Question

Q. Which of the following statements about vertical distribution of salinity is/are correct?

Select the correct answer using the code given below:

• A. 1 only
• B. 2 only
• C. Both 1 and 2
• D. None of the above

Answer 1

The correct option is B 2 only

Explanation:

• Salinity changes with depth, but the way it changes depends upon the location of the sea. Salinity at the surface increases by the loss of Surface salinity of oceans’ water to ice or evaporation or decreased by the input of freshwaters, such as from the rivers. Salinity at depth is very much fixed because there is no way that water is ‘lost, or the salt is ‘added.’
• Statement 1 is incorrect: Salinity, generally, changes with depth and there is a distinct zone called the halocline, where salinity increases or decreases sharply.
• Statement 2 is correct: There is a marked difference in the salinity between the surface zones and the deep zones of the oceans. The lower salinity water rests above the higher salinity-dense water. Other factors being constant, increasing the salinity of seawater causes its density to increase. High salinity seawater, generally, sinks below the lower salinity water. This leads to stratification by salinity.