Formation Of Coastal Landscapes Flashcards
How does stump form
Crack formation - Waves create cracks in the cliff through hydraulic action and abrasion
Cave formation - Continued erosion turns the crack into a cave
Arch formation - further erosion deepens the cave until it breaks through the headline to the other side
Stack formation - the arch eventually collapses due to the sheer weight and gravity, leaving an isolated areas of land
Stump formation - the stack is eroded at its base by waves, collapsing again into a stump
How does a blowhole form
Wave erosion - waves crash against cliff, weaken rocks
Crack formation - waves enlarge cracks in rock
Cave development - further erosion creates caves
Roof collapse - can’t support weight, leaves a vertical shaft
Air and water pressure - waves crash into cave, building up air and water pressure
When air and water pressure become too much, forced out of the cave
How is a geo formed
Crack in the rock - sea processes attack a weakness in the cliff like a crack
Erosion makes cave - hydraulic action and abrasion deepen the crack
Development of cave - constant erosion may cause the roof of the cave to collapse, although the cave hasn’t broken through the other side of the headland
Geo formation - the water keeps eroding the rock and a narrow step sided inlet called a geo forms
How does a wave cut notch form
Hydraulic action and abrasion wears away rock at the bottom of the cliff which is usually softer
Continued erosion and growth of the notch under the cliff
Eventually the rock above the notch collapses as it can’t hold its weight
Flat area of land left at the foot of the cliff known as wave cut platform
How does a split form
Longshore Drift: Waves move sediment along shore in zig-zag
Sudden Change in Coastline
Sediment Accumulation: Longshore drift continues to transport sediment, but now it accumulates where the coastline bends
Spit Formation: The bar of sediment extends out into the sea, creating a narrow, elongated landform called a spit.
Development of the Spit: Over time, the spit continues to grow as longshore drift deposits more sediment, often forming a curve at the tip due to changes in wave direction.
How does a bar form
Longshore drift carries sediment across a bay, reaching other side
Creates bar
Behind the bar is a lagoon, where water has been trapped
Overtime the lagoon will become filled in by silt and may gradually form a salt marsh
What is a mudflat
Found at the edges of permanently submerged marine zones
Exposed at low tide
They are not a permanent feature
Sustainable to:
Changes in sea level
Wave action
Changes in discharge
Tidal flows
What are the factors needed for a salt marsh to develop
Sheltered shorelines
River estuary where rivers meet and the sea
Salt water flowing gently into the estuary bringing fine sediment
