SECT. 4] 



SOLTND SCATTERING BY MARINE ORGANISMS 



503 



(min) 



(a) 



340 



TEMPERATURE ( F) 

 35 40 45 50 55 60 65 70 75 80 85 90 



(b) 



Fig. 4. (a) A shallow-water scattering layer recorded over the continental shelf south of 

 New England by a 12 kc/s echo-sounder. The position of this very thin layer conforms 

 to the position of the bottom of the temperature inversion shown in the bathy- 

 thermogram figured in 4b. 



(b) A bathythermogram made at the time of the echo-sounder record shown in 

 Fig. 4a. 



