Explain the effect of -

Deep ocean currents

Deep ocean currents are those water currents which flow beyond the depth of 500m. They are driven by density and temperature gradients. They constitute about 90% of the ocean water. The redistribution of the ocean water through the movement of deep ocean current is a continuous process and it takes around 500 years to complete one cycle of redistribution of ocean water. Redistribution of nutrients takes place when warm water is transferred to the bottom from the surface and the nutrient-rich cold water is circulated to the surface.