Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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The
type of magma that often produces a violent eruption can be described as a. | thin due to high
silica content. | c. | thin due to low
silica content. | b. | thick due to high silica
content. | d. | thick due to low
silica content. | | | | |
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2.
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Magma
forms within the mantle most often as a result of a. | high temperature and high
pressure. | c. | low temperature
and low pressure. | b. | high temperature and low
pressure. | d. | low temperature
and high pressure. | | | | |
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3.
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At
divergent plate boundaries, a. | heat from the Earth's core produces mantle
plumes. | b. | oceanic plates sink, causing magma to
form. | c. | tectonic plates move apart. | d. | hot spots
produce volcanoes. | | |
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4.
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Where
are volcanoes most likely to form? a. | near the center of continents | c. | along plate boundaries | b. | in deep
canyons | d. | in mountainous
areas | | | | |
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5.
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Lava
that is very runny probably a. | has a low silica content. | c. | has been cooled below the surface. | b. | is hotter than
most lava. | d. | comes from
explosive volcanoes. | | | | |
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6.
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Lava
fountains are ____ eruptions that can spray lava into the air. a. | explosive | c. | implosive | b. | nonexplosive | d. | pyroclastic | | | | |
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7.
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Which
of the following eruptions may resemble a nuclear explosion? a. | fissure
eruptions | c. | explosive
eruptions | b. | nonexplosive eruptions | d. | implosive eruptions | | | | |
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8.
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In an
eruption in 1915, Mount Lassen in northern California blasted a boulder larger than a grown man a
distance of 5 km! This was a(n) a. | lava flow. | c. | fissure eruption. | b. | nonexplosive
eruption. | d. | explosive
eruption. | | | | |
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9.
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Magma
that has a high silica content a. | has a thin, runny consistency. | c. | has a thick, runny consistency. | b. | has a thick,
stiff consistency. | d. | has a thin,
stiff consistency. | | | | |
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10.
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Gases
escape from a low-silica magma ____ from a high-silica magma. a. | more easily
than | c. | less easily
than | b. | at the same rate
as | d. | None of the
above | | | | |
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11.
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A
silica-rich magma tends to cause an explosive eruption because it a. | has a thick,
stiff consistency. | c. | tends to harden
in the volcano's vent. | b. | flows slowly. | d. | All of the above | | | | |
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12.
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Which
lava flows slowly, forming a glassy surface with rounded wrinkles? a. | pahoehoe | c. | blocky
lava | b. | aa | d. | pillow
lava | | | | |
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13.
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Which
lava erupts underwater, forming rounded lumps? a. | pahoehoe | c. | blocky lava | b. | aa | d. | pillow
lava | | | | |
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14.
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Which
pyroclastic material consists of pebble-like bits of magma that become solid before they hit the
ground? a. | volcanic
ash | c. | lapilli | b. | volcanic bombs | d. | volcanic blocks | | | | |
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15.
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Which
of the following is NOT a type of pyroclastic material? a. | lapilli | c. | volcanic
blocks | b. | pillow lava | d. | volcanic ash | | | | |
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16.
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Which
pyroclastic material is the smallest in size? a. | volcanic blocks | c. | lapilli | b. | volcanic
bombs | d. | volcanic
ash | | | | |
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17.
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Which
volcanic material would most likely predominate a nonexplosive eruption? a. | lapilli | c. | volcanic
ash | b. | pahoehoe | d. | volcanic
blocks | | | | |
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18.
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Which
statement best describes the effect of volcanic ash on the environment? a. | Volcanic ash can
cause the average global surface temperature to drop. | b. | Volcanic ash can
mix with rainwater and meltwater, flow downhill, and destroy or move objects in its
path. | c. | Volcanic ash can smother crops, causing food shortages and loss
of livestock. | d. | all of the above | | |
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19.
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The
eruption of Mount Pinatubo in 1991 caused average global temperatures to drop by as much as
0.5°C. What effect
could such a shift in temperature have worldwide? a. | It could cause worldwide famine. | b. | It could cause
the polar icecaps to melt. | c. | It could cause wetter, milder summers and longer, harsher
winters. | d. | all of the above | | |
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20.
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____
are built out of layers of lava from repeated nonexplosive eruptions. a. | Cinder cone
volcanoes | c. | Composite
volcanoes | b. | Shield volcanoes | d. | Stratovolcanoes | | | | |
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21.
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____
are sometimes referred to as stratovolcanoes. a. | Shield volcanoes | c. | Composite volcanoes | b. | Cinder cone
volcanoes | d. | both (a) and
(b) | | | | |
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22.
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Which
of the following is a type of volcano with gently sloping sides? a. | a cinder cone
volcano | c. | a
stratovolcano | b. | a shield volcano | d. | a composite volcano | | | | |
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23.
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Which
type of volcano erodes the fastest because its pyroclastic particles are not cemented together by
lava? a. | cinder cone
volcano | c. | composite
volcano | b. | shield volcano | d. | a stratovolcano | | | | |
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24.
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Which
of the following is a type of volcano that has a steep slope and a broad base? a. | a cindercone
volcano | c. | a composite
volcano | b. | a shield volcano | d. | both (a) and (b) | | | | |
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25.
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Which
of the following is a funnel-shaped pit that is found at the top of the central vent in most
volcanoes? a. | crater | c. | lava
plateau | b. | magma chamber | d. | caldera | | | | |
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26.
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A
____ is formed when magma erupts from long cracks in Earth's crust and spreads evenly over large
areas of Earth's surface. a. | caldera | c. | lava plateau | b. | vent | d. | crater | | | | |
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27.
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Rock
melts and forms magma when a. | the temperature of the rock
increases. | c. | the pressure on
the rock increases. | b. | the pressure on the rock
decreases. | d. | Both (a) and
(b) | | | | |
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28.
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Because the temperature of the mantle is relatively constant, ____ usually causes
magma to form. a. | increased
pressure | c. | an
eruption | b. | decreased pressure | d. | an earthquake | | | | |
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29.
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Magma
rises toward the surface of the Earth because it is ____ the surrounding rock. a. | denser
than | c. | as dense
as | b. | less dense
than | d. | None of the
above | | | | |
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30.
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Lassen Peak erupted in 1914 and continued to erupt intermittently until 1917. In 1916,
this volcano was probably classified as a. | extinct. | c. | inactive. | b. | dormant. | d. | active. | | | | |
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31.
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Hawaii's Mauna Kea, the tallest mountain on Earth, is an example of a a. | shield
volcano. | c. | composite
volcano. | b. | cinder cone volcano. | d. | stratovolcano. | | | | |
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32.
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As
tectonic plates separate, a deep crack, or ____, forms between the plates. a. | caldera | c. | rift | b. | subduction zone | d. | hot spot | | | | |
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33.
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The
volcano Paracutín, in Mexico, is made entirely of pyroclastic material. Paracutín is an
example of a a. | stratovolcano. | c. | shield
volcano. | b. | composite volcano. | d. | cinder cone volcano. | | | | |
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34.
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Long
undersea mountain chains that form at divergent boundaries are called a. | mid-ocean
ridges. | c. | hot
spots. | b. | subduction zones. | d. | mantle plumes. | | | | |
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35.
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The
place where two tectonic plates collide is called a a. | convergent
boundary. | c. | rift. | b. | divergent boundary. | d. | mantle plume. | | | | |
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36.
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Places on the Earth's surface that are located directly above mantle plumes are called
a. | mid-ocean
ridges. | c. | hot
spots. | b. | subduction zones. | d. | lava plateaus. | | | | |
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37.
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Scientists think that a combination of heat conducted upward from the core and heat
from radioactive elements keeps ____ rising in columns below hot spots. a. | mid-ocean
ridges | c. | rifts | b. | lapilli | d. | mantle plumes | | | | |
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38.
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Magma
forms at a convergent boundary when the oceanic plate a. | moves
downward. | c. | cracks. | b. | moves upward. | d. | stretches. | | | | |
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39.
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Which
type of lava does NOT form underwater? a. | pahoehoe | c. | blocky lava | b. | aa | d. | all of the
above | | | | |
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40.
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Which
of the following is a type of volcano that is formed by explosive eruptions of pyroclastic material
followed by quieter outpourings of lava? a. | cinder cone volcano | c. | composite volcano | b. | shield
volcano | d. | both (a) and
(b) | | | | |
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