Ocean Water Properties and Salinity

Ocean Water Properties

• Ocean water is salty due to the high salinity, which is the amount of salt dissolved in water.
• 97% of the Earth's water is found in oceans, but it's not usable for drinking, cooking, or watering plants due to its high salinity.

Salinity and Chemical Properties

• Most of the salt in oceans originated from land, carried by rain and moving water in rivers and streams, which wash over rocks containing sodium chloride (common table salt).
• Salt can also be introduced into oceans through underwater volcanoes, stirring up salt and other minerals from deep layers of the Earth.
• Salt becomes more concentrated over time as water from the ocean surface evaporates, leaving the salt behind.
• Ocean water contains other chemicals, such as magnesium, sulfate, calcium, and potassium, which are essential for sustaining life.
• Gases dissolved in ocean water include nitrogen (N2), oxygen (O2), and carbon dioxide (CO2).

Ocean Water Temperature

• Ocean temperatures range from highest at the equator to increasingly colder near the poles.
• Ocean water has a high heat capacity, meaning it takes a long time to change its temperature.
• The freezing point of ocean water is lower than freshwater, around 28°F, due to its high salinity.

Ocean Water Density

• Ocean water density depends on its temperature and salinity.
• Very salty ocean water is denser than less salty water, and cold ocean water is denser than warm ocean water.
• Cold, salty water is denser and sinks to the bottom of the ocean, while less dense water floats on top.

Summary

• Ocean water has a high salinity, which affects its freezing point and density.
• Ocean water contains essential chemicals and gases, and its properties impact the global climate and ocean life.