Sources of Energy at the Coast

Question 1

What causes waves to form?

Answer 1

wind moving across the surface of the water and causing water to ripple due to drag

Question 2

How do waves break?

Answer 2

• offshore, waves are not impacted by the sea bed
• as they approach the shoreline, the water gets shallower
• friction between the seabed and the water causes a more elliptical orbit
• as the rest becomes unstable, the waves break

Question 3

What factors impact the energy of waves?

Answer 3

• size of the fetch
• strength of the wind
• duration of the wind

Question 4

How do constructive waves impact the characteristics of the shore?

Answer 4

they usually lead to deposition, which causes a more gently sloped beach and depositional landforms

Question 5

How do destructive waves impact the characteristics of the shore?

Answer 5

they usually erode material, resulting in more steep beaches and erosional landforms

Question 6

How might storms affect wave type?

Answer 6

create more destructive waves because of stronger winds

Question 7

What is responsible for tides?

Answer 7

gravity, from the moon and sun

Question 8

What is a spring tide and when does it occur?

Answer 8

largest tidal range, when sun and moon are in alignment (equinox)

Question 9

What is a neap tide and when do they occur?

Answer 9

smallest tidal range, when sun and moon are perpendicular

Question 10

What forms ripcurrents?

Answer 10

large amounts of water from destructuve waves is forced away from the coast through a specific area

Question 11

What are high energy coastlines associated with?

Answer 11

powerful waves, typically more destructive. rate of erosion> rate of deposition

Question 12

What are low energy coastlines associated with?

Answer 12

less powerful, typically constructive waves in sheltered areas. rate of deposition> rate of erosion

Question 13

What is wave refraction?

Answer 13

process by which wave fronts are distorted as they approach the shoreline

Question 14

How might refraction impact landform development?

Answer 14

energy is focused on landforms out to sea, causing erosional landforms to form, whereas in sheltered areas such as bays, the waves lose energy and depositional landforms will form

Question 15

Compare the formation of destructive and constructive waves

Answer 15

destructive: form as a result local storms
constructive: form as a result of distant weather systems in open ocean

Question 16

How might wave type impact beach profile?

Answer 16

destructive: make profile more steep, over time will flatten it
constructive: make profile more gentle, over time will build up the beach

Question 17

How might tides affect coastal processes?

Answer 17

smaller tidal range means concentrated erosion which results in the formation of WCP and WCN

Question 18

Where are rocky coasts normally found?

Answer 18

high energy coastlines, where there are high rates of erosion

Question 19

Where are sandy/estuarine environments normally found?

Answer 19

low energy coastlines, where there are higher rates of deposition

Question 20

How might bays be considered negative feedback?

Answer 20

as the more concentrated erosion at headlands prevents the erosion of softer rock (which was the initial change in the system)

Question 21

How does upwelling occur?

Answer 21

• wind blows across water in a certain direction
• allows space for water from the deep ocean to move upwards

Question 22

What are tides?

Answer 22

the periodic rise and fall of the level of the sea

Question 23

Why do neap tides occur?

Answer 23

• sun and moon perpendicular
• so water pulled in different directions
• so sun reduces effect of the moon, leading to a smaller tidal range

Question 24

How do tides link to energy at the coast?

Answer 24

tidal range impacts the area that wave energy is concentrated over