GEOLOGY

Detailed explanation-1: -Seawater is denser than both fresh water and pure water (density 1.0 kg/L at 4 °C (39 °F)) because the dissolved salts increase the mass by a larger proportion than the volume. The freezing point of seawater decreases as salt concentration increases. At typical salinity, it freezes at about −2 °C (28 °F).

Detailed explanation-2: -As one moves toward the poles, the region of rain decreases and with less rain and more sunshine, evaporation increases. In comparison freshwater, in the form of water vapor, moves from the ocean to the atmosphere through evaporation causing the higher salinity.

Detailed explanation-3: -The more salt there is dissolved in the water, the greater its salinity. When comparing two samples of water with the same volume, the water sample with higher salinity will have greater mass, and it will therefore be more dense.

Detailed explanation-4: -saltwater has a higher density than freshwater. less dense matter will lie above more dense matter.

Detailed explanation-5: -Density increases as salinity increases and as temperature decreases. Because salt lowers the freezing point of water, sea water does not start forming the lattice structure that lowers its density until it is much colder than fresh water.