Name: ____________________________________
Class: _____________
Date: _____________
Self Assessment: Volcanoes
1. What is the major greenhouse gas emitted during a volcanic eruption?
a) carbon dioxide
b) methane
c) ozone
d) oxygen
2. The short term effect of a massive volcanic eruption would be _____.
a) a significant degree of global warming because of the greenhouse gases emitted
b) a significant degree of global warming because of the dust and gases thrown into the upper atmosphere
c) a significant degree of global cooling because of the greenhouse gases emitted
d) a significant degree of global cooling because of the dust and gases thrown into the upper atmosphere
3. A chain of volcanoes that are all active would most likely be found _____.
a) along a sliding (transform) juncture between a continental and oceanic plate
b) along a continent's edge where an oceanic plate is being subducted
c) over a "hot spot" under an ocean plate, formed as the plate moves
d) at the juncture where two continental plates collide
4. Properties of cinder cone volcanoes include _____.
a) steep sides, pyroclastic and lava composition, and long active lifetimes
b) steep sides, pyroclastic composition, and short active lifetimes
c) shallow sides, pyroclastic composition, and short active lifetimes
d) shallow sides, pyroclastic and lava composition, and short active lifetimes
5. How does higher silica content in magma result in more explosive eruptions?
a) Magma with higher silica content has a lower melting point, which means that it reaches higher
temperatures before it erupts.
b) Magma with higher silica content is more viscous, and impedes the upward migration of gases through
it.
c) Magma with higher silica content is less viscous, which allows expanding gases to bubble upward and
escape.
d) Magma with higher silica content has a higher melting point, which means that magma is much hotter
when it reaches the surface.
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Name: ____________________________________
Class: _____________
Date: _____________
Self Assessment: Volcanoes
6. Which gas makes up the majority of gas ejected during volcanic eruptions?
a) sulfur
b) carbon dioxide
c) water vapor
d) nitrogen
7. The four types of volcanic cones are _____.
a) cinder, pyroclastic, shield, lava dome
b) ash, pyroclastic, regolithic, mid ocean
c) cinder, pyroclastic, shield, mid ocean
d) cinder, composite, shield, lava dome
8. Which type of magma is most likely to form a composite volcano?
a) andesitic
b) granitic
c) rhyolitic
d) basaltic
9. A nuée ardente, or glowing avalanche, is a cloud of matter ejected from a volcano that can race downhill at
extreme speeds. What makes a nuée ardente move so fast?
a) particulate matter that adds weight to a slower moving cloud
b) rainwater that mixes with volcanic ash
c) low viscosity due to a low silica content
d) a near frictionless environment due to expanding volcanic gases
10. Shield volcanoes tend to erupt smoothly with lava flows rather than explosively with pyroclastics because
their magma has a lower _____.
a) gas content
b) average temperature
c) melting temperature
d) viscosity
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ANSWER KEY
1. a
2. d
3. b
4. b
5. b
6. c
ANSWER KEY Page 1
7. d
8. a
9. d
10. d