缓慢地震统计的起源在低摩擦的软颗粒状剪切中
Yuto Sasaki1, Hiroaki Katsuragi2
1Department of Earth and Space Science, The University of Osaka, 1-1, Machikaneyama, Toyonaka, 5600043, Osaka, Japan. sasaki.geoscience@gmail.com.
Nature communications
|December 1, 2025
概括
这项研究表明,缓慢的地震源于低摩擦,柔软的颗粒切割,模仿断层区域条件. 这些发现解释了缓慢地震的独特统计数据,与定期的地震事件不同.
科学领域:
- 地质物理学 地质物理学
- 软物质物理学 软物质物理学
- 实验性风病学 试验性风病学
背景情况:
- 与普通地震相比,缓慢的地震表现出明显的瞬间释放和大小分布.
- 驱动这些独特的缓慢地震统计数据的物理机制尚未完全理解,仍然存在争议.
- 了解缓慢地震对于地震危险评估至关重要,特别是在俯冲区.
研究的目的:
- 实验性地调查缓慢地震统计的物理起源.
- 为了确定低摩擦软颗粒切割是否可以复制观察到的缓慢地震特征.
- 阐明粒子特性和孔隙流体动力学在产生缓慢地震现象中的作用.
主要方法:
- 使用实验室模型模拟在热水条件下的故障材料,在滑液上使用低摩擦的软水凝颗粒层.
- 进行了受控的棒滑实验,以观察和分析剪切事件.
- 测量时刻释放率和事件大小分布,将它们与自然缓慢地震数据进行比较.
主要成果:
- 实验性滑动事件成功地复制了缓慢地震的特征,即瞬间释放率和大小分布规律.
- 与涉及摩擦刚性颗粒切割的实验相比,这些实验没有显示缓慢地震统计数据.
- 确定了剪切局部化和压力增强的相互竞争的效应,并将降低孔隙性作为滑动大小的关键决定因素.
结论:
- 在稀疏接触的剪切颗粒系统中,低摩擦和颗粒软度是缓慢地震统计的主要驱动因素.
- 孔腔流体动力学和断层区域内的剪切局部可能有助于观察到的现象.
- 这些实验发现为了解地质环境中的缓慢地震生成提供了物理基础.
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