Earth Science
Water on Earth
Distribution of Water on Earth
Study Tip
To help remember the function of reservoirs: Reservoirs reserve water.
Distribution of Water
- Earth’s oceans contain 97% of the planet’s water
- 3% of Earth’s water is fresh water, water with low concentrations of salt
- Most fresh water is trapped as ice in glaciers and ice sheets of Greenland
Study Tip
To help remember the function of reservoirs:
Reservoirs reserve water.
Reservoirs reserve water.
- Reservoir: storage location for water
- Can be an ocean, glacier, pond, or the atmosphere
- Water molecule may pass through a reservoir very quickly or remain for much longer
- Residence time: amount of time a molecule stays in a reservoir
The distribution of Earth’s water
Concept Check
- If Earth is the water planet, why is water sometimes a scarce resource?
- What are the reservoirs for water?
- In which reservoirs does water have the longest residence times? The shortest?
