32 



V. P. GORBATOVA 



the head waves formed in the n-th layer with a travel velocity of 6000 m/s 

 would vary with change in the velocity of the ith layer within the range 1500- 

 3500 m/s, as is shown by the curve in Fig. 8b which relates to the parameter 

 b = t',_j pli^i+i p = 0.21. The behaviour of all the curves in Fig. 8a and b 



1-00 



01 0-2 0-3 0-4 0-5 0-6 0-7 08 09 10 



1-00 



or 



+ 

 or 



X 0-75 



or 



01' 

 Ql" 



X 0-50 



q:" 



T 



O'l 0-2 0-3 0-4 0-5 0-6 07 0-8 0-9 10 



Vn,p 



Fig. 8. Curves for the variation in intensity of primary waves if the longitudinal 

 velocity changes in one of the upper layers. 



reflects the change in intensity of the heat waves from the low-lying horizons 

 Avhen the velocity in the ith layer changes. We cannot, however, compare the 

 ordinates of the various curves, since they give values for the coejfficients of 

 reflection at the boundaries of the ith layer which are proportional but 

 not equal to the intensity values when Vj „ changes. The coefficient of 



