Erosion And Deposition

Question 1

What is erosion

Answer 1

Erosion is the wearing away of the earths surface by the movement of weathered material.

Question 2

What are the three main agents of erosion

Answer 2

Water
Wind
Ice

Question 3

What is the difference between erosion and weathering.

Answer 3

Erosion wears away the earths surface through moving objects scouring the surface whilst weathering happens in one place.

Question 4

What is weathering

Answer 4

It is the breaking down of rocks and soil by actions of the weather.

Question 5

What is deposition

Answer 5

Deposition is the build-up of the weathered material that has been removed from the earths surface.

Question 6

What does weathering and erosion produce

Answer 6

Loose stones, soil, and mud

Question 7

What are deposition features

Answer 7

Features that form part of a landscape, created by deposition.

Eg: beaches, sand dunes.

Question 8

What are agents of erosion

Answer 8

Forces of nature that cause erosion.

Question 9

What is abrasion

Answer 9

It is the wearing away of the of the river banks or bed by the rivers load

Question 10

What is the start of a river called

Answer 10

The source

Question 11

What is the place where a river flows into the sea called

Answer 11

The mouth

Question 12

What is a river course

Answer 12

It is the length from the rivers source to mouth.

Question 13

What is river erosion and deposition influenced by

Answer 13

The speed the river flows at

The amount of water in the river

Question 14

What are the 3 sections of a river

Answer 14

Upper course
Middle course
Lower course

Question 15

What are the features of the upper course

Answer 15

The gradient is the steepest 
The width is narrow
Vertical erosion takes place
Flows the fastest 
Shallow depth
Creates waterfalls and Rapids

Question 16

What is vertical erosion

Answer 16

It is when the bed of the river is eroded and deepens the river channel

Question 17

What causes the river to move so fast

Answer 17

The steep gradient

Question 18

What weathers materials do rivers transport

Answer 18

Sand
Rock
Mud
Stones

Question 19

What is the spare energy in the upper course used for

Answer 19

To transport the large rocks

Question 20

How can erosion take place in the upper course

Answer 20

The movement of these large rocks against the bed of the river causes Vertical erosion

Question 21

Why are the sides of the valley so steep

Answer 21

So loose stones and soil can easily be washed into the river and add to the load

Question 22

What is a waterfall

Answer 22

It is a sudden drop in the gradient of a river,that looks like a cliff or sharp slope.

Question 23

Why do waterfalls occur

Answer 23

When the course of a river flows or soft rock that rock erodes quicker and creates a step in the bed.

Question 24

What are plunge pools and how are they formed

Answer 24

It is a small eroded pool of a river bed at the base of a waterfall due to the harder rocks of the land breaking off and falling into the river and being stirred around by the force of the waterfall.

Question 25

What are Rapids

Answer 25

They are fast flowing area of a river

Question 26

How are Rapids formed

Answer 26

When different types of rock cross the river course. The hard and soft rock erode differently causing uneven layers in the river bed.

Question 27

What are potholes

Answer 27

Potholes are deep surfaces in the ground.

Question 28

How do potholes occur

Answer 28

When stones carried in the load of a river spin around by the river currents. This action wears away deep holes in the river bed.

Question 29

What are Rapids

Answer 29

They are fast flowing area of a river

Question 30

How are Rapids formed

Answer 30

When different types of rock cross the river course. The hard and soft rock erode differently causing uneven layers in the river bed.

Question 31

What is a delta

Answer 31

A fan-shaped (semi-circular) area of sand and silt deposited at the mouth of a river.

Question 32

How do deltas form

Answer 32

When a river reaches a large area of water such as the sea, the river banks are low so that water can flow over them. The water spreads out and deposits load. This causes the river to divide into smaller channels.

Question 33

Why doesn't South Africa have large deltas

Answer 33

Because the force of our ocean waves and currents are too strong for deltas to form.

Question 34

What is a floodplain

Answer 34

It is a wide, flat area next to the river channel, usually covered by flood water.

Question 35

How are floodplains formed

Answer 35

When lighter silt and mud deposit on the flat valley floor

Question 36

What is a levee

Answer 36

A levee is deposition on top of a river bank,formed when river floods.

Question 37

How are levees formed

Answer 37

When a river floods the heavier load of the river material is deposited on the river bank.

Question 38

What is silt

Answer 38

It is either fine sand or rich soil from weathered material.

Question 39

What is a meander

Answer 39

The winding path that a river takes around obstacles for it has less energy to go over them.

Question 40

How do meanders form

Answer 40

By erosion around an obstacle (large rocks)

Question 41

What is an ox-bow lake

Answer 41

It is the remainder of a meander after being cut of by river erosion.

Question 42

How do of-bow lakes form

Answer 42

By repeated erosion on the outside of a meander, narrowing the distance between the two meanders. Deposition from the river load cuts off the old meander and makes it a short cut for the new path.

Question 43

What are the features of the middle and lower course of a river

Answer 43

``` Flatter land Erosion is lateral Slip offs River cliffs Meanders Ox-bow lakes Current is weaker ```

Question 44

What is lateral erosion

Answer 44

It is erosion that takes place sideways

Question 45

What is a river cliff

Answer 45

The outside bank of a river that undergoes erosion

Question 46

How are river cliffs formed

Answer 46

Because the current on the outside bend is faster, it erodes the bank and forms a river cliff.

Question 47

What is a slip of

Answer 47

It is the inside bank of a river that undergoes deposition

Question 48

How does a slip off form

Answer 48

Because the current on the inside of the river bend is weaker or slower, some of the load is deposited on the slip off slope.

Question 49

What causes meanders to change their shape and position

Answer 49

Erosion | Deposition