Question 1

Volcanic gas emissions are important because they tell geologists how flammable the gases in the magma are likely to be.

Accepted Answer

A) True 
 B)False

Question 2

Why is topographic monitoring sometimes useful in forecasting a volcanic eruption?

Accepted Answer

A)  A volcano sometimes swells as lava moves into the edifice.
B)  Volcanic eruption is more likely as an area undergoes tectonic uplift.
C)  Seismic activity occurs as the volcano rises.
D)  Topographic monitoring reveals the likelihood of lahar generation.

Question 3

What is one reason that ash fall is such a significant hazard?

Accepted Answer

A)  The basaltic magma that produces the ash is low in silica.
B)  The weight of the ash can cause structural damage to buildings.
C)  The pyroclastic flow that deposits the ash is a hot, glowing cloud.
D)  The associated lava flows can cover large areas.

Question 4

________ is a volcanic gas associated with acid rain and vog.

Accepted Answer

The answer of ________ is a volcanic gas associated with...

Question 5

The number of fatalities from the Mt. Pinatubo eruption was relatively low because

Accepted Answer

A)  the eruption was relatively small
B)  few people lived in the vicinity of the volcano
C)  the eruption was predicted successfully, and the area was evacuated
D)  the eruption, though large, was characterized by extensive lava flows

Question 6

The eruption of Mt. ________ in 1991 killed several tens of people with pyroclastic flows.

Accepted Answer

The answer of The eruption of Mt. ________ in 1991...

Question 7

Why are most active volcanoes associated with plate tectonic boundaries?

Accepted Answer

A)  Plate tectonic boundaries are created by volcanism.
B)  Spreading or sinking plates interact at plate boundaries with other materials to produce magma.
C)  Earthquakes at plate boundaries bring large amounts of magma to the surface.
D)  In reality, most volcanoes are in the plate interiors rather than at plate boundaries.

Question 8

At ________, Cameroon, a dense cloud of gas was released from a volcanic crater, flowing down the volcano and killing hundreds of people.

Accepted Answer

The answer of At ________, Cameroon, a dense cloud of...

Question 9

Mid-ocean ridge volcanism produces what type of volcanic rock?

Accepted Answer

A)  basalt
B)  andesite
C)  rhyolite
D)  tephra

Question 10

________ are small volcanoes formed from tephra accumulation near a volcanic vent.

Accepted Answer

The answer of ________ are small volcanoes formed from tephra...

Question 11

Composite volcanoes are typically associated with subduction zones.

Accepted Answer

A) True 
 B)False

Question 12

Composite cones typically are associated with what type of plate tectonic feature?

Accepted Answer

A)  mid-ocean ridge
B)  hot spot
C)  continental collision zone
D)  subduction zone

Question 13

The shape of shield volcanoes is a function of

Accepted Answer

A)  lava viscosity
B)  proportion of pyroclastic debris included in the edifice
C)  local variations in the tilt of the land surface
D)  the explosive nature of the eruptions that produce the shield

Question 14

________ are dangerous, hot masses of ash and gas that travel down the flanks of a volcano.

Accepted Answer

Ash flows ...

Question 15

Volcanic domes typically consist of the rock type ________.

Accepted Answer

The answer of Volcanic domes typically consist of the rock...

Question 16

Seismic activity serves as a tool of volcanic forecasting because

Accepted Answer

A)  moving magma causes earthquakes
B)  earthquakes and dangerous volcanoes are both associated with subduction zones
C)  seismic activity indicates emission of volcanic gases
D)  earthquake usually cause the volcanic summit to collapse, setting of an eruption

Question 17

Ash flows are rarely dangerous.

Accepted Answer

A) True 
 B)False

Question 18

Volcanic domes form on oceanic plates above hotspots.

Accepted Answer

A) True 
 B)False

Question 19

Caldera eruptions are very common features of subduction zones.

Accepted Answer

A) True 
 B)False

Question 20

Why do composite volcanoes consist of alternating lava and pyroclastic layers?

Accepted Answer

A)  Composite cones are created by lava composition alternating between basalt and rhyolite.
B)  Composite cones typically are interlayered with lava flows from nearby shield volcanoes.
C)  Composite cones are created by a mixture of explosive activity and lava flows.
D)  The lavas in composite cones are typically rhyolitic in composition.

Exam 8: Volcanic Activity

Seismic activity serves as a tool of volcanic forecasting because

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Why do composite volcanoes consist of alternating lava and pyroclastic layers?

Correct AnswerverifiedShow Answer

________ are small volcanoes formed from tephra accumulation near a volcanic vent.

Correct AnswerverifiedShow Answer

The eruption of Mt. ________ in 1991 killed several tens of people with pyroclastic flows.

Correct AnswerverifiedShow Answer

What is one reason that ash fall is such a significant hazard?

Correct AnswerverifiedShow Answer

Composite cones typically are associated with what type of plate tectonic feature?

Correct AnswerverifiedShow Answer

________ is a volcanic gas associated with acid rain and vog.

Correct AnswerverifiedShow Answer

Caldera eruptions are very common features of subduction zones.

Correct AnswerverifiedShow Answer

Volcanic gas emissions are important because they tell geologists how flammable the gases in the magma are likely to be.

Correct AnswerverifiedShow Answer

Why is topographic monitoring sometimes useful in forecasting a volcanic eruption?

Correct AnswerverifiedShow Answer

At ________, Cameroon, a dense cloud of gas was released from a volcanic crater, flowing down the volcano and killing hundreds of people.

Correct AnswerverifiedShow Answer

Why are most active volcanoes associated with plate tectonic boundaries?

Correct AnswerverifiedShow Answer

Volcanic domes typically consist of the rock type ________.

Correct AnswerverifiedShow Answer

Volcanic domes form on oceanic plates above hotspots.

Correct AnswerverifiedShow Answer

Mid-ocean ridge volcanism produces what type of volcanic rock?

Correct AnswerverifiedShow Answer

The number of fatalities from the Mt. Pinatubo eruption was relatively low because

Correct AnswerverifiedShow Answer

The shape of shield volcanoes is a function of

Correct AnswerverifiedShow Answer

________ are dangerous, hot masses of ash and gas that travel down the flanks of a volcano.

Correct AnswerverifiedAsh flows ...View AnswerShow Answer

Composite volcanoes are typically associated with subduction zones.

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Ash flows are rarely dangerous.

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Ash flows ...
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