巨大的地震破裂了平面巨型岩石
Quentin Bletery1, Amanda M Thomas2, Alan W Rempel2
1Department of Earth Sciences, University of Oregon, 1272 University of Oregon, Eugene, OR 97403, USA. qbletery@uoregon.edu.
概括
巨大的地震不需要快速融合或年轻的岩层. 相反,大型地震破裂与平坦,低曲率的俯冲区域有关,这些区域促进了广泛破裂的均质剪切强度.
科学领域:
- 地质学
- 地震学
- 构造学
背景情况:
- 2004年的苏门答腊-安达曼和2011年的东北-奥基地震显示,人们对大地震动态的理解不完全.
- 之前的假设将大地震与快速汇聚和年轻,活跃的岩层联系在一起,
研究的目的:
- 调查控制大地震破裂的几何因素.
- 确定潜伏区几何与大地震发生之间的关系.
主要方法:
- 在全球潜伏区的界面曲率的计算.
- 开发一个简化的分析模型来评估剪断强度的异质性.
主要成果:
- 超级地震主要发生在平面 (低曲率) 沉降界面上.
- 接口曲率与剪切强度的异质性增加相关.
- 平面巨型柱体具有更均的剪切强度,可以在更大的区域同时破裂.
结论:
- 俯冲区的几何形状,特别是界面的曲率,是大地震破裂的关键因素.
- 低曲率接口促进大面积,同时剪切应力释放特征的大型地震所必需的条件.
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