Transcript The Four Spheres of the Earth

The Four Spheres
of the Earth
Diagram of the Earth’s Spheres
1) Lithosphere
The lithosphere is the solid, outer layer of
the earth.
Since the lithosphere includes the soil, it
provides a home for many different
organisms.
How do human actions affect the lithosphere?
Negative
- mining- strips the earth of nutrients
- littering/using non-recyclables- ends up in landfills and contaminates the earth
- construction- destroys natural environments, decreases drainage
- pesticides- add unnatural chemicals to soils
- deforestation- increases soil erosion because tree roots no longer help hold soil
in place
Positive
-
composting- can decrease the amount of garbage in landfills
aeration- allows for air to enter soils
conservation areas and provincial parks- preserve/protect the land
planting trees- prevent soil erosion
gardening/green rooftops- regreens the landscape in urban areas
2) Hydrosphere
The hydrosphere consists of all of the water
on Earth. Of this water:
• 97% is salt water in the earth’s oceans
• 3% is freshwater such as in lakes and
streams
Since all living organisms need water, all
organisms depend on the hydrosphere.
How do human actions affect the hydrosphere?
Negative
- dumping garbage into the ocean- contaminates the water
- driving boats- adds gasoline to the water which contaminates it
- oil spills- contaminates water and can kill organisms in the water
- building on shorelines- can contaminate water or kill vegetation in the water
- overfishing- can decrease the amount of organisms in the water therby
decreasing nutrient content overall
- building dams- changes water levels which can destroy habitat and reduce the
amount of wildlife
Positive
- sewage treatment plants- water returning to the lakes and oceans contains less
contaminants
- fish sanctuaries- allow a safe habitat for fish which helps them survive and
contribute to the nutrients in the lake
3) Atmosphere
The atmosphere is the layer of gases that
surrounds the earth. It is composed of:
• 78% nitrogen, 21 % oxygen, 1% trace
gases (eg. carbon dioxide, water vapour)
Greenhouse gases in atmosphere trap the
sun’s energy to warm the earth so
organisms can survive.
How do human actions affect the atmosphere?
Negative
-
aerosols- deplete the ozone layer
driving cars- adds excess greenhouse gases to the atmosphere
factories- (same as cars)
burning tires/garbage- adds harmful gases to the atmosphere
Positive
- hybrid vehicles- decreases the amount of greenhouse gas emissions
- alternative power (wind/solar)- (same as hybrid vehicles)
- planting trees- absorbs CO2 from the atmosphere and adds O2
4) Biosphere
The biosphere is the part of the earth where
life exists including water, land and air.
The lithosphere, hydrosphere and
atmosphere interact to create the physical
environment of the biosphere.
• Venn Diagram:
atmosphere
Clouds
hydrosphere
biosphere
Water
Table
Top Soil
lithosphere
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