lesson 2 - energy input waves and winds

Question 1

crest?

Answer 1

highest point of a wave

Question 2

trough

Answer 2

lowest point of a wave

Question 3

backwash

Answer 3

any water returning down to the sea

Question 4

wave height

Answer 4

the distance between crest and trough

Question 5

swell

Answer 5

waves of low height, gentle steepness, long wavelength and period

Question 6

wave velocity

Answer 6

speed of movement of crest in a given time

Question 7

wave steepness

Answer 7

the ratio of wave height to wavelength

Question 8

wave period

Answer 8

the time taken for one wave to travel through one wavelength

Question 9

plunge line

Answer 9

the point where the wave breaks

Question 10

swash

Answer 10

the body of foaming water rushing up from the beach

Question 11

wavelength

Answer 11

the distance between two successive crests

Question 12

what are constructive waves?

Answer 12

depositional waves as they lead to sediment build up

Question 13

what are the characteristics of constructive waves?

Answer 13

low waves
strong swash 
weak backwash 
break on the shore and deposit material 
Common in summer 
6-8 waves per min

Question 14

what are the characteristics of destructive waves?

Answer 14

Common in winter - storms 
Stronger winds 
Strong backwash 
Weak swash
12-14 per min

Question 15

what is wave refraction?

Answer 15

shallow water around the headland
increases friction
causes wave to break at headland
energy is dissipated into bays

Question 16

what are waves?

Answer 16

the main input into the coastal system

Question 17

what does energy obtained by the waves depend on?

Answer 17

wind velocity
length of fetch
period of time during which wind has blown
depth of water