在寒冷的地幔角下发生的大型巨型地震,在劳森特蓝面下形成角
Hao Zhang1,2, Sylvain Barbot1, Zekang Yang3
1Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA.
Nature communications
|March 17, 2026
概括
在寒冷的俯冲区的大型地震可能起源于地幔角. 这项研究揭示,在特定的深度和温度下,lawsonite blueschist metagreywacke表现出有利于地震的摩擦行为.
科学领域:
- * 固体地球地质物理学
- * 构造物理学 构造物理学
- * 石化学 石化学
背景情况:
- *巨型地震通常发生在上层板块Moho或350°C的热带在温暖的俯冲区.
- * 大地震也在寒冷俯冲区的地幔角 (35-55公里深) 中观察到.
研究的目的:
- * 为了研究法索尼特蓝岩的摩擦行为metagreywacke,一种在寒冷的降温道中发现的岩石类型.
- * 了解变态级如何影响潜伏区的地震深度变化.
主要方法:
- * 在metagreywacke gouge上进行了速度步摩擦实验.
- *覆盖了从室温到500°C的温度范围.
- * 应用有效正常应力从50MPa到320MPa,以捕捉不稳定的摩擦和脆性到流量过渡.
主要成果:
- * 劳索尼特蓝甲灰瓦克 (Lawsonite blueschist metagreywacke) 在莫霍河以下的高温下表现出构成性行为,表明潜在的地震性行为.
- * 在测试的应力和温度范围内确定了不稳定的摩擦模式和脆性到流量过渡.
结论:
- *在大地幔角的大规模地震可以在寒冷的降温板块的lawsonite blueschist metasediment通道内发生.
- * 变态级别在控制俯冲区的大地震的深度和发生方面发挥着至关重要的作用.
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