地球内核边界的局部时间变化
1Department of Geosciences, State University of New York at Stony Brook, NY 11794, USA. Lianxing.Wen@sunysb.edu
概括
地球的内核半径在非洲下面本地增长了1.75公里. 通过地震波反射观察到的这种变化表明内核运动或快速增长.
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:
- 地球的内核是一个固体球体,主要由铁组成.
- 通过地球内部的地震波提供了对其结构和动态的洞察.
- 以前的研究表明,内核内部的复杂行为和潜在运动.
研究的目的:
- 用地震数据调查地球内核半径的变化.
- 为了分析地震波的传输时间,从地震的双倍.
- 了解观察到的变化对内核动态的影响.
主要方法:
- 在南三明治群岛地震双重 (1993年和2003年) 的压缩波分析.
- 在俄罗斯和吉尔吉斯斯坦的站点记录地震波.
- 测量地球内核边界反射波的到达时间.
主要成果:
- 2003年事件的压缩波比1993年事件的压缩波早39-70毫秒.
- 这种到达时间差异表明内部核心半径在非洲中部下方局部扩大了0.98至1.75公里.
- 观察到的变化发生在1993年12月至2003年9月期间.
结论:
- 这些发现表明,地球内核半径的局部变化.
- 这些变化可能归因于内核的微分运动或快速生长.
- 需要进一步的研究才能充分理解驱动内核动态的机制.
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