Earth As A System

Life on Earth

• There are nine planets in the solar system, but yet only one has life on it

• Why is that?• Why do other

planets not have life on them?

Earth as a System

Earth as a System

• Earth is much like the human body, with many different parts working together with the purpose of sustaining life

Earth

• Land covers 30% of Earth’s surface• Water covers about 70%• Atmosphere is layer of air around the

Earth, made up mainly of nitrogen and oxygen

• Weathering and erosion shape the Earth’s surface

• “Pulse of the Planet”

Earth

• Look at Cedar City on Google Earth

• Describe the physical characteristics of Cedar City, including type of landforms, rivers, etc.

Earth

• The inside of the Earth is a very busy place• Melted rock and other materials are always

moving• Activity builds up heat and pressure that

cause movements in the crust• Sometimes, these movements can be felt as

earthquakes, volcanoes, and the formation of mountains

Earth is Unique

• Compared to the other planets in the solar system, Earth is very unique

• Let’s look at a few reasons Earth is unique

Too Little Mass: Mars has very little atmosphere and mostly carbon dioxide

Earth is unique in our Solar System:Mass of Earth Holds Right Atmosphere Composition

Earth is unique in our Solar System:Atmosphere stops lethal radiation

Classroom Resource: ozone blocks UV radiation

Moon: tremendous diurnal fluctuations

(-250F to +250 F)

Venus: runaway greenhouse effect (864 F)

Earth is unique in our Solar System:Atmosphere keeps temperature even

Earth is unique in our Solar System:Atmospheric protects us from most (but not all) extraterrestrial objects

Gives us the Coriolis Effect (allowing atmosphere and oceans to spin and circulate)

But not too harshly, like jupiter

Earth is unique in our Solar System:Earth’s Spin is Just Right

Using the Earth’s Resources

• Anything we use from the Earth is considered a natural resource

• Air and Water are natural resources that are necessary for survival

Earth’s Resources

• Plants and animals we eat are resources

• So are rocks, minerals, soil, fossil fuels, and many other things

Renewable Resources

• Some resources can be replaced as they are used.

• Trees are on example of renewable resources.

• Can you think of any other examples?

Nonrenewable Resources

• Some resources cannot be replaced.

• Oil, Natural Gas, and Coal cannot be replaced.

• Can you think of any other examples of nonrenewable resources?

Earth’s Resources

• Think of Cedar City and the area around Cedar City. What are some resources in this area that you can think of? Name as many as you can.