Consider the following factors

1. Rotation of the Earth
2. Air pressure and wind
3. Density of ocean water
4. Revolution of the Earth

Which of the above factors influence the ocean currents?

1. 1 and 2 only
2. 1, 2 and 3
3. 1 and 4
4. 2, 3 and 4

Explanation

Rotation of the Earth is correct

• The Coriolis force, caused by Earth’s rotation, influences the direction of water flow and contributes to the formation of ocean currents.

Air pressure and wind is correct

• Surface winds, such as trade winds and westerlies, drive the movement of ocean currents by pushing water across the surface.

Density of ocean water is correct

• Differences in water density due to variations in temperature and salinity create thermohaline circulation, which drives deep ocean currents.

Revolution of the Earth is incorrect

• Revolution causes seasons and seasons are responsible for the poleward and equatorward migration of the pressure systems and ocean currents. Thus, they have an indirect effect on ocean currents.

Answer: (b) 1, 2 and 3; Difficulty Level: Easy