Coastal systems

Question 1

constructive waves

Answer 1

low wave high 
long wave length
low frequency 
high swash 
low backwash

Question 2

destructive waves

Answer 2

high wave height
short wave length
short frequency 
steep wave form
low swash
high backwash

Question 3

wave refraction

Answer 3

waves change direction and become parellel to shore

Question 4

coastal sediment budget

Answer 4

the balance of sediment being added and removed from the costal system

Question 5

sediment sources

Answer 5

where sediment is created such as the erosion of cliffs of sand dunes.

Question 6

high energy coastline

Answer 6

Where rate of erosion > deposition
Strong prevailing winds
destructive waves

Question 7

low energy coastlines

Answer 7

where rate of deposition > erosion

constructive waves

Question 8

Biological weathering

Answer 8

living organisms disintegrating sediment/rocks changing its structure

Question 9

physical weathering

• wetting and drying
• exfoliation
• crystallisation
• freeze-thaw

Answer 9

pressure exerted on rock due to change in its structure

Wetting and drying- rocks expand when wet and contract when dry

exfoliation- large sheets of rocks detatched due to pressure release

crystallisation- salt crystals deposited in cracks applies pressure to the crack

freeze-thaw- water gets into cracks and freeze causing expansion putting pressure on rock.

Question 10

chemical weathering

• carbonation
• oxidation

Answer 10

rain and sea water contain chemicals that can react with chemical compounds in the rock altering its structure.

carbonation- rocks containing calcium carbonate (e.g limestone) react with carbonic acid (co2 and rain) forming calcium bicarbonate causing weathering.

oxidation- oxidation of fe2+ H2O + O = Fe3+ causing rock browning and weathering

Question 11

Costal erosion

Hydraulic action

Answer 11

waves break against cliff
pushes air into gaps
compresses air

Question 12

Costal erosion

Cavitation

Answer 12

open of cavities in the cliff due to pressure changes

Question 13

Costal erosion

Abrasion

Answer 13

rocks thrown against cliff by waves breaking pieces of cliff

Question 14

Costal erosion

Quarrying

Answer 14

destructive waves put heavy pressure on cliff face. Vibration of rocks dislodges rocks.

Question 15

Costal erosion

Solution

Answer 15

chalk and limestone dissolved

Question 16

Costal erosion

Attrition

Answer 16

smoothing and rounding of angular rocks into pebbles shingles then sand.

Question 17

Erosional landform

Cave –> Arch –> Stack –> Stump

Answer 17

Cave- erosion causes crevices to appear in cliff face over time widens and becomes a cave. Cave grows due to wave refraction leading erosion onto the side of headland.
Arch- Caves develop of both side till they meet forming an arch.
Stack- Arch roof becomes narrower due to weathering until it collapses forming a stack
Stump- Stack is weathered by sub-arial processes until it collapses leaving a stump.

Question 18

wave cut notch/platform

Answer 18

Destructive Waves crash into base of cliff causes erosion through Hydraulic action, Abrasion and Solution forming a wave cut notch. Process continuous until gravity causes cliff to collapse

Question 19

Discordant coastline

Concordant coastline

Answer 19

Discordant- bands of different rock run right angle to the coast. = more coastal landforms

Concordant bands of different rock run parallel to coast.

Question 20

Dorset

Answer 20

High energy coastline(high fetch 5km)

Old Harry Rocks- caves, stacks and stumps
Durdle Door- arch
lulworth cove- cove
st aldhelms head- headland

Question 21

Sand dunes

Answer 21

Sand dunes are created when wind deposits sand on top of each other until a small mound starts to form

Question 22

Split

Answer 22

Prevailing winds cause Long Shore Drift. Constructive waves moves sediment along the beach eventually depositing sediment out to sea to form a stretch of beach.

Question 23

Bar

Answer 23

when a split forms completely across a bay

Question 24

Tombolo

Answer 24

when a split connects an island to mainland

Question 25

Mudflats

Answer 25

Flow of fresh water from rivers into Sheltered shorelines depositing slit/clay.
Flow of salt water into mouth with hide tides bringing in fine sediment
Flows meet causing fine particles to settle.
Builds up over time causing mudflats

Question 26

Saltmarshes

Answer 26

Low-lying vegetation (eelgrass) grows on mudflat slowing current = uneven deposition
Pioneers colonise area.
Halophytes (plants that tolerate salt water e.g spartina) dominates area slows down sea water = more deposition.
Plant layers become thicker = salt marsh grows= land rarely gets covered by sea.
Larger vegetation grows and eventually trees.

Question 27

Isostatic and eustatic change

Answer 27

Isostatic change is a local sea level change whereas eustatic change is a global sea level change