Headlands and bays form when rocks of different resistance are perpendicular to the sea.
It's rare for cliffs to erode at the same rate.
Headlands are sections of land that are particularly resistant to erosion.
They jut out into the sea, as their surrounding have been eroded.
They are most vulnerable to the power of the waves, which is why they often contain cliffs and wave-cut platforms.
Weaker sections of the coastline erode to form coastal inlets called bays.
They're more sheltered from the sea, as waves are less powerful and deposition usually dominates. This is why a sandy beach is a common feature of a bay.
Wave-Cut Notches and Platforms
A cliff is mainly eroded between the water level at high tide and at low tide.
Erosion (like hydraulic power, abrasion and corrasion) undercuts the cliff to form a wave-cut notch.
Over a long period of time, the notch gets deeper until the overlying cliff can no longer support its weight and collapses.
Through a continual sequence of wave-cut notches and cliff collapse, the cliff line retreats.
In the cliff's place will be a gently sloping, rocky platform called a wave-cut platform.
They are typically quite smooth due to abrasion, but may be pockmarked with rock pools in some places.
The wave-cut platform may become covered by sand and shingle from long periods of constructive waves.
Destructive waves associated with local winter storms remove the beach once again, exposing the wave-cut platform.
Caves, Arches and Stacks
1) Lines of weakness in a headland, like joints or faults are especially vulnerable to erosion. 2) Erosive processes like corrasion and hydraulic action gouge out the rock along the line of weakness to form a cave. 3) Over time, erosion may lead to two back-to-backcaves breaking through a headland, forming an arch. 4) Gradually, the arch is enlarged by erosion at the base and sides and by weathering processes acting on the roof. 5) The roof eventually collapses to form an isolated pillar of rock known as a stack. 6)This is then undercut and collapses to leave a stump, which is covered up at high tide.
Headland: A promontory of land jutting out into the sea. Bay: A broad coastal inlet often with a beach. Wave-Cut Notch: A small notch cut into a cliff roughly at the level of high tide, caused by concentrated marine erosion at this level. Wave-Cut Platform: A wide, gently sloping rocky surface at the foot of a cliff. Cave: A hollowed out feature at the base of an eroding cliff. Arch: A headland that has been partly broken through by the sea to form a thin-roofed arch. Stack: An isolated pinnacle of rock sticking out of the sea.