198 



TKANSMISSION OF EXPLOSIVE SOUND IN THE SEA 



A 

 D 

 O 



CURVES 



RANGE 12 00 YARDS 

 RANGE 2100 YARDS 

 RANGE 3600 YARDS 

 PREDICTED INTENSITY 

 FROM RAY THEORY, WITH 

 SOURCE STRENGTH CHOSEN 

 TO GIVE BEST FIT TO 1200 

 YARD POINTS 



1000 



RANGE IN YARDS 

 2000 



3000 



4000 



200 



FEET PER SECOND 

 4B80 4900 4920 



400l 



RAY DIAGRAM 



Figure 3. Comparison of observed peak pressures with values calculated from ray theory for a split-beam pattern. 



showed a weak negative gradient extending to the 

 surface; in the afternoon there was a strong negative 

 gradient at the surface. The ray diagram and theo- 

 retical intensities shown for the morning shots were 

 constructed from an average of the three tempera- 

 ture-depth curves taken during the morning, and 



thus are only a rough approximation to the truth 

 at any one time; however, the error should not be 

 serious except near the boundary of the shadow zone. 

 It will be seen that the agreement of the theoretical 

 and observed intensities is again fairly good. The 

 reduction of intensity in the shadow zone for this 



