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Natural Disasters, 7/e
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Volcano Case History: Killer Events

Multiple Choice Quiz


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

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

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

At which location would you expect relatively peaceful volcanic eruptions?
A)Mt. Shasta in California
C)Mt. Pinatubo in the Philippines
D)Paricutin in Mexico
E)Yellowstone in Wyoming

Floods associated with melting of glaciers during a volcanic eruption are referred to as ____________.
C)debris flows
E)pyroclastic flows

Gases that are commonly emitted during volcanic eruptions include all of the following except _______________.
A)water vapor
B)carbon dioxide
C)carbon monoxide

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

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

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

Melting of thick caps of snow on volcanoes, such as Mount St. Helens, can generate which of the following hazards?
A)pyroclastic flows
D)lava flows
E)volcanic gases

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
D)composite volcano

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.

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

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

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

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

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
E)St. Helena

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

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

Which of the following hazards to humans are related to volcanic eruptions?
A)Burial by volcanic-generated mudflows.
B)Asphyxiation from volcanic gases.
D)Being struck by pyroclastic debris.
E)all of the above

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.