Question 1

Which of the following volcanic features or textures suggest that significant amounts of water were present during an eruption?

Accepted Answer

A)  vesicles
B)  phenocrysts
C)  lava ropes
D)  pillowsE) All of the above
F) A) and B)

Question 2

Which of the following statements about the May 18,1980,climactic eruption of Mount St.Helens is false?

Accepted Answer

A)  Earthquakes began to occur underneath the volcano 6 years before the eruption.
B)  Volcanic ash was erupted up to 25 kilometers into the atmosphere.
C)  Approximately 60 people were killed by the eruption.
D)  The eruption was immediately preceded by a large earthquake and landslide.E) B) and C)
F) A) and C)

Question 3

Which of the following volcanic flows moves the most rapidly?

Accepted Answer

A)  basaltic lava flows
B)  lahars
C)  pyroclastic flows
D)  rhyolitic lava flowsE) B) and C)
F) A) and D)

Question 4

Which of the following statements about lava is true?

Accepted Answer

A)  The viscosity of a lava increases as the silica content decreases.
B)  High temperature lavas are less viscous than low-temperature lavas.
C)  The more gas a lava contains,the less violent the eruption.
D)  All of the statements above are true.E) A) and D)
F) All of the above

Question 5

What type of volcanic flows likely formed the volcano depicted in the cross section below?

Accepted Answer

A)  andesite flows
B)  basalt flows
C)  rhyolite flows
D)  volcanic mudflowsE) C) and D)
F) A) and B)

Question 6

Volcanic rocks derived from the Yellowstone hot spot get progressively older to the southwest.Based on this information,in which direction is the North American plate moving?

Accepted Answer

A)  northeast
B)  northwest
C)  southeast
D)  southwestE) A) and B)
F) C) and D)

Exam 12: Volcanoes

Volcanic rocks derived from the Yellowstone hot spot get progressively older to the southwest.Based on this information,in which direction is the North American plate moving?

Correct Answer
verified

Which of the following statements about the May 18,1980,climactic eruption of Mount St.Helens is false?

Correct Answer
verified

What type of volcanic flows likely formed the volcano depicted in the cross section below?

Correct Answer
verified

Which of the following volcanic features or textures suggest that significant amounts of water were present during an eruption?

Correct Answer
verified

Which of the following volcanic flows moves the most rapidly?

Correct Answer
verified

Which of the following statements about lava is true?

Correct Answer
verified

Exam 12: Volcanoes

Volcanic rocks derived from the Yellowstone hot spot get progressively older to the southwest.Based on this information,in which direction is the North American plate moving?

Correct AnswerverifiedShow Answer

Which of the following statements about the May 18,1980,climactic eruption of Mount St.Helens is false?

Correct AnswerverifiedShow Answer

What type of volcanic flows likely formed the volcano depicted in the cross section below?

Correct AnswerverifiedShow Answer

Which of the following volcanic features or textures suggest that significant amounts of water were present during an eruption?

Correct AnswerverifiedShow Answer

Which of the following volcanic flows moves the most rapidly?

Correct AnswerverifiedShow Answer

Which of the following statements about lava is true?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified