Quiz prepared by Leslie J. Sonder, Dartmouth College.
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1 | |
Most of the Earth's explosive volcanoes are located in a zone that encircles the Pacific Ocean called the Ring of Fire. The types of volcanoes that commonly form in this zone are called _____________ that form by the melting of asthenosphere and lithosphere rocks during _____________. |
| | A) | cinder cones, subduction |
| | B) | shield volcanoes, subduction |
| | C) | stratovolcanoes, subduction |
| | D) | stratovolcanoes, rifting |
| | E) | stratovolcanoes, formation of hot spots |
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2 | |
Melting of the mantle forms the most common type of magma that is extruded onto the Earth's surface because ______________. |
| | A) | this type of magma forms at high temperatures which allow it to rise to the surface before crystallizing completely to become solid rock |
| | B) | this type of magma has low percentages of SiO2 so it has low viscosity which allows it to move more easily to the surface |
| | C) | this type of magma is generally extruded in rift zones where there are fractures that provide avenues for flow |
| | D) | all of the above |
| | E) | none of the above |
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3 | |
Subduction zones are characterized by _______________. |
| | A) | andesitic to rhyolitic volcanic rocks |
| | B) | steep-sided volcanoes composed of alternating pyroclastic debris and lava flows |
| | C) | pyroclastic flows and calderas |
| | D) | answers A, B, and C |
| | E) | answers A and C |
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4 | |
At which location would you expect relatively peaceful volcanic eruptions? |
| | A) | Mt. Shasta in California |
| | B) | Iceland |
| | C) | Mt. Pinatubo in the Philippines |
| | D) | Paricutin in Mexico |
| | E) | Yellowstone in Wyoming |
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5 | |
Floods associated with melting of glaciers during a volcanic eruption are referred to as ____________. |
| | A) | jokulhlaups |
| | B) | lahars |
| | C) | debris flows |
| | D) | tsunami |
| | E) | pyroclastic flows |
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6 | |
Gases that are commonly emitted during volcanic eruptions include all of the following except _______________. |
| | A) | water vapor |
| | B) | carbon dioxide |
| | C) | carbon monoxide |
| | D) | methane |
| | E) | nitrogen |
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7 | |
What was the gas that caused widespread death of people and animals near Lake Nyos in 1986? |
| | A) | carbon monoxide |
| | B) | carbon tetrachloride |
| | C) | carbon dioxide |
| | D) | carbolic acid |
| | E) | carbonic acid |
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8 | |
During 1986 Lake Nyos eruption the most dangerous areas to be in were _________ because the gas was _________. |
| | A) | on top of hills, less dense than air |
| | B) | on top of hills, flammable |
| | C) | valleys, acidic |
| | D) | valleys, flammable |
| | E) | valleys, more dense than air |
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9 | |
The violent flank eruption of Mount St. Helens in 1980 was set off by _______________. |
| | A) | an earthquake that caused collapse of part of the mountain thus rapidly releasing pressure |
| | B) | interaction of hot magma with cold water |
| | C) | caldera collapse |
| | D) | a fault that ripped the mountain apart |
| | E) | none of the above |
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10 | |
Melting of thick caps of snow on volcanoes, such as Mount St. Helens, can generate which of the following hazards? |
| | A) | pyroclastic flows |
| | B) | earthquakes |
| | C) | lahars |
| | D) | lava flows |
| | E) | volcanic gases |
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11 | |
When magma is too viscous to flow it can form a sticky blob that blocks the conduit of a volcano and forms a steep-sided feature known as a _______________. |
| | A) | scoria cone |
| | B) | lava dome |
| | C) | cone |
| | D) | composite volcano |
| | E) | hornito |
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12 | |
If you were in an airplane flying over a subduction zone what would you expect to observe on the continent adjacent to the zone? |
| | A) | A long, narrow sea within a rift zone. |
| | B) | A plain of lava flows. |
| | C) | A chain of steep-sided volcanoes subparallel to the subduction zone. |
| | D) | A series of broad, shield-shaped volcanoes subparallel to the subduction zone. |
| | E) | A single, large cinder cone. |
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13 | |
In 1902, the town of St. Pierre near Mt. Pelee was destroyed and its population of 28,000 killed because of _________________. |
| | A) | a gaseous flow of incandescent volcanic ash and dust |
| | B) | a fast-moving basaltic lava flow that engulfed the town |
| | C) | a rain of volcanic bombs |
| | D) | an earthquake generated by the eruption |
| | E) | none of these |
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14 | |
What causes a pyroclastic flow to move at high velocities? |
| | A) | Gravitational collapse of an eruption cloud. |
| | B) | Energy from the eruption. |
| | C) | Internal turbulence that keeps particles in the air. |
| | D) | Release of gas from magma particles and heating of surrounding air creating a "popcorn" effect |
| | E) | all of the above |
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15 | |
Why are pyroclastic flows one of the most dangerous types of hazard associated with volcanic eruptions? |
| | A) | They can form with little or no warning and move at extremely high velocities. |
| | B) | They can cover large areas with a dense cloud of ash and dust that can asphyxiate an entire city. |
| | C) | The temperature of the cloud can be several hundred degrees Centigrade causing fires. |
| | D) | answers A and B only |
| | E) | answers A, B, and C |
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16 | |
Lahars created on stratovolcanoes have high destructive energy because _______________. |
| | A) | they move at velocities of 200-300 miles per hour |
| | B) | they flow on top of a cushion of hot gases and heated air |
| | C) | they are dense mass of water and rock that flows down steep slopes over thousands of feet of elevation |
| | D) | they gain energy as powerful eruptions eject material out of the vent |
| | E) | they form when an entire volcano collapses |
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17 | |
Which continental hot spot in the United States has posed the greatest threat in historic times? |
| | A) | Valles caldera |
| | B) | Long Valley caldera |
| | C) | Yellowstone caldera |
| | D) | Hawaii |
| | E) | St. Helena |
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18 | |
Lahars can form by all of the following except ________________. |
| | A) | melting of a snow cap on a volcano |
| | B) | flow of lava into the ocean |
| | C) | flow of pyroclastic material into a river |
| | D) | heavy rainfall during eruption of pyroclastic material |
| | E) | collapse of a crater lake or dam |
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19 | |
A pyroclastic flow can best be described as _________________. |
| | A) | a flow of gas and hot ash |
| | B) | a flow of hot gas |
| | C) | a flow of mud and pyroclastic material |
| | D) | a flow of hot lava |
| | E) | a rain of volcanic fragments |
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20 | |
Which of the following hazards to humans are related to volcanic eruptions? |
| | A) | Burial by volcanic-generated mudflows. |
| | B) | Asphyxiation from volcanic gases. |
| | C) | Tsunami |
| | D) | Being struck by pyroclastic debris. |
| | E) | all of the above |
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21 | |
The two most frequent causes of death from volcanic eruptions are |
| | A) | lava flows and suffocation from volcanic gases. |
| | B) | famine and jokulhaups. |
| | C) | pyroclastic flows and tsunami. |
| | D) | pyroclastic fall (bombs) and lahars. |
| | E) | debris avalanches and earthquakes. |
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