GEOLOGY

Detailed explanation-1: -In high latitudes, salinity increases with depth. In the middle latitudes, it increases up to 35 metres and then it decreases. At the equator, surface salinity is lower.

Detailed explanation-2: -Typically, the salinity decreases from the surface ocean to deep waters is very small, from about 36 g/L (ppt) at the surface to 35 g/L (ppt) in the deep water, thus there is a very small density decrease with depth given a constant temperature.

Detailed explanation-3: -Evaporation of ocean water and formation of sea ice both increase the salinity of the ocean. However these “salinity raising” factors are continually counterbalanced by processes that decrease salinity such as the continuous input of fresh water from rivers, precipitation of rain and snow, and melting of ice.

Detailed explanation-4: -The deeper you go under the sea, the greater the pressure of the water pushing down on you. For every 33 feet (10.06 meters) you go down, the pressure increases by one atmosphere .

Detailed explanation-5: -Cold, salty water sinks to the bottom of the ocean. Water gets colder with depth because cold, salty ocean water sinks to the bottom of the ocean basins below the less dense warmer water near the surface.