because of the pressure that's why the ocean get's deeper :)
The temperature of ocean water can be affected by the depth. The deeper it gets, the colder the temperature. The current also can affect the temperature of ocean water.
Arctic ocean
You could increase the salinity of the ocean by adding salt or removing water (ie: by evaporation).
salinity
In open ocean evaporation affects the salinity of the oceans, in closed oceans the lack of sunrays cause greater salinity levels.
salinity
The lowest areas of salinity in an ocean are near where fresh water rivers empty into them. This is because the influx of fresh water creates an area of lower salinity compared to the remainder of the ocean.
The Atlantic Ocean is deeper than the Indian ocean.
An increase in ocean salinity can increase density creating a convection current.
Salinity in the ocean is highest in regions where evaporation is high and precipitation is low. Density in seawater is determined by both temperature and salinity.
Salinity is increased.
under toe