在过去的1700年里,在华盛顿州南部的普吉特海峡突然升起
Science (New York, N.Y.)
|December 4, 1992
概括
南普吉特海峡在500-1700年前经历了快速的海岸线上升,高达7米. 这一与断层滑动相关的地质事件表明该地区的地震潜力.
科学领域:
- 地质地质地质地质地质地
- 地震学 地震学
- 古地质学 古地质学
背景情况:
- 南部普吉特湾和胡德运河的海岸线显示出显著的垂直陆地运动的证据.
- 之前的研究还没有完全详细说明这些过去海岸线变化的时间和程度.
研究的目的:
- 调查普吉特湾地区海岸线迅速升起的时间,规模和原因.
- 评估与该地区的地质活动相关的地震危险潜力.
主要方法:
- 在西雅图附近的海浪切割海岸平台的分析.
- 检查浮出水面,覆盖着泥炭的潮平面,距离升起区西南60公里.
- 升起事件与推断断裂活动的相关性.
主要成果:
- 在500年至1700年前,海岸线上升了7米.
- 证据表明突然升起,防止中间海岸线的形成,并改变潮平面到淡水环境.
- 最大的升起与1000-1100年前西雅图附近推断的逆断层滑动相吻合.
结论:
- 普吉特湾的地具有破坏性地震的潜力.
- 快速升起事件和相关的断层滑动是该地区确认的地质危险.
- 了解过去的地震活动对于评估未来的地震风险至关重要.
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