warm ECC water from what is very probably the cooler subtropical 

 component of the Peru Current; no subsurface salinity data are available 

 to support the identification of the cooler water as the subsurface northerly 

 extension of the Peru Current, but the temperature data are very suggestive. 

 The existence of the sharp thermocline in the face of moderate wind stirring 

 and other turbulences such as due to bottom friction and internal wave to 

 efface it, requires that there be continuous supply of the two water masses. 

 Hence, for a steady state, the maintenance of the low temperature near 

 the topographic bottom requires a cold bottom current to carry away 

 the heat diffused from above. The relative thicknesses of the water masses 

 of the ECC and of the Peru Current further implies that the Peru Current 

 is flowing there at a greater speed than that of the ECC. The causes for 

 the varying depth of thermocline which changed from 100 to 170 feet 

 are uncertain. 



In this southerly location the ECC water mass is absent. The surface 

 temperatures rise steadily from the coast out to the open Pacific as is 

 generally observed. But the presence of a relatively strong thermocline 

 indicates that no upwelling was in progress and that the warmer water 

 above the thermocline must have been advected into the reeion since it is 



^ 



3-1700 



5 VII 54 



Sl.c 4-£ll0 



5 VII 54 

 61.7 



KEY 

 1 cm = I'^F 

 1 cm = lUO ft. dentil 



8-19a5 

 6 VII 54 

 60.1 ; 



/ 



8- 131b 

 5 VII 54 

 60. e 



Ft. 

 ICO . 



EOO 



:!oo 



'station located at 

 15 n. oiles NNW oF THE Isla iialungo 



** station located in 185 ft. 

 of water northeast of 

 I. La Plata 



Figure 21. Bathythermograph Traces. 



63 



