how are coastal landforms developed - geomorphic processes

Question 1

5 processes of mass movement

Answer 1

landslides
rockfalls
mud flows
rotational slip/ slumping
soil creep

Question 2

rock fall

Answer 2

• cliffs 40 degrees or more rocks can become dethatched by physical weathering
• rocks fall to foot of cliff bc of gravity
• waves then remove this material

Question 3

landslides

Answer 3

cliffs made of softer rock slip when lubricated by rainfall

Question 4

mud flows

Answer 4

heavy rain causes fine material to move downhill

Question 5

rotational slip/ slumping

Answer 5

where softer material overlies resistant material and excessive lubricant takes place

Question 6

soil creep

Answer 6

very slow movement of soil particles downslope

Question 7

WAVE PROCESSES

Question 8

5 types of erosional wave processes

Answer 8

abrasion
attrition
hydraulic action
pounding
solution

Question 9

abrasion

Answer 9

sand/shingle/boulders picked up by the sea and hurled against the cliff

Question 10

attrition

Answer 10

the wearing down of rocks and pebbles as they rub against each other - making them smaller and rounder

Question 11

solution

Answer 11

when fresh water mixes with salt water - carbon-based rocks are broken down

Question 12

pounding

Answer 12

the mass of breaking wave exerts pressure on the rock causing it to weaken

Question 13

hydraulic action

Answer 13

the force exerted onto rocks from pounding waves

Question 14

saltation

Answer 14

SMALL stones BOUNCED along the seabed

Question 15

traction

Answer 15

LARGE boulders ROLLED along the seabed

Question 16

suspension

Answer 16

SMALL particles carried in moving water

Question 17

solution

Answer 17

materials that have been dissolved into a mass of moving water

Question 18

what is LDS

Answer 18

• when sediment it deposited onshore it is moved along shoreline by LSD
• waves approaching the shoreline at an angle due to prevailing wind direction
• when wave breaks, swash carries particles diagonally up the beach and the backwash perpendicular back down
• this creates a zig zag motion

Question 19

what is deposition

Answer 19

• material is deposited when there is loss of energy caused by decrease in velocity or volume of water

Question 20

when does deposition take place in a coastal system

Answer 20

• when sediment accumulation goes above the rate of removal
• when waves slow straight after breaking
• at the top of swash in the brief second when the water isn’t moving
• low energy environments -> like estuaries sheltered from winds

Question 21

whats settling velocity

Answer 21

• the velocity at which sediment particles are deposited
• the larger and heavier the particles, the more energy it takes to transport them

Question 22

what are fluvial processes - 3 types

Answer 22

• movement of water within a river system which helps create landforms
  Erosion
  Transportation
  Deposition

Question 23

fluvial erosion

Answer 23

• fluvial erosion in the upper catchment of a river is its main source of sediment load
• rivers use the same erosional processes to waves

Question 24

fluvial transportation

Answer 24

• rovers also transport material same to waves - traction, suspension, saltation, solution

Question 25

fluvial deposition

Answer 25

- when river enters sea, there is less velocity bc flowing water through narrow channel goes into static ocean. - energy is reduced and so all rivers sediment load is deposited - largest particles get deposited first and the finer materials taken further out - FLOCCULATION (clumping) of clay particles happens bc fresh and salt water meet bc to the differences in electrical charges. they become heavier then and sink to bottom of seabed

Question 26

what are aeolian processes - 3 types

Answer 26

- erosion, transport, and deposition of sediments by wind which forms landforms erosion transportation deposition

Question 27

aeolian erosion

Answer 27

- wind picks up sand and moves by DEFLATION - erosion happens by surface rolling and saltation

Question 28

aeolian transportation

Answer 28

- moving air can transport material the same as in water

Question 29

aeolian deposition

Answer 29

- materials carried by wind can b deposited when the wind speed falls as a result of surface friction - this happens inland in coastal areas where friction from vegetation is much greater than in the open sea