quiz 12 Flashcards
explain the formation of a spit
1.prevailing wind approaches the coast
2.swash carries sediment up the beach, backwash carries sediment down the beach
3. waves transport this sediment in an zig-zag pattern
4. there is a sudden change of coastline
5. waves lose energy and deposit sediment. this accumulates to form a spit
6. a change in wind direction causes hooked ends on the spit
7. behind a salt marsh forms
Explain the formation of headlands and bays
- prevailing wind changes direction of the wave making it move towards coastline
2.Headlands and bays are found where there are alternating bands of hard and soft rock an discordant coastline - softer rock is eroded more faster than harder rock as its less resistant to erosion
- the layers of hard rock stick out to sea because the soft rock is eroded more quicker its less resistant the layers, this is called a headland
- the layers of softer rock with erode more quickly create a bay
6.
Explain the formation of a beach
- 2 headlands shelter a bay with constructive waves
- constructive waves deposit the sediment they are carrying because of their strong swash and weak backwash
3.forming a beach
Explain the formation of a wave cut platform
- the high tide mark is the point where the sea and the base of the cliff meet, this the point when destructive waves erode
- destructive waves erode the base of the cliff at the high tide mark bia hydraulic action and abrasion causing the formstion of a wave cut notch
- destructive waves continue to erode via hydraulic action and abrasion widening the wave cut notch. This leads to the cliff above being unsupported so it collapses due to gravity
- the cliff will retreat inland leaving behind a steep wave cut platform that is pitted due to abrasion by rocks from collapsed overhang
Explain the formation of a cave
Faults and lines of weakness in the headland are eroded through processes such as hydraulic action and abrasion
Explain the formation of an arch
Faults and lines of weakness in the headland are eroded through processes such as hydraulic action and abrasion,
continued erosion deepens the cave. continued erosion deepens the cave and eventuallu it erodes all the headland to form an arch
Explain the formation of a stack
Faults and lines of weakness in the headland are eroded through processes such as hydraulic action and abrasion,
continued erosion deepens the cave. continued erosion deepens the cave and eventually it erodes all the headland to form an arch
The base of the arch becomes wider because of erosion. The top of the arch becomes more unstable due to weathering. Eventually the arch is to unstable and collapses, so a stack is formed
Explain the formation of a stamp
Faults and lines of weakness in the headland are eroded through processes such as hydraulic action and abrasion,
continued erosion deepens the cave. continued erosion deepens the cave and eventually it erodes all the headland to form an arch
The base of the arch becomes wider because of erosion. The top of the arch becomes more unstable due to weathering. Eventually the arch is to unstable and collapses, so a stack is formed
The isolated pillar of rock continues to the undercut because of erosion until eventually it collapes,leaving a stamp
Explain the formation of a meander
The fastest current is found on the outside bend. This is because the river is at its ddepest so the river has less contact with river bends and banks reducing friction. Therefore it erodes by hydraulic action and abrasion on the outside bend forming a river cliff
on the inside bend the current is slower. This is because the river is shallow, so there is more contact with the river beds and banks increasing friction. Ther
Explain the formation of a v-shaped valley
a v-shaped valley forms because the river erodes vertically creating steep valley sides. Freeze-thaw weathering weakens the valley sides until they collapse. A v-shaped valley is left behind which is narrow with steep sides
