coastal landforms Flashcards
how does rock type and structure influence coastal landforms
rock type and structure are important because it effects how quickly the rock is eroded by the sea. weaker rock types erode quicker than others, creating things like headlands and bays.
describe headland and bay formation
these are formed on discordant coastlines where rock type alternates between bands of hard and soft rock. the soft rock erodes faster creating indented bits of land called a bay, and vice versa.
explain a cliff formation
cliffs are formed when headlands or rocks are eroded at the base by the sea, forming a wave cut notch, until the front overhang becomes so weak mass movement forces it to collapse and retreat
explain a wave-cut platforms formation
a wave cut platform is formed when waves erode at the bottom of a cliff forming a small notch until the cliff face collapses down due to becoming too weak. the debris from the cliff is slowly eroded in this notch and transported away. as this happens over and over it eventually forms a smooth slope where the rock is pulled back along
explain cave formation
a cave is formed when a crack or weakness on a cliff is eroded open, often by hydraulic action, which repeatedly forces the hole wider and wider, until it begins to hollow out a hole in the cliff, called a cave.
explain an arch formation
an arch is formed when a cave is eroded so much that it hollows out an entire bit of a cliff, making it so you can see from one side of the cliff through to the other, whilst still having rock above with little underneath support
explain a stack formation
a stack forms when the top of an arch collapses due to weathering and gravity leaving a pillar of rock
explain a beach and its formation
a beach is an area of sediment that has been deposited on the coast where waves have lower energy and are largely constructive. it is the area between the lowest spring tide level and the highest winter storm tide. it is usually sediment on a wave cut platform
explain sand dunes
sand dunes are ridges/hills of sand found at the top of the beach made by sand blown against something
explain a spit
a spit is a large bit of sediment/beach formed when longshore drift blows out over an estuary
explain a bar
this is like a spit but it joins two bits of headland over a bay.
