Systems and processes - coasts

Question 1

How are waves formed?

Answer 1

● Winds move across the surface of the water, causing frictional drag which creates small ripples and waves . This leads to a circular orbital motion of water particles in the ocean
● As the seabed becomes shallower towards the coastline, the orbit of the water particles becomes more elliptical, leading to horizontal movement of the waves
● The wave height increases, but the wavelength (distance between two waves) and wave velocity both decrease
● This causes water to back up from behind the wave until the wave breaks (collapses) and surges up the beach

Question 2

What factors affect the wave energy?

Answer 2

Strength of the Wind: The larger the pressure gradient between two area, the stronger the winds. As waves are caused by the wind, stronger winds also mean stronger waves.

Duration of the Wind: If the wind is active for longer periods of time , then the energy of the waves will build up and increase.

Size of the Fetch: The fetch is the distance over which the wind blows and the larger it is, the more powerful the waves will be.

Question 3

What type of waves build up the beach and what type of waves remove the beach and decrease its size?

Answer 3

constructive waves build up and increase the size of the beach, destrctuctive waves remove and decrease the size of the beach

Question 4

features of constructive waves

Answer 4

• Formed by weather systems that operate in the open ocean
• Long wavelength
• 6-9 Per Minute
  -Low waves, which surge up the beach
  -Strong swash, weak backwash
  -Occurs on gently sloped beaches

Question 5

features of destructive waves

Answer 5

-Localised storm events with stronger winds operating closer to the coast
-Short wavelength
-11-16 Per Minute
- High waves, which plunge onto the beach
- Weak swash, strong backwash
- Occurs on steeply sloped beaches

Question 6

what are high energy coastlines?