NORTH SEA WINTER PROFILE 

 25 m SOURCE 



300 500 



FREQUENCY, Hz 



2000 



Figure 4.1. Propagation loss for optimum receiver depth vs frequency for 

 ranges of 50, 100 and 150 km. North Sea winter (positive gradient) 

 profile; source depth 25 m. 



RANGE (km) 

 50 



200 400 



FREQUENCY, Hz 



Figure 4.2. Propagation loss for optimum receiver depth vs frequency for ranges of 

 50, 100 and 150 km. North Sea summer profile; source depth 25 m. 



40 



