AIM: How does Earth’s water move through the Water

Cycle?

Earth’s surface is covered mainly by water.•Oceans cover about 70% of our planet’s surface.

What is the Water Cycle?Earth has been recycling its water supply for 4 billion years.•The Water Cycle is the continuous process by which water moves from Earth’s surface to the atmosphere and back.

•Driven by energy from the SUN.

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Processes of the Water Cycle

1. The Sun heats up the water in Earth’s oceans and lakes.

Processes of the Water Cycle

2. Evaporation: liquid water changes to a gas called water vapor.

Processes of the Water Cycle

• Transpiration: water vapor is released by plants.

Processes of the Water Cycle

• Respiration: As animals breathe small amounts of water vapor are released.

Processes of the Water Cycle3. Condensation:

•Warm air carries water vapor upward.

•The air cools and condenses into liquid water.•Convection: Warm air rises and cold air sinks.

•Tiny droplets of water clump together around tiny dust particles in the air, forming clouds.

Licancabur Volcano is located on the border between Chile and Bolivia.

• If a cloud is on, or just above, Earth’s surface, it is called FOG.

Processes of the Water Cycle

4. Precipitation:•As more water vapor condenses, the drops of water grow larger and heavier.

•The heavy droplets fall as precipitation (rain, snow, sleet, hail).

Processes of the Water Cycle

5. The precipitation that falls on land may:• soak into the soil and become groundwater

OR•Run off the land, eventually flowing back into the ocean.

Water that falls on the surface may run off into rivers and streams, eventually flowing back to a lake or ocean.

Water Cycle Video

How is Earth’s Water Distributed?

• About 97% of Earth’s water is salt water found in oceans.

• Only 3% is freshwater.

How is Earth’s Water Distributed?

• Oceans: the Pacific, Atlantic, Indian, and Arctic Oceans are all interconnected, covering the majority of Earth’s surface.

How is Earth’s Water Distributed?

• Ice: most of Earth’s freshwater is locked in thick sheets of ice near the Earth’s poles.

How is Earth’s Water Distributed?

• Rivers and Lakes: Only 0.02% of Earth’s water, but an important source of freshwater for people who live near them.

The Great Lakes contain almost 20% of all the

water in Earth’s freshwater Lakes

How is Earth’s Water Distributed?

• Groundwater: water that fills the cracks and spaces in underground soil and rock layers.