Layers of the Earth

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Layers of the Earth

• Geosphere

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The Earth as a System

• Integrated system of rock, air, water, and living
  things.
• This system is divided into four parts
• atmosphere (air)
• hydrosphere (water)
• biosphere (living things)
• geosphere (rock)

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Geosphere

• Geosphere- solid part of the Earths crust that
  consists of rock, soil and sediment.

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Earths Interior

• Seismic Waves the waves that travel through the
  Earths interior during an earthquake.
• Altered by the type of material that it travels
  through.

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Seismologists

• Scientists who measure changes in these waves to
  determine that the earths interior is made in
  layers.

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Composition of the Earth

• Three layers
• crust
• mantle
• core
• Density increases towards the center of the Earth

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Crust

• Thin, outer layer.
• The crust is composed of two rocks. The
  continental crust is mostly granite. The oceanic
  crust is basalt. Basalt is much denser than the
  granite. Because of this the less dense
  continents ride on the denser oceanic plates.
  less than 1 of Earths mass
• 5-32km thick

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Mantle

• Layer beneath the crust
• 80 of mass of Earth
• 2,868 km thick
• Made of
• lithosphere
• asthenosphere
• mesosphere

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Lithosphere

• Outer layer
• Crust and upper layer of the mantle
• cool, rigid
• divided up into huge tectonic plates

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Asthenosphere

• 250 km thick
• solid, plastic-y layer made of rock
• flows very slowly and allows tectonic plates to
  move across
• The middle mantle

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Mesosphere

• 2,250 km thick
• middle sphere
• lower part of mantle

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Core

• 3,248 km radius
• sphere of hot, dense nickel and iron
• 4,000 - 5,000 C
• 1/3 of the Earths mass
• Made of
• Outer Core
• Inner Core
• has temperatures and pressures so great that the
  metals are squeezed together and are not able to
  move

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Outer Core

• Outer Core 2,300 km thick, outer shell, made of
  liquid nickel and iron

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Inner Core

• Inner Core 1,228 km radius a sphere of solid
  iron and nickel