Geography Note: The Unstable Earth

Question 1

What is a natural hazard?

Answer 1

A naturally occurring process or event which has the potential loss of life or damage to property

Question 2

In what ways are the three layers of the earth arranged?

Answer 2

They are arranged according to their density. In general, the layers with lighter, less dense materials lie on the top.

Question 3

Crust explanation

Answer 3

Thickness: 60-70km
Density: low
Composition: silica, magnesium, aluminium
State: solid
Characteristics: forms the continents and ocean floors

Question 4

Mantle explanation

Answer 4

Thickness: 2900km
Density: high
Composition: iron and aluminium
State: semi-molten
Characteristics: made up of very hot molten rock called magma

Question 5

Core explanation

Answer 5

Thickness: 3470km
Density: highest
Composition: iron and nickel
State: outer liquid inner solid
Characteristics: the inner layer of Earth. It is made up of heavy metals

Question 6

Name major plates. (8)

Answer 6

Eurasian, Pacific, Indo-Australian, North American, South American, Antarctic, Nazca, African