Earth

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Chapter 1.2

• Earths Spheres

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Earth

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

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Sphere 1
THE ATMOSPHERE
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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

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Why Is the Atmosphere Important?

• Supports Life
• Animals need oxygen
• Plants need carbon dioxide (CO2)
• Regulates Climate
• Retains heat at night
• Shields from suns radiation during the day
• Wind transports heat from Equator and cold from
  Poles

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Sphere 2

• Geosphere

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The Geosphere

• The solid Earth
• 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

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Sphere 3
THE HYDROSPHERE
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What Is the Hydrosphere?

• All the earths 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!

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Sphere 4
THE BIOSPHERE
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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.