Glacial Erosion (Leaving Cert Geography): Flashcards
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15 cards from this deck
Two main processes of glacial erosion
Two main processes of glacial erosion
Plucking and abrasion
Plucking (glacial erosion process)
Plucking (glacial erosion process)
Meltwater seeps into cracks, refreezes & expands, weakens rock, glacier plucks it away
% water expands when refreezing in plucking
% water expands when refreezing in plucking
9%
Abrasion (glacial erosion)
Abrasion (glacial erosion)
Rock fragments in glacier grind/scrape valley floor like sandpaper
Striae/striations
Striae/striations
Deep scratches carved into bedrock by abrasion
3 factors affecting glacial erosion rate
3 factors affecting glacial erosion rate
Glacial thickness, gradient, rock resistance
Cirque characteristics
Cirque characteristics
Basin-shaped hollow, 3 steep sides, 1 gently sloping side
Bergschrund
Bergschrund
Deep crevasse in glacier created by plucking of back wall
Tarn/corrie lake
Tarn/corrie lake
Small round lake formed when cirque fills with water
Arête
Arête
Narrow, steep-sided ridge between two cirques
Pyramidal peak formation
Pyramidal peak formation
Steep pointed peak formed by 3+ cirques around same mountain
Glaciated valley shape
Glaciated valley shape
U-shaped: steep sides and wide, flat valley floor
Truncated spurs
Truncated spurs
Triangular cliffs left when glacier eroded through spurs
Hanging valley
Hanging valley
Tributary valley left at higher level than main valley floor
Fiord
Fiord
Drowned glacial valley flooded by sea water