Answer:
The only ocean surface current that is not driven by winds is “global conveyor belt.
This current is caused by changes in temperatures, salinity and density. The densest waters have to descend to the bottom of the sea moving the less dense towards the surface. The density of water depends on the degree of salinity and temperature. Colder waters are denser and go to the seabed, displacing the other hotter waters to the surface.
