Chapter 2: The Interior of the Earth

Question 1

What is the crust made of?

Answer 1

Solid rock

Question 2

What is the mantle made of?

Answer 2

Solid rock

Question 3

What is the outer core made of?

Answer 3

Liquid iron

Question 4

What is the inner core made of?

Answer 4

Solid iron

Question 5

Which layer of the Earth is the thinnest?

Answer 5

The crust

Question 6

Which layer of the Earth is the thickest?

Answer 6

The mantle

Question 7

Shear waves are also called what?

Answer 7

Secondary waves (S waves)

Question 8

Compressional waves are also called what?

Answer 8

Primary waves (P waves)

Question 9

S waves are able to go through what?

Answer 9

Solids only.

Question 10

P waves are able to go through what?

Answer 10

Solids, liquids, and gases.

Question 11

Are S waves faster or slower?

What about P waves?

Answer 11

S waves are slower and P waves are faster.

Question 12

What is a wave?

Answer 12

A wave is a motion that travels through a material and carries energy from one place to another.

Question 13

What does refraction mean?

Answer 13

1. Refraction is the deflection (or change in direction) of a ray of light or wave due to changes in its velocity as it passes from one medium to another.
2. Refraction is also a change in direction that happen when something changes gradually rather than suddenly.
3. Refraction is the change of wave’s speed/direction as it enters new materials due to changes in its velocity.

Question 14

What is a seismic wave?

Answer 14

A seismic wave is a general term for all elastic waves produced by earthquakes or artificially through explosions (Syn: earthquake wave)

Question 15

Define an earthquake.

Answer 15

An earthquake is a sudden motion or trembling in the Earth caused by the abrupt release of slowly accumulated strain.

Question 16

What is a fault?

Answer 16

A fault is a fracture or fracture zone along which there has been displacement of one mass of rock relative to another, parallel to the fracture.

Question 17

What is the core?

Answer 17

The core is the central part of the Earth, beginning at a depth of about 2,900 km, and consisting of iron-nickel alloy. It consists of mostly iron and a liquid outer core and solid inner core.

Question 18

What is the crust?

Answer 18

The crust is the outermost layer of the Earth, composed of rock, representing less than 0.1% of the Earth’s total volume.

Question 19

What is the mantle?

Answer 19

The mantle is the zone of the Earth beneath the crust and above the core. It is divided into the upper mantle and the lower mantle.

Question 20

What is a seismograph?

Answer 20

A seismograph is an instrument that detects, magnifies, and records when seismic waves reach the surface.

Question 21

What is the hydrosphere?

Answer 21

The hydrosphere is the part of the Earth system that includes all the planet’s water, including oceans, lakes, rivers, groundwater, ice, and water vapor.

Question 22

How do earthquakes produce seismic waves?

Answer 22

Earthquakes produce seismic waves by vibrations caused by large masses of rock to sliding past each other or explosions caused by humans.

Question 23

What is wave refraction?

Answer 23

Wave refraction is waves changing speeds in direction when entering new materials.

Question 24

What is the focus of an earthquake?

Answer 24

The focus is where the earthquake starts.

Question 25

How are earthquakes detected on the surface of the Earth?

Answer 25

Earthquakes are detected on the surface of the Earth using special instruments called seismographs.

Question 26

How do scientists know the Earth’s mantle is solid?

Answer 26

Scientists know the Earth’s mantle is solid because S waves are able to go through the mantle and S waves only go through solids.

Question 27

How do scientists know that the Earth’s core is made of a different material that that of the mantle?

Answer 27

Scientists know that the Earth’s core is made of a different material that that of the mantle because of the strong magnetic field Earth has, and S waves can’t go through the core.

Question 28

What do waves carry with them when they travel?

Answer 28

When waves travel, they carry energy with them.

Question 29

What is the Richter Scale?

What does a high number on the scale mean?

Answer 29

The Richter Scale is a way of measuring the magnitude of an earthquake using seismograph records.
A high number on the scale means that it’s capable of causing damage or it’s potentially very destructive.

Question 30

What are two waves seismic waves can weaken?

Answer 30

They spread their energy over a larger and larger area as they move.
And they lose energy because they create friction as they move through the Earth.

Question 31

What are shadow zones?

Answer 31

Shadow zones are zones where no S or P waves from a faraway earthquake don’t appear again at the surface and they show that there are places deep inside the Earth where there is an abrupt slowing of seismic-wave speeds.

Question 32

How do scientists know that the outer core is probably liquid and not a gas or solid?

Answer 32

S waves can’t go through the core and S waves only go through solids, so it has to be liquid or gas and if it were made of gas the crust and mantle would collapse.

Question 33

Shaking a material causes what?

Answer 33

Shaking a material causes vibrations.

Question 34

When you do what, you make your vocal chords vibrate?

Answer 34

When you speak/talk/sing, you are making your vocal chords vibrate.

Question 35

What happens during an earthquake?

Answer 35

During an earthquake, large masses of rock slide past each other, making powerful vibrations.

Question 36

An earthquake over a magnitude of what is considered a major earthquake?

Answer 36

Any earthquake over a magnitude 7 is considered a major earthquake.

Question 37

What do seismic waves do as they move through the Earth.

Answer 37

Seismic waves weaken as they move through Earth.

Question 38

A motion that travels through a material and carries energy from one place to another is what?

Answer 38

A motion that travels through a material and carries energy from one place to another is a wave.

Question 39

The order of the layers of the Earth is?

Answer 39

Crust, mantle, outer core, inner core.