Erosion Flashcards
Hardness of tools?
The harder the moraine, the easier the bedrock is eroded away.
Quantity of load?
The more sediment available, the quicker the bedrock is eroded away.
Quantity of meltwater?
More water can chemically and mechanically erode the rock. It also decreases the pressure making it easier for the glacier to move and erode.
Strength of bedrock?
Softer rock is easily eroded but less debris is collected. Harder rock is more resistant, but pieces are accumulated, adding to the hardness of tools.
Permeability of rock?
Less permeable rock means more meltwater, helping the glacier move faster and erode. More permeable rock means meltwater can enter ores and freeze, increasing chance of plucking.
Describe gelifluction
Soil freezes and moves up at 90• from the slope gradient. It moves forward during thawing, and then falls back vertically by gravity.
Describe pressure release?
The ice puts pressure on the bedrock. When the ice is lost during deglaciation, the rocks expand vertically as the pressure is reduced.
What is frost disintegration?
The shattering is rock caused by the freezing of water in cracks.
Describe plucking
The ice freezes to rocks on the ground; then as the ice continues to move down the slope the rocks are pulled out of the ground.
Describe abrasion
Rock/ sediment at the bottom of a glacier carves into the bedrock.
Basal sliding?
When a glacier slides over the bed due to meltwater under the ice caused by friction and pressure.
What are the 4 main weathering processes?
1) Freeze-thaw
2) Carbonation
3) Hydrolysis
4) Pressure release
How does thickness of ice affect erosion?
Thick ice creates more pressure on the bed rock, increasing plucking. This pressure also melts the ice, creating more erosion through meltwater.
