概括
发生在350-690公里深处的深度地震是由转变断层解释的. 这一过程涉及剪切不稳定性,与橄素丰富的矿石在引构造板块内的相变相相关.
科学领域:
- 地质物理学 地质物理学
- 地震学 地震学
- 矿物物理 矿物物理
背景情况:
- 俯冲区呈现倾斜的地震区域,具有明显的深度人口 (350-690公里).
- 传统的断裂机制 (脆碎的断裂,摩擦滑动) 在这些极端深度下是不可预期的.
- 了解深度地震需要新的地质物理和地力学概念.
研究的目的:
- 解释350公里以下深度地震的发生和特征.
- 测试转变断层作为深度地震的机制的假设.
- 为了将深度地震分布与地幔相位过渡相关联.
主要方法:
- 关于矿物相变化的实验地质物理数据的审查和综合.
- 在非水静压力条件下切割不稳定的理论建模.
- 对全球地震目录和地震数据进行深度事件的分析.
主要成果:
- 转换断层,在相位转换期间的剪切不稳定性,被确定为一个可行的机制.
- 据假设,深度地震发生在转移稳定的富含橄素的矿石中.
- 拟议的模型与观察到的全球和区域深度地震分布和特征保持一致.
结论:
- 变形断层为潜水带的深度地震提供了一个一致的解释.
- 转移稳定的橄烯的持久性解释了地震发生在690公里以下的情况.
- 地幔相位变化在深层地震事件的产生和深度极限中起着关键作用.
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