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Unit 2: Inside Earth
Ch. 1 Plate Tectonics, Ch. 2 Earthquakes, Ch. 3 Volcanoes
Objectives:
1. Describe ways in which geologists have learned about Earth’s inner structure.
2. Describe the characteristics of Earth’s three layers.
3. Explain the cause and effect of convection currents in Earth’s mantle and core.
4. Starting with Alfred Wegner’s hypothesis, explain continental drift, including the evidence that supports it,
and why it was initially rejected.
5. Explain the cause and effect of sea-floor spreading and the evidence that supports it.
6. Explain the theory of place tectonics and describe the three types of boundaries formed at plate edges.
7. Describe how stress in the crust changes Earth’s surface.
8. State where faults are usually found and why they formed.
9. Describe how the energy of an earthquake travels through the Earth.
10. Discuss the scales used to measure the strength of an earthquake.
11. Explain how scientists detect and try to predict earthquakes.
12. State damages caused by an earthquake and ways to reduce those damages.
13. Describe the relationship between plate boundaries and the location of volcanoes.
14. Explain how volcanoes are able to form far from plate boundaries.
15. Describe what happens during a volcanic eruption.
16. Describe the signs that scientists use to predict volcanic eruptions.
17. Describe the landforms created through volcanic activity.
Vocabulary:
Seismic Waves
Crust
Mantle
Lithosphere
Asthenosphere
Outer Core
Inner Core
Convection
Convection Current
Continental Drift
Pangaea
Fossil
Mid-Ocean Ridge
Sonar
Sea-Floor Spreading
Deep-Ocean Trench
Subduction
Plates
Plate Tectonics
Fault
Divergent Boundary
Convergent Boundary
Transform Boundary
Stress
Tension
Compression
Shearing
Normal Fault
Hanging Wall
Footwall
Reverse Fault
Strike-Slip Fault
Earthquake
Focus
Epicenter
P Wave
S Wave
Surface Wave
Mercalli Scale
Magnitude
Richter Scale
Seismogram
Moment Magnitude
Scale
Seismograph
Ch. 1.1 Earth’s Interior
Read p. 6-12 and make notes by answering the following questions.
What is the farthest depth that humans have dug and ventured into the Earth?
Friction
Liquefaction
Aftershock
Tsunami
Volcano
Magma
Lava
Ring of Fire
Island arc
Hot spot
Pyroclastic flow
Shield volcano
Cinder cone
Composite volcano
Since we are unable to go into the interior of the Earth, scientists must find ways to gain knowledge about what the
Earth is made up of and how it behaves. Describe these two ways.
As you go deeper into the Earth, what happens to the temperature and pressure?
Describe the three layers of the Earth in detail.
Ch. 1.2 Convection and the Mantle
Read p. 16-17 and make notes by answering the following questions.
What is convection?
As a fluid becomes hotter, what happens to its density?
What sets a convection current in motion?
Using the idea of convection currents, explain how and why rock is recycled on Earth.
Ch. 1.3 Drifting Continents
Read p. 18-22 and make notes by answering the following questions.
If the Earth was a jigsaw puzzle, which continents would fit together?
Describe Wegener’s hypothesis and give the name that we call it by today.
Describe the evidence that Wegener collected that supported his hypothesis.
Why was Wegener’s hypothesis rejected?
Describe how mountains form, according to Wegener.
What do you think causes continental drift?
Ch. 1.4 Sea-Floor Spreading
Read p. 23-29 and make notes by answering the following questions.
What do you think is heating the water that comes out of deep-ocean vents?
What are mid-ocean ridges and how were they detected?
Describe the process of sea-floor spreading.
How does sea-floor spreading relate to continental drift?
Describe the following evidence for sea-floor spreading: eruptions of molten material and the ages of rocks
themselves.
Where would you expect to find the oldest rock on the ocean floor?
Describe what happens at deep-ocean trenches.
Ch. 1.5 Sea-Floor Spreading
Read p. 32-36 and make notes by answering the following questions.
What is the theory of plate tectonics?
Describe how plates move.
What features are created from the movement of these plates?
What event do you think is created when plates move?
Describe the three types of boundaries created at the edge of plates.
What happens when an oceanic crust converges with a continental crust?
Ch. 2.1 Forces in Earth’s Crust
Read p. 44-47 and make notes by answering the following questions.
What is stress and how is it related to the energy in a rock?
Complete the following table:
Type of
Description of What Happens
Boundary
Stress
to the Rock
Kinds of
Faults
Divergent
Tension
Normal
Convergent
Compression
Reverse
Transform
Shearing
StrikeSlip
Description of What Happens to
the Rock and Feature Formed
Where do most faults occur?
Ch. 2.2 Earthquakes and Seismic Waves
Read p. 51-57 and make notes by answering the following questions.
What causes Earthquakes?
What causes stress in Earth’s crust, what does that do to the rock, and what does it lead to?
When an earthquake occurs, what happens to the rock?
Where do earthquakes begin?
How is a focus different from the epicenter?
What are seismic waves? Describe their movement.
Complete the following table to describe P, S, and surface waves.
Wave
Order
Movement / Vibration
P
S
Surface
Ground Effect
Complete the following table to describe the three commonly used methods of measuring earthquakes.
Scale
Measures
Scale
Pros/Cons
Mercalli
Richter
Moment
Magnitude
Ch. 2.3 Monitoring Earthquakes
Read p. 60-65 and make notes by answering the following questions.
In general, what kinds of motions are earthquake motion detectors trying to detect?
What are the three ways in which geologists use seismographic data?
Can scientists predict earthquakes? Why or why not?
Ch. 2.4 Earthquake Safety
Read p. 68-73 and make notes by answering the following questions.
How can geologists determine an area’s earthquake risk?
Why does the western United States have a high risk of earthquakes?
Describe the four ways in which earthquakes can cause damage.
To prevent earthquake damage, what should be done to older buildings and what should be taken into consideration
for new buildings?
Ch. 3.1 Volcanoes and Plate Tectonics
Read p. 82-85 and make notes by answering the following questions.
What is the difference between magma and lava?
Approximately, how many active volcanoes are on land?
Why are volcanoes found on the Ring of Fire? Where do most volcanic belts form?
Describe how volcanoes form along diverging boundaries. Give an example of where these types of volcanoes are
found.
Describe how volcanoes form along converging boundaries. Give an example of where these types of volcanoes
are found.
Describe how volcanoes form far from plate boundaries. Give an example of where these types of volcanoes are
found.
How is an arc island different from a hot spot?
Ch. 3.3 Volcanic Eruptions
Read p. 91-98 and make notes by answering the following questions.
The magma in the asthenosphere is under great pressure and temperature. It rises because it is hotter and
less
than the surrounding rock.
In terms of trapped gases, describe what happens during a volcanic eruption.
What kinds of gasses are released in a volcanic eruption?
Quiet eruptions have lava that
flow easily and the gasses are released gently. An example of a quiet volcano is on the
Big Island of Hawaii. Explosive eruptions have thick, sticky
Some volcanic eruptions are quiet, while others are explosive.
lava, which trap in gas bubbles. The gas bubble build up pressure until they explode, taking the lava with it. An
example of an
explosive volcano is Mount St. Helens.
What are some examples of pyroclastic flow?
What changes do geologists look for when trying to predict a volcanic eruption?
Ch. 3.4 Volcanic Landforms
Read p. 100-101 and make notes by answering the following questions.
Describe the three types of volcanoes (how they formed and their physical features).