在俯冲启动过程中,快速切割区在俯冲启动期间变弱
1Division of Geological and Planetary Sciences, Seismological Laboratory, California Institute of Technology, Pasadena, CA 91125.
概括
由于快速应变减弱,引启动迅速发生,正如在Puysegur的例子中观察到的那样. 这一发现为早期地球构造学和板块运动的开始提供了洞察力.
科学领域:
- 地质物理学 地质物理学
- 构造学 构造学 构造学 构造学
- 地球科学 地球科学 地球科学
背景情况:
- 俯冲区对于板块构造学至关重要,通过板块拉动和弱大的巨型冲击驱动板块运动.
- 俯冲启动与板块拉力积累和板块边界弱点有关,显著改变了地幔对流.
- 潜伏启动期间的短暂性质和强烈活动掩盖了关键证据,使其难以研究.
研究的目的:
- 通过分析受良好的约束的Puysegur示例来克服研究降温启动的局限性.
- 通过先进的计算和观察方法,研究俯冲启动的机制和特征.
主要方法:
- 进行了时间依赖的三维热力学计算.
- 与新的地质物理和地质数据 (地形学,地层学,地震性) 进行定量比较.
主要成果:
- 证明了潜伏启动与快速应变减弱一起发展,其特点是小位移 (48公里).
- 确定了快速减弱的潜在物理机制,包括粒径减小和流体加压.
- 普伊塞格尔的例子可以作为一个非常受约束的实例研究,用于降温启动.
结论:
- 在Puysegur观测到的快速压力减弱提供了对早期地球潜水带形成的见解.
- 了解俯冲开始是理解板块构造学开始和演变的关键.
- 这些发现对了解早期地球和潜在的其他行星天体上的构造过程有意义.
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