Coastal changes and conflict Flashcards

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1
Q

Describe concordant coasts

A
  • made up the same type of rock

- parallel to the sea

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2
Q

Describe discordant coasts

A
  • rocks type alternates in layers
  • perpendicular to the sea
  • forms headlands and bays
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3
Q

What are joints ?

A

small cracks in rock

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4
Q

What are faults ?

A

larger cracks in rock

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5
Q

Rates of erosion are mainly down to the geology, but what are the other 4 factors ?

A

(1) geology structure - e.g if soft and hard rocks occur together
(2) ‘wave climate’ - how powerful waves are, wave direction, wave height and how far they travel over open water
(3) local currents and tidal range
(4) groundwater levels - high groundwater is more vulnerable

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6
Q

Describe the formation of headlands

A
  • headlands are left sticking out where hard rock has resisted erosion (erosion of the sock rock forms bays)
  • they become more vulnerable to erosion because wave energy is concentrated there
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7
Q

Describe the formation of bays

A
  • bays form due to rapid erosion of soft rock / less resistant rock
  • they then become sheltered by headlands and stop eroding
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8
Q

How are caves formed ?

A

when the waves erode a weakness in the rock e.g a joint or a fault

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9
Q

How are arches formed ?

A

when two caves erode back from either side of a headland and meet in the middle

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10
Q

How are stacks formed ?

A

when an arch collapses

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11
Q

How are stumps formed ?

A

when a stack is eroded by wind and water

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12
Q

What are wave cut platforms and how are they formed ?

A
  • areas of flat rock at the base of the cliff
    1. rock face overhangs
    2. wave-cut notch is undercut by the waves
    3. cliff retreats inland and overhanging rock collapses
    4. wave-cut platform is formed
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13
Q

What are the 4 process that erode the coast ?

A
  • hydraulic action
  • abrasion
  • attrition
  • solution
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14
Q

Describe how hydraulic action erodes the coast

A
  • the sheer weight and impact of water against the coastline, will erode the coast
  • waves compress air in cracks in rock, forcing them apart and weakening the rock
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15
Q

Describe how abrasion erodes the coast

A

breaking waves throw sand and pebbles against the coast during storms

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16
Q

Describe how attrition erodes the coast

A

the rocks and pebbles carried by the waves rub together and break down into the smaller pieces

17
Q

Describe how solution erodes the coast

A

chemical action on some rocks, especially limestone

18
Q

What are the sub-aerial processes that also contribute to coastal erosion ?

A

MECHANICAL WEATHERING :
- freeze thaw, water in cracks freezes and expands, over time the crack widens and pieces of rock fall off

CHEMICAL WEATHERING :
- occurs when the rock’s mineral composition is changed

BIOLOGICAL WEATHERING :
- caused by plants and animals e.g. tree roots widen gaps in rocks

MASS MOVEMENT :

  • the downhill movement of material under the influence of gravity, the different types depend on…
  • the material involved
  • the amount of water in the material
  • the nature of the movement
19
Q

When do slumps occur ?

A

when the rock (often clay) is saturated with water and slides down a curved slip plane

20
Q

When does sliding occur ?

A

when loosened rocks and soil tumble down the slope

21
Q

Describe the stages of long shore drift

A
  • waves approach the coast at an angle
  • swash pushes sand and gravel up the beach at the same angle
  • backwash carries sand and gravel back down the beach at 90oC to the coastline
  • sand and gravel move along the beach in a zigzag fashion
  • sand is lighter than gravel so moves further up the beach
22
Q

What are the 4 types of transportation ?

A

TRACTION :
- large boulders are rolled along by the waves

SALTATION :
- smaller stones are bounced along the sea bed

SUSPENSION :
- sand and small particles are carried along in the flow

SOLUTION :
- some minerals are dissolved in seawater and carried along in the flow

23
Q

Describe the process of deposition

A

the load carried by waves is deposited by constructive waves, different factors effect deposition…

  • sheltered spots
  • calm conditions
  • gentle gradient offshore causing friction

all reduce the wave’s energy

24
Q

What are the 3 landscapes formed from deposition ?

A
  • beaches
  • spits
  • bars
25
Q

What are spits ?

A
  • narrow projections of sand that are attached to the land at one end
  • they extend across a bay where the coastline changes direction
  • formed by longshore drift powered by a strong prevailing wind
26
Q

What are bars ?

A
  • formed in the same way as spits

- grow right across the bay, cutting off the water to form lagoons

27
Q

What are the 5 human impacts on the coast ?

A
  • development
  • industry
  • agriculture
  • coastal management
  • tourism
28
Q

What are the positive and negative impacts of development on the coast ?

A

POSITIVE :
- raises interest in protecting the coastal landscape

NEGATIVE :
- the weight of the buildings increase cliff vulnerability

  • changes in drainage increase saturation
29
Q

What are the positive and negative impacts of industry on the coast ?

A

POSITIVE :
- brings jobs and wealth to an area

NEGATIVE :
- can cause air, soil, water and noise pollution

  • can destroy natural habitats for birds, animals and sea life
30
Q

What are the positive and negative impacts of agriculture on the coast ?

A

POSITIVE :
- wildlife habitats may be created and preserved

NEGATIVE :
- increased soil erosion

  • increased sedimentation
31
Q

What are the positive and negative impacts of coastal management on the coast ?

A

POSITIVE :
- some salt marshes, sand dunes, sand bars and spits are preserved / protected

  • helps reduce the risk of coastal flooding

NEGATIVE :
- can increase erosion further along the coastline

32
Q

What are the positive and negative impacts of tourism on the coast ?

A

POSITIVE :
- increased revenue benefits people living there

  • increased desire to protect the landscape so tourism continues

NEGATIVE :
- increased development for hotels and campsites impacts on natural processes e.g. erosion, transportation, deposition

  • increased pollution e.g. litter, noise, traffic fumes