Coastal Landforms Flashcards
How is a wave cut platform formed?
Weathering and wave erosion cause a notch to be eroded at the base of the cliff face. Over time that notch grows leaving an overhang of rock. Eventually that overhang will collapse due to gravity and a wave cut platform of rocks.
Give an example of a wave cut platform
Lannacombe Bay south Devon
How are headlands and Bays formed.
Headlands and bays form when there are bands of alternating types of rock on a coastline. Softer rock like chalk is eroded quicker than harder rock like granite leaving a headland and a bay.
How are caves arches and stacks formed?
Weak areas in the cliff face are eroded by processes such as abrasion and hydraulic action and cause small caves to form eventually the cave will reach the end of the other side of the cliff and form and arch. Due to gravity the arch will collapse and leave a stack. Then once the stack has been eroded and tumbled it leaves a smaller stump behind.
Which landforms are created by erosion?
Cliffs and wave cut platforms, headlands and bays, caves arches stacks and stumps.
Which landforms are created by deposition?
Beaches, spits, tombolos and offshore bars
How are beaches formed?
Beaches are formed when constructive waves deposit sediment onto the shore. They are a store in the coastal system. Shingle beaches are steep and narrow whereas Sandy beaches are wide and flat.
How are spits formed?
Spits are created when longshore drift deposits material across the river mouth continuing of the end of the headland leaving a bank of sand and shingle sticking out into the sea. Changes to the prevailing wind may mean that the spit is curved at the end and over time the area behind the spit will turn into a mudflat or salt marsh.
How are offshore bars and tombolos created?
Bars are formed when a spit joins two headlands together a lagoon is then formed behind the bar. If the bar is connected to an offshore island then it’s a tombolo.
How are sand dunes formed?
Formed when sand deposited by long shore drift is move up the beach by the wind and is met by an obstruction. Sand gets trapped in driftwood or burns and then is colonised by vegetation which stabilises the sand and encourages more to accumulate there. Over time they get bigger and then from embryo dunes to adult dunes.
Give an example of a headland and bay?
Holderness coast:
Headland: Flamborough head
Bay: Bridlington Bay
Give an example of a cave, arch and stack.
The green bridge of Wales, Pembrokeshire
Give an example of a beach
Polzeath, Cornwall
Give an example of a spit
Spurn Head, Holderness Coast
Give an example of a sand dune
Formby Beach dunes, Liverpool
