Geography

• Weathering


  The breakdown of rocks 'in situ' by physical and chemical processes.
• In situ


  In it's situation = Exactly where it is without moving
• Erosion


  Wearing away and removal of material from the landscape by a moving agent (such as water, wind or ice).
• Zone of accumulation


  The part of a glacier that, when viewed as a system, has more inputs than outputs.
• Zone of ablation


  The part of a glacier that, when viewed as a system, has more outputs than inputs.
• Equilibrium line


  The line that divides the two zones when a glacier is viewed as a system.
• Snout


  Front end of a glacier
• Plucking


  The process by which a glacier wears away bedrock as it freezes to pieces of rock and pulls then away as the glacier moves.
• Abrasion


  The process by which a glacier wears away bedrock by a sandpapering effect as rocks embedded in ice scrape away the ground beneath.
• Freeze-thaw 


  The process by which rock is loosened and broken down as water enters cracks in rocks, repeatedly freezing and expanding.
• Scree


  Sharp fragments of rock created by freeze-thaw weathering
• Corrie


  Large, bowl-shaped feature found on the side of a mountain.
• Tarn


  The lake in a corrie.
• Arete 


  Sharp ridge with corries either side
• Pyramidal peak


  Sharp peaked mountain with corries on it's sides.
• U-shaped valley


  Wide, deep and steep-sided landforms created by glacial processes.
• Hanging valley


  A U-shaped valley that joins a main valley from an elevated height.
• Truncated spur


  A cliff-like side to a hanging valley that would have interlocked with the valley opposite before glaciation.
• Misfit river


  A river that couldn't have eroded the valley it is found in.
• Ribbon lake


  A long, narrow and winding lake often found in the areas of softer rock in a U-shaped valley.
• Chemical weathering


  Occurs when the acid in rainwater causes rock to rot and crumble. Water and heat speeds this up.
• Freeze-thaw weathering


  Occurs when:

  • Water gets into a crack in rock
  • Freezes and expands, widening crack
  • Melts and allows more water to enter
  • Process repeats until rock splits
  • Remains called scree
  • Can only happen in temperatures fluctuating around 0, so water can melt and freeze
• Onion-skin weathering


  Occurs when rock is repeatedly heated and cooled, causing expansion and contraction. This causes pieces of the rock to peel off. Common in desert areas where it is hot in the day but cold at night.
• Glacier formation: stage 1


  Snowfall:

  • Fresh snow falls
  • Traps air and weighs on snow beneath
• Glacier formation: stage 2


  Layers:

  • Old snow is weighed down and compacted by new snowfall
  • Air is squeezed out by this weight
  • Snow that is a year+ old is called Firn
• Glacier formation: stage 3


  Summer melting:

  • Some snow melts in summer
  • Spills into air holes and cracks in ice
  • Freezes and closes gap, squeezing out air and acting like glue
• Glacier formation: stage 4


  Colour change

  • Snow changes from a white to blue
  • White shows the ice is full of air holes
  • Blue shows that there is hardly any air left inside
• Glacier formation: stage 5


  The glacier:

  • Intensely compacted
  • Solid, rock hard and smooth
  • Whole process takes 20 - 40 years
• Corrie formation: stage 2


  During ice age:

  • Freeze-thaw weathering weakens rock
  • Plucking erodes back wall, making it steep
  • Corrie floor deepened by abrasion leading to bowl shape
  • Glacier moves under gravity
  • Rock lip where there is less erosion due to less mass of ice

  A) Plucking

  B) Freeze-thaw weathering

  C) Abrasion

  D) Corrie lip

  E) Glacier moves downhill

  
• Corrie formation: stage 1


  Beginning of ice age:

  • Snow and ice collects in a hollow
  • Gravity pulls the ice downhill as it becomes a glacier
  • Glacier erodes hollow

  A) Fresh snow

  B) Compacted snow and ice forming glacier

  C) Glacier moves downhill under gravity

  D) Hollow in mountain

  
• Corries - key descriptive words


  After ice age:

  A) High, sharp peak

  B) Steep back wall

  C) Bowl-like base

  D) Front of bowl is lower and shallow

  E) Lip of corrie

  F) Surrounded by aretes or ridges

  
• Pyramidal peak - key descriptive words


  After glaciation:

  A) High, sharp peak

  B) Arete where corries meet

  C) corries

  D) Steep walls leading down

  
• Pyramidal peak formation


  During ice age:

  • 3+ corries form near each other
  • They meet to form aretes
  • In the centre there is a high, sharp peak
• Arete formation


  During ice age:

  • 2 corries form near each other
  • Cut back and a sharp ridge forms
• Arete - key descriptive words


  During ice age:

  A) Arete

  B) Steep back wall

  C) corrie

  D) corrie

  E) arete

  F) arete

  
• When did the devastating earthquake strike Christchurch, New Zealand?

  Tuesday the 22nd of February 2011
• How long did the earthquake last?

  12 seconds
• What were the immediate consequences of the earthquake in Christchurch?

  Billions of dollars worth of damage and 185 fatalities
• How does the Christchurch earthquake compare to previous earthquakes New Zealand has experienced?

  It was significantly more destructive than most previous earthquakes
• What is the Ring of Fire?

  The Ring of Fire is a region around the perimeter of the Pacific Plate that is prone to seismic activity