Coasts Flashcards
What is mechanical weathering?
Breakdown of rock without changing chemical composition
Name one type of mechanical weathering
Freeze thaw weathering
What is freeze thaw weathering
When water enters cracks in a rock and freezes, expanding and putting pressure on the crack, then it contacts. Over time the cracks widen causing the rock to break up.
What is chemical weathering
The breakdown of rock by changing its chemical composition
Name one type of chemical weathering
Carbonation
What is carbonation
Rainwater (weak carbonic acid) reacts with calcium carbonate in rock, dissolving it.
What is mass movement
Shifting of loose material down a slope
How is a mass movement caused
When the force of gravity on a slope is greater than the force supporting it
How does mass movement effect a coast
Causes the coast to retreat rapidly
When is mass movement more likely to happen, why
When material is full of water, acts like a lubricant and makes it heavier
What is a scarp
Steep cut in the side of a slope
Describe a slide
Material shifts in a straight line
Describe a slump
Material rotates along a curved slip plane
Describe a rockfall
Material breaks up, often along bedding planes, and falls down a slope
Describe a rockfall
Material breaks up, often along bedding planes, and falls down a slope
What is erosion
Rocks are Brocken down and carried away by something
How are waves created
wind blows over surface of the sea
What is a fetch
The distance the wind blows over the sea
How does fetch effect the waves
Larger the fetch bigger the wave
What waves erode the coast
Destructive waves
What quality’s do a destructive wave have
High frequency
Tall & steep
Backwash > Swash
Material is removed
What waves deposit material
Constructive waves
What quality’s do a constructive wave have
Low frequency
Low & long
Swash > backwash
Material is deposited
What are the 3 types of erosion
1.Hydraulic power
2.Abrasion
3.Attrition
