Chapter 1 - Earth Structure and Plates

Question 1

Name the layers of the earth’s interior from the outside inward.

Answer 1

Crust, mantle, inner core and outer core.

Question 2

Define the crust.

Answer 2

The crust is solid rock, which covers the surface of the earth. The continental crust that forms the continents is thicker than the crust under the oceans (oceanic crust). But the crust is not all in one piece - it is divided into sections called plates.

Question 3

Define the mantle.

Answer 3

The mantle is under the crust. It is composed of molten magma that is very hot. The magma flows in currents.

Question 4

Define the core.

Answer 4

The core is the centre of the earth and it is very hot - between 3,000°C and 5,000°C. It is mostly made of iron and it is solid in the centre. It is divided into the inner and outer core.

Question 5

What is the small distance moved by the plates each year called?

Answer 5

Continental drift.

Question 6

What happens when plates slide past each other?

Answer 6

Pressure builds up before the plates move. This movement causes earthquakes.

Question 7

What happens when plates separate?

Answer 7

When two plates separate, magma enters the cracks and forms volcanoes. Mid-ocean ridges are formed and new land is added. This new land forms island. This is a constructive plate boundary.

Question 8

What happens when plates collide?

Answer 8

When two plates collide, the heavier plate sinks under the lighter plate. Huge pressure builds up along the plate boundaries and this causes earthquakes, volcanoes and fold mountains. This is a destructive plate boundary.

Question 9

Define plate boundaries.

Answer 9

Plate boundaries are the lines or edges where plates meet.

Question 10

Define plate tectonics.

Answer 10

The term plate tectonics is used to describe the study of the plate movements and their effects - folding, faulting, earthquakes and volcanoes.

Question 11

What causes the plates to move?

Answer 11

Convection currents.

Question 12

What features are formed when plates collide?

Answer 12

Earthquakes, volcanoes and fold mountains.

Question 13

What features are formed when plates separate?

Answer 13

Volcanoes, mid-ocean ridges and earthquakes.

Question 14

What features are formed when plates slide past?

Answer 14

Earthquakes.

Question 15

Name one example of two plates that are colliding.

Answer 15

The Nazca plate and the South American plate.

Question 16

Name one example of two plates that are separating.

Answer 16

The Eurasian plate and the North American plate.

Question 17

Name one example of two plates that are sliding past each other.

Answer 17

The Pacific plate and the North American plate