can be traced across the equator; remnants of it are found at 1000 
meters in the Gulf Stream. 
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60 0) 60 
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Diagram of Thermocline Layer 
In the high southern latitudes another sort of water is 
produced which is much heavier than the aforementioned one. The 
heavy water sinks and goes to the bottom; it is the souzce of all of 
the bottom water. It dominates circulation in the Indian and Pacific 
Oceans. The pattern in the Atlantic is more complex. The Medi- 
terranean Sea continuously dumps a considerable volume of very saline 
water into the Atlantic system. Mediterranean water spreads laterally 
away and can be traced into the South Atlantic at mid depths. In the 
high latitudes of the North Atlantic surface water is cooled, sinks 
and spreads south toward the equator, but it is not dense enough to 
displace the antarctic bottom water. However, it does stay below 
the Mediterranean at gio 
Circulation Rate in the North Atlantic. 
The most evasive factor in determining the overturn rate is 
the amount of water that sinks in the northern latitudes and which 
moves toward the equator stirring things up rather gently. There 
are about 30 million cubic meters per minute being transported 
-55- 
