Earth Science
Water on Earth
Seawater Chemistry
Study Tip
Both the salinity and the density of water are responsible for the currents in the deep ocean.
Mineral Composition of Oceanwater
Because H₂O is a polar molecule, it has the ability to dissolve many different substances.
Study Tip
Both the salinity and the density of water are responsible for the currents in the deep ocean.
Salinity
The salt in seawater comes from ions that water picks up as it flows over rocks and soil.
The
salinity,
or the salt content, varies from location to location.
The salinity is higher if there is a lot of evaporation and little circulation of water.
Water Density
Water density increases if:
Salinity or pressure increases
Pressure decreases
Differences in water density are responsible for deep ocean currents.
The diagram above displays the concentrations
of minerals inside the ocean’s waters.
Concept Check
In general, what kinds of minerals are present in seawater?
What is salinity? When will the salinity rise or fall?
How does the density of water change? What does the density affect?