Theme 1 - Coasts

Question 1

What is Erosion?

Answer 1

When the rocks are broken down and then carried away e.g. By seawater

Question 2

What is Mechanical Weathering? And give an example

Answer 2

The breakdown of rock without changing its chemical composition e.g. Freeze thaw

Question 3

What is Chemical Weathering? And give an example

Answer 3

The breakdown of rock by changing its chemical composition e.g. Carbonation weathering

Question 4

Explain the 5 steps of how Freeze thaw breaks down rock

Answer 4

1) It happens when the temperature alternates above and below 0 degrees.
2) Water gets into rock that has cracks.
3) When the water freezes it expands, which puts pressure on the rock.
4) When the water thaws it contracts, which releases the pressure on the rock.
5) Repeated freezing and thawing widens the cracks and causes the rock to break up.

Question 5

How does Carbonation Weathering break down rock?

Answer 5

1) Rainwater has carbon dioxide dissolved in it which makes it a weak Carbonic acid.
2) Carbonic acid reacts with rock that contains calcium carbonate, so the rocks are dissolved when it rains.

Question 6

What is Hydraulic action?

Answer 6

When waves crash against rocks and compress the air in the cracks.

Question 7

What is Corrasion?

Answer 7

When eroded bits of rock in the water scrape and rub against rock, which erodes littles bits at a time.

Question 8

What is Attrition?

Answer 8

When eroded bits of rock in the water smash into each other breaking into smaller fragments and also rounding off their edges.

Question 9

What is Corrosion?

Answer 9

When weak carbonic acid in seawater dissolves the rock e.g. Chalk and Limstone

Question 10

What is Weathering?

Answer 10

The breakdown of rock where they are

Question 11

What are destructive waves?

Answer 11

Any wave that carries out an erosional process

Question 12

What attributes do Destructive waves have?

Answer 12

1) They have a high frequency.
2) They’re high and steep.
3) Their backwash is more powerful than their swash.

Question 13

What are the two main factors that affect size and power of destructive waves?

Answer 13

Wind and Fetch

Question 14

What are the five steps that cause cliff retreat?

Answer 14

1) Erosion
2) Wave cut notch and Unstable rock
3) Collapsed material
4) New wave cut notch and Material cleared
5) Cliff retreat and a wave cut platform

Question 15

A lot of things effect the rate of retreat give two examples

Answer 15

The geology of the cliff (soft rock erodes faster than hard rock) and the Vegetation (cliffs covered in vegetation are more stable)

Question 16

What needs to happen to the forces on a cliff to make them collapse?

Answer 16

The force of gravity on the cliff is greater than the force supporting it

Question 17

What are the three types of cliff movement?

Answer 17

Slides, Slumps and Rockfalls

Question 18

When is a cliff collapse classed as a slide?

Answer 18

When the material shifts in a straight line

Question 19

When is a cliff collapse classed as a Slump?

Answer 19

When material shifts with a rotation

Question 20

When is a cliff collapse classed as a Rockfall?

Answer 20

When the material shifts vertically

Question 21

How is a bay formed?

Answer 21

When the less resistant rock (clay) is eroded quickly and the resistant rock is eroded more slowly leaving it jutting out compared to the less resistant rock

Question 22

What are headland usually made of?

Answer 22

Resistant rocks

Question 23

What are the six steps of cracks in the headland forming an Arch and then erode into a stump?

Answer 23

1) Lines of weakness or cracks.
2) Sea cave
3) Arch
4) Arch collapse
5) Stack
6) Stump

Question 24

What were the three steps of forming Lulworth cove?

Answer 24

1) A river cut through and started to erode the soft rock.
2) The sea eroded through the thinner layers of hard rock from the front.
3) The sea hit the soft layers of rock behind the harder rock which eroded quicker creating a cover.