Coastal Processes Flashcards
What does sub-aerial mean?
Land based processes that change the shape of a coastline. A combination of weathering and mass movement.
What is mechanical weathering?
The physical break up of rock. One example is freeze thaw.
What is freeze thaw?
When water gets into cracks and joints in the rock, when it freezes it expands and cracks the rock open a little wider. Overtime the pieces of rock split off the rock face
What is chemical weathering?
Chemical weathering occurs when rocks are broken down by chemical processes.
What is the process of chemical weathering?
When rainwater is slightly acidic through absorbing carbon dioxide from the atmosphere.
This reacts with minerals in the rock, creating new material.
Rock type affects the rate of weathering.
What is biological weathering?
When rocks are worn away by living organisms.
What is the process of biological weathering?
Trees and other plants can grow within the cracks in a rock formation.
As the roots grow bigger, they push open cracks in the rocks.
Over time the growing tree eventually forces the rock apart.
What is mass movement?
The downhill movement of material under the influence of gravity.
What is throughflow?
The flow of water through the ground.
What is runoff?
The flow of water over the land.
What causes an increase in the likelihood of mass movement?
Throughflow and runoff caused by heavy rain reduce the stability of cliffs.
What is a slump?
A slump is formed when a large area of land moves down a slope in one piece due to the rock becoming too saturated and heavy
Do slumps more commonly occur on weaker or stronger rock types?
Weaker
What are the three sub aerial process that can affect the shape of a cliff?
Freeze thaw weathering
Mechanical weathering
Chemical weathering
What is a wave cut platform?
A wide gently sloped surface found at the foot of a cliff
