利用时间域中计算小地震震源参数的方法,求出了京津地区1987年4月至1987年11月间M_L> 1.8级20个地震的震源参数,如表1所示。表1中T,为由地震图中测出的(?)波初动半周期,u_(αm)为(?)波初动振幅,α为求出的震源半径,M_0为地震矩,Δ_σ为应力降。震源半径α是利用参考文献[1]中的T_r—α/v关系曲线,假定Q=400,破裂速度v=2.75公里/秒求出的。由[1]中图2的α/v—u′_(αm)关 Using the method of calculating the source parameters of small earthquakes in the time domain, the source parameters of 20 earthquakes with magnitude M_L> 1.8 were obtained from April 1987 to November 1987 in Beijing-Tianjin region, as shown in Table 1. In Table 1, T is the initial half-period of the (?) Wave measured from the seismogram, u_ (αm) is the initial vibration amplitude of the wave, α is the radius of the source obtained, M_0 is the seismic moment, and Δσ is Stress drop. The source radius α is calculated using the T_r-α / v relationship in Reference [1] assuming Q = 400 and rupture velocity v = 2.75 km / sec. Α / v-u ’_ (αm) OFF of Figure 2 in [1]