ILLUSTRATIONS (Continued) 



19 Power spectrum computed from successive half-minute 

 interval readings of depth of 9°C isotherm, leg three, 

 cruise 2 . . . 32 



20 Power spectrum computed from successive half-minute 

 interval readings of depth of 14°C isotherm, leg two, 

 cruise 2 . . . 33 



21 Power spectrum computed from successive half-minute 

 interval readings of depth of 16 °C isotherm, leg three, 

 cruise 2 . . . 34 



22 Schematic of the relative motions of ship with chain (C) 

 moving at 6 knots and the dominant wave crests moving 

 at 1.5 knots ... 37 



23 Frequency factor of the relative direction of ship and internal 

 wave motion using the speed of 6 knots for ship and 1. 5 knots 

 for waves ... 38 



24 Vertical temperature structure resulting from four circular 

 tows with the thermistor chain. The same depth intervals on 

 the four 2-mile-diameter tows are arranged together for 

 comparison . . . 39 



25 Vertical temperature structure resulting from two circular 

 tows with the thermistor chain. The same depth intervals on 

 the two 6-mile-diameter tows are arranged together for 

 comparison . . . 40 



Three-dimensional construction of the 9°C isothermal surface 

 based on two repeated 6-mile-diameter tows with the thermis- 

 tor chain (vertical scale equals about 200 times 

 horizontal) . . .42 



