Depositional landforms Flashcards
What percentage of the world’s coastline is made up of deposition?
20%
This highlights the significance of depositional processes in coastal geography.
What are the two types of beaches?
- Swash aligned beaches
- Drift aligned beaches
Swash aligned beaches form when waves break parallel to the coast, while drift aligned beaches are formed by longshore drift.
What is the primary source of beach material?
90% fluvial
5% offshore
5% cliff erosion
This distribution indicates the major contributions to coastal sediment.
What are the four zones of a beach?
- Offshore
- Nearshore
- Backshore
- Foreshore
Each zone has distinct characteristics and functions in beach dynamics.
How do sand beaches differ from shingle beaches in terms of slope?
Sand beaches create gentle slopes, while shingle beaches create steep slopes
This difference is due to energy dissipation and friction.
What weather conditions influence beach formation in summer and winter?
- Summer: calm weather, constructive waves
- Winter: storms, destructive waves
This seasonal variation affects sediment transportation and beach morphology.
What is a storm ridge?
A depositional landform created by destructive waves depositing material at the back of the beach
Erosion occurs at the bottom while deposition remains untouched.
What is a berm?
A feature formed by different tide levels leading to varying deposition levels
Spring tides accentuate deposition while neap tides diminish it.
What causes a beach cusp?
Wave orthogonals direct to horns, causing heavy sediment deposition at the horns and finer sediment at embayments
This results in minimal erosion and is similar to mini headlands and bays.
What are ridges and runnels?
- Ridges: small raised areas of sand from wave action
- Runnels: shallow troughs between ridges holding water at low tide
These features are influenced by tidal changes.
What is a spit?
A landform formed when waves carry sand and pebbles along the beach, creating an extension into the sea
The formation is influenced by longshore drift.
What is a tombolo?
A depositional landform where an island and mainland are joined by a spit
Example: Chesil Beach in Dorset, but it was not classified as a tombolo due to sediment size inconsistencies.
What is the process that leads to the formation of barrier beaches?
Formation occurs due to glacial periods where melted ice leads to sea level rise and deposition of sediment
The Flandrian Transgression is an example of this process.
What are the three types of deltas?
- Cuspate
- Arcuate
- Bird’s foot
Deltas form where rivers meet the sea and deposit sediment.
What defines a salt marsh?
A flat, muddy area near the sea where grasses and small plants grow, influenced by tidal changes
Halophytes are salt-tolerant plants that thrive in these environments.
What is flocculation in the context of salt marshes?
The process where tiny particles of mud and clay clump together after mixing with salty seawater, aiding sediment settlement
This process contributes to the accumulation of deposition in salt marsh areas.
What is an onshore bar?
A ridge of sand or sediment that forms parallel to the shoreline, usually offshore
It develops through wave action and longshore drift.
