Landforms Flashcards
How are headlands and bays formed
Weakness in a hard rock
Hydraulic action and abrasion causes rock to erode inwards when alternating bands of hard and soft rock run parallel to coast
When it reaches soft rock, eroded faster creating a cove as its fastest
Formation of wave cut platforms
Weather weakens top of the cliff
Sea attacks base forming notch
Notch increases causing cliff collapse
Backwash carries rubble towards sea forming platform
Process continues and cliff continues to retreat
Formation of a stump
Large crack in cliff by HA Crack grows into cave by HA and abrasion Cave creaks through headland = arch Arch is eroded and collapsed Leaves a stack Erosion and weathering form a stump
Bars formation
Spit increases and goes across whole of a bay to form a lagoon behind them
Tombolo formation
Spit increases and joins and island
Lagoon forms behind bar
Sand dune formation
Sand deposited by LSD, is moved up the beach by wind
Sand trapped by driftwood or colander plants
Vegetation stabilised sand and encourages more sand = embryo dunes
2 types of beaches
Swags aligned
Drift aligned
Swash aligned beach charactertics
3
Generally orientated parallel to the incoming Wavecrest
experience minimal longshore drift
can be found on a regular coastlines were Longshore drift is impeded
Drift aligned beaches
4
Generally orientated parallel to the direction of longshore drift
can have considerable amounts of sediment transported long distances along
initially develop a section of coastline is very regular
can extend out from the coastline if there is a sudden change in the direction of coastline
Beach formation
Features developed at the point where the land meets the sea and represent the accumulation of sediment between low spring tides and the higher points reach by storm waves
usually composed of sand and shingle
9 features of a beach
Storm beach burms Beach cusps ripples Breached ridge runner Ridge Lower beach Upper beach
What is a barrier beach or island
An elongated bank of deposited sand line parallel to the coast line and not submerged by incoming tides
Mudflat and salt marshes formation
Form in sheltered low energy environments
Silly and mud deposited by the river or the tide and develop they colonised by vegetation and can survive the high salt levels and long periods of submergence
More mud and silt gradually build up to create an area of salt marsh
Formation of a spit
Longshore drift continues to deposit material across the river mouth leaving a bank of sand and shingle sticking out into the Sea
occasional changes to the dominant wind and wave direction may lead to Spit having a curved end or curved and behind spit is where mudflats and saltmarshes often form
