Earth Science
Water on Earth
Water Distribution
Study Tip
Studying diagrams for this topic will help you visualize the relative amounts of water.
Distribution
- Earth’s oceans contain 97% of the planet’s water.
- That leaves just 3% as fresh water (water with low concentrations of salts).
- Most are trapped as ice in vast glaciers and ice sheets in Greenland.
Study Tip
Studying diagrams for this topic will help you visualize the relative amounts of water.
Reservoirs
- A reservoir is a storage location for a substance (e.g. the atmosphere is a reservoir for carbon dioxide).
- A water molecule may pass through a reservoir very quickly or may remain.
- The residence time is the amount of time a substance remains in a reservoir.
Concept Check
- Compare the amount of fresh water to the amount of salt water.
- What is the relationship between reservoir and residence time?
