Glacier Erosion

Glacier Erosion

1. Processes

   • Abrasion
     • Material within the glacier rubs against the valley bottom and sides. Large debris can leave striations on the valley edges.
       • Affected by
         • Size of Debris
         • Ice thickness
         • Relative hardness of rock.
   • Plucking
     • Meltwater enters joints in the rock of the valley side or floor; when the water freezes, the glacier freezes to the rocke; when the glaciers advances, the rock is pulled away

2. LANDFORMS

   • Hanging Valley
     • Tributary valleys connected to the main valley that may be a higher distance above sea level causing a water fall to form
     • Church Beck - Lake District
   • Glacial Trough
     • U Shaped valley. Consists of a flat floor and may contain a ribbon lake or Roche Moutonnee.
     • 1km - 50km
     • Nant Ffrancon Valley - Snowdonia
   • Arete
     • Steep, Knife-edged ridge which seperates two corries or troughs.
     • 2km max and height 700m max
     • Striding Edge - Lake district
   • Roche Moutonee
     • A lump of resistant rock found on the floor of a glacial valley. It is an asymmetrical feature as it consists of a gentle polished like end and a jaggered side
     • 1m-10m height
     • Nant Francon Valley
   • Corrie
     • 0.5-1km
     • An armchair like hollow witha steep back wall - 60 degree angle. it may consist of a rock lip and a tarm
     • Cwm Idwal - Snowdonia

3. DEPOSITION LANDFORMS

   • Moraines
     • Ridges of material formed at the side or front of a glacier. This could be lateral, medial. terminal or recessional
     • Unsorted TILL
   • Drumlins
     • Smooth oval shaped hills. Have a stoss (steep side) in the upstream and a leeside (gentle slope) in the downstream end