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Year 9 Science > Earth Science > Flashcards

Flashcards in Earth Science Deck (41):
1

Lithosphere

The outermost layer of the earth which is also known as the crust.

2

Asthenosphere

Layer of the earth between the lithosphere and the mantle. Also versatile between solid and liquid.

3

Mantle

Liquid layer of the earth that is made up of rocks and takes up 80% of the earths volume

4

Core

Contains two layers of the earth which are situated on the inside and outside. It is also the hottest part of the earth.

5

Seismic waves

waves of energy that travel through the Earth's crust, caused by earthquakes

6

Continental drift

movement of the plates of the Earth's crust in relation to each other

7

Pangaea

A super-continent that existed about 225 million years ago.

8

Panthalassa

the vast sea surrounding the supercontinent of Pangaea

9

Plate Tectonics

the theory concerning the movement of the continental plates

10

Convection Current

circular movement that occurs when warmer, less dense fluid particles rise and cooler, denser fluid particles sink

11

Continental Crust

the plates of the Earth's crust that make up the land

12

Oceanic Crust

one of the types of crust that makes up the Earth's outer layer.

13

Boundaries

the edges of tectonic plates

14

Subduction

process in which two tectonic plates push against each other

15

Destructive plate boundaries

a convergent boundary where two plates collide

16

Constructive plate boundaries

plate that creates new land from cooling magma

17

Ocean ridges

an area where the tectonic plates move apart, allowing magma from the mantle to rise. This forms underwater volcanos

18

Conservative plate boundaries

boundaries between sliding plates

19

Laurasia

one of the two smaller continents created when the supercontinent Pangaea broke apart about 200 million years ago

20

Gondwanaland

one of the two smaller continents created when the supercontinent Pangaea broke apart about 200 million years ago

21

Hotspots

a localised place where an activity occurs

22

Tremors

vibration on the Earth's surface caused by an earthquake

23

Epicentre

the point on the Earth's centre directly above the site where an earthquake originates

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Focus

the point at which an earthquake begins

25

Triangulation

finding a location by using at least three different sources of detection

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Seismograph

an instrument used to detect and measure the intensity of an earthquake

27

Richer scale

a scale that measures the amount of energy released during an earthquake

28

Primary waves

compression waves that move through the Earth in the same way that sound waves move through air

29

Secondary waves

the second set of waves to be detected after P-waves. During seismic activity, secondary waves or S-waves travel in the form of transverse waves.

30

Body waves

waves that travel through the interior of the Earth; P-waves and S-waves are said to be body waves

31

Surface waves

earthquake waves which travel only through the Earth's crust; they are responsible for the majority of an earthquake's destructive power

32

Seismologists

a scientist who studies earthquakes

33

Tsunamis

a powerful ocean wave triggered by an undersea earth movement

34

Meltdowns

the melting of a nuclear-reactor core as a result of a serious nuclear accident

35

Volcanoes

natural opening in the Earth's crust connected to areas of molten rock deep inside the crust

36

Magma

a very hot mixture of molten rock and gases, just below the Earth's surface, that has come from the mantle

37

Lava

mixture of molten rock and gases that has reached the Earth's surface from a volcano

38

Volcanic bombs

large rock fragment that is blown out of erupting volcanoes; also known as a lava bomb

39

Active

describes a volcano that is erupting or has recently erupted

40

Extinct

describes a volcano that has not erupted for thousands of years and is effectively dead

41

Dormant

describes a volcano that has not erupted for more than 20 years but is not considered extinct