Erosional landforms Flashcards
what are the factors which influence the nature of a eroding coastline
1) Direction, strength and frequency of waves. the power of waves is focused on the side of headlands due to wave refraction
2) geology- rock type and structure determine the landforms produced
how are cliffs produced?
produced when coastal erosion undermimes the land which leads to slumping and the formation of steep edges along the edge of the land
what are cliffs which are made up of multiple rock types known as?
composite cliffs
what type of cliff do hard rocks dipping away from the sea produce?
steep cliffs
what type of cliff do hard rocks with rocks dipping towards the sea produce?
low angle cliffs which are prone to collapse
what type of cliff does weak rock produce?
produces a more gently sloping, stepped cliff profile
what happens when there is less resistant rock at the bottom of the cliff?
undercutting and collapse
what happens when there is less resistant rock at the top of the cliff?
sub-aerial weathering and wave undercutting
what type of coastline do bays and headlands form along
discordant- where bands of less resistant and hard resistant rock alternate along the coastline
what is a wave cut notch?
a concave indentation at the base of the cliff. the top of the notch always shows the high tide mark
what is a wave cut platform?
a gently sloping area of rock at the base of a cliff reaching out to sea over which waves pass. The platform is covered by the sea at high tide and exposed to the atmosphere at low tide
how is a wave platform formed?
it is formed due to wave recession and sub aerial processes. undercutting of the cliff forms a wave cut notch. The overhanging cliff is no longer supported and the cliff collapses. this process is repeated and as the platform becomes bigger the waves break further over to sea and not at the cliff base
