Coasts

Question 1

Why is the coast classed as an open system ?

Answer 1

The coast is classed as an open system because it receives inputs and transfers outputs into the coastal system.

e.g sediment carried into coast by a river eroded rock material trasnported offshore

Question 2

What are inputs of a coastal system?

Answer 2

Inputs are material or energy moving into the system from the outside
eg. precipitation and wind

Question 3

What is coastal energy?

Answer 3

Coastal energy

Question 4

What are coastal stores/components?

Answer 4

Coastal stores and components are the indiviual elements/parts of a system E.G beach es, sand dunes, nearshore sediment

Question 5

What is erosion?

Answer 5

Erosion is the wearing away of earths surface by the mechanical action of processes of glaciers, wind, rivers, marine waves and wind.

Question 6

What is fetch?

Answer 6

A stretch of open water which the wind blows

Fetch refers to the distance of open water over which a wind blows uninterrupted by major lane obstacles. The length of the fetch helps to determine the magnitude (size) and energy of the waves reaching the coast.

Question 7

Why is the coastal system important?

Answer 7

The coastal system is important because
- 50% of the worlds population live in coastal areas.
-75% of all large cities are coastal
-the enviroment is used for many things
-the coastal system is dynamic
-

Question 8

What is dynamic equilibrium?

Answer 8

Dynamic Equilibrium represents a state of balance in an everchanging system.
e.g constructive waves build up a beach making it steeper this leads to the formation of destructive waves that plunge rather than surge

Question 9

What are stores/components?

Answer 9

Stores/components are the individual elements/ parts of a system.

e.g beaches is a store/sink

Question 10

What is a flow/transfer?

Answer 10

A flow/transfer are the links or relationships between components

e.g wind blown sand, mass movement processes.

Question 11

What is positive feedback?

Answer 11

Positive feedback is where a flow/transfer leads to an increase or growth

e.g coastal management can Inadvertently lead to an . increase in erosion

Question 12

What is negative feedback?

Answer 12

Negative feedback is when a flow/transfer to a decrease/decline

e.g when the rate of weathering and mass movement exceeds the rate of cliff foot erosion this leads to the formation of a scree slope protecting the cliff face from erosion

Question 13

What are sources of energy at the coast?

Answer 13

• The suns energy = warms the land and sea through thermal expansion
• Wave energy = main source of energy at the coast
  -Wind energy = winds are caused by moving air from high to low pressure and the bigger the pressure difference the stronger the wind

Question 14

What factors affect wave energy?

Answer 14

• The strength of the wind - determined by the pressure gradient
• The duration of the wind - the longer the wind blows the more powerful the waves will become

Question 15

Where in the UK are the biggest waves?

Answer 15

Cornwall has the biggest waves because of the dominant prevailing wind facing the coastlines has a large fetch creating stronger waves

Question 17

What is storm surge and its role?

Answer 17

Storm surge = is a rising in sea level as a result of wind and atmospheric pressure changes associated with a storm

• Storm surge is caused by low pressure
• 1mb drop = 1cm rise in water level
  -Strong winds drive water onshore
  -Typical in North sea (depression) and in tropical warer (tropical storms)
• Excaberted by funneling

Question 18

What are destructive waves?

Answer 18

Form during local srorms and are responsib;e for:
- Weak swash strong backwash
- Beach loss
- Usually associated with sleeper beach profile although overtime they flatten the beach
- Wave frequency 10-14 per min

Question 18

How are waves formed?

Answer 18

• Waves are formed by the wind blowing over the surface of the ocean
• Causes disrtubance/fictional drag to the warer surface
• Forming waves ripples = waves
  Waves move in orbital fashion in deep water (offshore zone) but a more elliptical motion in shallower water
• The change in motion of the wave wull cause it to break
• The water becomes shallower and the circular orbit of water particles changes or elliptical shape
  The wave length (distance between two cresrs ) and the velocity both decrease
  Wave height increases causing water to back up from behind andrise into a point wgere it starts to topple over and break
  Water rushed up the beach as swash and flows back as back wash

Question 19

What are constructive waves?

Answer 19

Form as distant weather systems generate these waves in the open ocean:
- Strong swash, weak backwash
- Low surging waves approx 1m high long wave lenth >100m
- Beach gain
- Usually associated with a gentle beavh profile although overtime tehy build up beach making it steeper
- Wave frequenecy 6-8 per min

Question 20

What are tides?

Answer 20

Tides are a regular rise and fall of sea levels around the globe

When the moon and sun and earth are at 90 degrees to eachother this creates a lower gravitational pull - neap tide is twice a month

Question 21

What causes tides?

Answer 21

Todes are the rise and fall in the level of sea caused by gravitational pull of the sun and the moon and the moon has a far stronger influence as it is closer

As the moon orbits the earth, high tides follow it, in the UK we have two high tides and two low tides per day and during the high tide there is a bulge

When the sun moon and earth are in allignment creates a strong gravitational pull therefore the biggest high tide spring tide happens twice each month

Question 22

What is spring tide?

Answer 22

When the sun moon and earth are in allignment creates a strong gravitational pull therefore the biggest high tide spring tide happens twice each month

Question 23

What is neap tide?

Answer 23

When the moon and sun and earth are at 90 degrees to eachother this creates a lower gravitational pull - neap tide is twice a month

Question 24

What is a sediment cell?

Answer 24

A sediment cell = is a stretch pf coasyline usually borded by two headlands where the movement of headlands is contained

Question 25

What is a sediment budget?

Answer 25

Sediment budget = Is the balance between sediment being added to and removed from the coastal system

Question 26

What are high energy coastlines?

Answer 26

High energy coastlines = wave energy is strong for most of the year Dominal process = erosion exposed to large fetch Produces headlands, arhces, stack stumps etec Tend to be rocky Waves can meet up to 30m height - destructive waves

Question 27

What are low energy coastlines?

Answer 27

Low energy coastline = wave energy is weak for most of the year Dominant process is deposition produces beaches in sheltered areas Spits, sand dunes, large coastal exposed to small fetch Constructive discordant coastlines

Question 28

What is wave refraction?

Answer 28

Wave refraction = where incoming waves are disorted as they approach an indented shoreline Causes energy to be concentrated at headlands and disspated on bays accounting for erosional and depostional landforms -Headlands force the incoming waves to refract (bend) concentrating this wave energy onto the headland increases the waves erosive power - steepening of cliffs and the production of stacks and stumps - As waves bends around headland wave energy is lost and disspated - deposotion within vats - beaches - Negative feedback occurs here as bays and headlands are created by variations ceauses wave refraction which encourages erosion on headlands and deposition in bays.

Question 29

What are currents

Answer 29

Currents are powerful underwater continuous, predictable, directional movement of sea water by gravity wind adn water density

Question 30

What are rip currents?

Answer 30

Rip currents are powerful underwater currents occuring in areas close to the shoreline -on some beaches when plunging waves cause abuild u of water at the top of the beach - backwash forced under surface due to resistance from breaking waves forming under water current an energy source and can lead to outputs of sediment from beach area Occur when the backwash of a wave troughs in offshore zone could be argued that the prfile of the beach affects localised waveenergy strong underwayer currents

Question 31

What is tidal range

Answer 31

Tidal range is the difference in height between high and low tides -Small tidal range the power of the waves will be concentrated on a narrow section of coastline casuing high amounts of erosion A high tidal range creates powerful currents as the tide rises and falls causing large amounts of transportation particularly in esturaries

Question 32

What is rock litohology

Answer 32

Rock lithology = the rocls physcia; characteristics strengths and chemisrty of the rock

Question 33

What is beach profile?

Answer 33

Beach profile = the shape of the beach in cross section

Question 34

What is beach profile or shingle beaches?

Answer 34

Shingle: - Water percolates rapidly through shingle, so backwash can be limited and sediment isnt moved back down the beach easily -Energy lpst through friction - Strong backwash removes beach material High rates of erosion beach becomes steeper

Question 35

What is beach profile for sandy beaches?

Answer 35

Sandy profile: - Gentle profile (<5degrees) - Sand becomes compact when wet and prevents percolation : most swash returns as backwash - Little energy lost through frction Material depositied on the beach little material eroded from beach beach profile is kept flat

Question 36

What is a berm?

Answer 36

Berm = series of smaller ridges found further down the beach and formed by succesivley lower high tides and constructive waves

Question 37

What is a storm beach

Answer 37

Storm beach= A ridge found at the top of the beach, made of larger material deposited by high energy waves at high tide during storm condtions

Question 38

What are ridges?

Answer 38

Ridges = Accumulations of sediment found at LWM run parralel to shoreline on sandy beaches - mateiral deposited by the wind

Question 39

What are runnels?

Answer 39

Runnels (depressions) found at LWM run parralel to shoreline on sandy beaches - mateiral deposited by the wind

Question 40

What are cusps?

Answer 40

Cusps = semi circular depressions on a beach which form when both swash and backwash are strong occuring in the junction of sand/shingle The horn shape channels swwash producing stronger backwash

Question 41

What are ripples?

Answer 41

Ripples = caused by wave action and tidal current

Question 42

What is a tombolo?

Answer 42

A tombolo = formed whena spit connects to the mainland coast to an isalnd * Found on drift aligned beaches where a spit joins up mainland with an offshore island * May be created at high tide

Question 43

What is a bar?

Answer 43

A bar = a spit that joins two headlands together * Found on drift aligned beaches where a spit extends across a bay between two headlands * The trapped water behind the bar creates a lagoon ( also believed to be formed by sediment deposited at the end of the ice age

Question 43

What is a swash aligned beach?`

Answer 43

Swash aligned beaches = parraele to the incoming wave crests, waves hit coastlien headon and moves sediment up and down the beach * Experience minimal LSD and found on discordant coastlimes with small bays/coves and headlaves * Waves are refracted as they appraoch the coastline * High energy waves will leave behind large angular material and low energy waves will deposit sand

Question 44

What is a drift aligned beach?

Answer 44

Drift aligned beaches = parralel to the direction of lsd, moves sediment along the coastline, found where waves approach beach at an angle * Found on concordant coastlines which are regulr in shape * Can produce spits,bars, tombolos and relies on equilibitiom * Without a continual supply of sediment/lsd would remove sediment faster than it was deposited * Material is often graded smaller and smoother sdiement found further along the beach

Question 45

What is a summer beach profile?

Answer 45

Summer beach profile is often steeper, when waves are more constructive than destructive * Constructive waves are less frequent and have a longer wave length * Wave energy is therefore disspated and deposists over a wide area weakening backwash

Question 47

What is a winter beach profile?

Question 48

What is a spit and how is it formed?

Question 49

What are transportational methods?

Question 50

What factors effect coastal transportation?

Question 51

What factors affect coastal erosion?

Question 52

What is solution?

Question 53

What is attrition?

Question 54

What is hydraulic action?

Question 55

What is abrasion?

Question 56

What is wave quarrying?

Question 57

What is corrasion?

Question 58

What is attrtion?

Question 59

What is mass movement?

Question 60

What are landslides?

Question 61

What are rockfall?

Question 63

What is landslip?

Question 64

What is slumping?

Question 65

What is soil creep?

Question 66

What is mud flow?

Question 66

What is solification?

Question 67

What is runoff?

Question 67

WHat is weathering?