generally sloped downward from west to east from approximately 135 meters 

 at station 15 to 170 meters at station 18. 



3. Longitudinal Cross Section - The longitudinal cross section, ex- 

 tending from south to north (Fig. 15), shows the same general features 

 described in the latitudinal cross sections. The main thermocline 

 slopes downward from south to north, from a mean depth of 150 meters at 

 station 4 to a maximum depth of 190 meters at station 13. The factors 

 producing such a change can be attributed to either piling up of water 

 under wind pressure or tidal influence. The direct cause cannot be 

 determined precisely inasmuch as the survey was conducted in approxi- 

 mately 4 days. 



4. Anchor Station Data - Surface temperature of the T0T0 water at 

 24°35'N, 77°34'W ranged from 23.61° to 23.99°C, or a range of 0.28°C, 

 during the six days SAN PABLO was tied in the mooring bridle system. 

 During this same period of time, layer depth fluctuated from 525 feet 

 to 695 feet, or a range of 170 feet. Daily fluctuations of layer depth 

 were as follows: 



Day 

 March 



7 



8 



9 

 10 

 11 

 12 

 13 

 14 



C. SALINITY 



1. Surface - The horizontal distribution of surface salinity shows 



a gradual increase from the entrance of the Tongue of the Ocean^southward. 

 At the southernmost transect, salinity values ranged from 36.60 /00 on the 

 western side to 36.75 /00 on the eastern side. At the northernmost 

 transect, values were nearly the same, displaying properties typical of 

 open ocean conditions. The transect extending across the central portion, 

 on the other hand, showed higher salinity values on the western side 

 than on the eastern side. Under normal conditions, higher salinity 

 values would be expected on the eastern side, principally due to shoalness 

 of the water area and its ability to produce high saline water. Salinity 

 values along the central transect varied from 36.70 /00 to 36.52 /00. 



2. Vertical Cross Sections 



a. Stations 3 through 6 - Approximately 4 hours were required 

 to occupy stations 3 through 6; therefore, the data obtained on this 



Layer Depth 



Range of Layer Depth 



Feet 



Feet 



580-650 



70 



595-640 



45 



605-685 



80 



650-695 



45 



605-685 



80 



610-655 



45 



530-655 



125 



525-575 



50 



