Geol 101: Physical Geology
PAST EXAM QUESTIONS
LECTURE 11: VOLCANOES II
11. About how many potentially active volcanoes are there in the western United States?
A. 5
B. 10
C. 20
D. 50
E. 100
11. Which western US volcano last erupted about 70,000 years ago?
A. Mount Mazama
B. Mount Rainier
C. Mount Hood
D. Craters of the Moon
E. Yellowstone
11. The most active volcano in the Cascades is (1) __________ but the largest known eruption that occurred here in
pre-historic times was the eruption of (2) __________.
A. (1) Crater Lake
(2) Mt. St. Helens
B. (1) Mt. St. Helens
(2) Lassen Peak
C. (1) Mt. St. Helens
(2) Mt. Mazama
D. (1) Mt. Mazama
(2) Mt. Tehama
E. (1) Mt. Shasta
(2) Mt. St. Helens
11. Which Cascades range volcano has erupted 14-15 times in the past 4000 years?
A. Mount Mazama
B. Mount Rainier
C. Mount Hood
D. Mount St. Helens
E. Lassen Peak
11. Before Mount St. Helens erupted in 1980, the last Cascades volcano to erupt was:
A. Mount Mazama
B. Mount Rainier
C. Mount Hood
D. Mount St. Helens
E. Lassen Peak
11. The cities of Seattle and Tacoma are at risk from lahars that could be produced during an eruption of:
A. Mount St. Helens
B. Mount Rainier
C. Mount Hood
D. Mount Shasta
E. Lassen Peak
11. Which Cascades volcano is actually the world’s largest lava dome that sits inside the caldera of the ancient
volcano called Mount Tehama?
A. Crater Lake
B. Mount Shasta
C. Lassen Peak
D. Mount Hood
E. Mount St. Helens
11. Which of the following features were NOT produced when Mount St. Helens erupted in 1980?
A. lahar
B. lateral blast
C. pahoehoe lava flows
D. pyroclastic flow
E. Plinian column
11. Which of the following statements about the 1980 eruption of Mount St. Helens is FALSE?
A. it was the 15th or so eruption of Mt. St. Helens in the past 4000 years
B. the eruption was triggered by a gigantic landslide on the side of the volcano
C. the eruption started off as a lateral blast and then formed a Plinian column
D. prevailing winds carried ash eastwards across Washington and Idaho
E. the eruption came as a complete surprise to volcanologists