Restless Earth

Restless Earth

1. Structure of the Earth

   • Crust; outer layer, up to 75km thick
     • Split into 2 types of crust; oceanic crust and continental crust
       • Continental crust
         • Granite
         • Less dense
         • Light
         • Thin
         • Old
       • Oceanic crust
         • Basalt
         • Dense
         • Heavy
         • Thick
         • New
   • Mantle (magma); up to 2800km thick
     • The upper part forms part of the lithosphere and is rigid
     • The lower part is semi-molten and forms part of the asthenosphere
     • 1200 degrees celsius
   • Outer core
     • Has liquid properties
     • 3000 degrees celsius
   • Inner core
     • Inner most part of the Earth
     • 5000 degrees celsius
     • Iron and nickel

2. Plate boundaries

   • Destructive (colliding)
     • Eurasian and Pacific
   • Constructive (pull apart)
     • Indo Australian and Antarctic
   • Collision (two continents collide)
     • Eurasian and Indo Australian; forming Himalayas
   • Conservative (slide past)
     • Pacific and North American
   • East African Rift Valley
     • A rising convection current (plume) creates a hot spot below the continental crust & weakens it, the diverging current splits the plates apart
       • Continent splits, land sinks to from a rift valley with active volcanoes throughout the length
         • Rift valley can collect water and form giant lakes