CONTENTS 



1 . INTRODUCTION . . . page 7 



1 . 1 Intent of Report ... 7 



1 .2 Background ... 7 



1.3 Organization of Report ... 7 



2. PROCEDURES ... 8 



2.1 Site Selection ... 8 



2.2 Sound Speed Profiles ... 9 



2.2.1 Assessment ... 9 



2.2.2 Characteristic Profile Selection ... 14 



2.3 Normal Mode Calculations ... 16 



3. SITE DATA. . . 18 



3.1 North Sea. . . 18 



3.2 Strait of Juan de Fuca ... 21 



3.3 East of Singapore ... 24 



3.4 Lands End ... 26 



3.5 Korea Strait ... 29 



3.6 Straitsof Sicily ... 33 



3.7 Shallow Bering Sea ... 36 



3.8 Bass Strait ... 37 



3.9 North Coast of Brazil ... 37 



3.10 Summary ... 38 



4. ACOUSTIC RESULTS ... 39 



4.1 Propagation Loss Calculations ... 39 



4.1.1 North Sea ... 39 



4. 1 .2 Strait of Juan de Fuca ... 43 



4.1.3 East of Singapore ... 45 



4. 1 .4 Lands End ... 46 



4.1.5 Korea Strait ... 48 



4.1.6 Straitsof Sicily ... 52 



4.2 Propagation Loss Comparisons ... 53 



4.2.1 Comparison Among Four Areas ... 53 



4.2.2 Propagation Loss Comparisons Including the Korea Strait and 

 the Straits of Sicily ... 59 



4.2.3 Effects of Sediment Attenuation ... 59 



4.3 Comparison with Cylindrical Spreading ... 61 



5. SUMMARY OF RESULTS AND CONCLUSIONS ... 66 



6. RECOMMENDATIONS ... 66 



7. REFERENCES ... 67 



