COASTS Flashcards
(40 cards)
What is the wave crest
The highest point of the wave
What is the wave trough
The lowest point of the wave
Features of a constructive wave?
Low frequency
Long wavelength
Strong swash
Weak backwash
Created in calm weather
Features of a destructive wave
Created from storms
Powerful
Strong backwash, weak swash
Created steeper beaches
Shingle beaches
High frequency
What 3 factors affect wave energy
Strength of the wind
Duration of the wind
Size of the fetch
What factors affect the rate of erosion
Waves
Beach size
Rock faults
Rock lithology
What are the processes of transportation
Traction
Saltation
Suspension
Solution
Examples of mechanical (physical) weathering
Freeze thaw
Salt crystallisation
Wetting and drying
Examples of chemical weathering
Carbonation
Oxidation
Solution
Biological weathering
Plant roots
Birds
Rock boring
Seaweed acids
Decaying vegetation
Examples of mass movement
Soil creep
Mudflows
Rockfall
Landslides
Runoff
How do spits occur
When the coast changes direction.
Longshore drift deposits the material
Sea changes in wind direction. Leads to a curved end of the spit.
How are barrier beaches created
When a beach or spit is extended across to a bay
Traps water from the lagoon
Separated from the mainland
Common in areas of low tidal range
How are tombolos created
Bar or beach that connects the mainland to an offshore island
Due too wave refraction
What is isostatic change
Occurs when land rises or falls close to the sea.
Localised change.
What is ecstatic change
Affects sea level across the whole planet.
Due to thermal expansion or changes in glacial processes.
What are groynes
Timber or rock that trap sediment from LSD
Help to build up the beach
Increase tourist potential
Visually unappealing
Increases erosion elsewhere
Sea walls
Concrete structures
Absorb and reflect wave energy
What is abrasion
A form of erosion
Where loose material ‘sandpapers’ the walls and floors of the river, cliff or glacier
What is coastal recession
The retreat of a coastline due to erosion, sea-level rise or submergence
What us eustatic
Global changes to sea level
What is freeze thaw
Water freezes in the cracks of a rock, expands and enlarges the crack, this weakens the rock.
Type of physical sub-aerial weathering
What is geology
The structure and arrangement of a rock
What does impermeable mean
Rock that does not allow rainwater to pass through