Sources of energy in coasts

Question 1

What are the 4 sources of energy in coasts?

Answer 1

Wind, wave, currents and tides

Question 2

If there is low wind pressure, what will the waves be like?

Answer 2

Big waves as air is lifting

Question 3

What does prevailing wind often cause?

Answer 3

High energy waves

Question 4

Name 3 ways that wind is important in the coastal systems

Answer 4

• wind can erode coastline through abrasion as it picks material up and transports it to wear away coastline.
• wind forms waves by transferring energy to surface water creating frictional drag.
• prevailing winds often bring high energy waves

Question 5

What are the 3 factors that affect the size and strength of waves?

Answer 5

• strength of wind
• fetch ( the distance of open water which wind blows uninterrupted by land obstacles)
• duration of wind - longer it blows the more powerful the waves.

Question 6

What is the fetch?

Answer 6

The distance of open water which wind blows uninterrupted by land obstacles.

Question 7

The longer the fetch…

Answer 7

The stronger the wave

Question 8

What are the 2 types of waves?

Answer 8

Constructive and destructive

Question 9

Name 3 of characteristics of constructive waves

Answer 9

• strong swash, weak backwash
• builds up beach profile
• forms when beach gradient is gentle

Question 10

Name 3 characteristics of destructive waves

Answer 10

• strong backwash, weak swash
• high waves with short wave length
• erodes coastline and forms on steep gradient beach

Question 11

What is the alternating cycle, when it comes to waves?

Answer 11

Constructive waves build up the beach profile which then encourages destructive waves as a steep beach gradient formed. Creating a negative feedback loop

Question 12

What is wave refraction?

Answer 12

the process by which waves turn and lose energy around a headland on irregular coastlines.

Question 13

What happens in wave refraction?

Answer 13

The waves are refracted so that their energy is concentrated into the headlands and the rest of the energy is gently dissipated at the bays. Meaning that the headland is eroded at faster rate than the rest of coastline.

Question 14

Why is wave refraction an example of negative feedback?

Answer 14

The headland will erode back to become level with the rest of the coastline and then be even again.

Question 15

What is the name given to the highest monthly tide?

Answer 15

Spring tide

Question 16

Describe the location of the sun and moon during a spring tide.

Answer 16

The sun and moon are in line with the earth

Question 17

What is the name given to the lowest monthly tide?

Answer 17

Neap tide

Question 18

Describe the location of the sun and moon during a neap tide

Answer 18

Sun and moon are at right angle to each other.

Question 19

What are tides?

Answer 19

The periodic rise and fall of the sea caused by gravitational pull of the sun and moon.

Question 20

Name 2 ways that the tides are important in the coastal system

Answer 20

• significant flow of water can generate strong currents which influence the direction and scale of coastal sediment.
• Larger the tidal range, the more extensive the intertidal zone which is subject to erosion.

Question 21

How many times a month do spring tides occur?

Answer 21

twice a month

Question 22

How many times a month do neap tides occur?

Answer 22

twice a month

Question 23

What are rip currents?

Answer 23

powerful, localised, underwater currents - consistent swash, swash, swash so not enough time to backwash.
Backwash forced under surface due to resistance from breaking waves.

Question 24

What is upwelling?

Answer 24

When winds push the surface water away from the shore and the deeper water rises to fill the gap.