2012 · GeographyPrevious Year Question
Q45.
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?
A. 1 and 2 only
B. 1, 2 and 3
C. 1 and 4
D. 2, 3 and 4
Answer

B

Explanation

Ocean currents are influenced by: (1) Rotation of Earth — Coriolis effect deflects currents clockwise in Northern Hemisphere and anticlockwise in Southern Hemisphere. (2) Air pressure and wind — trade winds, westerlies drive surface currents. (3) Density of ocean water — differences in temperature and salinity create thermohaline circulation (deep ocean currents). Revolution of the Earth (statement 4) does NOT directly influence ocean currents.