TTNCT A.SSTFTF.n 



SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) 



REPORT DOCUMENTATION PAGE 



1. REPORT NUMBER 



NOSC TR 242 



2. GOVT ACCESSION NO, 



4. T\TLE (end Subtitle) 



INTERACTION OF SOUND WITH THE OCEAN BOTTOM: 

 A THREE-YEAR SUMMARY 



READ INSTRUCTIONS 

 BEFORE COMPLETING FORM 



3. RECIPIENT'S CATALOG NUMBER 



5. TYPE OF REPORT a PERIOD COVERED 



Research 

 1974-1977 



6. PERFORMING ORG. REPORT NUMBER 



7. AUTHORfs; 



H. E. Morris, E. L. Hamilton, 

 H. P. Bucker, R. T. Bachman 



B. CONTRACT OR GRANT NUMBERfs; 



9. PERFORMING ORGANIZATION NAME AND ADDRESS 



Naval Ocean Systems Center 

 San Diego, California 92152 



70105 NESC 

 16409 NSSC 



II. CONTROLLING OFFICE NAME AND ADDRESS 



Naval Electronic Systems Command 

 Washington, D.C. 



12. REPORT DATE 



30 April 1978 



13. NUMBER OF PAGES 



83 



U. MONITORING AGENCY NAME ft ADDRESSf// dlllereni Itom Controlling Office) 



15. SECURITY CLASS, (of thia report) 



UNCLASSIFIED 



tSa. DECLASSIFICATION/ DOWNGRADING 

 SCHEDULE 



16. DISTRIBUTION STATEMENT (ol this Report) 



Approved for public release; distribution unlimited 



Woods Hole Oceanographic Institution? 



17. DISTRIBUTION STATEMENT (of the abatract entered In Block 30, If different from Report) 



IB. SUPPLEMENTARY NOTES 



19. KEY WORDS (Continue on reverae aide If neceaaary and Identify by block number) 



20. ABSTRACT (Continue on reverae aide If neceaaary and Identity by block number) 



This report documents the results of a three-year study of the interaction of sound with the sea floor. 

 The investigation covered sea floor properties of interest in underwater acoustics, including velocity gradients 

 in the sea floor, density, shear-wave velocities and other properties; research on acoustic propagation models, 

 especially at low frequencies (2 to 200 Hz); and the development of accurate and efficient methods for 

 coupling geoacoustic models to standard propagation models such as ray theory, normal mode theory and P. E. 

 (a numerical method using the Parabolic Equation approximation to the wave equation). 



During this period numerous reports were distributed to the acoustic community. Various predictions 

 for the surveillance community have been calculated using the geoacoustic and acoustic models, support was 



DD ,:5 



EDITION OF I NOV 6S IS OBSOLETE 

 S/N 0102-014-6601 | iii 



UNCLASSIFIED 



SECURITY CLASSIFICATION OF THIS PAGE (Whan Data Sntarad) 



