Earthquakes & Volcanoes Test Review Answers
1) Identify the general term for waves released from an earthquake.
Seismic Waves
2) What is the rating scale used to classify an earthquake?
Richter Scale
3) What is a fault line?
A break in Earth’s crust where blocks of crust slide relative to one another
4) What is the difference between an earthquake’s epicenter and focus?
Epicenter: where seismic waves (Surface waves) of an earthquake are released
on Earth’s surface
Focus: where seismic waves (P- and S-waves) of an earthquake are released
under the Earth’s surface
5) Along a fault line, when is energy stored and released?
Energy stored: Earthquake is likely
Energy released: Earthquake has occurred
6) Earthquakes can occur in what three ways?
1) Movement along fault lines
2) Movement of magma
3) Volcanic eruptions
7) Where do most earthquakes occur?
At tectonic plate edges
8) What are the characteristics of a primary seismic wave?
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Can travel through any state of matter
First and Fastest seismic wave
Comes from the Focus
9) What are the characteristics of a surface seismic wave?
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Cause the greatest damage
Waves move up and down on Earth’s surface
10) For each type of fault, identify the force required for the crust movement.
Normal Fault: Tension Force
Reverse Fault: Compression Force
Strike-slip Fault: Shear Force
11) Identify the geologic event that can occur at a transform boundary.
Earthquake
12) In magma formation, what are the temperature and pressure requirements?
High Temperature & High Pressure
13) Be able to describe viscosity in terms of lava movement.
High Viscosity: Thick, slow-moving lava
Low Viscosity: Thin, fast-flowing lava
14) What is pyroclastic material?
Forms when magma explodes into the air and hardens to create rock
fragments
15) Where are volcanoes most likely to form?
Along plate boundaries
16) What are the required factors for an explosive volcanic eruption?
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Thick magma/lava
High water content/concentration
High gas pressure
17) What would a nonexplosive eruption look like?
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Fluid, thin, calm magma/lava
Low water content/concentration
Low gas pressure
Nothing blown into the air (Smoke, Ash, Dust, Rock Fragments)
18) Identify the three types of volcanoes and be able to describe their appearance.
Shield: gently sloping sides, wide base
Composite: tall, mountain-like with snow cap
Cinder Cone: small base with steep sides
19) Identify the cause of climate change during a volcanic eruption.
Ash blocks sunlight, causing temperatures to drop
20) What are the characteristics of a dormant volcano?
Record of past eruptions, might erupt again
21) What are the characteristics of an extinct volcano?
No modern record of past eruptions, will probably never erupt again