Unit 5 - Coastal change and conflict Flashcards
How do waves erode the coast?
Hydraulic action, abrasion and attrition.
What are the landforms created on hard rock coasts?
Caves, Arches, stacks and stumps.
What is a wave cut platform?
What is left behind after the land above a wave cut notch has collapsed.
What is longshore drift?
This is the movement of sediments down a coast.
How does long shore drift work?
As a wave breaks on a beach it pushes the sediments up the beach, often at an angle due to the direction of the wave. The backwash then pulls the sediment straight down and it is then pushed up again at an angle, moving the sediment slowly down the beach.
What are the properties of a soft rock coast?
High, not steep and not rugged, piles of mud and clay at the foot of the cliff, will have very few hard rocks at the foot of the cliff.
What are the features of a hard rock coast?
High, steep and rugged, bare cliff faces, will have some rocks at the foot and erosional features such as caves, arches and stacks.
What is the difference between concordant and discordant coastlines?
Concordant means that the whole of the cliff is one type of rock, e.g. hard rock. Discordant is alternating rock types which creates many headlands and bays.
What factors affect the speed at which a coast retreats?
Rock type, number of faults, fetch, cliff exposure, storms and sea defences.
What are the consequences of coastal erosion?
Houses destroyed, loss of land, loss of roads, loss of income.
Name three hard engineering methods of coastal management.
Sea wall, groynes, rip rap, off shore reef.
Name three soft engineering methods of coastal management.
Beach replenishment, managed retreat and cliff regrading.
