Earth Science- CH8 Flashcards Preview

Year 9 Science > Earth Science- CH8 > Flashcards

Flashcards in Earth Science- CH8 Deck (41):
1

Lithosphere

the tough, outer part of the earth, consisting of the crust and upper mantle

2

Ashenosphere

the upper layer of the earth's mantle, below the lithosphere, in which it is made up of plastic

3

Mantle

the region of the earth's inside between the crust and the core, believed to consist of hot, dense silicate rocks/lava

4

Core

The very bottom of Earth’s interior consisting of both the inner and outer core. This is where the hottest part of the earth.

5

Seismic Waves

Waves of energy that travel through the Earth’s crust, caused by Earthquakes

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Continental Drift

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

7

Panthalassa

the vast sea surrounding the supercontinent of Pangaea

8

Pangaea

a super-continent that existed about 225 million years ago. All of the landmasses that existed at this time were joined together to form this super-continent.

9

Plate Tectonics

the theory concerning the movement of the continental plates

10

Convection currents

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. Oceanic crust is thinner than continental crust and made up of dense, heavy rocks such as basalt.

13

Boundaries

the edges of tectonic plates

14

Subduction

process in which two tectonic plates push against each other, and oceanic crust sinks below the less dense continental crust

15

Destructive plate boundaries

a convergent boundary where two plates collide

16

Constructive plate boundaries

plate that creates new land from cooling magma

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Ocean ridges

an area where the tectonic plates move apart, allowing magma from the mantle to rise, forming underwater volcanoes and creating new oceanic crust as it is cooled and solidified by sea water

18

Conservative plate boundaries

boundaries between sliding plates, like the San Andreas Fault in the United States

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

24

Focus

the point at which an earthquake begins

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Triangulation

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

26

Seismograph

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

27

Richter Sclae

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 Wave

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

(or L-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

Tsunami

a powerful ocean wave triggered by an undersea earth movement

34

Volcanoes

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

35

Magma

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

36

Lava

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

37

Volcanic Bombs

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

38

Lava Bombs

see volcanic bomb

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Active

describes a volcano that is erupting or has recently erupted

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Extinct

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

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Dormant

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