Coasts (Coastal Systems & Landscapes)

Question 1

Define Backshore

Answer 1

Area from HWM to inland storm limit

Question 2

Define Foreshore

Answer 2

Area from HWM to LWM - most important for marine processes

Question 3

Define Inshore

Answer 3

Area between LWM and where waves have no impact on land beneath them

Question 4

Outline the 3 zones the foreshore and inshore are further divided into

Answer 4

Swash Zone = waves wash up the beach
Surf Zone = Mass of broken water in breaker zone of shoreline - high wave activity
Breaker Zone = waves break on shoreline

Question 5

Define Offshore

Answer 5

Waves cease to impact upon sea bed - deposition main activity

Question 6

Outline the type of system the coast is

Answer 6

Open system - inputs, flows and outputs of energy and matter

Question 7

Outline the inputs that occur in the Coast

Answer 7

1. Energy to provide the system = waves, winds, tides and currents - irregularly boosted by storm surges and tidal waves
2. Sediment = rivers, eroded cliffs and waves transporting sediment
3. Human activity

Question 8

Outline the processes that occur on the coasts

Answer 8

Wave action, tidal movement, erosion, weathering, transportation (lsd) and deposition

Question 9

Outline the outputs that occur on the coasts

Answer 9

Sediment = washed out to sea or deposited on coast
Coastal Landforms = erosive and depositional
Wave energy loss

Question 10

Define waves

Answer 10

Transfer of energy from the wind blowing over the sea surface

Question 11

Outline the factors that influence the level of energy gained by a wave

Answer 11

Wind strength
Length of time the wind blows over
Distance over which it blows (fetch)

Question 12

Define wave crest

Answer 12

Highest point of a wave

Question 13

Define wave trough

Answer 13

Lowest point of a wave

Question 14

Define wavelength

Answer 14

Distance between 2 adjacent crests

Question 15

Define wave frequency

Answer 15

N° of waves/min

Question 16

Define wave steepness

Answer 16

Ratio wave height : wavelength (can’t be steeper than 1:7 as wave breaks)

Question 17

Define wave period

Answer 17

Time taken for a wave to travel between 1 wavelength

Question 18

Define wave energy

Answer 18

E ∝ LH
L = wavelength
H = wave height

Question 19

What is it called when waves wash up on the beach?
What is it called when waves wash back towards the sea?

Answer 19

Swash
Backwash

Question 20

What is wave height affected by?

Answer 20

Wind speed and fetch
High speed + large fetch = High wave -> bigger impact on shore

Question 21

What happens when a wave reaches the shore?

Answer 21

Wave breaks - sea bed friction slows bottom -> elliptical motion -> crest rises and collapses

Question 22

Outline and define the 2 types of wave

Answer 22

1. Constructive waves
2. Destructive waves

Question 23

Define Constructive Waves

Answer 23

Low waves
Low hz (6-8 waves/min)
Long wavelength (100m)
Gentle
Depositional (swash>backwash)

Question 24

Define Destructive Waves

Answer 24

Steep waves
High frequency (10-14 waves/min)
Short wavelength
Powerful (backwash>swash)

Question 25

Outline the equilibrium between constructive and destructive waves

Answer 25

Constructive waves build up material = steep beach Steep beach = encourage destructive waves Destructive waves move material back to sea = reduce beach angle Reduced beach angle = encourage constructive waves

Question 26

Define wave refraction

Answer 26

Waves approach an irregular coastline - become increasingly parallel to coastline