用近场记录研究唐山地震的震源过程

通过对唐山地震近场记录的波形拟合,研究了震源短周期运动过程的基本特征,推断了主要破裂事件的震源参数.结果表明,高频地震波中的主要部分来自几个局部区域的破裂过程.它们的错距分布相当集中,上升时间为1.1-1.5s.由5次破裂事件组成的震源模型中引人随机扰动量,较好地描绘了地面运动的高频状态.

SOURCE PROCESS STUDY OF THE TANGSHAN EARTHQUAKE USING THE NEAR-FIELD RECORDS

By modelling the near-field waveforms of the Tangshan Earthquake, we have studied the fundamental characteristics of source process at short period and estimated the source parameters of major subevents. It has shown that the high frequency radiations are mainly from the contributions of faulting events occuring at several local regions. They are found to have cen-trilized slip distributions and short dislocation rise time from 1.1s to 1.5s. The very high frequency behaviour of ground motion can be characterized by the stochastic parameters in the source model.