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Flashcards in Earth Science Deck (38):
1

Lithosphere

The rough outer part of the earth, consisting also the upper most of the mantle.

2

Asthenosphere

The upper layer of the earths mantle, located below the lithosphere, plastic flow and convection is thought to occur

3

Core

The core is made primarily of iron and nickel and has two parts, an inner solid core and an outer liquid core

4

Seismic waves

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

5

Continental drift

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

6

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.

7

Panthalassa

The vast sea surrounding the supercontinent of Pangaea

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Plate tectonics

the theory concerning the movement of the continental plates

9

Convection current

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

10

Continental crust

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

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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.

12

Boundaries

the edges of tectonic plates

13

Subduction

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

14

Destructive plate boundaries

Destructive plate boundaries: a convergent boundary where two plates collide

15

Hotspots

a localised place where an activity occurs

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Mantle

thick layer inside the Earth, below the crust. Most of the mantle is solid rock, although the upper part is molten rock called magma.

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Conservative plate boundaries

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

18

Laurasia

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

19

Gondwanaland

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

20

Tremors

vibration on the Earth's surface caused by an earthquake

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Epicentre

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

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Triangulation

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

23

Seismograph

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

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Richter scale

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

25

P-waves or Primary waves

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

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S-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.

27

Body waves

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

28

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

29

Seismologists

a scientist who studies earthquakes

30

Meltdown

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

31

Tsunamis

a powerful ocean wave triggered by an undersea earth movement

32

Volcanos

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

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Magma

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

34

Lava

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

35

Volcanic Bombs

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

36

Extinct volanos

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

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Active volcanos

describes a volcano that is erupting or has recently erupted

38

Dormant

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