由于外部升高的脆性-柔性损伤导致的动态板块细分
T V Gerya1, D Bercovici2, T W Becker3,4,5
1Department of Earth Sciences, Swiss Federal Institute of Technology Zurich, Zurich, Switzerland. tgerya@ethz.ch.
Nature
|November 11, 2021
概括
在沟中曲的板块会造成损坏,导致板块减弱和细分. 这种现象解释了主要的沉降特征,并暗示了地球历史上频繁的板块断裂事件.
科学领域:
- 地质学
- 构造学
- 地球科学
背景情况:
- 降温是板块构造和地球热化学进化的主要驱动力.
- 在外升和沟的曲过程中,潜管板经历了显著的正常断裂.
研究的目的:
- 调查曲引起的板损伤对潜水动态的影响.
- 模拟脆性和性变形之间的相互作用,包括颗粒损伤,在沉降过程中.
主要方法:
- 数字潜伏模型.
- 包括谷物损伤在内的脆性和延展性变形的自相一致的追踪.
- 对板块减弱和细分的分析.
主要成果:
- 由于外部上升的结合脆性和延展性损伤局部化,发生了普遍的板块削弱和细分.
- 这种板块损坏现象解释了强板/弱板二分法,正常断层发展,地震异常和沟附近的粘度减少.
- 在更高的地幔温度下,易碎粘性损坏的板块倾向于脱离.
结论:
- 曲引起的板块损伤是控制潜水区特征的关键过程.
- 这些发现协调了强板块和弱板块的观测,断层,地震异常和粘度变化.
- 间歇性沉降与频繁的板块断裂可能在整个地球历史中比以前认为的更常见.
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