Dynamic shoreline

Question 1

Breaking waves provide

Answer 1

energy that changes shape/texture of beach deposits

Question 2

Shallow water waves

Answer 2

waves shoal (touch bottom) and wavelength/speed decrease and height increases and waves refract

Question 3

refraction

Answer 3

bending of waves in shallow water, break parallel to shore

Question 4

why waves topple

Answer 4

waves steepen and become unstable

Question 5

perpendicular to coast

Answer 5

waves break and bring up sediment and water (swash) and then travel back and water rushed back to shore

Question 6

parallel to coast

Answer 6

long shore drift

Question 7

light wave activity

Answer 7

swash dominates, wider beach, summer

Question 8

heavy wave activity

Answer 8

backwash dominates, narrow, winter

Question 9

waves generate (perpendicular/parallel)

Answer 9

rip currents (perpendicular), LSD (parallel)

Question 10

swift

Answer 10

when two opposing LSD meet and make rip tides

Question 11

beach divided into areas

Answer 11

offshore/nearshore (breaker zone/surfer zone/swash zone)/backshore

Question 12

waves advance with…

Answer 12

high tides, retreat with low

Question 13

beach profile

Answer 13

cross section of beach, perpendicular to coast

Question 14

swell profile

Answer 14

concave upwards, broad berm, flat backshore, sediment build up, steep beach fade

Question 15

storm profile

Answer 15

broad beach fade, eroded berm

Question 16

sand budget

Answer 16

difference between sand lost and gained

Question 17

formation of coastal cells

Answer 17

sand from river gets moved by LSD and moves to submarine canyon, and travels to submarine terrace

Question 18

formation of dunes

Answer 18

sand is moved landward by wind

Question 19

well developed dunes

Answer 19

have sinusoidal profile (primary dunes at land edge and secondary further in)

Question 20

saltation

Answer 20

sand bounces on windward side and reaches top where it builds up and topples over, causing dune migration

Question 21

vegetation

Answer 21

adds stability, traps sand

Question 22

blowouts

Answer 22

wind scoured breaks in dune, usually happens when vegetation is destroyed

Question 23

sea cliff

Answer 23

land that’s above sea level

Question 24

where are sea cliffs vulnerable to erosion

Answer 24

at base, waves push air into cracks which expand, dissolves rock or sediment banged against wall

Question 25

rate of cliff recession depends on…

Answer 25

cliff material, weakness

Question 26

deltas

Answer 26

where river meets sea, sediment build up

Question 27

how to stop erosion

Answer 27

interrupt LSD, groynes/jetties

Question 28

sea walls

Answer 28

divert energy

Question 29

beach nourishment

Answer 29

expensive/temporary

Question 30

alternatives to hard engineering

Answer 30

building elsewhere, move structures