Coastal Weathering Flashcards
Mechanical Weathering
Is the break down of rocks without any chemicals change e.g freeze thaw Weathering
Freeze thaw
Water enters crack e.g granite
Water 💦 freeze and expands 9% and gives the rock pressure
It thaws and contracts releasing pressures when melted
This continues to make cracks
Chemical Weathering
Breakdown of rock by changing its composition
Carbonation Weathering
Rainwater has co2 dissolve in it which makes it a weak carbonic acid
This reacts with rock that contains calcium carbonate e.g limestone so rocks are dissolved in it
Mass movement
Shifting of rocks down slope by the force of gravity acting on the slope is greater than the force supporting
Mass movement causes coast to
Retreat rapidly
Slides mass movement
Material shifts in a straight line
Slumps mass movement
Material shifts with a rotation
Rockfall
Material breaks up and falls down slope
Mass movement is likely when
Materials are filled with water it acts like a lubricant
Swash
Movement of water on beach
Backwash
Movement of water back into the sea
Crest
Top of the wave
Trough
The base of the wave
Wave height
The vertical distance from trough to crest
Wave length
The horizontal distance between two crest
Wave frequency
The number of waves breaking per minute
Fetch
The distance of open water over which the wind can blow the longer the fetch the more powerful the wave can become
Constructive waves
Weak backwash strong swash
Builds up beach
Long length low frequency
Constructive waves waves
strong swash as they have lots of energy which pushes the material up beach but little energy is left for the backwash
Destructive waves
Weak swash strong back wash
Remove sediments of beach
Creates stumps and arches
Destructive waves waves
Strong length high frequency
Strong back wash as they have plenty of energy left from swash
