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近期发展的震源反演方法并没有充分利用区域地震图的宽频带性质,原因是用平行层模型计算的格林函数和真实地壳的复杂传播现象不同。这种反演通常去掉了短周期成分,并且只反演记录中选定的部分。在本文中,我们介绍一种估算震源参数的方法,它可以较好地应用整个宽频带记录,而且只采用目前仅有的不完善的格林函数即可。这个方法通过分别拟合格林函数的各个部分来使得记录图与合成图主要的地壳到达波到时差别不大。确定震源参数的原则是:用地震矩M_0、走向、倾角、滑动角这4个参数表示的平均L1,L2范数为最小值,L2误差强调长周期面波的影响,而L1误差着重于短周期体波。我们通过模拟长周期和宽频带信号得到整张图。深度估计可直接从表面反射震相SP_mP或sS_mS得到,或通过用与深度有关的格林函数反复拟合得到。除了震源参数外,我们还得到“δt”相位校正偏移值,它可以用作重新定位其他事件的格林函数修正或者作为推导新地壳模型的参考。
The recent development of the source inversion method does not make full use of the broadband characteristics of the regional seismogram because the Green’s function calculated by the parallel layer model is different from the complex propagation phenomenon of the real crust. This inversion usually removes short-period components and only inverts selected portions of the record. In this paper, we introduce a method of estimating hypocenter parameters that can apply the entire wide-band record well, using only the presently imperfect Green’s function. This method makes the difference between the recorded crust and the main crust arrival wave of the composite map not much different by fitting each part of the Green’s function separately. The principle of determining source parameters is: the average L1, L2 norm expressed by four parameters of seismic moment M_0, strike, dip and sliding angle is the minimum, L2 error emphasizes the effect of long-period surface wave, and L1 error focuses on short Periodic body wave. We get the whole picture by simulating the long-period and wide-band signals. Depth estimates can be obtained directly from the surface reflection facies SP_mP or sS_mS, or by iterative fitting with depth-dependent Green’s function. In addition to the source parameters, we also obtain a “δt” phase-corrected offset value, which can be used as a Green’s function correction to relocate other events or as a reference for deriving new crustal models.