Physical Landscapes Flashcards
Constructive wave characteristics
They are created in calm weather and are less powerful than destructive waves. They break on the shore and deposit material, building up beaches. They have a swash that is stronger than the backwash. They have a long wavelength, and are low in height.
Destructive wave characteristics
Destructive waves are created in storm conditions.
They are created from big, strong waves when the wind is powerful and has been blowing for a long time.
They occur when wave energy is high and the wave has travelled over a long fetch.
They tend to erode the coast.
They have a stronger backwash than swash.
They have a short wave length and are high and steep.
What’s mechanical weathering
The breakdown of rock without changing its chemical composition
One main type is freeze-thaw weathering which affects coasts
What’s chemical weathering
Breakdown of rock by changing its chemical composition
What’s carbonation weathering
Type of chemical weathering that happens in warm and wet conditions
What are the erosional processes
Hydraulic action, abrasion, attrition, solution
What’s hydraulic action
Waves crash agains rock and compress air in crack which puts pressure on rock which when repeated widens crack
What’s abrasion
Eroded particles in the water scrape and rub against rock removing small pieces
What’s attrition
Eroded particles in water smash into each other and break into smaller fragments their edges also get rounded off as they rub together
What’s the difference between weathering and erosion
Weathering is the breakdown of rocks where they are, erosion is when the rocks are broken down and carried away by something
What’s mass movement
The shifting of rocks and loose material down a slope
Happens when force of gravity on slope is greater than force supporting it
Cause coasts to retreat rapidly
More likely to happen when material is full of water as it acts as a lubricant and makes the material heavier
What are the three types of mass movements
Slides - material shifts in a straight line
Slumps- material shifts with a rotation
Rockfalls- material breaks up and falls down slope
Where do headlands and bays form and how
They form where erosion resistance is different
Soft rocks or rocks with lots of joints have low resistance to erosion
Hard rocks with a solid structure have a high resistance to erosion
Headlands and bays form where there are alternatives are bands of resistant and less resistant rock along the coast
Less resistant rock for example play is a rooted quickly this forms a bay bays have a gentle slope
Resistant rock for example chalk is a eroded slowly and left jetted out forming a head land headlands have state signs
Cliffs and wave cut platforms
Waves cause most oration at the foot of a cliff
Forming a wave cut-notch- enlarged as erosion continues
