118 



T. I. Oblogina 



From this formula we can see that the expression for w^, as well as that for 

 i;i, can be regarded as consisting of two multipliers, one of which is the 

 function /(i — Oor), and the other all the rest of the expression which goes 

 before this function. The function f{t — a^r) itself also gives the variation in 

 time of the components of displacement (that is, the shape of the wave), 

 and the multipher mth it gives the change in the shape of the wave as a func- 

 tion of the position of the observation point % on the profile, the first onset 

 time ^0, the velocity values I/aq and l/aj, the distance on the profile from 



E 



-0-2 



Fig. 11. Theoretical seismograms for a diffracted wave a-trace of horizontal com- 

 ponent of displacement; 6-trace of vertical component of displacement. 



