coasts Flashcards
1
Q
What is abrasion?
erosion or deposition
A
- rocks and pebbles destroy cliffs and cause pieces of rock to break off
- erosion
2
Q
What is Hydraulic action?
erosion or deposition
A
- waves and the sediment in the waves crash against the rock face causing the rock to erode
- erosion
3
Q
What is Solution?
erosion or deposition
A
- chemical action on rocks by seawater. eg. limestone because calcium reacts with the sea
- erosion
4
Q
What is Attrition?
erosion or deposition
A
- rock fragments collide with each other and reduce in size
- erosion
5
Q
Defenition of a head land?
erosion or deposition
A
- an area of more resistant rock jutting out into the sea from the cliff line
- erosion
6
Q
Defenition of a bay?
erosion or deposition
A
- an area of sea, curved in shape which has been eroded between two headlands
- erosion
7
Q
Defenition of a wave-cut platform?
erosion or deposition
A
- a flat area of rock at the bottom of cliffs and seen at low tide
- erosion
8
Q
Defenition of a cliff?
erosion or deposition
A
- a steep rock face
- erosion
9
Q
Defenition of a cave?
erosion or deposition
A
- a hollow at the base of a cliff which has been eroded backwards by waves
- erosion
10
Q
Defenition of an arch?
erosion or deposition
A
- the rock bridge formed over a passage through a headland, eroded by waves
- erosion
11
Q
Defenition of a stack?
erosion or deposition
A
- an isolated column of rock, standing just off the coast that was once attached to the land
- erosion
12
Q
Defenition of a stump?
erosion or deposition
A
- a short piece of rock found at the end of a headland formed after a stack has collapsed
- erosion
13
Q
Formation of headlands and bays
erosion or deposition
A
- headlands and bays occur in areas with alternate HARD, resistant rock and SOFT, less resistant rock
- the soft rock is eroded more quickly than the hard rock
- the soft rock is eroded by hydraulic action and abrasion
- erosion
14
Q
Formation of wave-cut platform and notch
erosion or deposition
A
- at HIGH tide the sea erodes the BASE of the cliff
- the erosion processes are hydraulic action and abrasion
- with wave energy at its maximum, the waves undercut the foot of the cliff to form a WAVE-CUT NOTCH
- eventually the heavy cliff will collapse and debris from the fallen rock will either be washed away or settle to form a WAVE-CUT PLATFORM
- erosion
15
Q
Formation of C, A, S, S
erosion or deposition
A
- weaknesses in the rock are attacked by erosional processes
- processes such as hydraulic action and abrasion make cracks in the rock
- OT the cracks will develop and become CAVES
- when the caves are back to back they erode to become an ARCH
- weathering processes attack the heavy roof of the arch and OT it collapses
- once the roof has collapsed it leaves a STACK
- the stack then gets eroded down to form a STUMP
- erosion
16
Q
Formation of spits
erosion or deposition
A
- due to fetch and prevailing wind, material is moved along the coast by LSD
- when the LSD reaches the edge of the coast it deposits the sand and shingle
- the feature builds up slowly
- ocassionllly the wind changes direction and this means material from the end of the spit may be pushed round to form a curved end
- water behind the spit
- deposition
17
Q
What is a bar?
Formation of bars
erosion or deposition
A
- a bar is a ridge or barrier of sand or shingle which stretches across a sheltered bay
- it is only able to extend across a bay due to the absence of a river
- a lagoon is often formed on the landward side of the bar
- the formation of a bar begins in the same way as a spit
- material is transported along the coastline by LSD and deposited where there is a bend in the coastline
- deposition then continues in a line across the entrance to the bay or river mouth, trapping fresh water behind
- deposition
18
Q
Formation of beaches:
pebble and sand
erosion or deposition
A
- beaches are formed when eroded material is transported by LSD and deposited by constructive waves.
- sandy beaches are often found in sheltered bays. they are usually wider than pebble beaches and slope gently down to the sea
- pebble beaches are often found in areas where cliffs are being eroded and there are high energy waves. they have steep gradients.
- the profile of beaches are rarely smooth.
- deposition
19
Q
Defenition of a spit?
erosion of deposition
A
- aa spit is a permanent resulting ffrom marine deposition. it is a long, narrow accumulation of sand or shingle, with one end attached to the land, and the other projecting at a narrow angle either into the sea or across a river estuary. many spits have a hooked/curved end
- deposition
20
Q
Deposition occurs …
A
- when the sea has no more energy to carry the sediment and so it is laid down. eg. sand
- it occurs in sheltered areas where the build-up of sand and shingle is greater than the removal (LSD)
