Question

Name the factors affecting salinity.

Answer 1

The salinity of water in the surface layer of oceans depend mainly on evaporation and precipitation.

Due to the sun’s heat, evaporation happens at a faster rate. Evaporated water turns into water vapour and reduces in quantity. But amount of salt remains the same in the remaining water and therefore the salinity of water increases.

• In seas where the rate of evaporation is high than the supply of fresh water, salinity is high.
• In seas where the supply of freshwater exceeds the rate of evaporation, salinity is low.
• Salinity is not affected much in seas where both the supply of freshwater and evaporation of water is low.
• Seas where rivers meet, such as the Bay of Bengal, and where ice melts, such as the Arctic Ocean, lack fresh water.
• Marine currents in the open ocean control and balance alkalinity. Alkalinity increases due to blockage of flows in landlocked seas. An example of this is the Mediterranean Sea.