COASTS

Question 1

extent of coastal zone area

Answer 1

60km onshore

370km offshore

Question 2

coastal environment

Answer 2

where sea interacts with the and, shaping and influencing it by natural and human elements eg. through tides

Question 3

discordant coastline

Answer 3

rock bands of differential resistance perpendicular to coastline

Question 4

eg discordant coastline

Answer 4

swanage bay

Question 5

sediment sources

Answer 5

• offshore marine deposits
• materials from mass movements
• wind-blown deposits
• artificial beach nourishment

Question 6

sediment cell

Answer 6

a closed system, usually bound by headlands, in which sediment is trapped and transported around

Question 7

swash-alligned beach

Answer 7

swash is 90 degrees to coastline - hardly any sideways movement of sediment up/down beach (minimal longshore drift)

Question 8

drift-aligned beach

Answer 8

orientated obliquely to crests of prevailing waves - controlled by longshore drift with features eg. spits, bars, tombolos

Question 9

recurved spit

Answer 9

made from a series of spits - several recurved edges on landward side

Question 10

cusps

Answer 10

semicircular depressions occurring on swash aligned coastline - channel swash towards middle of embankment creating strong backwash down middle (therefore erosion)

Question 11

runnel

Answer 11

a channel which collects water and slowly flows back to the sea

Question 12

ridge

Answer 12

elevated area between runnels

Question 13

berms

Answer 13

all ridges before storm beach

Question 14

conditions for spits to occur

Answer 14

• abundant material available
• coastline irregular due ro geographical variation
• estuaries / major rivers

Question 15

tombolo

Answer 15

ridge of material linking island to mainland

Question 16

cuspate forelands

Answer 16

shingle ridges deposited in a triangle shape - result of 2 spits joining or combined effect of 2 distinct sets of storm waves

Question 17

offshore bar formation

Answer 17

coarse sand/shingle - develop offshore due to gently shelving sea bed - waves feel bottom far offshore, causing a disturbance in the water - leading to deposition , forming a bar BELOW sea level

Question 18

barrier beach formation

Answer 18

natural sandy breakwaters which form parallel to a flat coastline

Question 19

conditions needed for barrier beach formation

Answer 19

• gently sloping, low-lying coast, unprotected by cliff
• faces the ocean
• rising sea levels = break over dunes, creating lagoon behind ridge
• waves wash sand inland from island, leading to creating of new islands

Question 20

methods used to slow dune migration

Answer 20

• planting of grasses/vegetation - eg. marram grass - with long root systems which bind sand together
• erecting brushwood fences to reduce sand movement
• planting conifers which can stand saline environment + poor soils

Question 21

storm beach

Answer 21

biggest boulders thrown to back of beach during storm activity at highest fo spring tides

Question 22

bar formation

Answer 22

if a spit joins 2 headlands across a bay

Question 23

eustatic sea level change

Answer 23

when sea level increases due to change In volume of ocean basin or volume of water (global)

Question 24

isostatic sea level change

Answer 24

change in sea level caused by rise or fall of the land (local)

Question 25

wave height

Answer 25

distance between wave trough and crest

Question 26

wave length

Answer 26

length of wave from trough to trough

Question 27

wave frequency

Answer 27

number of waves passing a certain point per minute

Question 28

wave crest

Answer 28

point of maximum height of a wave

Question 29

wave through

Answer 29

lowest point of a wave

Question 30

fetch

Answer 30

the distance of open water a wave travels over

Question 31

swash

Answer 31

the constructive movement of a wave up a beach

Question 32

backwash

Answer 32

the destructive movement of a wave down the beach, back out to sea after breaking on the shore

Question 33

constructive wave

Answer 33

wave with a long wavelength, low frequency, low height, a weak backwash and a strong swash, which results in the deposition of sediment

Question 34

destructive wave

Answer 34

a wave with a short wavelength, high frequency and height, strong backwash and weak swash which results in the erosion of sediment

Question 35

wave refraction

Answer 35

when waves hit a headland, slowing down and and causing the waves on either side to bend towards the slowest point of movement - resulting in erosion of headlands