erosion weathering transportation and deposition

Question 1

Abrasion

Answer 1

rocks and sediment transported by the waves smash and grind against rocks and cliffs breaking bits off and smoothing surfaces

Question 2

hydraulic action

Answer 2

air in cracks in cliffs is compressed when waves crash in. Pressure exerted by the compressed air breaks off rock pieces

Question 3

cavitation

Answer 3

as waves recede, compressed air expands violently again exerting pressure on the rock and causing pieces to break off

Question 4

wave quarrying

Answer 4

energy of a wave as it breaks against a cliff is enough to detach pieces of rock

Question 5

solution

Answer 5

soluble rocks (e.g limestone, chalk) get gradually dissolved by the seawater

Question 6

attrition

Answer 6

bits of rock in the water smash against each other and break into smaller bits

Question 7

solution

Answer 7

substances that can dissolve are carried along in the water

e.g limestone dissolved into water that’s slightly acidic

Question 8

suspension

Answer 8

very fine material whipped up by turbulence and carried along the water
most eroded material transported this way

Question 9

saltation

Answer 9

larger particles such as pebbles or gravel bounce along the sea bed
too heavy to be carried in suspension

Question 10

traction

Answer 10

very large particles e.g boulders are pushed along the sea bed by the force of the water

Question 11

marine deposition

Answer 11

sediment carried by sea water is deposited

Question 12

aeolian deposited

Answer 12

sediment carried by wind deposited

Question 13

when does deposition occur?

Answer 13

sediment load exceeds the ability of the water or wind to carry it

Question 14

why is the water no longer able to carry sediment?

Answer 14

sediment load increases (e.g landslide)

water flow slows down (loses energy)

Question 15

why do waves and wind lose energy? (friction)

Answer 15

If wave enters shallow water or wind reaches land friction ,between water/wind and ground surface increases, slows down water or wind

Question 16

why do waves and wind lose energy? (turbulence)

Answer 16

water or wind encounters obstacle (current moving in the opposite direction or area of vegetation) flow becomes rougher and overall speed decreases

Question 17

what happens when wind drops?

Answer 17

wave height speed and energy decrease

Question 18

sub-aerial weathering

Answer 18

gradual break down of rock in situ

Question 19

why is weathering significant?

Answer 19

weakens cliffs and makes them more vulnerable to erosion

Question 20

salt weathering

Answer 20

caused by salty water
enters pores and cracks in rocks at high tides
as tide goes out rocks dry and water evaporates forming salt crystals
salt crystals expand exerting pressure

Question 21

where does freeze thaw occur?

Answer 21

areas where temperatures fluctuate above and below freezing
if temperature goes blow freezing water in the cracks freeze and expand
over time repeated freeze thaw action weakens the rock causing pieces to fall off

Question 22

wetting and drying

Answer 22

some rocks contain contain clay

when clay gets wet it expands exerting pressure

Question 23

chemical weatheing

Answer 23

breakdown of rock by changing its chemical composition

Question 24

example of chemical weathering

Answer 24

carbon dioxide in the atmosphere dissolves in rainwater forming weak carbonic acid. Acid reacts with rocks containing calcium carbonate so rocks are gradually dissolved

Question 25

biological weathering

Answer 25

plant roots growing into cracks and widening them