在尼泊尔的喜马拉雅中部,有证据表明有一个伟大的中世纪地震 (公元约1100年)
1Laboratoire de Géodynamique des Chaînes Alpines, BP53, 38041 Grenoble, France. jlave@ujf-grenoble.fr
概括
古地震证据显示,大约在公元1100年,尼泊尔中东地区发生了大规模地震. 这次大地震带来了显著的表面移位,可能需要对喜马拉雅地震危险模型进行修订.
科学领域:
- 地质地质地质地质地质地
- 地震学 地震学
- 古地震学 (paleoseismology) 是一种关于古地震的科学.
背景情况:
- 在过去的一个世纪里,喜马拉雅山脉的地震源经历了几次大型推力地震 (Mw 7.8-8.5).
- 对于这些近期的喜马拉雅大地震,没有记录到表面破裂.
研究的目的:
- 为了调查尼泊尔中东地区的古地震证据.
- 了解该地区过去大地震的断裂特征.
主要方法:
- 在尼泊尔中东的前沿推力断层的古地震分析.
- 地质证据的年代测定用于重建过去的地震事件.
主要成果:
- 有证据表明,公元1100年左右的一次地震事件破裂了前沿推力断层.
- 这次地震表现出大约17米的表面移位.
- 事件的横向范围可能超过240公里,其强度可能达到8.8.8MW.
结论:
- 过去在喜马拉雅山脉发生的大地震 (Mw <8.2) 可能没有到达地表.
- 公元1100年记录的事件表明,大规模地震的破裂行为不同.
- 目前的区域性地震危险模型可能需要根据这些古地震发现进行重大更新.
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