Earth Science

Question 1

Lithosphere

Answer 1

the rigid outer part of the earth, consisting of the crust and upper mantle.

Question 2

Asthenosphere

Answer 2

the upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

Question 3

Mantle

Answer 3

the region of the earth’s interior between the crust and the core, believed to consist of hot, dense silicate rocks (mainly peridotite).

Question 4

Core

Answer 4

the dense central region of a planet, especially the nickel–iron inner part of the earth.

Question 5

Seismic waves

Answer 5

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

Question 6

Continental drift

Answer 6

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

Question 7

Pangaea

Answer 7

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.

Question 8

Panthalassa

Answer 8

the vast sea surrounding the supercontinent of Pangaea

Question 9

Plate tectonics

Answer 9

the theory concerning the movement of the continental plates

Question 10

Convection current

Answer 10

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

Question 11

Continental crust

Answer 11

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

Question 12

Oceanic crust

Answer 12

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.

Question 13

Boundaries

Answer 13

the edges of tectonic plates

Question 14

Subduction

Answer 14

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

Question 15

Destructive plate boundaries

Answer 15

a convergent boundary where two plates collide

Question 16

Constructive plate boundaries

Answer 16

A plate that creates new land from cooling magma

Question 17

Oceanic ridges

Answer 17

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

Question 18

Conservative plate boundaries

Answer 18

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

Question 19

Laurasia

Answer 19

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

Question 20

Gondwanaland

Answer 20

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

Question 21

Hotspots

Answer 21

a localised place where an activity occurs

Question 22

Tremors

Answer 22

vibration on the Earth’s surface caused by an earthquake

Question 23

Epicentre

Answer 23

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

Question 24

Focus

Answer 24

the point at which an earthquake begins

Question 25

Triangulation

Answer 25

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

Question 26

Seismograph

Answer 26

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