3.3 - Coastal geomorphology processes Flashcards Preview

A-Level Geography - Coastal; systems and landscapes > 3.3 - Coastal geomorphology processes > Flashcards

Flashcards in 3.3 - Coastal geomorphology processes Deck (41)
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1

Define subaerial

Process at base of atmosphere which breaks down the coastline and weaken the underlying rock so a sudden movement of erosion can happen easily

2

What is a marine process?

Operate upon a coastline and are connected with the sea (LSD, tides)

3

Define LSD

Long short drift - prevailing winds at an angle to the coastline and swash transports sediment up the beach then backwash transports it towards sea at a right angle.
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4

What is an offshore current?

E.g. rip current - move material to sea at a right angle. Sediment is deposited t form a sand bank or reshape depositional landforms

5

Describe upwelling

Movement of cooler water from deep ocean due to surface winds pushing water away.

6

What is a longshore current

Approach coast at an angle and generate a current running parallel to the shore. Transports sediment and water

7

3 causes of a current

Wind, water temperature, salinity

8

Define current

Large movement of water in one direction

9

What is a rip current

Formed when a series of plunging waves cause a temporary build up at the top of a beach. Met will resistance from breaking waves. Backwash is forced below surface.

10

Define bore

Wall of water that travels upstream for a considerable distance

11

What is solution (transportation)

Dissolved material that is not visibly moving

12

What is suspension

Small particles oved by light currents

13

What is saltation

Pebbles bounce of sea bed

14

What is traction

Rocks are dragged/rolled on sea bed

15

4 reasons why energy flow declines and description

Energy source changes - weaken currents/prevailing winds

Discontinuity in flow - turbulence between opposite currents (end of spit)

Increased friction - more energy needed to big rocks deposited

Increased load - energy of system isn't sufficient (sudden river discharge or landslip)

16

What is the different between corrasion and abrasion

Corrasion - throw at cliff
Abrasion - drag along floor (sand paper)

17

How does the wave steepness impact the rate of erosion?

Wave steepness - high energy = longer fetch = high and steep

18

What are aeolian processes

Entrainment, transport and deposition of sediment by wind

19

3 types of weathering

Biological, chemical, physical/mechanical

20

What is biological weathering?

Action of vegetation and organisms. E.g. seaweed and plant roots

21

2 examples and processes of mechanical weathering

Freeze thaw = +- 0oc. Water enters crack, freeze and expand up to 10%, exert pressure and crack widens (pressure relief)

Salt crystallisation - sea water enters crack, freeze and expand, evaporate and salt left behind, repeat

22

Name the 5 types of chemical weathering

Oxidation

Hydration

Hydrolysis
Carbonation

Acid rain

23

Define mass movement

Downslope movement of material due to gravity

24

Define rockfall

Blocks dislodged by weathering fall

25

Define landslide

Block of rock rapidly move along seaward dipping plane

26

Define rotational slump

Sections of cliff give way on concave surface and rock/soil s unconsolidated

27

Define mudflow

Storm/intense rainfall - soil lying over impermeable bedrock

28

Define creep

Slow downslope movement of individual soil particles

29

Define solifluction

Slow downslope of waterlogged regrowth. End of ice age (thaw)

30

What influences mass movement (4)

Angle of slope
Rock type/structure
Vegetation cover
How wet ground is