Unit 3: Water systems on Earth

Big Ideas of Unit

• 1.0 Water exists naturally in all three states on Earth’s surface

• 2.0 The different characteristics of salt and fresh water support a diversity of living things

• 3.0 Bodies of fresh and salt water are created by geological processes

• 4.0 Waves, tides and currents are powerful forces that interact with the environment

• 5.0 Large bodies of water and glaciers affect the environment

• 6.0 People’s use of water can affect Earth’s water supply and the environment

• What is this a picture of?• How are these two places different? The same?

Mars vs Earth

• Earth and Mars both have four seasons, mountains, valleys, storms and icecaps

• Biggest difference is that Mars is half of the diameter of Earth, has a different atmosphere and Earth has an abundance of liquid water

• Evidence of water has recently been found on Mars• Mars one is planning on travelling to Mars and setting up

colonies to live there

Uses of Water

• Brainstorm, identify which ones may waste water• Demo- water, water everywhere

• 1000ml graduated cylinder• 970 ml remaining represents water in the ocean• 30 ml represent fresh water

• 23 ml of this would be trapped in glaciers and icecaps

• 7 ml remains• Of this one drop or 0.003% of the original

1000 ml represents the amount of fresh water available to us

• 74% of the earth’s surface is water

1.0 Water exists in all three states on Earth’s surface

• Most of the water on Earth can be found in liquid form (ocean, river, streams and lakes)

• A tiny amount is found as a vapor (gas)• You can not see it but you can ‘feel’ the humidity in

the air• Most fresh water is trapped in a solid or frozen state

• Found at the Artic and Antarctica and help to keep the Earth cooler since it is white and reflected sunlight

The Water Cycle

• Water constantly cycles on Earth

Terminology

1. Evaporation- changes from liquid to gas

2. Transpiration- plants releasing water vapor into the air

3. Condensation- vapor changes to water, occurs in the clouds and is the reason for rain

4. Precipitation- water falls from the clouds (rain, snow, etc)

Activity

• The water cycle in action• Once finished be sure to write a paragraph that

describes how our mini cycles compare to the Earth’s water cycle

The Water Table

• Do you get water from a well? Where does this water come from?

• A well accesses ground water that sits in an underground aquifer

• Watershed is an area that drain water into rivers, lakes and rivers

• Surface water is where water collects on the surface of the earth (lakes, rivers)

• Ground water is water that has collected underground• The water table describes the level that ground water

reaches

Discussion• What would happen to the water table if there is a

drought?• Why do you think that wells would go dry?

Questions

1. Explain how the water cycle differs from summer to winter?

2. What do you think happens if the water table reaches the surface of the ground? Why?

3. Predict what happens in the following situations:

a) Sewage is spilled onto a field?

b) Too much water is removed from a well?

c) A huge parking lot is built?