Weathering and coastal landforms

Question 1

What is weathering?

Answer 1

Weathering is the breakdown of rocks at the Earth’s surface by the action of rainwater, extreme temperatures or biological activity. It doesn’t involve the removal of rock. It involves no moving agent

Question 2

What is Erosion?

Answer 2

Erosion is the process when soil and rock particles are worn away and moved elsewhere by wind, water or ice.

Question 3

What are the 4 types of weathering?

Answer 3

Freeze thaw, Onion skin, Chemical weathering and Biological weathering

Question 4

What is freeze thaw weathering?

Answer 4

When water fills a crack in a rock and the water freezes. Over time, the crack gets bigger and the rock finally breaks into pieces

Question 5

What is Onion skin weathering?

Answer 5

When rock continuously gets heated and cooled, the rock expands and contracts. Some rock peels off like the skin on onions. Usually happens in a desert

Question 6

What is Chemical Weathering?

Answer 6

Rainwater contains small amounts of acid. It comes in contact with rock, the acid attacks the rock which causes it to crumble and rot

Question 7

What it Biological Weathering?

Answer 7

Seeds may fall into the cracks of rocks. As the roots develop the crack expands and the rock falls apart-rabbits and moles can also cause this

Question 8

How to rivers cause erosion?

Answer 8

Rivers wear away the bed and banks of the channel. Material is deposited downstream by the water and it gets deposited when the water slows down. During a flood, large boulders can be eroded and transported downstream

Question 9

How does the sea cause erosion?

Answer 9

Waves attack the coast and the rock is weakened and breaks off. The current deposits it elsewhere

Question 10

How does ice cause erosion?

Answer 10

A glacier is a tongue of ice which moves down a valley and as it moves, it transports material down the valley. Stones and boulders freeze into the glacier acting like sandpaper. Glaciers erode both the sides and bottom of valleys

Question 11

How does wind cause erosion?

Answer 11

Wind picks up tiny sand particles and the wind uses these particles to erode away anything which is in the way. Wind erodes rock in the desert to create shapes

Question 12

How do rivers shape the land?

Answer 12

The river erodes downwards as boulders and rocks scrape along it. As the river cuts in, the sides are affected by weathering. This breaks up and loosens the rock. The loosened material is washed away and the end result is a ‘V’ shaped valley

Question 13

How does the sea shape the land? Explain the different stages of the erosion?

Answer 13

1) The sea attacks and creates small cracks
2) The crack becomes a cave
3) The cave wears away and becomes and arch
4) More erosion causes the arch to collapse and become a stack
5) The sea erodes it more making it a stump

Question 14

What are the 4 types of coastal erosion?

Answer 14

Abrasion-Bits of rock grind down cliff surfaces
Attrition-Waves smash rock into the shore, they break and become smoother
Hydraulic Action-Air gets trapped in the cracks of rocks and the air is compressed when a wave breaks and this weakens a cliff
Solution-Acids contained in sea water will dissolve some types of rock such as chalk or limestone

Question 15

How is a beach created?

Answer 15

When material is worn away from one part of the shore to another

Question 16

How does longshore drift happen?

Answer 16

Sand particles go out to sea by the waves and they are then sent back to the shore, this repeats so that the sand particles have travelled in a zig zag motion

Question 17

What is a spit?

Answer 17

Material in the coastline which has been eroded is transported by the sea and this creates some land which sticks out of the mainland

Question 18

What are the 2 types of waves? explain them

Answer 18

Constructive wave- builds the beach because of it having a stronger swash than back swatch
Deconstructive wave-Destroys the beach because of a stronger back swatch than swash

Question 19

Name some sea defences

Answer 19

Sea Walls, Groynes, Reventments and Offshore Breakwater

Question 20

What are advantages and disadvantages of sea walls?

Answer 20

It lasts for a long time and very effective, the curve takes the wave’s energy. But it is very expensive and needs a lot of maintenance

Question 21

What are advantages and disadvantages of Groynes?

Answer 21

They are easy to build and last for 20 years and reduce movement of sediment. However, they are expensive and need to be replaced often

Question 22

What are advantages and disadvantages of reventments?

Answer 22

They are quick to build and easy to maintain, but they look ugly, have a short lifespan and are expensive

Question 23

What are advantages and disadvantages of offshore breakwaters?

Answer 23

They give protection from all waves and still function after minor damage. But they can be expensive, ugly and they don’t reduce all wave energy