Coasts

Question 1

What are sediment cells ?

Answer 1

Length of a coastline which is self contained as far as movement of sediment is concerned. Interruptions to movements will not affect each independent sediment cell.

Question 2

Define wave period

Answer 2

Time it takes for a wave to travel 1 wave length

Question 3

What are characteristics of constrictive waves?

Answer 3

Long wavelength
Low frequency 
Low height
Build up beach
Strong swash 
Weak backwash

Question 3

What are characteristics of destructive waves?

Answer 3

Short wavelength
High frequency
High height
Pulls material away from the beach
Weak swash 
Strong backwash

Question 5

Define hydraulic action

Answer 5

Waves move towards a cliff and the water enters the cracks, trapping air in the cliff face creating pressure. This continues and weakens the cliff making it unstable so the cliff falls.

Question 6

What are sub-cells ?

Answer 6

A sediment cell spilt into smaller more manageable units with boundaries at which there’s only a limited exchange of sediment.

Question 7

Define abrasion

Answer 7

The tides picking up rocks and then throwing them at a cliff due to the waves power. This damages the base of cliffs making them weak.

Question 8

Define solution ?

Answer 8

Where the waves dissolve the base of cliffs making them slowly weaker.

Question 9

Define backwash

Answer 9

The return of water back down the beach as a result of gravitational pull. This moves sediment back down the beach.

Question 10

Define wave trough

Answer 10

Lowest point of a wave

Question 11

Define attrition

Answer 11

Where rocks scrape along the base of a cliff causing the cliff to erode due to the force of friction.

Question 12

Types of transportation

Answer 12

Backwash/swash
Longshore drift
Traction, saltation, suspension in waves
Traction and saltation of beach sand

Question 13

Types of sub-aerial weathering

Answer 13

Salt crystal growth
Freeze thaw
Acidic rainfall
Biological weathering

Question 14

What does mass movement include ?

Answer 14

Rock fall
landslides
mudflows
slumps

Question 15

Describe estuarine coastlines

Answer 15

Found in mouths of rivers

Gradual transition from land to sea

Question 16

What is runoff

Answer 16

Effects of surface wash over cliff faces as well as the effects of rivers entering the sea

Question 16

Define wave frequency

Answer 16

Number of waves per minute

Question 17

Define Wave crest

Answer 17

Highest point of a wave

Question 18

Define waves

Answer 18

Created by the transfer of energy from the wind blowing on the surface of the sea. Therefore waves are movement of energy in water.

Question 21

Define Wave steepness

Answer 21

Ratio of wave height to the wave length

Question 22

Define fetch

Answer 22

Distance over which the wind blows over water. Greater distance means to increased wave energy.

Question 22

Define swash

Answer 22

Movement of water up the beach from a breaking wave. It goes up the same angle as it breaks and carries sediment up the beach with it.

Question 23

Define Wave length

Answer 23

Distance between 2 successive crests

Question 24

What are the sources of sediment?

Answer 24

Anywhere outside the cell, for example rivers and eroded cliffs.

Question 26

What are cliff profiles ?

Answer 26

The height and angle of a cliff face as well as all of its features.

Question 27

What is the littoral zone?

Answer 27

Area where the land meets the sea, most erosion occurs here and shoreline areas are permanently submerged.

Question 27

What factors affect coasts ?

Answer 27

``` Resistance erosion of rock Faults Joints Fissures Dip of rock strata in relation to the coastline ```

Question 28

How can you classify coasts?

Answer 28

Cliffed coastlines Sandy coastlines Estuarine coastlines

Question 29

Describe a cliffed coast

Answer 29

Transition from land to sea is abrupt Low tides Foreshore zone exposed

Question 30

Describe sandy coastlines

Answer 30

Dune vegetation stabilises the coast and erosion

Question 31

Define mass movement

Answer 31

Process where soil, sand and rocks fall under the force of gravity

Question 32

Define wave refraction

Answer 32

When waves leave deep water they're affected by drag from the sea bed. Waves will therefore realign themselves parallel with the coastline. However on irregular coastlines the waves concentrate on the headland meaning more erosion there and deposition at bays due to the low energy waves.

Question 33

Define tides

Answer 33

Rise and fall of sea level due to the gravitational pull of the sun and moon

Question 34

Define spring tides

Answer 34

Highest monthly tidal range when the moon sun and earth are in a straight line and tide raising force is strongest.

Question 35

Define neap tides

Answer 35

Lowest monthly point due to the moon and sun are 90 degrees apart from each other in relation to earth.

Question 36

What influences the size/energy of waves?

Answer 36

Wing speed Duration of wind Fetch

Question 37

Define sub-aerial processes

Answer 37

Non-marine processes that affect the coastline.

Question 38

Define freeze thaw

Answer 38

Process where water repeatedly freezes and and melts within cracks of rock. This means that the rock will expand as water expands by around 9% when frozen. Therefore the rock gets weaker and can easily break off.

Question 39

Define diurnal range

Answer 39

Temperature change over night

Question 40

Define biological weathering

Answer 40

Can be due to tree roots growing into joints in rocks or animal burrowing.

Question 41

Define chemical weathering

Answer 41

Carbonation occurs as co2 dissolves into rain water and as it falls onto rocks made of limestone, the carbonic acid attacks the calcium in the rock forcing it to break away.

Question 42

Run-off

Answer 42

Move small materials downslope like soil in areas where there's little vegetation.

Question 43

What are output systems ?

Answer 43

Where a loss of energy occurs from a natural process.