Chapter 6.2

Question 1

Define “Crust”

Answer 1

Also known as the lithosphere, the crust is the outer layer of the earth and is 7-50km thick.

Question 2

What is the crust made out of?

Answer 2

Rocks and minerals and it’s 70% covered by water.

Question 3

Define “Mantle”

Answer 3

The layer of molten rock located beneath the Earth’s crust and is about 2800km thick. Temperatures near the crust are about 500°C and at the bottom of the mantle reach 3000°C. Although the bottom of the mantle is solid, nearer the top the rock slowly moves due to convection currents.

Question 4

Define “Core”

Answer 4

The core is the centre of the Earth. There are 2 parts: Inner core and outer core.

Question 5

What is the outer core made up of?

Answer 5

The outer core is mainly made of metals; the main metal being iron, possibly with some nickel. It is a very hot liquid, with temperatures ranging from 4000°C - 6000°C, coming from nuclear reactions.

Question 6

What is the temperature of the inner core?

Answer 6

Almost 10 000°C. The inner core does not melt or boil due to the force of the rest of the Earth pushing down on it.

Question 7

Where do tectonic plates float?

Answer 7

On the semiliquid magma at the top of the mantle.

Question 8

What speed to plate tectonics move?

Answer 8

Between 1cm and 10cm per year