coastal studies

Question 1

what is a constructive wave

Answer 1

a wave with strong swash but weak backwash

Question 2

what is a destructive wave?

Answer 2

a wave with a weak swash but a strong backwash

Question 3

what is swash?

Answer 3

the part of the wave that pushes up onto the beach or shoreline

Question 4

what is backwash

Answer 4

the movement of water back down the beach due to gravity

Question 5

define coastal EROSION

Answer 5

the land is worn away by tall powerful destructive waves which are usually found in windy/stormy conditions

Question 6

define coastal Depostition

Answer 6

smaller constructive waves dump sand and shingle to create new land such as beaches and sand dunes usually in more calm sheltered conditions

Question 7

what are the three ways in which waves erode the coast and how do they work

Answer 7

Hydraulic action : the pounding force of the water and compressed air breaking up rocks
Abrasion (corrasion): sand and rocks in the sea are thrown against the land by waves and wear it away like sandpaper.
Solution (corrosion): Salt and other chemicals in the sea dissolve rock

Question 8

explain the formation of bays and headlands

Answer 8

1. A coastline has bands (areas) of hard and soft rock which are at right angles to the coast
2. The areas of soft rock are eroded rapidly by the sea
3. the sea erodes these areas with; Hydrolic action, abrasion, Solution
4. These areas of soft rock for bays
5. the areas of hard resistant rock are left sticking out into the sea as headlands
6. often sand gets deposited by weaker waves in the sheltered bay to form a beach
   (use diagram)

Question 9

Explain the erosion of cliffs

Answer 9

1. The waves erode the bottom of the cliff to create a wave cut notch through hydraulic action, abrasion and solution
2. Eventually the cliff above collapses, the collapsed material forming a rocky beach called a wave cut platform. This process continued to erode the cliff further and further inland.
   (use diagram)

Question 10

Explain the formation of caves, Arches and stacks

Answer 10

1. A headland gets eroded by powerful destructive waves. Weaknesses in the headland such as cracks get eroded by hydrolic action; the force of the waves and compressed air
2. The cracks eventually develop into a cave and the cave gets eroded rapidly under high pressure
3. when the cave is eroded right through to the other side, an arch is formed
4. The base of the arch gets eroded by waves through abrasion and solution. The arch gets wider and wider until the roof collapses leaving a free standing stack.
5. the base of the stack continues to be eroded and eventually collapses leaving a stump

Question 11

What is coastal deposition

Answer 11

Waves which have little energy, deposit sand and shingle to form sandy features such as beaches and sand dunes. These area waves are described as SMALL CONSTRUCTIVE WAVES. Over time, these develop into permanent land. usually these are found in more sheltered locations such as bays

Question 12

What is longshore drift

Answer 12

sometimes due to the prevailing (most common) winds on a coastline, waves can approach the beach at a sideways angle. This drags the sand along the beach as shown and one end of the beach and one end of the beach gets narrower whilst the other gets wider

Question 13

explain the formation of a sand spit and bar (not finished card)

Answer 13

1. A sandy beach is deposited by small constructed waves
2. Sometimes the waves approach the beach at a sideways angle due to the prevailing (most common) wind direction then come back out to sea at right angles due to gravity
3. This pushes sand sideways along the beach
4. this causes the whole beach to get pushed sideways in a process called longshore drift
5. the coastline suddenly changes direction at a bay