Energy at the coast

Question 1

How is the sun a form of energy at the coast?

Answer 1

Heat and light from the sun is converted by natural processes to form energy.
The primary source of energy for all natural systems.

Question 2

How is the wind a form of energy at the coast?

Answer 2

Wind is the movement of air from one place to another - high pressure to low.
Variations in atmospheric pressure reflect diff.s in surface heating by the sun.
The greater the pressure gradient the stronger the wind.

Question 3

What is the main form of energy at the coast and what are they usually formed by?

Answer 3

Waves are the main source of energy at the coast and they are formed by the wind.

Question 4

What factors affect wave energy?

Answer 4

Strength of wind - pressure gradient
Duration of wind - longer wind blows more powerful wave
The fetch - distance of open water over which wind blows, further = more powerful.

Question 5

How are waves formed?

Answer 5

As air moves across surface of water, frictional drag disturbs the surface and creates ripples. In open sea there is orbital movement of water particles. Closer to the shore, the particles begin to make an elliptical shape as the wave breaks on the shore.

Question 6

What happens as a wave reaches the shore?

Answer 6

• Water becomes shallower, circular orbit of particles becomes elliptical
• Wavelength and velocity decrease, height increases
• Water rushes up beach as swash and runs down as backwash

Question 7

What are the diff. types of waves?

Answer 7

constructive and destructive

Question 8

What are the characteristics of a constructive wave?

Answer 8

Distant weather systems generate these in open ocean. Low surging waves w/ long wavelength. Strong swash and weak backwash. Beach gain. Create gentle beach profile but over time wave builds up making it steeper.

Question 9

What are the characteristics of a destructive wave?

Answer 9

Local storms generate these waves. High plunging waves w/ short wavelength. Weak swash and strong backwash. Beach loss. Steep profile but will flatten over time.

Question 10

What are low energy coastlines?

Answer 10

Sandy and estuarine coastlines indicate low energy. Hear the waves are less powerful. The coast is sheltered from large waves. The rate of deposition exceeds the rate of erosion.
Landforms like beaches, spits and coastal plains.