厚度不同的高速夹层地震模型的研究

A STVDY OF SEISMIC MODEL FOR HIGH-SPEED INTERLAYERS OF VARIOUS THICKNESS

北京大学地球物理系

本文以模型地震学中普遍采用的二维地震模型的理论为基础,建立了一个有15种不同厚度的二维高速夹层地震模型。对不同厚度的平界面高速夹层产生的首波性质,进行了较详细的观测和讨论。实验结果表明:首波的形成、速度、能量和频谱都与高速夹层的厚度有关。实验结果还表明:在二维情况下,首波沿高速层界面传播时可以深入高速层半个首波波长。

In this paper the nature of head waves generated in flat-bedded highspeed interlayers of various thickness is observed and discussed in detail with the help of a seismic model for 2-D high-speed interlayers of 15 different thickness built on the basis of 2-D seismic modeling theory widely used in model seismology. The results of experiments show that the formation, velocity, energy and spectrum of head waves are all dependent upon the thickness of high-speed interlayers, and that head wave can get into high-speed layers by half of its wave length only when propagating along the interface of high-speed layers in terms of 2-D.