Coasts Flashcards
Give 3 factors of wave energy
Distance wind has been blowing
Wind speed
Time wind has been blowing
Give 4 qualities of constructive waves
Low energy
Deposition
Backwash < swash
Small fetch
Give 4 qualities of destructive waves
High energy
Erosion
Backwash > swash
Large fetch
Name the 4 types of erosion and what they are
Hydraulic Action - wave power breaks rock
Abrasion - Material rubs against cliff
Attrition - Waves break up material
Solution - Acidic water dissolves chalk/limestone
Name 4 types of transport and what they are
Solution - cliff minerals dissolved
Suspension - currents carry small pieces
Saltation - load bounded along sea level
Traction - large sediment rolled along sea bed
Name 4 coastal landforms (not stack) and how they are formed
Beaches - constructive waves build up beaches
Wave-cut platforms:
- Weather weakens clifftop
- Sea strands base -> wave cut notch
- Notch gets bigger -> collapse
- Backwash moves rubble -> sea
Spits:
- Extended stretch of deposited material
- Formed by longshore drift at prevailing wind direction on coastline
- Spit grows, kept there by plant roots
- Waves can’t get past it - silt deposits in sheltered ares -> salt marsh
Headlands and Bays:
- Hard rock resistant to erosion - left jutting out -> headlands
- Soft rock easy to erode -> bays
Explain how a stump is formed, step by step
- Cliff undergoes hydraulic action -> crack -> cave
- Cave erodes further -> arch
- Top of arch collapses -> stack
- Stack erodes -> stump
Give 3 factors of cliff recession
Larger fetch = larger waves
Slowed down by sea defences
Hard rock erodes slower
Name 3 human impacts of cliff recession
Property loss
Low house prices
Hard to get insurance
Give 1 natural impact of cliff recession
Habitat destruction
Give 4 causes of coastal flooding
High tides
Rising sea levels
Strong, stormy waves
Storm surges
Give 1 way coastal flooding can be reduced through prediction
Environment Agency monitors sea conditions
Give 4 ways coastal flooding can be reduced through planning
Early warning system
Flood education
Escape routes
Advice from Health Protection Agency
Give 3 ways coastal flooding can be reduced through prevention
Flood barriers
Open space on flood plains to absorb water
Name 4 examples of hard engineering sea defences, and the advantages of disadvantages of them
Sea Wall (Hornsea):
Ad: Protects cliff and buildings
Dis: Expensive (£10k/m2)
Groynes (Hornsea):
Ad: Stops longshore drift
Dis: Exposes other areas
Rip Rap:
Ad: Absorbs energy cheaply
Dis: Hard to transport
Offshore Reef (Bournemouth): Ad: Waves break on reef, loses power Dis: Expensive, messes with boats