Coasts - Coastal Landforms Flashcards
Describe the formation of headlands and bays.
A softer, less resistant rock will be eroded by the sea faster to form a bay. This happens by hydraulic action (sheer force of the wave hitting the coast, pushing air into the cracks and causing the rock to break away) and corrasion (small rocks and pebbles within the water breaking away the cliff). A harder more resistant rock gets eroded much more slowly to form a headland which protrudes from the ocean.
Describe the formation of cliffs and wave cut platforms.
The sea attacks the base of the cliff by hydraulic action and corrasion (if limestone or chalk is present then corrosion as well). This makes a wave cut notch. The overhang above the notch falls from gravity and it’s own pressure. The cliff retreats back and leaves a rocky platform at it’s base - the wave cut platform. The sea continues to erode the cliff, creating notches, overhangs and collapses which continues to retreat the cliff and forms a rocky beach.
Describe the formation of Caves, Arches, Stacks and Stumps.
They are formed on headlands where there is a fault. Corrasion and hydraulic action wear away the fault until a small cave is formed. If a cave forms on both sides and erodes all the way through then an arch will form. Biological and freeze thaw weathering will weather the roof of the arch which will eventually collapse forming a stack. Over time the stack will be eroded by hydraulic action and corrosion to form a stump
