308 Lecture 16 
ke 6 to 20 miles —_—__»| 
Radio waves 
Water waves 
Hydroph ones 
Velocity V, 
| SUNN E ATCO 000000 reeneenecrernccen 
i Tl 
= MANTLE ROCK 
Velocity V4 
inim 
Fig. 16.7. Principle of seismic refraction method showing different paths by which waves can travel 
from explosion to sono buoy. 
Distance 
Fig. 16.8. Graph of travel times against distance for seismic refraction shooting. 
