非火山震的潮调制
Justin L Rubinstein1, Mario La Rocca, John E Vidale
1Department of Earth and Space Science, University of Washington, Box 351310, Seattle, WA 98195, USA. justin@ess.washington.edu
概括
在卡斯卡迪亚海底沉降区的非火山震动和缓慢滑动事件受潮力量的影响. 这些地震事件发生在非常弱的断层上,与正常的地震不同.
科学领域:
- 地质物理学 地质物理学
- 地震学 地震学
- 构造学 构造学 构造学 构造学
背景情况:
- 在日本和卡斯卡迪亚等俯冲区观察到非火山震动和缓慢滑动事件.
- 这些事件在它们的源头和缩放性质上不同于典型的地震.
- 普吉特湾/温哥华岛南部的卡斯卡迪亚地区最近发生的事件被记录得很好.
研究的目的:
- 为了研究潮力和非火山震动/缓慢滑动事件之间的关系.
- 了解控制卡斯卡迪亚潜伏区震起源的因素.
主要方法:
- 分析最近在卡斯卡迪亚潜伏区发生的地震数据.
- 震动脉冲周期与主要的月球和月球太阳潮周期的比较.
主要成果:
- 震动活动呈现出明显的脉冲,周期与月球 (12.4小时) 和月球太阳 (24-25小时) 潮相匹配.
- 潮压力显著影响震的产生,远远超过正常的地震.
- 石静态应力是数量级大于潮应力的数量级.
结论:
- 这种强烈的相关性表明,潮压力实际上会引发非火山性震动.
- 震可能始于极其弱的断层,因为它们对小的潮应力敏感.
- 这一发现提供了关于缓慢滑动事件和潜伏区断层行为的机制的见解.
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