基于极值理论对华北地区的地震危险性的估计

Seismic hazard estimation in North China based on the extreme value theory

本文首先回顾了极值理论方法的原理及修改前后极值分布函数的对比,并结合华北地区1830~2010年共181年的历史地震资料和现代小震资料,应用修改后的极值理论方法对该研究区域未来50年的地震危险性进行估算分析。研究结果表明,修改后的极值分布函数更能接近实际观测情况:较大地震的复发周期变长了;随着时间的增加,震级趋于研究区域极大震级上限,且华北地区未来50年发生7级以上地震的概率较小。

The article firstly reviewed the extreme value theory and the modified extremal distribution function.Combining the historical seismic data and the modern small earthquake events from 1830~2010,we applied the modified extreme value theory to estimate the seismic risk in future 50 years.The result indicates that the modified extremal distribution function is closer to actual observation:the recrudescent cycle of huge earthquakes gets longer;magnitude tends to the upper limit earthquake magnitude of the studied area;the probability of earthquake above magnitude 7 is small in next 50 years.