1. Chapter 1.2
Earth’s Spheres

2. Earth The only planet currently known to support life.
This capacity is due to the interactions among its 4 spheres…
Atmosphere
Hydrosphere
Geosphere
Biosphere

3. Sphere #1
THE ATMOSPHERE

4. What Is the Atmosphere?
A mixture of gases, mostly nitrogen (N) and oxygen (O) with smaller amounts of argon, carbon dioxide, and other gases
Held to the Earth by gravity
Thins with altitude

5. Why Is the Atmosphere Important?
Supports Life
Animals need oxygen
Plants need carbon dioxide (CO2)
Regulates Climate
Retains heat at night
Shields from sun’s radiation during the day
Wind transports heat from Equator and cold from Poles

6. Sphere #2
Geosphere

7. The Geosphere The solid Earth The geosphere is slowly changing
Rocks, mountains, beaches, ocean basins, magma, mantle
The geosphere is slowly changing
Volcanic eruptions form new land
Mountains are uplifted
Continents are in slow but constant motion

8. Sphere #3
              
THE HYDROSPHERE

9. What Is the Hydrosphere?
All the earth’s water
Most of this water is salt water
3% of the hydrosphere contains fresh water
Most of this water is frozen in glaciers
Remaining water is found in groundwater, lakes, water vapor, and river water.
All the water on Earth is recycled…
No new water is ever created!

10. Sphere #4
THE BIOSPHERE

11. What Is the Biosphere? The zone inhabited by life
Includes the uppermost geosphere, the hydrosphere, and lower atmosphere
Includes all forms of life
Single-celled protozoans, to jellyfish to redwood trees to people.