Glacial Landscapes Flashcards
(13 cards)
How does a glacier form
When more snow falls in winter than melts in the summer
Often in north facing hollows where there is less sunlight
Over many years the weight of the snow compresses the previous years snow into ice
The weight of the ice and gravity pull the glacier down hill
What is plucking
When ice sticks onto rocks at the side of the valley and rips them out as it moves. This action erodes a steeper hollow
What is abrasion
When rocks frozen into the base of the glacier grind the valley floor as the glacier moves. This action erodes a deeper hollow
What is freeze-thaw action
Water gets into cracks in rocks, when it freezes the water expands. Repeated over many times this rock can shatter away from the rock face
What is a corrie called in welsh
Cwm
What is a corrie called in Scotland
Corrie
What is a corrie called in France
Cirque
How is a corrie formed
Snow gathers in a north facing hollow and compresses into ice
Due to the weight of the ice and gravity the ice starts moving down the valley
Plucking (insert definition) occurs which makes the hollow steeper
Abrasion (insert definition) occur which makes the hollow deeper
After the ice has melted it leaves an arm-chair shaped hollow known as a corrie in the mountain
What are the lakes at the bottom of a corrie called
Corrie lake or tarn
How is an arete formed
Snow gathers in a north facing hollow and compresses into ice
Due to the weight of the ice and gravity the ice starts moving down the valley
Plucking (insert definition) occurs which makes the hollow steeper
Abrasion (insert definition) occur which makes the hollow deeper
After the ice has melted it leaves an arm-chair shaped hollow known as a corrie in the mountain
Another corrie then forms on the other side of the corrie which then creates a arete
How is a pyramidal peak formed
Snow gathers in a north facing hollow and compresses into ice
Due to the weight of the ice and gravity the ice starts moving down the valley
Plucking (insert definition) occurs which makes the hollow steeper
Abrasion (insert definition) occur which makes the hollow deeper
After the ice has melted it leaves an arm-chair shaped hollow known as a corrie in the mountain
Another 2 corrie form on the back sides of the original corrie which make a steep triangle shaped point known as a pyrimidal peak
How is a U-shaped valley formed
Snow collects and is compressed into ice
Due to the weight of the ice and gravity the ice starts to move down the valley
Plucking (insert definition) occurs which makes the valley wider
Abrasion (insert definition) occurs which makes the valley deeper
Once the ice melts it creates a U-shaped valley wide and steep walls and a flat floor
Formation of a truncated spur
Spurs are small ridges that stick out from the main mountain
Snow collects and is compressed into ice
Due to the weight of the ice and gravity the ice starts to move down the valley
When the ice moves down the valley it cuts the ends off of the spurs at the sides creating truncated spurs
