Earth Science- Earthquake and Volcano Flashcards Preview

8th Grade > Earth Science- Earthquake and Volcano > Flashcards

Flashcards in Earth Science- Earthquake and Volcano Deck (57)
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1
Q

Where do earthquakes occur?

A

On fault lines; near plate boundaries

2
Q

Crack in the crust where rocks have moved, NOT along a plate boundary

A

A fault

3
Q

Name the four types of faults

A

Normal
Strike
Reverse
Dip- Slip

4
Q

Which direction do normal Faults move in?

A

◀️▶️

5
Q

Which direction do Strike Faults move in?

A

◀️

▶️

6
Q

Which direction do Reverse Faults move in?

A

▶️◀️

7
Q

Which direction do Dip-Slip Faults move in?

A

↔️↕️↘️↗️

8
Q

What are the 3 types of seismic waves?

A

Primary, Secondary, and Surface

9
Q

What is the slowest wave?

A

Secondary

10
Q

What is the first wave to arrive at a seismic station?

A

Primary

11
Q

What is the most destructive type of wave?

A

Surface

12
Q

What type of waves move side to side?

A

Primary

13
Q

What types of waves move at right angles?

A

Secondary

14
Q

What types of waves have vertical and horizontal displacement?

A

Surface

15
Q

What type of wave is the fastest?

A

Primary

16
Q

Where is the focus?

A

Beneath the surface

17
Q

Where is the epicenter?

A

On the surface

18
Q

The spring back of a rock. Is reacts like a rubber band

A

Elastic rebound

19
Q

Smaller earthquakes that follow the main earthquake

A

Aftershock

20
Q

Instrument to measure earthquakes

A

A seismograph

21
Q

What tells you the info on the seismograph

A

Seismogram

22
Q

A small earthquake that often precede a major earthquake by days, or in some cases, by as much a several years

A

Foreshock

23
Q

What wave arrival times do geologists measure between?

A

Primary and secondary

24
Q

Relationship between arrival time and distance to the earthquake epicenter:

A

The greater the interval between the arrival of the first Primary wave the the first Secondary wave, the greater the distance to the earthquake.

25
Q

How many seismic stations are needed to locate an earthquake?

A

Three

26
Q

The process of locating an earthquake

A

Triangulation

27
Q

Scale that is most commonly used to measure earthquakes

A

Richter scale

28
Q

What does the Richter scale go from?

A

1-10

29
Q

At what magnitude can we feel an average earthquake?

A

3.0

30
Q

A weak spot in the crust where molten material, or magma comes to the surface

A

Volcano

31
Q

The resistance of a liquid flowing

A

Viscosity

32
Q

What happens when lava is highly viscous?

A

It forms a plug in the pipe which rises or is blown out and becomes sticky

33
Q

Example of high viscosity

A

Syrup, honey

34
Q

Example of low viscosity:

A

Water, vinegar

35
Q

What does the viscosity of magma in a volcano depend on?

A

Silica content and temperature

36
Q

Relationship between silica and viscosity:

A

The more silica magma has, the higher is viscosity

The less silica magma has, the lower its viscosity

37
Q

Types of volcanoes:

A

Sheild, Cinder come, and composite

38
Q

A broad, slightly domed structure. It looks like a pancake

A

Shield volcano

39
Q

What do shield volcanoes erupt?

A

Basaltic Lava

40
Q

Steepest smile at which material is still stable: small

A

Cinder cone Volcano

41
Q

What do cinder cone volcanoes erupt?

A

Cinder (tephra)

42
Q

A large, nearly symmetrical structure

A

Composite volcano

43
Q

What does a composite volcano erupt?

A

Alternating layers of lava and pyroclastic materials mater

44
Q

An explosive eruption that girls out a mixture of hot gases, ash, cinders, and bombs

A

Pyroclastic flow

45
Q

A type of mudflow; ash and water mixed to create mud that runs down the side is a volcano

A

Lahar

46
Q

Name the three types of magma

A

Basaltic Magna, Andesitic Magma, and Rhyolitic

47
Q

What is the silica content of basaltic magma?

A

Least 50%

48
Q

What is the silica content of Andesitic magma?

A

Intermediate 60%

49
Q

What is the silica content of Rhyolitic?

A

Most 70%

50
Q

One of the most abundant materials in the earths crust. Made of oxygen and silicon

A

Silica

51
Q

The vibration of Earth, produced by the rapid release of energy

A

Earthquake

52
Q

When do earthquakes occur?

A

When there is a break in rock mass along which movement has occurred (when places move)

53
Q

What does high viscosity indicate?

A

It is sticky

53
Q

What does low viscosity indicate?

A

It is runny

53
Q

What happens when there is more silica magma and the viscosity is high?

A

It is going to be light in color

53
Q

What happens when there is less silica magma and the viscosity is low?

A

It will be high in color

54
Q

How do composite volcanos explode?

A

Quietly and destructively