Sources Of Energy

Question 1

What are the energy sources (4)

Answer 1

Wind
Waves
Tides
Currents

Question 2

Where does wind move (2)

Answer 2

Air moves from areas of high atmospheric pressure to areas of low atmospheric pressure
Larger pressure gradient between two places = stronger wind

Question 3

Waves in UK specifically (2+)

Answer 3

The prevailing (most usual) wind direction is from the south-west
Before reaching our coast = winds blown over the broad expanse of the Atlantic Ocean

Question 4

What is the fetch

Answer 4

The distance wind travels over open water

Question 5

What affects wave energy (3+)

Answer 5

Fetch
Strength of wind
Duration of wind

Question 6

What is wind an agents of (2+)

Answer 6

Erosion = pick up and remove sediment from the coast and use it to erode other features
Moving sediment = it can pick up and move material

Question 7

What agent does waves act as

Answer 7

Shaping the shoreline

Question 8

Constructive waves what (5+)

Answer 8

Swash pushes more material from offshore up the beach than the backwash removes
Long wavelength
Low in height
Low in frequency
Deposition

Question 9

Constructive wave beach look like (2+)

Answer 9

Gentle beach profile
Over time they will build up the beach and make it steeper

Question 10

Destructive waves (5+)

Answer 10

Steep in height
Short in frequency
High in energy
Swash is short-lived and the backwash is forceful and takes material down the beach
Net effect = removal of beach material along the shoreline

Question 11

Beaches and waves negative feedback (4+)

Answer 11

Constructive waves build up a beach
Beach profile steepens which can encourages destructive waves = remove material from the beach and deposit it offshore
Result = beach profile becoming less steep again = encouraging constructive to form
This will continue until a state of dynamic equilibrium is reached

Question 12

Waves around a headland (4)

Answer 12

Tend to ‘bend’ and have a higher frequency
Wave height steepness = erode
Waves approaching the headland meet shallower water first = friction with the sea floor
Slows headland-approaching waves and causes their frequency to increase

Question 13

Waves around a bay (3+)

Answer 13

Waves spread out and become less frequent
Leads to a reduction in wave energy
Deposition

Question 14

What is ave refraction (2+)

Answer 14

When waves approach a coastline that is indented they are refracted
Become increasingly parallel to the coastline

Question 15

Overall impact of wave refraction (2)

Answer 15

Wave energy becomes concentrated on the headland
Presence of erosive features at headlands and deposition features in bays

Question 16

Theory of wave refraction (2)

Answer 16

Continued erosion of the headland and deposition in the bays
State of equilibrium where the shape of the coastline remains static

Question 17

What does the term current refer to

Answer 17

The permanent or seasonal movement of surface water in the seas and oceans

Question 18

Type of currents (3)

Answer 18

Longshore
Rip
Upwelling

Question 19

What is a longshore current (3)

Answer 19

Occur because most waves approach the coastline at an angle
Result is a flow of water running parallel to the shoreline
Moves water and transports sediment parallel to the shoreline

Question 20

What is a rip current (3)

Answer 20

Strong localised underwater currents
Move water away from the shoreline
The fast-flowing offshore surge of water can be hazardous to swimmers

Question 21

How does a rip current form (2++)

Answer 21

When a series of plunging waves cause a temporary build-up of water at the top of the beach
Met with resistance from the breaking waves - the backwash is forced just below the surface following troughs in the beach profile

Question 22

What is an upwelling (3+)

Answer 22

Movement of cold water from deep in the ocean towards the surface
The dense cold water replaces warmer surface water = nutrient rich cold ocean currents
Form part of the pattern of global ocean circulation current

Question 23

What creates tides (2+)

Answer 23

Rise and fall in sea levels
Due to gravitational force of the moon, the sun and the rotation of the earth

Question 24

What does moon do to form tides (3+)

Answer 24

Pulls water towards it = high tide
There is a compensatory bulge on the opposite side of the Earth
In areas of the world between the two bulges = the tide is at its lowest

Question 25

What is tidal range

Answer 25

The relative difference in height between high and low tides

Question 26

What do tidal ranges determine

Answer 26

The upper and lower limits of erosion and deposition

Question 27

What is spring tide (3+)

Answer 27

Twice a month = the sun, the moon and earth form a line
Tidal force is at its maximum
Total range is at its highest

Question 28

What is the neap tide (3)

Answer 28

Sun and moon at 90°
Solar tidal force cancels the moon gravitational force
Tidal range + force at their minimum

Question 29

Features of a high energy coastline (4)

Answer 29

Strong waves
Strong prevailing winds
Long fetch
Rate of erosion bigger than deposition

Question 30

Example of high energy coast in UK (2)

Answer 30

Cornwall
North-west Scotland

Question 31

Low energy coastline features (3)

Answer 31

Waves are less powerful
Rate of deposition is greater than erosion
Wave energy is low

Question 32

Example of low energy coast in UK

Answer 32

Lincolnshire