Coastal Dynamics and Landform Development
- Coastal landscapes are shaped by the interplay of erosion, transport, and deposition.
- These processes create distinctive landforms that evolve.
Understanding these landforms helps us appreciate the dynamic nature of coastlines and their vulnerability to change.
Erosional Landforms
Wave-Cut Platforms: Evidence of Cliff Retreat
- Wave-cut platforms are flat, rocky surfaces found at the base of cliffs.
- They form as cliffs erode and retreat, leaving a platform exposed at low tide.
Formation Process
- Hydraulic Action and Abrasion: Waves crash against the cliff, compressing air in cracks and dislodging rock fragments.
- Undercutting: Erosion creates a notch at the cliff base, weakening its structure.
- Collapse: The unsupported cliff top collapses, and debris is washed away by waves.
- Platform Exposure: As the cliff retreats, a flat platform is left behind.
Wave-cut platforms are typically less than 500 meters wide and slope gently seaward at an angle of about 1°.
ExampleThe wave cut platform at Flamborough Head, UK, is a classic example, showcasing the relentless power of wave erosion.
Cliffs and Stacks: Sculpted by Wave Action
- Cliffs are steep rock faces formed by the continuous erosion of coastal land.
- Over time, they can evolve into dramatic features like stacks and arches.
Formation of Cliffs
- Wave Erosion: Waves attack the base of the rock, creating a notch.
- Collapse: The overhanging rock collapses, forming a steep cliff.
- Repetition: The process repeats, causing the cliff to retreat.
Formation of Stacks
- Caves: Erosion exploits weaknesses in the rock, forming caves.
- Arches: Caves deepen and break through the headland, creating an arch.
- Stacks: The arch collapses, leaving a pillar of rock called a stack.
- Stumps: Continued erosion reduces the stack to a stump.
