Headlands
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Transcript of Headlands
Erosional landforms: Headlands
Coast The maximum distance over which waves can travel is known as the…
Fetch One of the erosion processes that involves large waves hurtling beach material at a cliff is called……..
Corrasion The landform created along stretches of less resistant coastlines (i.e. areas made of clay) are known as…….
Bays The name given to waves with a weak swash but strong backwash is……
Destructive The process that involves beach material being dropped is more technically known as….
Deposition What is the name given to the predominant force affecting the coastal landscape of the UK…….
Prevailing Winds The process that carries material up and down the beach is known as…….
Longshore Drift What is the name of the process that carries / returns wave energy back down the beach
Backswash The erosion process that breaks up large boulders into small particles by bumping them against each other is known as…..
Attrition The areas of land left protruding into the sea as they are more resistant to wave erosion are called…..
Headlands The force of waves compressing air into cracks in a cliff is an erosion process called…
Hydraulic Action Coastlines can dissolved by salts and acids in seawater. This is also known as….
Corrosion The narrow contact zone between land and sea is more commonly called the…
Match the keyword with its meaning
For the exam
You will have to be able to identify and explain different landforms
They are split in to 2 groups:
Erosional landforms (created by erosion), e.g. headlands, cliffs, caves, etc.
Depositional landforms (created by deposition), e.g. beaches, spits, etc.
Headland landforms
The different properties of rocks means they are more or less resistant to erosion.
This means they will change shape in different ways.
Watch the animation of headland landforms being created. headland animation
Headland erosion
Pop-up headlands
Follow the instructions to make a pop-up headland that shows caves, arches, stacks, etc.
1
2
3
4 5
6Add a label alongside your pop-up showing what they are: fault,
wave-cut notch, cave, arch, stack, stump
thanks to Tony Cassidy
Step by step...
Hydraulic action affects headlands by eroding weak ............ in the rocks.
Firstly, a .............. ..................... is created.This is eroded more over time to become a ...........Hydraulic action, corrosion, abrasion and attrition
work to erode the cave to become an .................Eventually the arch ............... under its own weightThis leaves a ................ standing on its ownOver time, weathering and erosion ................. the
stack and it collapses to form a small ................. .
stump collapses undercutarch
stack faults wave-cut notch cave
Old Harry Rocks and Ballard Down.
What processes
created this?
What landform is this?
Durdle Door Arch in Dorset
What landform is this?
How was this created?
The Needles, Isle of Wight
What landforms are
these?How will they change over
time?
Birchington-on-Sea
What landform is this?
Case study: Old Harry Rocks
Jurassic Coast: Swanage Bay
Differing rock hardness is picked out and exaggerated by wave action.
The hard rocks form headlands and the softer rocks form bays.
Currents are weaker in the bays so beach sediments are deposited.
Old Harry Rocks, Near Swanage,
Dorset
Old Harry Rocks are found at Handfast Point at one of the headlands enclosing Swanage Bay. The chalk headland in fact once formed a land bridge between the mainland and the Isle of Wight.
What can you tell from the map?
The map above shows the stretch of coastline to the west of Lulworth Cove. The features along this stretch provide excellent examples of landforms forming on destructive coastlines. What features can you identify?
What can you tell from the map?
What might happened here in the future?.......... ...........................
.....
What feature is
this? ...........................
What feature is
this? ...........................
YOUR CASE STUDY: Erosion landform
Old Harry Rocks
The Old Harry Rocks are two chalk stacks located at on the Dorset coast in England
About 4 km NE of SwanageThe rocks are part of the Jurassic CoastThe cliff is chalk, with some bands of flint, which
have been gradually eroded over the centuries, Some of the earlier stacks have fallen away (Old Harry's original wife fell in 1896), while new ones have been formed.
Old Harry and his Wife
Old Harry Rocks
Watch the animation
Old Harry Rocks story cards
Read the information cards you have been given
Cut them up, and stick them in to your books in an order that tells the story of what created Old Harry and his wife.
Further erosion causes the arch to enlarge and become unstable.
Hydraulic action and abrasion takes place.
The area is known as the Isle of Purbeck. It is on the Jurassic Coast.
Chalk is a more resistant rock than clay.
The wave-cut notch undercuts the cliff above, making it unstable.
The stack is still eroded and will eventually collapse and become a stump.
A column of rock is left standing on its own. This is a stack.
Most of this area is clay.
Most wave erosion happens at the base of the cliff.
This stack is called ‘Old Harry’.
The arch eventually collapses under it’s own weight.
A wave-cut notch is eroded along the cliff base between high and low tides.
Because the headland juts out in to the sea, it takes the full force of wave erosion.
When chalk is formed, it contains joints which means it has areas of weakness.
Wave erosion picks out the areas of weakness in the chalk cliffs and splits rocks apart in to cracks.
Caves develop on both sides of the headland.
Several lines of weakness go right through the headland cliff, wave action can erode these.
Small faults (cracks) are formed.
Small caves are formed. Wave erosion enlarges the caves.
Old Harry Rocks are in Dorset.
Chalk does not crumble away as easily as clay.
Caves are eroded so far back in to the headland that they meet in the middle and a hole is created that goes through. This creates an arch.
Old Harry’s wife is a stump. She was created when a stack collapsed a long time ago.
The headland is made of chalk.
Homework reminder
Extended homework sheet
This does not mean leave it to the last minuteEach week I want an update on what you
have found out so far.This should be a detailed project = it is
graded!Due: 21st October
Keyword bingo
Match up the keyword with my description5 in a rowYou must also be able to explain the keyword
in your own words to win
The Durdle Door arch
Lulworth Cove
Stair Hole, left. Lulworth Cove, Dorset right and below
Lulworth Cove is a horseshoe shaped bay that formed because the inland rocks are less resistant than the headland.
It is obvious how different rock types are affected at different rates.