基于余震序列分布信息的地震极灾区快速判断方法研究

Rapid Determination Method of Extreme Earthquake Disaster Area Based on Aftershock Sequence Spatial Distribution

利用震级加权标准差椭圆法研究了基于震后短期内(24 h)余震序列判定地震极灾区的方法,研究结果表明:1利用该方法判断宏观震中是一种比较可行的方法,不同震源破裂方式的震例利用该方法判断宏观震中的精度不同,倾滑-近倾滑型破裂方式的震例利用余震序列判定宏观震中的精度最高;2整体上看,利用该方法判断极灾区长轴方向的准确性低于利用距震中最近活动断裂判断的准确性,但对于倾滑-近倾滑型破裂方式的震例,利用该方法的准确性高于利用断层数据判定的准确性。

Determination method on earthquake disaster area based on aftershock sequence in a short time af-ter an earthquake （within 24 h）is studied by using the magnitude weighted standard deviation ellipse method.The results are as follows：① It’s feasible to use this method in determining the macro-epicenter,while the accuracy varies with earthquake cases of different seismic source rupture types.Cases of the dip-slip rupture type have the highest accuracy;② Generally,this method shows a lower accuracy in determining the direction of long axis than the method of using active faults closest to the epicenter.However,as to cases of the dip-slip rupture type,this method is higher than method of faults data judgment in accuracy.