大规模巨型冲击地震发生后,深度冲击的地震性发生变化
Blandine Gardonio1,2, David Marsan3, Thomas Bodin4
1Univ Lyon 1, ENSL, CNRS, LGL-TPE, F-69622, Villeurbanne, France. blandine.gardonio@univ-lyon1.fr.
Nature communications
|January 3, 2024
概括
大规模的巨大冲击地震在很远的距离上显著影响深度地震. 在日本发生的一次大地震,在破裂区的北部和南部,深度地震的发生率发生了50%以上的变化.
科学领域:
- 地质物理学和地震学
- 构造板的相互作用 构造板的相互作用
- 地震科学 地震科学 地震科学
背景情况:
- 俯冲区产生地球上最强大的地震.
- 越来越多地认识到浅层和深层地震活动之间的相互作用.
- 地震后的变形过渡表明了深层和浅层板块相互作用.
研究的目的:
- 为了分析2011年东北地震前后日本的时空地震性变化.
- 为了研究大冲击地震对深层板块地震性的影响.
- 为了了解潜电板内部的大规模应力状态的变化.
主要方法:
- 在2000年至2013年期间,对日本的分散的地震数据进行分析.
- 在东北地震之前和之后的中间到深层区域 (150-450公里) 的地震率的比较.
- 地震性变化的相关性与GPS衍生的表面位移数据.
主要成果:
- 在东北奥基破裂区以南,中度至深度地震发生率下降了55%.
- 在破裂区域以北发生了中度至深度地震率的30%加速.
- 观察到的地震性变化与GPS测量表面变形一致.
结论:
- 巨大的冲击地震可以改变横向 (2500公里) 和深度范围内的压力状态.
- 地震相互作用发生在远远超过直接破裂区的规模.
- 深层地震性对主要浅层巨型冲击事件引起的应力变化敏感.
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