Coasts (better Version) Flashcards
(12 cards)
What is longshore drift?
The zig-zag movement of sediment along the beach due to swash at an angle and backwash straight down.
Name and define the four types of coastal erosion.
- Hydraulic action: air compressed in cracks
- Abrasion: rocks scraping against rock
- Attrition: rocks colliding and breaking up
- Solution: acids dissolving rocks (chemical weathering)
What is a wave-cut platform?
A flat area of rock left behind after a cliff retreats due to erosion.
Name two landforms of deposition.
- Spits
- Bars
How does a spit form?
Longshore drift carries material past a bend in the coastline; deposition builds up into a narrow landform.
What is hard engineering?
Building physical structures (e.g. sea walls, groynes) to defend the coast.
How do groynes affect longshore drift?
Trap sediment, widening the beach, but starve areas further down the coast of sand.
Give one advantage and one disadvantage of sea walls.
+ Very effective at preventing erosion and flooding
− Expensive and can be visually unappealing
What is soft engineering?
Working with natural processes (e.g. beach nourishment, dune planting) to protect the coast.
What are the 4 shoreline management strategies?
- Hold the line
- Advance the line
- Managed realignment
- Do nothing
Where are coral reefs found and what conditions do they need?
30°N and 30°S; warm, salty, shallow water (23–28°C).
What are threats to mangroves?
- Aquaculture
- Tourism development
- Deforestation
