D. SEISMIC PROFILER (cont'd) 



16. Evaluation and recommendations: 



a. Equipment has been used for routine surveys in bays and on 



the Continental Shelf. Deep-sea work has been experi- 

 mental. 



b. Equipment is capable of either very high resolution or rela- 



tively deep penetration with the selection of suitable 

 frequencies, recorder scale, and writing rate. 



c. The speed of sound in sediments can be measured by using 



this equipment with a wide separation of the transmitting 

 and receiving transducers. 



d. Equipment is used at WHOI with a 1,- to 4- (usually 2-) 



channel PGR. The flexibility of the PGR, or simplified 

 PGR, appears to make the Seismic Profiler (with spark 

 source) more versatile than the SDR (with spark source). 

 However, no quantitative information is known to exist 

 on the actual comparative capabilities of the Seismic 

 Profiler and the SDR when operated in the same area 

 under controlled conditions. 



17. References: X-7 and X-12 



E. SUBSUREX (SUBSURFACE EXPLORER) 



The Subsurex equipment and system is protected by U. S. Patent 

 No. 2,866,512. The U. S. Government has a royalty-free license 

 covering use of the equipment for governmental purposes. Patent 

 protection for certain system components has been applied for. A 

 second experimental model is being constructed privately by Mr. 

 Padberg (written communication). 



1 „ Model: No model number; experimental, designed by L. R. 

 Padberg, Jr. 



2. Manufacturer: NEL 



3. Approximate cost new: $100,000 (probably includes development 



cost) 



4. Maximum water depth in which operative: 



Empirically determined: 3,000 feet 



Estimated: Greatest known depths (L. R. Padberg, Jr., 

 written communication) 



D-8 



