HOURS 

 1200 1210 1220 1230 1240 1250 1300 1310 1320 1330 



Figure 5. Example of vertical-temperature-gradient field in °C/ft x 10 . 

 Entire field is negative gradient. 



direction. For this reason, the horizontal portions of zero con- 

 tours are dashed. 



The horizontal-gradient field alternates in sign. The 

 gradient values in shaded areas are negative and those in the 

 unshaded areas are positive (fig. 6) . The gradient sign is affixed 

 on the basis of encounter, as experienced in time and distance 

 through the temperature structure at a given depth. The 

 horizontal -temperature-gradient fields for the other 16 sample 

 areas are contained in Appendix C. 



17 



