Coasts KQ1

Question 1

What is a system?

Answer 1

Aims to maintain equilibrium by using feedback loops so as to not exceed the threshold

Question 2

Give 5 types of energy at the coast?

Answer 2

1.Kinetic
2.Potential
3.Solar/Thermal
4.Geothermal
5.Gravitational

Question 3

Why is interdependency so important at the coastline?

Answer 3

The coast is interdependent and complex, it relies on other stores, e.g. without erosion from cliffs there would be virtually no sediment inputs to the coastline

Question 4

How many sediment cells are in the UK?

Answer 4

11

Question 5

Define Sediment cell.

Answer 5

A stretch of coastline and its nearshore areas where the movement of coarse sediment, sand and shingle is largely self-contained

Question 6

Are sediment cells closed or open?

Answer 6

The topography and any natural physical barriers significantly reduce transfer of sediment between cells, however this is inevitable due to variations in wind and other factors

Question 7

What are the 5 physical factors?

Answer 7

1. Geology
2. Tides
3. Ocean Currents
4. Wind
5. Waves

Question 8

Give 2 ways in which wind influences coastal landscapes?

Answer 8

1. The longer the fetch, the greater the wind speed, the more frictional drag across the sea and greater the wave energy
2. Wind approaching the coast at an oblique angle allow for longshore drift to take place

Question 9

What type of energy is possessed by waves due to its position above the trough?

Answer 9

Potential

Question 10

Between Wave height and wave period, which of the 2 are greater factors in determining the wave energy? Provide evidence

Answer 10

In the Atlantic ocean, wave height is up to 8x higher than that in the English channel, both have similar wave periods, with wave energy 70x higher in the Atlantic, so wave height is more important.

Question 11

What are the 3 characteristics of swell waves?

Answer 11

1. Formed in open oceans and can travel long distances
2. Long wavelength
3. Period of up to 20 seconds

Question 12

What are the 3 characteristics of storm waves?

Answer 12

1. Shorter wavelength
2. greater height
3. shorter wave period

Question 13

Explain how a wave breaks.

Answer 13

As wave approach shallow water the deepest circling water molecules start to drag across the bottom due to friction, this causes them to slow down, the wavelength starts to decrease as successive waves bunch up and the crest advances ahead of the base and will eventually break when the depth of water is 1.3 x wave height, there is then a significant movement of not only water but energy.

Question 14

How do waves move up the beach?

Answer 14

The waves move up the beach as swash driven by the energy from the waves breaking, the speed will eventually decrease due to friction and a steeper uphill gradient, when energy can no longer move it forwards, it will return as backwash.

Question 15

Describe what constructive waves are and how they break. As well as there frequency

Answer 15

They have a longer wavelength and less height, and frequency of 6-8/min, they break by spilling forwards, where the swash travels a long way up the gently sloping beach, the backwash occurs before the next swash so energy is retained

Question 16

Describe what destructive waves are and how they break.As well as there frequency

Answer 16

Shorter wavelength, greater height, and frequency of 12-14/min, backwash will exceed the swash, the waves break by plunging forwards, little transfer of forward energy, over a steeply sloping beach, the swash doesn’t travel far before it moves back again as backwash where it meets the swash, causing frictional effect

Question 17

What is the relationship between wave type and beach gradient?

Answer 17

High energy waves, typical of winter, tend to remove material, reducing the gradient, where as in summer low energy waves, build up the beach through deposition of material

Question 18

How are tides formed?

Answer 18

Tides form due to the gravitational pull of the moon

Question 19

How do spring tides form and how often?

Answer 19

They are formed when the sun, earth and moon are aligned and occur 2x a lunar month with a high tidal range

Question 20

How do neap tides form and how often?

Answer 20

They form when the earth, moon and sun are right angles to each other and occur 2x a lunar month and have a low tidal range

Question 21

How do tidal ranges impact the shape of the coastline? Use Tunisia and Severn estuary as examples

Answer 21

In Tunisia, tidal ranges can be up to 1.5m, which is lower than the 14m at the Severn, these tidal ranges impact weathering processes

Question 22

List 4 types of Lithology from strongest to weakest and give the properties of each

Answer 22

1. Igneous- e.g. granite, they are much more likely to form cliffs, with interlocking crystals, strong and resistant
2. Metamorphic e.g. Marble, they often have foliation which makes them more susceptible to erosion
3. Sedimentary- e.g. chalk, is more soluble and vulnerable to chemical weathering, often clastic so less resistant
4. Unconsolidated clay

Question 23

Meaning of porosity

Answer 23

Volume of spaces

Question 24

Meaning of perviousness

Answer 24

rocks such as limestone have joints so more weaknesses

Question 25

Meaning of strata

Answer 25

Layers of rock running parallel to coast

Question 26

List the meaning of these 3 words:
Dips
Faults
Joints
Bedding planes
Folds
Planform

Answer 26

1. Dips- angle of strata in relation to the coastline
2. Faults- weaknesses formed by tectonic processes
   3.Joints- vertical cracks which can form as land lifts up or dries out
3. These are horizontal cracks, often found in sedimentary rock
4. These are compressions, with both synclines and anticlines
5. structure of rock e.g. discordant or concordant

Question 27

What are discordant coastlines? and what 2 features do they form.

Answer 27

These run at right angle to the coast and can form headlands and bays

Question 28

What are concordant coastlines?

Answer 28

These run parallel to the coast

Question 29

What are Rip Currents and what can cause them to be formed?

Answer 29

They are localised currents, caused by narrow seaward flowing waves against the breaking winds and are generated by waves at right angles to the coast. They can also have a velocity of up to 1-2 feet per second

Question 30

What 2 things at a global scale drive ocean currents?

Answer 30

Earths rotation and convection

Question 31

Where do warm ocean currents travel from and what do they impact most?

Answer 31

They travel from the latitudes to the pole, driven by onshore winds and they typically impact western facing coastlines the most

Question 32

Where do cooler ocean currents travel from and what do they impact most?

Answer 32

They travel from the pole to latitudes and are driven by offshore winds and they usually don’t impact coastlines

Question 33

How do ocean currents impact sub aerial processes?

Answer 33

Ocean currents can transfer heat energy to the surrounding and increase air temperature, impact sub aerial processes

Question 34

How may ocean currents be impacted in the future due to climate change?

Answer 34

They may slow down or become warmer and lead to more destructive waves

Question 35

What 3 things supply the coast with sediment?

Answer 35

1. Terrestrial
2. Offshore
3. Human

Question 36

Describe 2 ways in which offshore sources supply the coast with sediment.

Answer 36

1. Wind which carries very fine sediment, it has less energy than water
2. Constructive waves bring sediment to the shoreline via marine deposition

Question 37

How are humans sources of sediment to the coast?

Answer 37

Beach nourishment is done to bring about equilibrium, done globally, when the sediment supply is in deficit

Question 38

70% of the coastal sediment budget can come from..

Answer 38

wave erosion from high energy waves during storm surges, where cliffs can be eroded to provide boulders and rocks as cliffs are undercut

Question 39

Can sediment delivery be intermittent (irregular)?

Answer 39

YES!! absolutely, e.g. from floods

Question 40

Give 2 other ways in which sediment can be supplied from terrestrial sources.

Answer 40

1. Rivers- which in some locations can amount for up to 90% of the total sediment budget,
2. Longshore drift