SEA -SURFACE SLICKS 



Sea- surface slicks are character- 

 ized by capillary waves that are smaller 

 than those in adjacent waters. The slicks 

 appear glassy because they reflect the 

 sky better than does the rougher water 

 outside the area. 



Slick bands, occurring where 

 lighter-than-water film is concentrated, 

 are related to the downward motion of 

 internal waves. These bands signal the 

 presence of active sinking zones. 



Sea- surface film from near the 

 tower has been collected. It appears to 

 be composed of organic compounds, 

 probably derived from decomposed or- 

 ganisms. The surface tension of sea- 

 water samples from outside a slick area 

 was found to range between 70. 5 and 73. 5 

 dynes per centimeter at 20 degrees 

 centigrade, while specimens collected in 

 slick areas gave lower surface tension 

 values of from 49. 2 to 68. 8 dynes per 

 centimeter. 



The orientation, speed, and direc- 

 tion of internal wave movement may be 

 determined from time-lapse photographs 

 of slick bands. This information gives 

 a three-dimensional perspective of sub- 

 surface thermal structure and movement. 

 However, under conditions of high wind 

 speeds the internal wave slicks are 

 broken up. The slicks then orient a little 

 to the right of the wind direction. 





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The film on the slick reduces both surface tens 

 and the small capillary waves, thus making the a 

 smoother and increasing its ability to reflect light. 



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