West Wind Drift (Great Eastward Drift) 
The West Wind Drift, described by the Soviets as the Great Eastward 
Drift, is the largest ocean current on earth; in the Southern Hemisphere, 
it is a barrier between the warm water of the lower latitudes and the 
cold water flowing around the Antarctic. The West Wind Drift, like other 
large ocean currents complex in origin, is a homogeneous flow comprising 
a thick layer of water from surface to great depths which cannot be 
regarded strictly as a drift or wind-driven current. The fairly steady, 
large-scale, and deep flow is believed to originate mainly as the result 
of the combined action of friction and gravity forces generated by the 
westerly winds that prevail in this region. 
The speed of the West Wind Drift increases considerably toward 
Drake Passage, where it averages up to 0.7 knot, a value about three 
times higher than in the open ocean. Current speeds decrease slightly 
with depth, and the average speed of the surface flow is only about 
twice that at 2,000 feet (610 meters). An analysis of oceanographic 
observations at various locations around Antarctica shows the following 
computed mean speeds at various depths. These figures, shown in Table 14, 
may be considered lower than the actual speeds but nevertheless can be 
used as a general description of the currents. 
APPROXIMATE DEPTH MEAN COMPUTED VELOCITIES 
meters feet cm/sec knot 
O O 720 < 0.2 
50 165 50) Opal 
200 660 4.0 << Ooi 
600 1,970 B20) Oem: 
1,000 3,300 20D Ooal 
2,000 6,560 Lo) @oal 
2,500 8,200 Om Qo dl 
Table 14 Computed speeds at various depths 
8h 
