Water Cycle
What powers the water cycle?
Where is most of Earth's freshwater stored?
In glaciers and ice caps
What percentage of Earth's water is saltwater?
About 97%
What structure is often built by cities to collect and store freshwater?
A reservoir
A city dams a river and makes a lake that stores its freshwater supply. This is an example of an artificial what?
reservoir
What is the process by which water vapor turns into liquid water?
Condensation
What percentage of Earth's water is freshwater?
About 3%
What is the main way oceans contribute to the water cycle?
Through evaporation
Name one human activity that can reduce access to clean water.
Factory runoff or pollution
A sealed plastic bottle falls into the ocean off Australia. Three years later, the bottle is found on a beach in France. How could this happen?
Currents
Which process involves water moving downhill after precipitation?
runoff
Which source provides the largest amount of surface drinking water?
Lakes
Which two features most influence ocean temperature?
Depth and proximity to the equator
What is a common strategy to conserve water in areas with limited freshwater access?
Reducing usage
What is it called when a solid turns into a gas?
sublimation
Arrange these steps of the water cycle: evaporation, runoff, condensation, precipitation
1) Runoff, 2) Evaporation, 3) Condensation, 4) Precipitation
Name one way humans can increase access to clean freshwater.
Digging aquifers or building reservoirs
What is the salinity threshold (in ppm) for water to be considered saltwater?
At least 1,000 ppm
Why is desalination important for some cities?
It provides freshwater by removing salt from seawater.
What is it called when water vapor is released into the air through plant's leaves?
transpiration
The water cycle connects oceans to all freshwater bodies through evaporation, condensation, and what other process?
Precipitation
Which two water samples, alpha (38,000 ppm), beta (250 ppm), gamma (700 ppm), or delta (40,000 ppm), are freshwater?
Beta and Gamma
Where would you expect to find a water sample with 40,000 ppm salinity?
In the ocean
How do ocean currents affect marine ecosystems?
They distribute nutrients and oxygen, supporting marine life.
What acts as a natural water purifier by filtering sediments and other pollutants out of the water?
Wetlands