The document discusses the four primary spheres that make up planet Earth: the hydrosphere, atmosphere, biosphere, and lithosphere. The hydrosphere is all water on Earth, including oceans, lakes, ice and groundwater. The atmosphere surrounds the planet and is composed mainly of nitrogen, oxygen and trace gases. The biosphere is the global ecological system interacting with the atmosphere, hydrosphere and lithosphere, supporting life. The lithosphere is the outermost solid shell of the Earth.

1. The Earth’s Spheres
What are the 4 primary components of
planet Earth?
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2. The Earth’s Spheres
Water Life Air Land
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4. The Earth’s Spheres
Hydrosphere Atmosphere
Biosphere Lithosphere
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6. The Atmosphere
The atmosphere is
the layer of gases
surrounding the
Earth.
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7. The Atmosphere
It is composed of:
78% N2
21% O2
1% other gases (Ar, H2O, CO2, etc.)
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8. The Atmosphere
Why is the atmosphere important?
•It moderates temperatures on Earth’s
surface.
•It blocks some incoming solar radiation.
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9. The Atmosphere
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10. The Lithosphere
The lithosphere is the solid outer layer of
the Earth.
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11. The Lithosphere
It includes mountains and ocean floors,
and ranges from 50km to 150km thick.
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12. The Lithosphere
It contains many valuable resources, such
as metals, minerals, and fossil fuels.
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13. The Lithosphere

14. The Hydrosphere
The hydrosphere is all of the water on
Earth.
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15. The Hydrosphere
It includes
lakes, oceans, clouds, ice, snow, and
groundwater.
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16. The Hydrosphere
97% of the Earth’s water is contained in its
oceans.
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17. The Biosphere
The Biosphere is any zone around Earth
where life can exist.
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18. The Biosphere
The biosphere must exist within the other
3 spheres.
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19. The Gaia Hypothesis
The Gaia Hypothesis believes that the
Earth is able to act like a living being.
Mother Earth
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20. The Gaia Hypothesis
As a living being, the Earth can react to
changes in or around it and regulate itself
over time.
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21. The Gaia Hypothesis
The Gaia Hypothesis is not fact, but the perception of Earth as
a living thing promotes awareness and stewardship for Earth.
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