COASTS

Question 1

What are the stages of sand dune succession

Answer 1

1. Wind carries loose sand inland
2. Sand is deposited behind an obstacle
3. Pioneer species grow on the dune, stabilising it and adding organic matter
4. Foredunes develop, colonised by plants such as marram grass
5. Grey dunes develop; the change of colour reflecting the higher organic content
6. A climatic climax community of scrub and woodland is achieved

Question 2

How dynamic equilibrium is reached regarding waves and beach profile

Answer 2

1. Constructive waves have a strong swash and build up beaches
2. Steeper beaches mean destructive waves are more likely to form, with a stronger backwash than swash
3. This reduces the gradient of the beach
4. Less steep beaches mean constructive waves are more likely to form
5. This creates dynamic equilibrium in the system between the wave type and the beach shape

Question 3

What makes a landslip/slump different to a land slide?

Answer 3

The slide surface is curved

Question 4

What is the name for the movement of individual soil particles down slope?

Answer 4

soil creep

Question 5

What is a sediment cell?

Answer 5

A stretch of coastline where movement of sediment is mainly contained

Question 6

What are subaerial processes?

Answer 6

the processes of weathering and mass movement.

Question 7

What is an input?

Answer 7

Material or energy moving into the system from outside

Question 8

What is an output?

Answer 8

Material or energy moving out of the system

Question 9

What is positive feedback?

Answer 9

When a flow/transfer leads to an increase or growth

Question 10

what is negative feedback?

Answer 10

When a flow/transfer leads to a decrease or decline

Question 11

What is dynamic equilibrium?

Answer 11

This represents a state of balance within a constantly changing system

Question 12

3 factors affecting wave energy

Answer 12

Wind strength - determined by the pressure gradient
Wind duration - the longer the wind blows, the more powerful the waves will become
The fetch - the distance of open water the wind blows - the longer the fetch, the more powerful the waves

Question 13

Outline how waves are formed

Answer 13

1 - As air moves across the water, frictional drag disturbs the surface forming ripples or waves
2 - The water particles orbit in a circular motion
3 - As the water becomes shallower, the circular orbit of the water particles changes to an elliptical shape
4 - The wavelength and the velocity decrease, and the wave height increases
5 - the water backs up from behind and rises to a point where it breaks
6 - the water rushes up the beach as swash and flows back as backwash

Question 14

what is the tidal range?

Answer 14

The relative distance in height between high and low tides

Question 15

What is spring tide?

Answer 15

Spring tide is when the the tidal range is at its greatest. The sun and moon are in line with the Earth. Gravitational pulls act together to create higher high tides and lower low tides

Question 16

What is neap tide?

Answer 16

Neap tide is when the tidal range is at its smallest. The Moon is at right angles to the Sun. Gravitational pulls act against each other to create lower high tides and higher low tides.

Question 17

Outline the formation of a rip current.

Answer 17

Rip currents are strong localised underwater currents. They are commonly formed when a series of plunging waves cause a temporary build up of water at the top of the beach. Met with resistance from the breaking waves, the backwash is forced just below the surface following troughs and small undulations in the beach profile.

Question 18

Landforms typically found in high energy coastlines

Answer 18

Erosional landforms ie:
Cliffs, headlands, wave-cut platforms
rocky coasts

Question 19

Landforms typically found in low energy coastlines

Answer 19

Depositional landforms ie:
Spits, bars, beaches and coastal plains
sandy and estuarine coastlines

Question 20

what is wave refraction?

Answer 20

the distortion of wave fronts as they approach an indented shoreline.

Question 21

What is the backshore

Answer 21

The area between the high water mark and the landward limit of marine activity. Changes normally take place here only during storm activity

Question 22

What is the foreshore?

Answer 22

The foreshore is the area lying between the HWM and the LWM. It is the most important zone for marine processes ain times that are not influenced by storm activity

Question 23

What is the inshore

Answer 23

The area between the LWM and the point where waves cease to have any influence on the land beneath them.

Question 24

Offshore

Answer 24

The area beyond the point where waves cease to impact upon the seabed and in which activity is limited to deposition of sediments.

Question 25

Define nearshore

Answer 25

The area extending seaward from the high water mark to the area where waves begin to break. Includes
swash zone, surf zone and breaker zone

Question 26

Define swash zone

Answer 26

The area where a turbulent layer of water washes up the beach following the breaking of a wave

Question 27

Surf zone define

Answer 27

The area between the point where waves break, forming a foamy bubbly surface, and where the waves then move up the beach as swash in the swash zone

Question 28

Define the breaker zone

Answer 28

The area where waves approaching the coastline begin to break, usually where the water depth is 5 to 10m

Question 29

Define upwelling

Answer 29

The movement of cold water from deep in the ocean towards the surface. The more dense cold water replaces the warmer surface water and creates nutrient rich cold ocean currents. These currents form part of the pattern of global ocean circulation currents.

Question 30

Define rip currents.

Answer 30

strong currents moving away from the shoreline. They develop when seawater is piled up along the coastline by incoming waves. Initially the current may run parallel to the coast before flowing out through the breaker zone, possibly at a headland of where the coast changes direction. These can be extremely hazardous to swimmers and small boats.

Question 31

Define longshore currents

Answer 31

Longshore currents occur as most waves do not hit the coastline head on but approach at an angle to the shoreline. This generates a flow of water running parallel to the shoreline.

Question 32

Define spring tide

Answer 32

Earth, moon and sun are in a straight line leading to the highest monthly tide

Question 33

Define neap tide

Answer 33

Moon and sun are 90 degrees from the earth, leading to the lowest monthly tide.

Question 34

How does soil creep happen

Answer 34

Soil creep is very slow movement, occurring on very gentle slopes because of the way soil particles repeatedly expand and contract in wet and dry periods.

When wet, soil particles increase in size and weight, and expand at right angles. When the soil dries out, it contracts vertically