Chapter 2: A Living Planet

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Chapter 2 A Living Planet

• Section 1 The Earth Inside and Out

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Physical Geography A Living Planet

• The geography and structure of the earth are
  continually being changed by internal forces
  (like plate tectonics) and external forces (like
  weather).

3
Continental Puzzle

• The 7 continents on earth fit together like a
  jigsaw puzzle
• Francis Bacon (1620)- first to suggest that the 7
  continents were once one
• Continental Drift- hypothesis of Alfred Wegner
  (1912)
• Said earth was once supercontinent call Pangea
  (all earth)
• Pangea split into many plates that slowly drifted
  apart

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The Structure of the Earth

• Inside the Earth
• Core- center of the earth made up of iron and
  nickel (outer core liquid)
• Mantle- surrounds the core
• Has several layers
• Contains most of the earths mass

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Inside, On, and Above the Earth

• Inside the Earth
• Magma- molten rock that forms in the mantle
• Crust- thin layer of rock at the Earths surface
• On and Above the Earth
• Atmosphere- layer of gases surrounding the earth
• Contains oxygen
• Protects Earth from radiation
• Medium for weather and climate

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Structure of Earth

• On and Above the Earth (continued)
• Lithosphere- solid rock portion forms ocean
  floors
• Hydrosphere- water elements of earth
• Biosphere- atmospherelithospherehydrosphere
• Plants and animals live within the biosphere

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Bodies of Water and Landforms

• Water covers about ¾ of earths surface
• Ocean Motion
• The ocean circulates in 3 ways
• Waves- swells or ridges made by wind
• Currents- rivers flowing through the ocean
• Tides- regular rising and falling of the ocean
  (created by the gravitational pull of the moon or
  sun).

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Waves
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Currents
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Ocean Motion Continued

• The motion of the ocean helps distribute heat on
  the planet
• Winds are cooled and heated by ocean water

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Hydrologic Cycle

• The cycle of water between the atmosphere,
  oceans, and earth

12
Lakes, Rivers, and Streams

• Hold more than 95 of the earths fresh water
• Freshwater lakes are a result of glacial action
• Saltwater lakes form when outlets to the sea are
  cut off
• Rivers and streams carry water to and from larger
  bodies of water
• Tributaries- small rivers/streams that feed
  larger ones
• Drainage Basin- the area drained by a river and
  its tributaries

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Drainage Basin
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Landforms

• Landforms are naturally formed features on the
  Earths surface
• Oceanic landforms
• Continental shelf- sea floor from the continents
  edge to the deep ocean
• Sea floor has ridges, valleys, mountain ranges,
  etc.
• Islands- formed by volcanoes, sand, or coral

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Continental Shelf
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Continental Landforms

• Relief- difference in landform elevation from the
  lowest to highest point
• 4 categories of relief
• Mountains
• Hills
• Plains
• Plateaus
• Topography- the configurations and distributions
  of landforms
• Topographic map shows vertical dimensions