Consider the following statements regarding ocean salinity and density:

1. The salinity of ocean water is highest at the equator due to intense evaporation.

2. An increase in salinity always leads to an increase in water density.

3. Deep ocean water has higher density than surface water due to lower temperatures and higher salinity.

4. Freshwater inflow from rivers increases ocean salinity near coastal areas.

How many of the statements given above are correct?

The correct answer is option 1.

Key Points

• Statement 1 – Incorrect – While evaporation is high at the equator, heavy rainfall reduces salinity. Maximum salinity is found in subtropical regions (20°–30° latitudes), where evaporation is high, but precipitation is low.
• Statement 2 – Incorrect – An increase in salinity generally increases density, but if temperature rises, density may decrease despite high salinity (due to thermal expansion).
• Statement 3 – Correct – Deep ocean water has higher density due to lower temperatures and higher salinity, making it heavier and more stable.
• Statement 4 – Incorrect – Freshwater inflow from rivers reduces salinity, as it dilutes ocean water.