F. MARINE SEISMIC SYSTEM 



1. Model: Not known 



2. Manufacturer: Socony Mobil Oil Co., Inc., Dallas, Texas 



3. Approximate cost new: Not known 



4. Maximum water depth in which operative: 



Empirically determined: 140 feet 

 Estimated: 1,000 feet or more 



5. Maximum penetration of sediment: 



Empirically determined: 8,000 feet (for sand and shale) 

 Estimated: Possibly greater than 8,000 feet for other sedi- 

 ments 



6. Transducers: 



Type: Transmitter: gas gun (which uses liquid propane at 

 a rate of 12 gallons per hour, oxygen at 300 standard 

 cubic feet per hour, and air at 10,000 standard cubic 

 feet per hour); Receiver: ADP crystals 



Location: Transmitter: outboard; Receiver: 20 receivers in 

 a string 150 feet long towed 450 feet astern of the trans- 

 mitter. 



7. Acoustic power: About 6,500 watts (in water) 



8. Acoustic frequency: 



Approximate range: 5 to 400 c.p.s. 

 Peak: 50 c.p.s. 



9. Acoustic pulse length: 10 milliseconds 



10. Acoustic pulse repetition rate: 20 pulses per minute 



11. Receiver band pass filter network: Adjustable 



High pass: 25 to 284 c.p.s. 

 Low pass: 9 to 200 c.p.s. 



12. Graphic record: 



The recorder utilizes a magnetic drum compositor on which 

 the signal is mixed and composited before being recorded. 

 Scale: 3 seconds of time are equivalent to 18 inches of paper. 

 Paper type: Wet, electrosensitive (Alfax A) 

 Paper dynamic range: 20 db 



D-10 



