为什么全世界的地震风险模型似乎过度预测了历史强度观测?
Leah Salditch1, Molly Margaret Gallahue2, Seth Stein2,3
1U.S. Geological Survey, Golden, CO, USA.
Science advances
|May 1, 2024
概括
可能的地震风险评估 (PSHA) 可能会高估地震震动. 新的研究表明,模型或观测中有系统偏差,影响建筑规范和地震安全.
科学领域:
- 地震科学 地震科学
- 地震学 地震学
- 地质物理学 地质物理学
背景情况:
- 概率性地震危险评估 (PSHA) 对抗地震建筑规范至关重要.
- 在预测实际地震震动强度方面,PSHA的准确性尚未得到充分理解.
研究的目的:
- 评估加利福尼亚州,日本,意大利,尼泊尔和法国最近PSHA的预测准确度.
- 在地震危险模型或观测数据中识别潜在的系统偏差.
主要方法:
- 将PSHA预测 (高峰地面加速/速度) 与历史上观察到的地震震动强度进行比较.
- 通过数字模拟在各种构造性环境中分析了差异.
- 研究了仪器和定性摇措施之间的转换方程的影响.
主要成果:
- 最近的PSHA总是过度预测历史上观察到的地震震动强度.
- 数字模拟表明,观察到的震动同样可能高于或低于PSHA预测.
- 差异部分归因于将仪表指标与定性摇摆报告联系起来的转换方程.
结论:
- 在当前的地震危险模型,观测数据或两者之间存在潜在的系统偏差.
- 需要进一步研究将定性历史震动报告与仪器地震测量相联系.
- 改进定性观测的转换对于准确的地震危险评估至关重要.
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