大陆斜坡是由内部潮所塑造的
D A Cacchione1, L F Pratson, A S Ogston
1Coastal and Marine Geology MS-999, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, USA.
Science (New York, N.Y.)
|April 27, 2002
概括
半日内潮影响大陆斜坡梯度和沉积. 它们的能量传播和反射加剧了接近底部的电流,抑制了斜坡上细沉积物的沉积.
科学领域:
- 海洋学 海洋学 海洋学
- 海洋地质学海洋地质学
- 地质物理学 地质物理学
背景情况:
- 大陆的斜坡梯度是由各种海洋过程形成的.
- 内部潮,特别是半日潮,是海洋中重要的能量驱动因素.
- 斜坡上的沉积模式对水力动力学力很敏感.
研究的目的:
- 调查半日内潮内能量传播在确定平均大陆斜坡梯度中的作用.
- 分析内部潮加剧的近底水速度和剪切应力如何影响沉积和斜坡形态.
- 评估半日内潮对大陆坡上的沉积物沉积过程的影响.
主要方法:
- 分析半日内潮的能量传播角度.
- 检查接近底部的水速度和底部切割应力.
- 从案例研究中对沉积模式和底部梯度的审查 (例如,加利福尼亚州和新泽西州的大陆斜坡).
主要成果:
- 半日内潮能量传播的角度与大陆平均斜率梯度 (2-4度) 相对应.
- 半日内潮的反射导致接近底部速度的加剧和剪切应力.
- 估计的底部剪切速度足以防止在大陆斜坡上细粒度沉积物的沉积.
结论:
- 半日内潮在塑造大陆斜坡地形和影响沉积方面发挥着至关重要的作用.
- 内部潮产生的水力动力力可以抑制沉积,影响斜坡的总体沉积物预算.
- 了解内部潮动态对于预测沉积物运输和海洋盆地的斜率演变至关重要.
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