Earthquakes and Volcanoes

Question 1

How are earthquakes made?

Answer 1

When friction between moving plates work against convection currents to build up stress, and when the plates can’t take it anymore, they release a powerful wave of energy.

Question 2

Where do earthquakes occur? Where do most earthquakes occur?

Answer 2

Anywhere on Earth.

Earthquakes often occur at tectonic plate boundaries.

Question 3

Define focus.

Answer 3

The location inside Earth where an earthquakes starts.

Question 4

What begins at the focus?

Answer 4

Energy release of an earthquake.

Question 5

Define epicentre.

Answer 5

The point on Earth’s surface directly above the focus.

Question 6

How do scientists classify earthquakes?

Answer 6

By the depth of the foci (plural for focus)

Question 7

How deep is a shallow focus?

Answer 7

1 to 70 km

Question 8

How deep is a intermediate focus?

Answer 8

70 to 300 km

Question 9

How deep is a deep focus?

Answer 9

300km +

Question 10

The amount of surface damage an earthquake can cause depends on its ________.

Answer 10

depth

Question 11

Do shallow-focus earthquakes cause more damage or deep-focus earthquakes?

Answer 11

Shallow-focus earthquakes

Question 12

Define seismology

Answer 12

The study of earthquakes and seismic waves.

Question 13

Define seismic waves.

Answer 13

Vibrations from energy released by an earthquake.

Question 14

What can P-waves travel through?

Answer 14

Everything

Question 15

What affects the movement of body waves?

Answer 15

The composition and depth of the different layers of Earth.

Question 16

What are seismometers (seismographs)?

Answer 16

Devices that measure the amount of ground motion caused by an earthquake.

Question 17

What is a seismogram?

Answer 17

A record of ground motion produced by a seismometer.

Question 18

Define magnitude.

Answer 18

A number that rates the strength of an earthquake.

Question 19

Ratio of magnitude and size of seismic waves.

Answer 19

1-step increase on magnitude scale = 10 times larger seismic waves

Question 20

What can seismograms show scientists?

Answer 20

• Time of the earthquake
• How long it lasted
• Amount of ground shaking
• How fast seismic waves are travelling

Question 21

What are the three distinctive types of volcanoes?

Answer 21

`composite volcanoes

• shield volcanoes
• rift eruptions

Question 22

What is a composite volcano?

Answer 22

A large, cone-shaped, belching ash, rocks, and lava volcano. Basically the typical one.

Question 23

Why are composite volcanoes cone-shaped?

Answer 23

It’s because of repeated eruptions of ash and lava, wich builds up layers. (or strata)

Question 24

Describe the process of eruption.

Answer 24

As the magma approaches the surface, gas gets trapped below, and pressure builds up. Once the pressure is too great to be contained, there is an explosive eruption.

Question 25

Where are composite volcanoes usually found?

Answer 25

Near subduction zones

Question 26

What are the largest type of volcanoes?

Answer 26

Shield volcanoes.

Question 27

Where do shield volcanoes form?

Answer 27

Over hot spots.

Question 28

Where does a hot spot occur?

Answer 28

It occurs where a weak part of the lithosphere allows magma to break through.

Question 29

Where do shield volcanoes typically occur?

Answer 29

In ocean basins.

Question 30

Define supervolcano.

Answer 30

A term used to describe past volcanoes with massive eruptions that not only destroy nearby areas, but also affected life around the planet.

Question 31

Where do rift eruptions occur?

Answer 31

Through long cracks in the lithosphere.

Question 32

What are the characteristics of rift eruptions?

Answer 32

• not very explosive or violent
• curtain-like eruptions
• Releases enormous amounts of lava.