Platetectonics

Question 1

Mantle

Answer 1

The layer below the crust

Question 2

Convection current

Answer 2

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

Question 3

Continental crust

Answer 3

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

Question 4

Oceanic crust

Answer 4

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 5

Subduction

Answer 5

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

Question 6

Destructive plate boundary

Answer 6

a convergent boundary where two plates collide

Question 7

Constructive plate

Answer 7

plate that creates new land from cooling magma

Question 8

Oceanic ridges

Answer 8

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 9

Laurasia

Answer 9

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

Question 10

Gondwanaland

Answer 10

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

Question 11

Hotspots

Answer 11

A localised place where an activity occurs

Question 12

Folding

Answer 12

buckling of rocks caused when rocks are under pressure from both sides

Question 13

Anticline

Answer 13

Fold the bends upwards

Question 14

Synclines

Answer 14

folds that bend downwards

Question 15

Fault

Answer 15

A break in a rock structure causing a sliding movement of the rocks along the break

Question 16

Rift valleys

Answer 16

a sunken area where two blocks of crust have dropped down between faults

Question 17

Horst

Answer 17

a block of the Earth’s crust, with faults on either side, that has been pushed upwards by the forces below

Question 18

Slip fault

Answer 18

a geological feature where movement along a fault is sideways—that is, where the blocks of crust slip horizontally past each other

Question 19

Tremors

Answer 19

vibration on the Earth’s surface caused by an earthquake

Question 20

Epicentre

Answer 20

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

Question 21

Focus

Answer 21

the point at which an earthquake begins

Question 22

Triangulation

Answer 22

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

Question 23

Plate tectonics

Answer 23

the theory concerning the movement of the continental plates

Question 24

Seismograph

Answer 24

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

Question 25

Richter scale

Answer 25

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