Coasts and how they are eroded Flashcards
What is a coastline?
The narrow strip of land that separates land from sea.
What is a concordant coastline?
Same type of rock running parallel to a coast
What is discordant coastline?
Different types of rock running parallel to a coast.
What is a headland?
A headland is a cliff that juts out into the sea. They are composed of hard rock. They have steeper slopes
What is a bay?
a broad inlet of the sea where the land curves inwards. An area sheltered by land by three sides. Sometimes contains sand and found near headlands. They have gentle slopes
In which circumstance are headland and bays formed?
When there are discordant coastlines.
Give an example of a hard rock
Clay
Give an example of a hard rock
Chalk
What is a cove?
A cove is a circular wide bay
Explain the erosion of a cliff
- ) Processes of EROSION such as hydraulic action and abrasion erode the part of the cliff under water. This created a WAVE - CUT - NOTCH and causes OVERHANGING.
- ) Processes of WEATHERING such as physical and chemical affect the part of the cliff on top.
- ) The cliff can eventually become unstable and collapses and a new wave-cut notch forms
- ) Repeated collapsing results in the cliff RETREATING
- ) It also makes a WAVE - CUT PLATFORM that is the platform left behind
- ) Cliff collapses are mass movements. They happen due to strong gravity.
Name three three types of cliff collapses / mass movements
Slumps, Slides and Rockfalls
Define rockfalls
Material shifting and falling vertically downwards
Define slides
Material shifting and falling in a straight line at an angle
Define slumps
Material shifting and falling with a rotation.
Define wave-cut notch
An area of heavy erosion found near the base of the wave.
Define wave - cut platform
The platform under water in front of a cliff that has been created due to retreating of the cliff
Explain how headlands and bay forms
.Certain types of rock are more resistant to erosion than others. Headlands and bays form where there is a discordant line.
. The less resistant rock is eroded quickly forming a gentle sloped bay
. The more resistant rock is eroded slowly jutting out forming a headlands that has steeper slides
Describe the erosion of a headland
. Headlands are made of resistant rock
. Wave crash into headlands and erode the rock through hydraulic action and abrasion forming CRACKS
. The rock that usually gets eroded is called BEDDING PLANES.
. Repeated erosion causes enlargement and the cracks causes a CAVE to form
. Eventually erosion deepens the cave until it breaks through forming an ARCH
. Erosion continues to wear the rock supporting the arch and eventually it collapses forming a STACK
. A stack eventually also wears away to give a STUMP.
Describe the formation of a cove
.They form where there is alternating bands of hard and soft rock
. The resistant rock slowly erodes and then eventually it reaches the softer rocker
. In the softer rock, erosion occurs quickly laterally and vertically
. When it reaches the resistant rock rate of erosion decreases.
Name a hard rock
Clay
Name a soft rock
Chalk - It is a type of sedimentary rock
Formation of a blow hole
. Waves erode into the cave under water
. Processes of erosion take place
. Wave gets forced up out of the blow hole at the surface under pressure.
What is a anticline?
A structure formed by the folding of rock strata(rock layers) into an arch like shape. Looks like an A shape.
What is a sycline?
Anticlines are folds in which each half of the fold dips away from the crest. Looks like an S shape
