What causes deep currents?

What causes deep currents?

• A. Differences in density of ocean water
• B. Wind patterns
• C. Temperature variations
• D. Tides

Answer: (A)

Deep currents form because seawater density varies throughout the ocean. Cold water and water with higher salinity are denser, so in polar regions dense surface water sinks and begins to flow along the bottom. This sinking water creates a slow, global conveyor belt that moves large amounts of water through the deep ocean. As the deep water travels, it eventually upwells elsewhere, continuing the cycle and transporting heat and nutrients at depth. Wind mainly drives surface currents, and tides influence coastal and some shallow regions, but the deep, density-driven flow is set by differences in density caused by temperature and salinity.

Deep currents form because seawater density varies throughout the ocean. Cold water and water with higher salinity are denser, so in polar regions dense surface water sinks and begins to flow along the bottom. This sinking water creates a slow, global conveyor belt that moves large amounts of water through the deep ocean. As the deep water travels, it eventually upwells elsewhere, continuing the cycle and transporting heat and nutrients at depth. Wind mainly drives surface currents, and tides influence coastal and some shallow regions, but the deep, density-driven flow is set by differences in density caused by temperature and salinity.