开始. 这一发现影响了气候变化模型和对全球海洋循环的理解.
科学领域:
- 古海洋学是古海洋学.
- 气候科学 气候科学
- 地质地质地质地质地质地
背景情况:
- 了解纪海洋循环对于北半球气候建模至关重要.
- 格陵兰 - 苏格兰山脊历史上限制了北极 - 北大西洋交换.
- 之前对费罗群岛-什特兰盆地深水循环开始的估计是矛盾的 (3500万-1500万年前).
研究的目的:
- 为了准确地追溯北极和北大西洋之间的深水循环的开始.
- 为了解决这个关键的海洋学事件之前的年龄估计中的差异.
- 改进古代海洋循环的数值模型.
主要方法:
- 发现和分析的东南法罗群岛漂流,一个120公里的沉积物沉积物.
- 使用石油勘探钻井数据来测定漂流中沉积开始的日期.
- 根据漂移的沉积模式来解释古海洋学条件.
主要成果:
- 确定了法罗群岛东南部的漂移,提供了古海洋学特征的直接证据.
- 约定沉积开始时间为奥利古纪早期,大约3500万年前.
- 确定漂流是在南方流动状态下形成的,这表明早期的深水连接.
结论:
- 从挪威海到北大西洋的深水循环始于大约3500万年前.
- 这一开始早于古代海洋循环的许多当前数值模型中的假设.
- 这些发现需要对古海洋学重建和气候建模进行修订.
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