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Flashcards in The Earth's Structure Deck (17):
1

PUT YOUR HANDS IN THE AIR FOR THE LAYERS OF THE EARTH

INNER CORE

OUTER CORE

MANTEL

and CRUST

(only need to know 'core' not the inner and outer bits)

2

Describe the basic shape and structure of the Earth

1. Almost spherical

2. Has a layered structure

3

Describe the crust

1. Very thin (5-50km)

2. Surrounded by the atmosphere

4

Describe the mantle

1. Below crust

2. Has all the properties of a solid except that it can flow very slowly

5

What happens within the mantle?

What does this do?

Radioactive decay

Produces lots of heat, which causes the mantle to flow in convection currents

6

Describe the core

1. At the centre of the Earth

2. Made of iron and nickle (we think)

7

Which 2 metals do we think the core is made of?

Iron and nickle

8

Define 'tectonic plates'

The large pieces that the crust and upper-mantle are cracked into

9

What causes the tectonic plates to drift?

The convection currents in the mantel

10

What speed are most plates moving at?

A few cm per year

(relative to each other)

11

What causes an earthquake?

The tectonic plates moving very suddenly

12

Where do earthquakes and volcanoes often occur?

At the boundaries between two tectonic plates

13

Can scientists predict when earthquakes and volcanic eruptions will occur?

No - it is impossible to predict when tectonic plates will move

14

Give an example of a 'clue' that scientists are looking for in order to predict when tectonic movement is likely to happen

Strain in underground rocks

15

Name a flaw with using clues to predict sudden tectonic movement

They will only be able to predict when an earthquake is likely to happen, not the exact time

16

Name a clue that could indicate an imminent volcanic eruption

Before an erruption, molten rock rises up into the chambers near the surface, causing the ground surface to bulge slightly.

This causes mini-earthquakes near the volcano

17

Name a flaw with using mini-earthquakes near a volcano to predict eruptions

Sometimes molten rock cools down instead of erupting, so mini-earthquakes can be a false alarm