Coastal changes and conflict Flashcards Preview

EDEXCEL Geography > Coastal changes and conflict > Flashcards

Flashcards in Coastal changes and conflict Deck (32):
1

Describe concordant coasts

- made up the same type of rock

- parallel to the sea

2

Describe discordant coasts

- rocks type alternates in layers

- perpendicular to the sea

- forms headlands and bays

3

What are joints ?

small cracks in rock

4

What are faults ?

larger cracks in rock

5

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

(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

6

Describe the formation of headlands

- 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

7

Describe the formation of bays

- bays form due to rapid erosion of soft rock / less resistant rock

- they then become sheltered by headlands and stop eroding

8

How are caves formed ?

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

9

How are arches formed ?

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

10

How are stacks formed ?

when an arch collapses

11

How are stumps formed ?

when a stack is eroded by wind and water

12

What are wave cut platforms and how are they formed ?

- 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

13

What are the 4 process that erode the coast ?

- hydraulic action

- abrasion

- attrition

- solution

14

Describe how hydraulic action erodes the coast

- 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

15

Describe how abrasion erodes the coast

breaking waves throw sand and pebbles against the coast during storms

16

Describe how attrition erodes the coast

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

17

Describe how solution erodes the coast

chemical action on some rocks, especially limestone

18

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

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

When do slumps occur ?

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

20

When does sliding occur ?

when loosened rocks and soil tumble down the slope

21

Describe the stages of long shore drift

- 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

What are the 4 types of transportation ?

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

Describe the process of deposition

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

What are the 3 landscapes formed from deposition ?

- beaches

- spits

- bars

25

What are spits ?

- 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

What are bars ?

- formed in the same way as spits

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

27

What are the 5 human impacts on the coast ?

- development

- industry

- agriculture

- coastal management

- tourism

28

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

POSITIVE :
- raises interest in protecting the coastal landscape

NEGATIVE :
- the weight of the buildings increase cliff vulnerability

- changes in drainage increase saturation

29

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

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

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

POSITIVE :
- wildlife habitats may be created and preserved

NEGATIVE :
- increased soil erosion

- increased sedimentation

31

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

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

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

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