Unit 1C - Glacial Landscapes in the UK

. Water in cracks in rock

. Water freezes -> pressure on rock

. Crack widens outwards and/or downwards

. Water thaws -> pressure released

. Repeated process -> rock breaks up

Rocks trapped and frozen to ground beneath glacier

Glacier moves -> rocks plucked out from ground

Create jagged landscape

Plucked rocks can cause abrasion

Sand paper effect

Caused by weight of ice scouring floor

Rocks from freeze-thaw and plucking scour valley floor

Ice melts

Visble as large scratches/ marks - STRIATIONS

Step 1 - Snow collects in hollow and compresses into ice

Step 2 - freeze thaw above galcier

• plucking steepens backwall
• abrasion deepens hollow
• morraine left at end of glacier

Step 3 - jagged summit

• steep backwall
• deep rock basin and rock lip
• scree collects
• corrie lake (tarn) formed after glacier melts

Before glaciation - tributory streams

• main river
• INTERLOCKING SPURS

During glaciation - glacier errodes valley making it steeper/wider

• ridges and peaks above ice shattered by freeze-thaw
• rocks plucked from sides and base of valley used for abrasion

After gaiciation - arête

• pyramidal peak
• tarn
• corrie
• ribbon lake
• Glaciated trough/ valley with steep sides and level floor
• valleys of tributary streams left above valley as hanging valleys
• interlocking spurs straightened/chopped off leaving truncated spurs