Question 1

Which of the following characteristics would you NOT expect from an effusive eruption?

Accepted Answer

A)   Central vent and fissures are the lava source.
B)   Flows of basaltic lava.
C)   Quiet, nonexplosive eruption event.
D)   Large volumes of pyroclastic materials produced.E) B) and C)
F) C) and D)

Question 2

Compared to rhyolitic lavas, basaltic lavas tend to be:

Accepted Answer

A)   higher in viscosity and retain dissolved gases.
B)   higher in viscosity but easily release dissolved gases.
C)   lower in viscosity and easily release dissolved gases.
D)   lower in viscosity and retain dissolved gases.E) B) and C)
F) B) and D)

Question 3

Which of the following events would you NOT expect from the gigantic Toba ash- flow eruption?

Accepted Answer

A)   Worldwide drop in human populations.
B)   Burial of Asia under a thick blanket of ash.
C)   Worldwide rise in sea level.
D)   Initiation of a six- year- long global "volcanic winter."E) B) and C)
F) A) and D) C

Question 4

Volcanoes are beneficial to humanity in many ways. All of the following are benefits EXCEPT:

Accepted Answer

A)   volcanoes give scientists insight into subterranean rock composition.
B)   some gases released by volcanoes are toxic to humans.
C)   many volcanic soils prove fertile for agriculture.
D)   some volcanoes provide sources of clean energy.E) A) and B)
F) A) and C)

Question 5

A welded tuff forms when:

Accepted Answer

A)   hot lava flows over rocks, causing them to become metamorphic.
B)   semi- molten volcanic bombs fuse together.
C)   particles within a lahar cool and crystallize.
D)   particles within a nue´e ardente cool and crystallize.E) All of the above
F) C) and D)

Question 6

Discuss two of the secondary environmental effects associated with volcanic eruptions.

Accepted Answer

There are two main secondary environmental effects associated with volcanic eruptions. The first involves the emission of sulfur dioxide from the volcano. Atmospheric moisture combines with the sulfur to form sulfuric acid, which in turn produces acid precipitation. The second effect involves volcanic gas and ash that are spewed into the atmosphere. Gases and particles are often emitted in sufficient quantities to reduce the amount of sunlight reaching the Earth for four or more years following the eruption. This effect results in cooler temperatures and a shortening of the warmer seasons.

Question 7

Of the following, the magma with the highest viscosity would have:

Accepted Answer

A)   a high silica content and low temperature.
B)   a high silica content and high temperature.
C)   a low silica content and high temperature.
D)   a low silica content and low temperature.E) A) and B)
F) C) and D)

Question 8

How did the cataclysmic eruption of Krakatau in 1883 affect global climate?

Accepted Answer

The eruption produced a black cloud of d...

Question 9

Explain why felsic magmas have a higher viscosity and retain gases more than mafic magmas.

Accepted Answer

Higher viscosity occurs in felsic magmas...

Question 10

What are ash- flow eruptions?

Accepted Answer

Ash- flow eruptions are pyroclastic erup...

Question 11

Describe the differences in the volcanic products of basaltic and rhyolitic volcanoes.

Accepted Answer

Basaltic volcanoes often produce nonviolent pahoehoe and 'a'a lava flows, columnar jointing, lava tubes, and pillow structures. Rhyolitic volcanoes produce explosive expulsions of pyroclastics such as volcanic blocks and other tephra, rapid flows of hot gas and ash (nue´e ardentes), and volcanic mudflows (lahars).

Question 12

Which of the following is a likely product of a subaqueous basaltic eruption?

Accepted Answer

A)   'A'a.
B)   Pillow structures.
C)   Pumice.
D)   Pahoehoe.E) B) and D)
F) A) and D)

Question 13

What is the most common way of predicting volcanic eruptions?

Accepted Answer

A)   Abnormal animal behavior.
B)   Harmonic tremors.
C)   Drop in sea level.
D)   Water wells suddenly dry up.E) B) and D)
F) B) and C)

Question 14

All of the following events could indicate an impending eruption EXCEPT:

Accepted Answer

A)   a highly eroded, volcanic peak.
B)   discovery of new hot springs around the volcano.
C)   swarms of small earthquakes in the region.
D)   a measurable bulge or swelling of the volcano.E) B) and C)
F) A) and B)

Question 15

Why is the Olympus Mons volcano on Mars so much larger than similar shield volcanoes on Earth?

Accepted Answer

Evidence indicates that Earth's shield v...

Question 16

Whether they are basaltic or rhyolitic, almost all volcanoes have both:

Accepted Answer

A)   volcanic domes and calderas.
B)   volcanic cones and craters.
C)   lava flows and ash flows.
D)   pahoehoe and aa flows.E) A) and D)
F) None of the above

Question 17

If a volcano has not erupted in the past few thousand years, but is likely to erupt sometime in the future, it is considered to be:

Accepted Answer

A)   active.
B)   extinct.
C)   dormant.
D)   none of the above.E) A) and B)
F) B) and C)

Question 18

Which of the following statements regarding volcanoes is NOT true?

Accepted Answer

A)   Basaltic volcanoes have more gentle slopes than rhyolitic volcanoes.
B)   Violent volcanoes tend to occur at convergent plate boundaries, whereas gentle volcanoes tend to occur at divergent plate boundaries.
C)   Rhyolitic volcanoes usually form calderas, while basaltic volcanoes form shield cones.
D)   Magma of gentle volcanoes has a higher silica content and a higher viscosity than magma of violent volcanoes.E) A) and C)
F) B) and D)

Question 19

Discuss why efforts to predict volcanic eruptions sometimes fail.

Accepted Answer

Methods for predicting eruptions are fai...

Question 20

All of the following are likely environmental effects of a volcanic explosion EXCEPT:

Accepted Answer

A)   acid precipitation.
B)   decreased global temperatures.
C)   decreased sunlight.
D)   an increased growing season.E) B) and C)
F) None of the above

Exam 4: Volcanoes and Volcanism

Which of the following characteristics would you NOT expect from an effusive eruption?

Correct Answer
verified

Compared to rhyolitic lavas, basaltic lavas tend to be:

Correct Answer
verified

Which of the following events would you NOT expect from the gigantic Toba ash- flow eruption?

Correct Answer
verified
C

Volcanoes are beneficial to humanity in many ways. All of the following are benefits EXCEPT:

Correct Answer
verified

A welded tuff forms when:

Correct Answer
verified

Discuss two of the secondary environmental effects associated with volcanic eruptions.

Of the following, the magma with the highest viscosity would have:

Correct Answer
verified

How did the cataclysmic eruption of Krakatau in 1883 affect global climate?

Correct Answer
verified
The eruption produced a black cloud of d...
View Answer

Explain why felsic magmas have a higher viscosity and retain gases more than mafic magmas.

Correct Answer
verified
Higher viscosity occurs in felsic magmas...
View Answer

What are ash- flow eruptions?

Correct Answer
verified
Ash- flow eruptions are pyroclastic erup...
View Answer

Describe the differences in the volcanic products of basaltic and rhyolitic volcanoes.

Which of the following is a likely product of a subaqueous basaltic eruption?

Correct Answer
verified

What is the most common way of predicting volcanic eruptions?

Correct Answer
verified

All of the following events could indicate an impending eruption EXCEPT:

Correct Answer
verified

Why is the Olympus Mons volcano on Mars so much larger than similar shield volcanoes on Earth?

Correct Answer
verified
Evidence indicates that Earth's shield v...
View Answer

Whether they are basaltic or rhyolitic, almost all volcanoes have both:

Correct Answer
verified

If a volcano has not erupted in the past few thousand years, but is likely to erupt sometime in the future, it is considered to be:

Correct Answer
verified

Which of the following statements regarding volcanoes is NOT true?

Correct Answer
verified

Discuss why efforts to predict volcanic eruptions sometimes fail.

Correct Answer
verified
Methods for predicting eruptions are fai...
View Answer

All of the following are likely environmental effects of a volcanic explosion EXCEPT:

Correct Answer
verified

Exam 4: Volcanoes and Volcanism

Which of the following characteristics would you NOT expect from an effusive eruption?

Correct AnswerverifiedShow Answer

Compared to rhyolitic lavas, basaltic lavas tend to be:

Correct AnswerverifiedShow Answer

Which of the following events would you NOT expect from the gigantic Toba ash- flow eruption?

Correct AnswerverifiedC

Volcanoes are beneficial to humanity in many ways. All of the following are benefits EXCEPT:

Correct AnswerverifiedShow Answer

A welded tuff forms when:

Correct AnswerverifiedShow Answer

Discuss two of the secondary environmental effects associated with volcanic eruptions.

Of the following, the magma with the highest viscosity would have:

Correct AnswerverifiedShow Answer

How did the cataclysmic eruption of Krakatau in 1883 affect global climate?

Correct AnswerverifiedThe eruption produced a black cloud of d...View AnswerShow Answer

Explain why felsic magmas have a higher viscosity and retain gases more than mafic magmas.

Correct AnswerverifiedHigher viscosity occurs in felsic magmas...View AnswerShow Answer

What are ash- flow eruptions?

Correct AnswerverifiedAsh- flow eruptions are pyroclastic erup...View AnswerShow Answer

Describe the differences in the volcanic products of basaltic and rhyolitic volcanoes.

Which of the following is a likely product of a subaqueous basaltic eruption?

Correct AnswerverifiedShow Answer

What is the most common way of predicting volcanic eruptions?

Correct AnswerverifiedShow Answer

All of the following events could indicate an impending eruption EXCEPT:

Correct AnswerverifiedShow Answer

Why is the Olympus Mons volcano on Mars so much larger than similar shield volcanoes on Earth?

Correct AnswerverifiedEvidence indicates that Earth's shield v...View AnswerShow Answer

Whether they are basaltic or rhyolitic, almost all volcanoes have both:

Correct AnswerverifiedShow Answer

If a volcano has not erupted in the past few thousand years, but is likely to erupt sometime in the future, it is considered to be:

Correct AnswerverifiedShow Answer

Which of the following statements regarding volcanoes is NOT true?

Correct AnswerverifiedShow Answer

Discuss why efforts to predict volcanic eruptions sometimes fail.

Correct AnswerverifiedMethods for predicting eruptions are fai...View AnswerShow Answer

All of the following are likely environmental effects of a volcanic explosion EXCEPT:

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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C

Correct Answer
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Correct Answer
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Correct Answer
verified
The eruption produced a black cloud of d...
View Answer

Correct Answer
verified
Higher viscosity occurs in felsic magmas...
View Answer

Correct Answer
verified
Ash- flow eruptions are pyroclastic erup...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Evidence indicates that Earth's shield v...
View Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
Methods for predicting eruptions are fai...
View Answer

Correct Answer
verified