Coasts - Theme 2 - WAVES

Question 1

What is wind

Answer 1

-The movement of air from a high pressure to a low pressure

Question 2

What is the direction of prevailing wind in the uk

Answer 2

• South westerly preveling wind

- Noth-east trade winds

Question 3

What is a wave in a coastal system

Answer 3

• A transfer of energy

- It gains the energy from the wind

Question 4

How are waves formed?

Answer 4

• The air pressure makes the indentation in the waves
• The wind transfers energy through friction - “frictional drag”
• Wave energy is dependent on fetch

Question 5

What happens to a wave on shallow water

Answer 5

• There is friction with the surface so the bottom slows down
• There is no additional friction on the peak - keeps speed
• Causes wave to break

Question 6

What are swell waves

Answer 6

-Waves in open water - long wavelength and reduced height

Question 7

What are storm waves

Answer 7

-Waves generated by local winds which only travel short distances

Question 8

What are constructive waves

Answer 8

• low frequency low energy
• low wave height
• long wave length - up to 100m
• low frequency 6-8 mins
• small crest
• orbit becomes more eliptical
• Strong swash weak backwash
• net effect of beach
• long wave period
• builds up a wide flat beach
• known as swell waves

Question 9

What are destructive waves

Answer 9

• High frequency high energy
• Large crest
• Gains a lot of height
• Orbit becomes more eliptical
• Strong backwash
• Weak swash
• net effect of erosion
• prodcues a steep beach
• Short wave length
• High frequency - 10-14min
• short wave period
• Plunging waves

Question 10

What is the feedback loop of waves on a coastline

Answer 10

-Negative feeback loop

Question 11

Why does the cycle of waves create a negative feeback loop

Answer 11

-Constructive waves build up a beach
-Creates a steep beach
-encourages destructive
-creates sloped beach
-encourages constructive waves
REPEAT

Question 12

why is it rare for true dynamic equilibrium to be on a coast

Answer 12

• coastal managemnt
• extreme weather
• beach nourishment
• groynes

Question 13

What are the four zones on a coast (land to sea)

Answer 13

• Backshore
• Foreshore
• Inshore
• Offshore

Question 14

What are the charactoristics in the Backshore

Answer 14

• berms - narrow ridges parrellel to coast - sand and shingle - above high water mark
• land to high water mark
• ONLY DYNAMIC IN STORMS

Question 15

What are the charactoritics in the Foreshore

Answer 15

• starts at high water mark to start of inshore

- Includes following swash zone

Question 16

What are the charactoristics in the Inshore

Answer 16

• end of foreshore to low water mark
• can contain a bar and trough
• contains the breaker zone

Question 17

What is the near shore

Answer 17

• inshore+backshore

- has swash zone, surf zone and breaker zone

Question 18

What is the offshore

Answer 18

-beyond point where waves have impact

Question 19

what is wave refraction

Answer 19

• where waves become increasing parrell to the coast line
• when come to a headland they move twoards the headland
• There is shallow water at the foot of the headland
• This creates destructive waves
• This causes erosion at the foot of the headland
• This causes a longshore current across the beach
• This protects the beach

Question 20

What feedback loop does wave refraction create

Answer 20

-Negative feeback loop