Geography week 30

• Crust


  Solid rock that covers the surface of the earth, can be continental or oceanic
• Mantle


  Under the crust, temperature of 4,000°C, made of magma
• Outer core


  Made of iron and nickel, temperature of 5,000°C
• The Earth's crust was once just one super continent - Pangaea
• The plates are moving very small distances every year, this is called continental drift
• Plates move


  Because of the heat in the magma
• Plates


  • Can collide
  • Can separate
  • Can pass by each other
• Waterfall


  • Rivers - feature of erosion
  • River flows over uneven riverbed
  • Hydraulic action erodes in a notch
  • Soft rock
  • Hard rock e.g. Granite/soft rock e.g. Sandstone
  • Hard rock overhang collapsed rock cave
  • Attrition, abrasion, and solution
  • Vertical hydraulic action
  • Soft rock waterfall retreats forming overhang
  • Vertical hydraulic action to the notch into a plunge pool
  • Overhang will eventually collapse due to undercutting
  • Notch hole in soft rock
  • Vertical erosion - water evading rock vertically
• Waterfall


  • Powerscourt, Co. Wicklow
• Waterfall features vertical erosion - water eroding rock vertically
• Inner Core Temperature


  The estimated temperature of the Earth's Inner Core is approximately 11,000°C (19,800°F).