深层地幔的高粘度流和热化学结构是从地震和地力学数据推断出来的
1Department of Earth Sciences, University of Western Ontario, Biology & Geology Building, London, Ontario, N6A 5B7 Canada. aforte@uwo.ca
Nature
|April 27, 2001
概括
地质物理数据显示,地球地幔的高度粘性层接近2000公里深. 这层影响地幔流动,抑制深层混合,并支持活跃的巨型羽毛.
科学领域:
- 地质物理学 地质物理学
- 地球科学 地球科学 地球科学
- 地幔动力学地幔动力学
背景情况:
- 表面的地质物理数据提供了洞察力地幔的形学和密度.
- 热对流是控制地幔动态的一个关键过程.
研究的目的:
- 通过使用地球物理数据,研究地球地幔的浮力学特性.
- 模拟地幔流动及其对深层地幔结构和动态的影响.
主要方法:
- 分析与热对流相关的表面地质物理数据.
- 开发和应用粘性流模型.
- 集成高分辨率的地震模型和矿物物理数据.
主要成果:
- 推断一个高有效粘度区域在2,000公里的深度附近.
- 观察到地幔流的重新组织,从短到长的水平尺度.
- 抑制深层地幔中流动诱导的变形和对流混合.
- 预测与地震速度异常相一致的组成和热异质性.
结论:
- 深层地幔呈现出一种高粘度层,影响流动模式.
- 在太平洋和非洲的海底,巨大的羽毛是浮力和活跃的上游结构.
- 由地质物理数据所限制的地幔对流模型改善了我们对地球深层过程的理解.
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