地震波在垂向不均匀介质中传播问题的某些探讨

A DISCUSSION ON THE PROBLEM OF SEISMIC WAVE PROPAGATING THROUGH VERTICAL INHOMOGENEOUS MEDIA

摘要:

本文计算了含有高速夹层介质中首波的理论地震图。通过分析得到,当高速夹层薄到一定程度时,就会产生干涉型首波,从而从一个侧面证明了射线理论的局限性。通过对地震波反射-折射系数能量守恒关系的分析,探讨了反射-折射系数大于1的可能性。最后,介绍了一种计算垂向不均匀介质中拉梅问题理论地震图的数值方法——有限差分法。

Abstract:

The synthetic seismograms of head waves are computed,which propagate through the medium with a high velocity layer in it.1t is seen that interference head waves will occur if the high velocity layer becomes thinner until a certain extent.The limitation of ray theory is proved in a flank.Analyzing the energy conservation relation of reflection and refraction coefficients of seismic wave,it has been noticed that the probability of reflection and refraction coefficients is greater than one.A numeral method of computing synthetic seismogram,finite difference method is introduced,which can be used to calculate Lamb problem in vertical inhomogeneous media.