Chapter 3 - Coastal systems and landscapes

Question 1

What is Erosion?

Answer 1

• The wearing away of the Earth’s surface by the mechanical action of processes of glaciers, wind, river, marine waves, and wind.

Question 2

What is fetch?

Answer 2

• Refers to the distance of open water over which a wind blows uninterrupted by major land obstacles. The length of fetch helps to determine the magnitude (size) and energy of the waves reaching the coast.

Question 3

What is the mass movement?

Answer 3

• The movement of material downhill under the influence of gravity, but may also be assisted by rainfall.

Question 4

What is weathering?

Answer 4

• The breakdown and /or decay of rock at ir near the Earth’s surface creating regolith that remains in situ until it is moved by later erosional processes.

Question 5

What is backwash?

Answer 5

• The action of water receding back down the beach towards the sea.

Question 6

What are constructive waves?

Answer 6

• Waves with low wave height, but with love wavelength and low frequency of around 6 - 8min. Their swash tends to be more powerful than their backwash. Meaning beach material is built up.

Question 7

What are the destructive waves?

Answer 7

• Waves with a high wave height with a steep form and high frequency (10 - 14min). Their swash is generally stronger than their backwash, so more sediment is removed than is added.

Question 8

What is swash?

Answer 8

• The rush of water up the beath after a wave breaks.

Question 9

What is longshore drift?

Answer 9

• Where waves approach the shore at an angle and swash and backwash then transport material along the coast in the direction of the prevailing wind and waves.

Question 10

What is wave refraction?

Answer 10

• When waves approach a coastline that is not a regular shape, they are refracted and become increasingly parallel to the coastline. The overall effect is that the wave energy becomes concentrated on the headland, causing greater erosion.

Question 11

What are tides?

Answer 11

• The periodic rise and fall of the level of the sea in response to the gravitational pull of the sun and moon.

Question 12

What is the coastal sediment budget?

Answer 12

• The balance between sediment being added to and removed from the coastal system, that system being defined within each individual sediment cell.

Question 13

What is the high energy coast?

Answer 13

• A coastline where strong, steady prevailing winds create high energy waves, and the rate of erosion is greater than the rate of deposition.

Question 14

What high energy coast?

Answer 14

• A coastline where strong, steady prevailing winds create high energy waves, and the rate of erosion is greater than the rate of reposition.

Question 15

What is the low energy coast?

Answer 15

• A coastline where wave energy is low and the rate of deposition often exceeds the rate of erosion of sediment.

Question 16

What are sediment cells?

Answer 16

• A distinct area of coastline separated from other areas by well-defined boundaries, such as headlands and stretches of deep water.