Download Volcanoes

Lesson 2
Volcanoes
Predict three facts that will be discussed in Lesson 2 after reading the headings. Record your
predictions in your Science Journal.
Define volcano. Include in your definition the term for the molten
What is a volcano?
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.
rock beneath Earth’s surface.
How do volcanoes form?
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Identify the cause of the formation of volcanoes.
.
Cause:
Effect:
formation of
volcanoes and the
eruptions that result
Sketch the movement of plates where volcanoes occur.
.
Convergent
boundaries
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Divergent
boundaries
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.
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Earthquakes and Volcanoes
Sketch
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Hot spots
Area
Lesson 2 | Volcanoes (continued)
Where do
volcanoes form?
Identify the location of most of the world’s active volcanoes.
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.
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Explain the relationship between the Ring of Fire, volcanoes, and
plate boundaries.
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Record 4 factors that scientists monitor to determine the likelihood
of a volcanic eruption.
1.
2.
3.
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4.
Identify the 2 characteristics scientists use to classify
Types of Volcanoes
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volcanoes.
1.
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2.
Model the shapes and sizes of the 3 types of volcanoes.
Label your drawings.
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Lesson 2 | Volcanoes (continued)
Volcanic Eruptions
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Identify 3 factors that affect eruption style.
.
Factors That affect
eruption style
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Distinguish among magmas with different silica content.
Silica
Content
Viscosity
Where these eruptions
commonly occur
Low
High
Intermediate
.
Sequence steps that lead to explosive eruptions as dissolved
gases escape from magma.
Magma moves toward the surface.
caused by overlying rock
. The ability
of gases to stay dissolved also
.
begin to form. As the magma rises,
the
become
begins to
, and gas
.
It is more difficult for bubbles to escape from
lavas. This combination
can result in
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Earthquakes and Volcanoes
eruptions.
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Lesson 2 | Volcanoes (continued)
Describe four effects of volcanic activity.
Activity
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Lava flows
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Ash fall
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Mudflows
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Pyroclastic
flow
Volcanic Eruptions and
Climate Change
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Effects
Identify the effect of volcanic eruptions on climate.
.
Cause:
Effect:
Ash and droplets
occurs, emitting
and
which forms tiny sulfuric
acid droplets in the
sunlight
,
, which causes a
in
.
.
The Cascade Range in the northwestern United States has many
volcanoes, including Mount St. Helens. These mountains are at a convergent plate
boundary. Identify the type of volcano you would most expect to find in the Cascade
Range and the nature of its eruptions.
Earthquakes and Volcanoes
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