Coastal Processes and Landforms
This page provides a comprehensive overview of coastal processes, including transportation, wave action, mass movement, weathering, and erosion. It also explains the formation of various coastal landforms.
Transportation Processes
Coastal transportation occurs through four main processes:
- Solution: Minerals are dissolved and carried in water.
- Suspension: Tiny undissolved particles are carried in the water flow.
- Saltation: Small rocks and pebbles bounce and skip along.
- Traction: Large rocks roll along the seabed.
Vocabulary: Longshore drift is the movement of sediment along the coastline, caused by waves approaching the coast at an angle.
Wave Action
Waves play a crucial role in shaping coastlines. Key terms include:
- Swash: Water flowing towards the beach when a wave breaks.
- Backwash: Water flowing back towards the sea.
- Fetch: The distance a wave has traveled.
Wave size and energy depend on fetch, wind strength, and wind duration.
Example: A constructive wave builds up the beach with a strong swash and weak backwash, while a destructive wave removes material with a strong backwash and weak swash.
Mass Movement
Mass movement refers to large-scale downward movement of material. Types include:
- Rockfall: Pieces of rock fall from the cliff face, often due to freeze-thaw weathering.
- Mudflow: Saturated soil flows down a slope.
- Landslide: Large blocks of rock slide downhill.
- Rotational slip: Saturated soil slumps down a curved surface.
Definition: Mass movement in Geography refers to the downslope movement of rock and soil under the influence of gravity.
Weathering
Weathering is the breakdown of rocks in situ. Two types are explained:
- Freeze-thaw weathering: Water enters cracks, freezes, expands, and widens cracks over time.
- Biological weathering: Plant roots grow in cracks, causing rocks to break apart.
Longshore Drift
Longshore drift is the process by which sediment is transported along the coastline. It occurs in a zig-zag motion due to waves approaching the coast at an angle.
Highlight: The longshore drift process is crucial in shaping coastlines and forming features like spits and bars.
Erosional Processes
Coastal erosion occurs through several processes:
- Hydraulic action: Water and air are forced into rock gaps, causing erosion.
- Abrasion: Landscapes are worn away by friction from water carrying sand and pebbles.
- Attrition: Rocks smash against each other, becoming smaller and more rounded.
- Corrosion: Landscape is worn away by dissolved minerals in water.
Example: The formation of a wave-cut notch demonstrates how 5 processes of coastal erosion work together to shape cliffs.
The page also explains the formation of coastal features such as wave-cut platforms, caves, arches, stacks, and stumps through these erosional processes.
