地幔流驱动海洋板块的沉降
1Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka, 237-0061, Japan. adam@uevora.pt
概括
海底深度主要受到地幔流动的控制,而不仅仅是岩层年龄. 这项研究揭示了深度变化跟随从山脊距离的平方根,挑战以前的冷却模型.
科学领域:
- 地质物理学 地质物理学
- 海洋学 海洋学 海洋学
- 板块构造学是一种板块构造学.
背景情况:
- 海底沉降传统上归因于石质层随着年龄的增长而被动冷却和密集.
- 石质层的结构基本上与地幔对流有关,这表明流动动力学是至关重要的.
研究的目的:
- 为了研究底层地幔流对石层结构和海底深度的影响.
- 重新评估海底深度,石质层年龄和地幔动态之间的关系.
主要方法:
- 分析沿着代表地幔流动路径的轨迹的海底深度变化.
- 应用边界层方程来建模石层冷却和沉降.
主要成果:
- 海底的深度随着整个板块从中洋山脊到距离的平方根不断增加.
- 观察到的深度变化与地幔流动预测一致,不需要在石质层底部增加热源.
- 该模型证明了距离山脊和深度之间的连续关系,反驳了之前的"平坦化"观测.
结论:
- 地幔流动力学,而不是仅仅是石层年龄,是海底沉降的主要驱动因素.
- 已建立的边界层冷却模型准确地预测了沿地幔流线的海底深度.
- 这项研究完善了我们对海洋石化层演变及其与地幔对流的关系的理解.
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