Coastal landscapes

Question 1

Fetch

Answer 1

The distance of open sea over which wind blows- a long fetch will give bigger waves than a small one.

Question 2

What happens when a wave nears a coast?

Answer 2

As it nears the coast the sea bed slows down the bottom of the wave due to friction. The circular orbit becomes more oval creating a crest. The crest topples over and causes the wave to break.

Question 3

Swash

Answer 3

The forward movement of water up the beach

Question 4

Backswash

Answer 4

The backward movement of water after the wave has broken.

Question 5

What are the main types of waves

Answer 5

Constructive

Destructive

Question 6

Destructive wave

Answer 6

High wave height
Weak swash
Powerful backwash
Short wave length

Question 7

Constructive wave

Answer 7

Low wave height
Long wave length
Powerful swash
Weak backwash

Question 8

What are the main types of coastal processes?

Answer 8

Weathering
Mass movement
Erosion
Transportation
Deposition

Question 9

What are the main types of weathering?

Answer 9

Physical
Biological
Chemical

Question 10

Physical weathering

Answer 10

Freeze thaw- the constant expansion of water in cracks in the rock- cause large chunks to flake off
Haloclasty-Saltwater enters cracks and dries leaving salt crystals- they build up until the rock breaks apart

Question 11

Biological weathering

Answer 11

Roots of vegetation break up the rocks
Acidic bird poo dissolves rock
Rabbits burrow through soil which allows inundation to happen

Question 12

Chemical weathering

Answer 12

Carbonation- limestone is dissolved by acid rain
Hydrolosis- acid rain breaks down the rock by causing it to rot
Oxidation- rocks react with air

Question 13

Mass movement-slumping

Answer 13

1. Rainwater soaks into porous rock like sandstone
2. The saturated rock is heavy and puts pressure on the underlying rock
3. The underlying rock can’t cope with the pressure and a huge part of the cliff slips into the sea

Question 14

What factors affect mass movement?

Answer 14

Rainfall
Geology
Angle of teh slope
Vegetation cover
Human activity

Question 15

Flow

Answer 15

Fine loose material become saturated and flows down the slope

Question 16

Fall

Answer 16

Freeze thaw weathering widens cracks in the cliff which then break off- forms scree slopes

Question 17

Slide

Answer 17

Top layer of rock become ssturated and slides (under the force of gravity) over the layer of rock below

Question 18

Creep

Answer 18

Soil particles expand and are lifted from the slope before shrinking- gravity pulls them down

Question 19

Hydraulic action

Answer 19

The relentless force of destructive waves pounding the base of a cliff. The waves force air into cracks (this widens them) and chunks of rock fall of the cliff.

Question 20

Abrasion

Answer 20

Destructive waves hurl rocks at the cliff slowly chipping away at it.

Question 21

Attrition

Answer 21

During transport pebbles collide with each other and slowly shrink in size.

Question 22

Solution

Answer 22

Some rock dissolve in seawater e.g chalk

Question 23

Tides

Answer 23

Caused by the gravitational pull of the moon on the earth,

Question 24

LSD

Answer 24

Occurs when the prevailing wind blows at an angle this means the swash carries sediment up the beach at an angle. The backswash transports sediment back down the beach at a right angle. It is repeated.

Question 25

Factors that shape a coastline?

Answer 25

Geology
Sediment supply
Beach profile
Shape of the coastline

Question 26

Concordant

Answer 26

rocks are parallel to the wave front and therefore rate of erosion are similar along the coastline

Question 27

Discordant

Answer 27

differential erosion may occur where bands of hard and soft rock outcrop at right angles to the sea. Headlands and bays form along discordant coastlines.

Question 28

Headlands and bays

Answer 28

Softer rocks are worn away more quickly than harder rocks. The eroded rock is deposited by the sea in bays, making the water here shallower. The harder rock puts out to sea and is called a headland. The water here is deeper
Shallower water encourages deposition. Deeper water encourages erosion.
Because the water is shallower in the bays the waves deposit material thus building up this bit of the coastline again. On the other hand, the deeper water at the foot of the headland encourages the waves to erode the coastline more and more.