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In this lesson we are going to discuss about the Factors Influencing Ice Movement

Answer Text:
Factors Influencing Ice Movement
a) Gradient of the Land
Ice moves faster on steep slopes than on gentle slopes due to the influence of gravity.
b) Season
Ice movement is faster in summer due to frequent thawing melting compared to winter when thawing is rare.
c) Friction
Central parts of ice move faster than sides and bottom which are in contact with rock beneath due to friction.
d) Thickness of Ice
Thicker masses of ice cause more pressure between them and rocks beneath which cause slight melting and therefore faster movement.
Glacial Erosion
Processes/Ways in Which Ice Erodes
a) Plucking
- Pulling away of parts of a rock at the base of glacier when the ice freezes into the cracks of a well jointed rock.
b) Abrasion
- Scratching of the underlying ground by stones and boulders carried by the ice as the glacier moves.
Factors Influencing Glacial Erosion
a) Nature of Underlying Rock
- Abrasion is more effective on soft rocks than hard rocks.
- Well jointed and faulted rocks are more eroded than those which are not because cracks and joints enable water
to enter rocks and freeze which facilitates plucking.
b) Gradient of Slope
- Glacier on steep slopes moves faster and has greater kinetic energy to erode than slow moving glacier
c) Thickness of Ice
- Thick ice is heavier and exerts greater pressure on rock debris making them to abrade the underlying rock more effectively.
d) Availability of Debris
- The more the rock debris the more effective abrasion will be since it acts as abrasive tools.
- Too heavy debris makes erosion impossible since ice is not able to transport it but
glides over it without acting on the rock below.