Systems And Processes Flashcards Preview

A Level Physical Geography > Systems And Processes > Flashcards

Flashcards in Systems And Processes Deck (104)
Loading flashcards...
1

Name the two types of geomorphological processes

Marine processes
Sub-aerial processes

2

Define marine processes

Coastal processes that link with the sea
Eg waves, tides, longshore drift.

3

Define sub-aerial processes

Land based processes that shape the coastline by sub-aerial weathering or mass movement

4

Name the types of marine erosion

Hydraulic action
Wave quarrying
Abrasion
Attrition
Solution

5

Define hydraulic action

The weakening of rocks by the force and pressure created by waves hitting them

6

Define wave quarrying

The weakening / breaking off of the cliff face when waves compress air into fissures / joints, which is quickly released when the waves withdraw.
-> like an explosion

7

Define abrasion

The weakening of rocks by sediment in the sea being thrown against the cliffs / wave cut platform.

8

Define attrition

Material in the sea wear each other down as they collide in the water.

9

Define solution

When acidic water dissolves calcium based rocks eg limestone.
-> usually a mixture of sea water and fresh water in localised areas.

10

How can carbon based rocks be eroded by solution process?

Carbon based rocks eroded by rainwater flow from the land -> pH of this water is usually slightly acidic

11

How can salt from sea water residue erode rock as part of the solution process?

Sea water residue in rocks evaporates -> salt crystals form -> expand -> weaken / break rock

12

Name the factors that affect the rate of marine erosion

Wave steepness
Breaking point
Fetch
Sea depth
Coastal configuration
Beach presence
Human activity

13

How does wave steepness affect the rate of marine erosion?

Steeper waves -> higher energy -> more erosive

14

How does breaking point of waves affect the rate of marine erosion?

Closer the waves break to the shore -> more they erode the rocks (haven't lost energy)

15

How does fetch affect the rate of marine erosion?

Waves that have travelled a long distance before reaching the shore -> more energy -> more erosive

16

How does sea depth affect the rate of marine erosion?

Steeper-shelving sea bed by the shore -> higher, steeper waves -> more energy -> more erosive

17

How does coastal configuration affect the rate of marine erosion?

Headlands attract wave energy through refraction.
Concordant / discordant -> resistant/non rock exposed

18

How does beach presence affect the rate of marine erosion?

Beaches dissipate wave energy -> lower rate of erosion.

• Steep, narrow beaches -> dissipate flatter waves.
• Flat, wide beaches -> dissipate high, rapid energy output -> because energy is spread out over larger area.
• Shingle beaches -> dissipate steep waves -> due to friction, percolation.

19

How does human activity affect the rate of marine erosion?

Increase erosion rate -> removing protective sand / shingle.
Decrease erosion rate -> installing sea defences (these may increase erosion elsewhere).

20

Define lithology

Refers to the characteristics of rocks
Esp resistance to erosion, permeability.

21

Define differential erosion

The variation in rates that rock types erode
Eg at discordant coastlines.

22

Define concordant coastline

When rock types run parallel to the shoreline
Eg Lulworth Cove

23

Define discordant coastline

When rock types run perpendicular to the shoreline
Eg Swanage Bay

24

Define 'dip' of rocks

Refers to the angle of rock layers in cliffs -> affects steepness of cliffs

25

Which direction of 'dip' leads to steep cliffs?

Rock strata = horizontal / dipping inland -> steepest cliffs

26

Which direction of 'dip' leads to sloping cliffs?

Rock strata = dipping seaward

27

Name the types of marine transportation

Traction
Saltation
Suspension
Solution

28

Define traction as a process of marine transportation

Large rocks / boulders slide along the seabed in high energy locations due to the movement of the water.

29

Define saltation as a process of marine transportation

Small stones bounce along the seabed / beach in high energy locations, dislodging other stones

30

Define suspension as a process of marine transportation

Very small particles of sand / silt are picked up by and carried in the water -> murky appearance