Layers Of The Earth And River Landscapes

Question 1

What is the crust?

Answer 1

Outer layer of the earth. Very thin. 60-70 km deep

Question 2

Mantle

Answer 2

Thick layer. Jammy consistency. Temperatures between 1300C to 5000C

Question 3

Inner core

Answer 3

Solid and made of iron. Temps reach 5,500*C

Question 4

Outer Core

Answer 4

Liquid and largely made of iron

Question 5

Features of the upper course of a river

Answer 5

Interlocking spurs. Source. Steep V-shaped valley. Rapids and large boulders. Fast moving

Question 6

Features of the middle course of a river

Answer 6

Meanders. Ox-Bow Lakes. Wide floodplains. U-shaped valley. Gorges

Question 7

Features of the lower course of a river

Answer 7

Wide. Flat. Slows down river flow and decreases in energy. Raised banks (levees) caused by flooding.

Question 8

What is the Thalweg?

Answer 8

Fastest flow in the middle of a river

Question 9

What is the Watershed?

Answer 9

The area of high land surrounding the basin

Question 10

What are Tributaries?

Answer 10

Small streams that feed main river

Question 11

What is the Mouth?

Answer 11

Where the river ends and meets the sea/a lake

Question 12

What is the Source?

Answer 12

Where the river begins, high up in the mountains, the upper course

Question 13

What is a Confluence?

Answer 13

Where 2 or more tributaries meet together

Question 14

What is the Channel?

Answer 14

The main body of the river in which water flows

Question 15

What is Erosion?

Answer 15

The gradual removal of rock from a river’s banks and bed

Question 16

What are the types of erosion?

Answer 16

-Hydraulic action - The sheer force of the water hitting the banks and bed
-Corrasion/Abrasion - Particles in the river wearing down the banks and bed
-Attrition - Material in the river bump into each other, breaking down
-Solution/corrosion - The water slowly dissolves the banks and bed

Question 17

How is a V-shaped valley formed?

Answer 17

The river erodes downwards, as it goes down the sides break down due to weathering, the loose material creeps down the slope and is washed away.

Question 18

How are waterfalls formed?

Answer 18

1. River flows over layers of hard rock and solid rock
2. The soft rock starts to erode over time leaving an overhang of hard rock
3. A plunge pool is created at the base of the waterfall
4. The rocks in the plunge pool begin to wear away and the pool becomes deeper
5. The hard rock eventually becomes weak and collapses

Question 19

What is a Bedload?

Answer 19

Material carried by a river as it moves

Question 20

What are the transportation processes on a river?

Answer 20

-Traction
-Saltation
-Suspension
-Solution

Question 21

What is Traction?

Answer 21

The largest rocks/material being rolled along the river bed by the force of the water - Upper Course

Question 22

What is Saltation?

Answer 22

Smaller material being bounced along the river bed - Upper and Middle courses

Question 23

What is Suspension?

Answer 23

Small bits of material are carried by the water - All the courses

Question 24

What is Solution?

Answer 24

The material have been resolved into the water - Middle and Lower courses

Question 25

How is an Ox-Bow lake formed? (4 stages)

Answer 25

Stage 1: Meanders get bigger because of erosion (Hydraulic action and abrasion)
Stage 2: The bend gets eroded quickly by the Thalweg and the neck becomes narrow
Stage 3: When water levels are high the river has enough energy to push through the neck and make a Meander cut-off
Stage 4: The river then deposits material, creating a split between the Ox-bow lake and river.

Question 26

How do levees form?

Answer 26

Levees are made when a river floods and then material is deposited on the banks of the river

Question 27

How are flood plains formed?

Answer 27

When a river floods, the smallest material are deposited over the plains around the river