在高压下铁烯酸中旋转交叉:一个地震学上透明的过渡?
Daniele Antonangeli1, Julien Siebert, Chantel M Aracne
1Institut de Minéralogie et de Physique des Milieux Condensés, UMR CNRS 7590, Institut de Physique du Globe de Paris, Université Pierre et Marie Curie, Université Paris Diderot, 75005 Paris, France. daniele.antonangeli@impmc.upmc.fr
概括
地球下层地幔的铁旋转转变会影响剪切模块,但不会影响总体地震速度. 这解释了缺乏地震特征的原因,尽管它影响了剪切波异形性.
科学领域:
- 地质物理学 地质物理学
- 矿物物理 矿物物理
- 地震学 地震学
背景情况:
- 地球地幔的地震不连续性与温度,化学或结构的变化有关.
- 下层地幔的铁旋转状态过渡可能会改变地震波的速度,但缺乏直接证据.
研究的目的:
- 为了研究压力诱导的铁旋转转移在ferropericlase的地震学影响.
- 为了确定旋转过渡是否在下层地幔中产生可检测的地震异常.
主要方法:
- 在 (Mg{0.83) Fe{0.17)) O-ferropericlase上进行了不弹性X射线散射实验.
- 在铁旋转过渡的压力范围内进行了测量.
主要成果:
- 铁旋转过渡主要影响弹性张力的剪切模块.
- 在总地震速度中没有观察到任何显著的偏差,这解释了1D地震信号的缺失.
- 发现旋转过渡会影响ferropericlase. . 的剪切异构性.
结论:
- 在下层地幔中由压力诱导的铁旋转转变不会产生总体地震速度的可检测异常.
- 旋转过渡有助于在下层地幔中观察到的地震剪切波异型性.
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