Glacial landforms Flashcards
What is an abrasion?
Abrasion occurs when sub-glacial material scrapes the base of the valley, creating scratches called STRIATIONS
What is plucking?
Plucking occurs when outcrops of rock freeze to the glacier. When the glacier advances the outcrops of rock are plucked out of the ground leaving hollows and creating subglacial material.
What is rotational movement?
A glacier moves around a pivot point due to weight and gravity, making the glacier erode with a scooping action and deepens the base of a corrie.
What are the 3 feature of a corrie?
Over-deepened base/armchair shaped hollow with steep back wall and sides/rock lip and corrie lake
What is the material called at the base of the glacier?
Sub-glacial material
What is supraglacial material?
material which is found on the surface of the glacier
What s ffreeze thaw?
water enters cracks and freezes at night when the temp falls below 0c. Water in cracks expands by 9%. During the day this melts and this cycle continues until the rock breaks off creating loose rock called scree
What are all the processes of erosion and weathering?
Abrasion/Plucking/Rotational Movement/Freeze-Thaw
What are three features of a ribbon lake?
Long, thin, deep and found in the bottom of a u-shaped valley
What are four features of a u-shaped valley?
Steep sided, Wide Flat Base, Straight, Misfit stream in the bottom.
What are three features of an arete?
Steep sided, narrow, ridge
What are 3 features of a hanging valley?
small u-shaped valley inside of a main
u-shaped valley, the base of valley hangs above the valley floor, Waterfall
What landform do you find as a part of a pyramidal peak?
an arete
What are three features of truncated spurs?
flat-ended/hard rock/ interlocking spurs with truncated ends
What are three features of a drumlin?
Whale shaped feature/steep stoss end/tapered lee slope
