3.2 Coastal Landforms Flashcards
What factors do affect waves?
They are energy that flow through water factors such as:
- Wind strength (stronger fetch)
- Wind duration (longer fetch)
- Water depth
- Fetch
What is a fetch?
Uninterrupted distance across water that wind blows.
What is a swash?
Flow of water up beach as wave breaks.
What is a backswash?
Flow of water down beach.
What are constructive waves?
- Depositional waves
- Low frequency
- Strong swash, weak backswash
- Low energy, low frequency
What are destructive waves?
- Erosional waves
- Larger fetch
- Weak swash, stronger backswash
- High energy, high frequency
What are subaeral processes?
Land-processes which can alter the coastline such weathering.
What is weathering?
The breakdown of rocks, with no movement.
What is mechanical weathering? (freeze-thaw)
Exertion of physical force of breaking material.
What is chemical weathering?
Chemical reaction with products that break down material. (acid rain)
What is biological weathering?
Plant/bacteria/animal action eg plant roots or overgrazing.
What is mass movement?
The sudden movement of large amounts of material typically rock and soil.
What is longshore drift?
Waves hit coast at prevailing wind angle, swash carries material up beach angle, backswash carries material down beach at 90 degrees.
What is a spit?
Longshore drift desposits sediment across a bay.
What is a Bar/Barrier beach?
Spit extends across bay, forms lagoon behind it.