Glossary: Restless Earth Flashcards Preview

Geography GCSE > Glossary: Restless Earth > Flashcards

Flashcards in Glossary: Restless Earth Deck (42):
1

Collision boundary/ margin

Where two plates are moving together (destructive) and upward, creating mountains.

2

Conservative boundary/ margin

Where two plates pass alongside each other.

3

Constructive boundary/ margin

Where two plates move apart.

4

Continental drift

The theory that describes how plates have moved over millions of years.

5

Convention current

Movement of magma within the Earth's mantle, formed by radioactive decay creating heat.

6

Crust

The outermost layer of the Earth.

7

Earthquake

A sudden and violent shaking of the Earth's crust.

8

Fold mountains

Mountains formed by plate collision, crumpling rock layers.

9

Hot spot

Where magma plumes rise away from plate boundaries, breaking through the crust.

10

Magma

Molten rock within the Earth's mantle.

11

Outer core

An inner section of the Earth - liquid comprising mostly of iron, at 10-12 g/cm cubed.

12

(Tectonic) Plate

A huge section of the Earth's crust.

13

Plate boundary/ margin

Where any two plates meet.

14

Plate tectonics

The theory of the distribution of earthquakes, volcanoes, fold mountains and plate movement.

15

Richter scale

Measures the strength/magnitude of an earthquake - 0 to 10.

16

Subduction

The sinking movement of one plate beneath another at a destructive margin.

17

Tectonic activity

Changes taking place in the structure of the Earth.

18

Tsunami

A wave, often generated by an earthquake, which displaces water and causes devastation.

19

Vent

The opening of a volcano.

20

Volcano

Cone-shaped mountain created by lava from repeated eruptions.

21

Basic lava

Thin 'runny' lava, low silica content, flows long distances.

22

Caldera

The depression of a supervolcano, marking the collapsed magma chamber

23

Composite volcano

Steep-sided cone with successive layers of ash and lava

24

Epicentre

The point at the Earth's surface directly above the focus of an earthquake

25

Fissure

Extended opening along a line of weakness, allow magma to escape to the surface

26

Focus

The point where an earthquake originates

27

Geyser

A geothermal feature in which water erupts into the air under pressure

28

Geothermal

Water that is heated beneath the ground, which comes to the surface in a variety of ways

29

Hazard

An event where lives and property are threatened, resulting in damage and/ or death

30

Immediate responses

How people react as the disaster happens and in the immediate aftermath

31

Lahar

Secondary effect of a volcano where mudflows form from the mixing of ash and melted ice/ water

32

Lava

Name for magma once at the Earth's surface

33

Long term responses

Later reactions that occur in the weeks, months and years after the event

34

Mantle

The dense, mostly solid layer between the outer core and the crust

35

Mercalli scale

Measures the destructive power of an earthquake - I to XII

36

Ocean trenches

Deep sections of ocean where an oceanic plate subducts below a continental plate

37

Prediction

Attempts to forecast an even - where and when it will happen - based in current knowledge

38

Protection

Constructing buildings so that they are safe to live in and will no collapse

39

Preparation

Organising activities and drills so that people know what to do in an earthquake

40

Shield volcano

Gentle sides, wide base made of basic lava

41

Shock waves

Seismic waves generated by an earthquake that pass through the earth's crust

42

Supervolcano

A colossal volcano that erupts at least 1,000 km cubed of material