基于广义极值分布的东昆仑山断裂带周边区域地震危险性分析

Seismic Risk Analysis in East Kunlun Fault Zone and Its Surrounding Area based on Generalized Extremum Distribution

为了更合理地从统计分析角度描述地震危险性评价指标,基于几何分布特征,重新定义了地震重现期和重现最大震级。在此基础上,系统地阐述了用于地震危险性评价的极值分析模型的构建过程,并将其应用于对东昆仑断裂带周边区域的地震危险性评估中。研究表明,东昆仑断裂带周边区域每半年的平均最大发震为M_(S)5.2,M_(S)6以上强震发生频率很高,M_(S)7.4左右的超强震约50年一遇,该区域地质活动频繁,未来一段时间在该区域东部发生M_(S)7左右的超强震危险性较高。

In order to describe the seismic risk assessment indexes more reasonably by statistical analysis,we redefined the earthquake recurrence interval and maximum recurrence magnitude based on geometric distribution characteristics.On this basis,we systematically introduced the construction process of the extreme value model for seismic risk assessment,and then applied this model in the evaluation of the seismic risk in East Kunlun fault zone and its surrounding area.The results are shown that,the semi-annual maximum magnitude of earthquakes is M_(S)5.2,the occurrence frequency of M_(S)≥6.0 earthquakes is very high,and the M_(S)7.4 super-strong earthquakes occur once every 50 years in the Eastern Kunlun fault zone and its surrounding area.Besides,in this area,the geological activity is frequent,and the risk of super-strong earthquakes with M_(S)7.4 is very high in the future.