郯庐断裂带鲁苏沂沭段对汶川地震波的隔震效应

Isolation Effect of Tanlu Fault on Wenchuan Earthquake Waves

郯庐断裂带鲁苏沂沭段由几务平行的深大断裂构成。地震波传播通过郯庐断裂带会产生多次的反射与折射,适当的条件下会产生断层隔震效应。本文报告了江苏地区在汶川地震中的人员反应,根据弹性波传播理论分析了江苏境内的汶川地震记录。分析结果表明,郯庐断裂带在嘉山以北为郯庐断裂带鲁苏沂沭段,几条平行的深大断裂有隔震效应,汶川与嘉山南侧的连线形成一条地震动屏蔽线。在此线以北,郯庐断裂带鲁苏沂沭段阻碍了地震波的传播,其东侧,紧邻郯庐断裂带并为郯庐断裂带屏蔽的强震观测台如宿迁台、新沂台和淮安台都没有触发,这表明了郯庐断裂带对地震波的隔震作用。

The middle section of Tanlu Fault Belt is consisted of 4 ~ 5 parallel deep huge faults.When earthquake waves transmit through the fault,which can inject and be reflected several times in the inner fault,and can be isolated in some conditions.The human responses in Jiangsu to Wenchuan earthquake are studied.And the process of wave transmiting is analyzed.A line from Wenchuan toward Jiashan forms a character line.In region of the North of the line and west of Tanlu Fault Belt,the peak acceleration of Wenchuan earthquake is remarkablely redused.The fact of fault isolation is thus verified.