Coasts

Question 1

Explain a constructive wave

Answer 1

Constructive waves are created in calm weather. They break on the shore and deposit material, building up beaches. They have a stronger awash than backwash.

Question 2

Explain a destructive wave

Answer 2

Destructive waves are created in storm conditions. They are big, strong, high energy waves. They tend to erode the coast as they have a strings backwash than swash

Question 3

Explain the 4 erosional processes

Answer 3

Corrasion - water fling pebbles and rocks against the coastline wearing it away like sandpaper

Attrition - bits of rock is bashed together and break each other into smaller bits

Solution - water dissolves rock like a tablet in water

Hydraulic action - water is forced into cracks and forces the crack apart, widening it

Question 4

State the 3 stages involved in the formation of a headland and bay

Answer 4

Stage 1 - destructive wave
Stage 2 - 4 erosional processes
Stage 3 - formation of a headland and bay

Question 5

Explain the formation of a headland and bay

Answer 5

Coastlines have alternating band of soft rock and hard rock. Hard rock is more resistant to the 4 erosional processes creating a headland. Soft rock is less resistant to the 4 erosional processes, creating a bay

Question 6

State the 3 stages involved in the formation of caves, arches, stacks and stumps

Answer 6

Stage 1 - destructive wave
Stage 2 - 4 erosional processes
Stage 3 - formation of caves, arches, stacks and stumps

Question 7

Explain the formation of caves, arches stacks and stumps

Answer 7

The sea will attack the base of the cliff, opening up small cracks and weaknesses in the rock.

Further wave action with widen the crack until a cave forms.

A blowhole may be created when compressed air is pushed upwards by the power of the waves and vertical erosion occurs.

All by the processes of corrasion, attrition, solution and hydraulic action.

The cave will get widened and deepened until it cuts through the headland to form an arch.

Further erosion causes the roof of the cave to collapse. This leaves a pillar of rock standing in the sea, known as a stack.

Due to constant weathering and being under attack of erosion, the stack will eventually collapse leaving only a stump.

Question 8

State the 3 stages involved in the formation of a cliff

Answer 8

Stage 1 - destructive wave
Stage 2 - 4 erosional processes
Stage 3 - formation of a cliff

Question 9

Explain the formation of a cliff

Answer 9

Soft rock such as sand and clay erodes easily to create gently sloping cliffs. Hard rock such as chalk is more resistant and erodes slowly to create steep cliffs

Question 10

State the stages involved in the formation of a wave cut notch and platform

Answer 10

Stage 1 - destructive wave
Stage 2 - 4 erosional processes
Stage 3 - formation of a wave cut notch and platform

Question 11

Explain the formation of a wave cut notch and platform

Answer 11

Weather weakens the top of the cliff.

The sea also attacks the base of the cliff forming a wave cut notch.

The notch increases in size causing the cliff to collapse.

The backwash carries the rubble towards the sea forming a wave cut platform.

The process repeats and the cliff continues to retreat

Question 12

State the 3 stages involved in the formation of a sand spit

Answer 12

Stage 1 - constructive wave
Stage 2 - longshore drift
Stage 3 - formation of a sand spit

Question 13

Explain longshore drift

Answer 13

Waves approach the coast at an angle, determined by the wind direction.

When wave breaks, swash carries water and material(sand and pebbles) up the beach at the same angle.

Gravity pulls backwash and material back down the beach at right angles to the coast.

This results in the zig zag movement of material along the coast.

Question 14

Explain the formation of a sand spit

Answer 14

A spit is a long, narrow accumulation of sand or shingle.

One end is attached to land and the other projects out into the sea.

Spits are formed by longshore drift.

Spits form where the coastline changes direction.

Longshore drift cannot turn corners. It continues to transport material along the coast in relation to the dominant wave direction.

Because this process of longshore drift begins to slow/losing its energy depositing the larger material first.

The area needs to be sheltered with calm water to allow the spit to accumulate.

The spit may have a hooked end and this could be due to a change in the prevailing wind.

The shallow, sheltered area behind the spit fills with mud. This is called a salt marsh.

Question 15

State the 4 stages involved in the formation of a sandbar

Answer 15

Stage 1 - constructive wave
Stage 2 - longshore drift
Stage 3 - sand spit
Stage 4 - formation of a sand bar

Question 16

Explain the formation of a sand bar

Answer 16

Sand bars form where longshore drift transports material across a bay, joining one headland to another.

Question 17

Give an example of a sand bar

Answer 17

Slapton sands in devon

Question 18

State the 4 stages involved in the formation of a tombolo.

Answer 18

Stage 1 - constructive wave
Stage 2 - longshore drift
Stage 3 - sand spit
Stage 4 - formation of a tombolo

Question 19

Explain the formation of a tombolo

Answer 19

A tombolo is a spit connecting an island to the mainland

Question 20

Explain the 8 stages in the hydrological cycle

Answer 20

1. Heat from the sun heats up the ocean and it evaporates into water vapour.
2. As the vapour rises, it cools and condenses to form clouds.
3. The clouds live inland through the process of advection.
4. The clouds release the water as precipitation.
5. When this water falls on land it either infiltrates into the soil or remains on top of land as surface e flow.
6. If the water remains of the surface it could be intercepted by vegetation, absorbed and turned back into water vapour by evapotranspiration.
7. Water can be added through glaciers melting, this again infiltrates or remains as surface flow.
8. If this water infiltrates it either remains on the soils as ground water storage or returns back to a body of storage through ground water flow. This is a closed cycle.

Question 21

Explain the hydrographs

Answer 21

• the peak rainfall occurs at (time) at (mm)
• the rising limb is steep between (time) and (time). It rises from (cumecs) to (cumecs). This is a difference of (cumecs)
• the falling limb is steep between (time) and (time). It falls from (cumecs) to (cumecs). This is a difference of (cumecs)
• peak discharge occurs at (time) at (cumecs)
This is a long/short lag time of (hours)

Question 22

Give reasons for a short lag time

Answer 22

1. The precipitation fell as rain and not snow.
2. The drainage basin has lots of tributaries.
3. The drainage basin could have steep sides.
4. The drainage basin has hard rock geology meaning rocks will not hold water increasing surface runoff
5. The drainage basin has storm channels which provides quick access for water back to the river.

Question 23

Give 5 reasons for a long lag time

Answer 23

1. The precipitation fell has snow and took a long time to melt.
2. The drainage basin is flat or has gentle sides.
3. There is a lot of vegetation therefore the water has been intercepted.
4. The drainage basin has soft rock geology meaning rocks are porous and hold water.
5. The drainage basin is large in size meaning water will take longer to reach the river.