热化学流将地球内核的增长与地幔异质性相结合
Julien Aubert1, Hagay Amit, Gauthier Hulot
1Dynamique des Fluides Géologiques, Université Paris-Diderot, INSU/CNRS, 4, Place Jussieu, 75252, Paris cedex 05, France. aubert@ipgp.jussieu.fr
Nature
|August 8, 2008
概括
地球的内核表现出东半球和西半球之间的地震差异. 一个新的模型将这些地震异常与地幔驱动的外部核心流量联系起来,影响内部核心的增长.
科学领域:
- 地质物理学 地质物理学
- 地震学 地震学
- 地球科学 地球科学 地球科学
背景情况:
- 地震波揭示了地球内核半球中独特的地震特性.
- 半球二分法对理解地球的合层面构成了挑战.
研究的目的:
- 为了解释内核半球地震二分法的起源.
- 将地震异常与核心动力学和地气动力学上的地幔控制联系起来.
主要方法:
- 从内核顶部100公里的地震波数据分析.
- 在外核中建模热化学对流和动纳摩作用.
- 集成地震,古磁和核心流量数据.
主要成果:
- 热化学对流的单一模型解释了观测到的地震,磁力和流动模式.
- 一个大规模的外部核心流量将内部核心异质性与下层地幔条件相结合.
- 在亚洲以下的旋风循环集中了磁场,并影响了内核的结.
结论:
- 内核结速率的地幔诱导的变化可能会导致地震异常.
- 这项研究为地幔-核心合和地动纳摩过程提供了一个统一的模型.
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