Glaciation Flashcards
Explain how a Glacier is made.
Snow accumulates and compresses in a north facing hollow to form glacial ice.
Explain how a Corrie is formed.
Snow collects in a north facing hollow,
snow accumulates and compresses to form glacial ice.
The ice moves downhill due to gravity.
Abrasion makes the floor deeper and Plucking makes the back wall steeper.
When the ice melts it leaves behind an armchair shaped hollow called a corrie. A lip, made from moraine, is left at the front as ice loses power.
When water remains in the corrie it is called a lochan or a tarn.
Named example of a Corrie lochan.
Red tarn
Explain the process of Plucking.
Between the glacier and the rock underneath there is a thin film of melt water.
This water sometimes freezes so the glacier becomes attached to the rock.
Then, when the glacier moves forward, it pulls the rock away.
Explain the process of Abrasion
This is when rock is frozen into glacial ice.
The glacier moves and the rocks scrape across the valley floor and side eroding it.
This is known as the sandpaper effect.
Explain the process of Freeze-Thaw
Rain water enters cracks in rocks and, in winter it freezes to form ice.
When it freezes and expands, this forces the crack wider.
Due to a change in temperature, it melts and water fills the crack and then refreezes.
This process is repeated as the water freezes and thaws and eventually pieces of rock break off.
What are the processes of Erosion?
Freeze-thaw, Abrasion and Plucking.
Explain the formation of on Arête.
When two glaciers erode back to back by plucking.
This forms 2 corries, the space in between these corries are called arêtes.
Named Example of an Arête
Striding Edge
Named example of pyramidal peak
Seafell Pike in the Lake District
Named example of u shaped valley
Patterdale in the Lake District
Truncated spur
The three sisters in glencoe
hanging valley
lost valley in glencoe
ribbon lake
lake windermere on lake district
