Science

^^Earth crust:^^

• The outer layer of the earth.

• thinnest layer

• Made up of both continental
  (land)and oceanic crust(under
  the ocean).

• least dense

• Composed of mostly granite and basalt

  @@Earth@@ @@Mantle:@@

• ^^Largest layer of the Earth^^

• ^^Composed of silicate rocks rich in
  magnesium and iron^^

• Intense heat causes the rocks to rise
  and then cool and sink.

• ^^The process is called convection,
  which causes the crust to move.^^

• Average temperature 3000

• ^^Made up of mostly magma^^

• ^^Contains convection currents that move the tectonic plates^^

^^Earth^^ ^^outer^^ ^^core^^^^:^^

• Liquid layer 2,300 km thick, second larges
• Composed of liquid iron and nickel
• Lies between inner core and mantle
• Because the magma moves around the inner core, Earth’s magnetic field is created.

Average temperature 4000o -5000o

%%Earth%% %%Innercore:%%

• ^^A solid ball of metal^^
• ^^Made of solid nickel and iron^^
• ^^Densest layer of the Earth^^
• Average temperature 5000-6000
• Spins at a speed faster than the Earth
  rotates
• ^^So hot it melts everything in the outer
  core^^
• ^^a soild^^

^^Seismic:^^

• Seismic waves are used to
  determine which layers of the
  Earth are solid or liquid.

• Some seismic waves cannot
  pass through certain layers
  giving us a clue to the layer’s
  composition.

  ^^Oceanic Crust:^^

• A thin layer of crust that
  overlies the ocean basins

• More dense than continental
  crust

• Mostly basalt rock

• Thinner than continental crust.

• Younger (newer) than
  continental crust

  Continental Crust

  ^^Continental Crust:^^

• Layer of rock which forms the
  continents

• Less dense than oceanic crust

• Mostly granite

• Thicker than oceanic crust

• Older than oceanic crust