Coastal Processes

Question 1

How do waves form?

Answer 1

Wind waves are caused by friction and pressure on the sea’s surface from the wind.

Question 2

How do tidal waves form?

Answer 2

Tidal waves are caused by gravity, mainly from the moon.

Question 3

How do tsunamis form?

Answer 3

Tsunamis are caused by geological disturbances such as earthquakes, volcanic eruptions etc

Question 4

What kind of waves are very large?

Answer 4

Destructive waves

Question 5

What kind of waves are small?

Answer 5

Constructive waves

Question 6

Characteristics of a constructive wave:

Answer 6

-strong swash
-weak backwash
-wave crests far apart
-gently sloping wave front
-breaking wave spills forwards

Question 7

Destructive wave characteristics:

Answer 7

-strong backwash
-waves close together
-steep wave front
-breaking wave plunges downwards

Question 8

Wave length of destructive waves:

Answer 8

Under 20m apart

Question 9

Wave height of destructive waves:

Answer 9

Over 1m in height

Question 10

Wave frequency of destructive waves:

Answer 10

10-15 per minute

Question 11

Swash of destructive waves:

Answer 11

Weak

Question 12

Back wash of destructive waves:

Answer 12

Strong

Question 13

Dominant process of destructive waves:

Answer 13

Erosion

Question 14

Wave length of constructive waves:

Answer 14

Over 20m apart

Question 15

Wave height of constructive waves:

Answer 15

Under 1m in height

Question 16

Wave frequency of constructive waves:

Answer 16

6-10 per minute

Question 17

Swash of constructive waves:

Answer 17

Strong

Question 18

Backwash of constructive waves:

Answer 18

Weak

Question 19

Dominant process of constructive waves:

Answer 19

Deposition

Question 20

What is transportation?

Answer 20

The movement of sediment from one part of the coastline to another.

Question 21

What is weathering?

Answer 21

Sub-aerial processes (such as rain) wearing away rock over time.

Question 22

What is erosion?

Answer 22

The action of the waves causing the coastline to wear away.

Question 23

What is mass movement?

Answer 23

The bulk movement of soils or rock down hill.

Question 24

What is hydraulic action (also known as “water on cliff”)?

Answer 24

The water traps air in cracks and caves in the rock. This air is compressed by the incoming waves placing great pressure on the rocks, causing them to eventually crack.

Question 25

What is attrition (also known as “rock on rock”

Answer 25

Particles carried by the waves crash against each other and are broken up into smaller rocks.

Question 26

What is abrasion (also known as rock on cliff) - sand paper effect?

Answer 26

Particles carried by waves crash against the cliffs, eroding the cliffs.

Question 27

What is solution( also known as “chemical on cliff” )

Answer 27

Salt in the seawater slowly dissolves the cliffs. The material produced is carried away by the process of solution.

Question 28

What is chemical weathering?

Answer 28

Acidic rainwater dissolves chalk and limestone.

Question 29

What is biological weathering?

Answer 29

Plant roots get into cracks and expand. Animals dig into and burrow into the rocks.

Question 30

What is mechanical weathering?:

Answer 30

Water builds up in the cracks. When it gets cold the water freezes causing the water to expand, then as it gets hotter, the ice melts and seeps deeper into the rock causing the rock to weaken. Sea water with salt goes into the rock, when the water leaves, salt crystals left behind expand causing the rock to break.

Question 31

What is a mudslide?

Answer 31

Rainwater saturated into the dirt makes the dirt heavier and easier to fall down so it causes a mudslide Unsaturated soil “flows downhill” -at the bottom of the cliff s lone forms

Question 32

What is a landslide

Answer 32

-the mass movement of rock down a cliff or hill -can happen due to weathering

Question 33

What is rockfall?

Answer 33

-Occurs on steep cliffs -fragments of the rock break away from the cliff due to weathering E.g freeze thaw

Question 34

What is longshoreman drift?

Answer 34

-Long shire drift is the movement of material along the shore by wave action -waves approach the beach at an angle determined by the prevailing wind -the swash (waves moving up the beach) moves material up and along the beach. -the backwash (waves moving back down the beach) moves material back at a right angle -contributes to the formation of landforms -e.g- a spit

Question 35

How do steep cliffs form?

Answer 35

Steep cliffs are formed when hydraulic action and abrasion erode the base of a cliff due to destructive waves. -If there is softer rock then this will erode faster, leaving hard rock -chemical,biological and mechanical weathering also weaken the tips of cliffs, causing rockfall to occur -overtime The steep cliffs will retreat

Question 36

Characteristics of the upper course

Answer 36

-steep gradient -vertical erosion -landforms of erosion -low discharge -shallow + narrow channel -velocity is lower than middle/lower course