Deck 5: Volcanoes and Volcanic Hazards

Question 1

________ is a material's resistance to flowing.

A)Viscosity
B)Volatiles
C)Composition
D)Quiescent

Answer 1

A

Question 2

Lavas erupting from composite cones are generally ________-rich, making them very viscous.

A)magnesium
B)iron
C)aluminum
D)silica

Answer 2

D

Question 3

Which volcanoes have flanks with the steepest angle of repose (between 30° and 40°)?

A)Shield volcanoes
B)Cinder cones
C)Composite cones
D)Lava domes

Answer 3

B

Question 4

Around which volcano is a scientist likely find pillow basalts?

A)Mount St.Helens
B)Parícutin
C)Fujiyama
D)Kilauea

Question 5

What is the name of the small holes created by gas bubbles on the surface of scoria?

A)Lapilli
B)Pumice
C)Vesicles
D)Volatiles

Question 6

Based on the structure of the cone and the rock making it up, what interpretations can be made about the gas content of eruptions from cinder cone volcanoes compared to those of shield volcanoes?

A)Less gas than shield volcanoes
B)Same gas content as shield volcanoes
C)More gas than shield volcanoes
D)Gas is not found in volcanoes

Question 7

Which of the following lavas make up 90 percent of the total volume of lava on Earth?

A)Basaltic
B)Andesitic
C)Rhyolitic

Question 8

In order to cover such large expanses of seafloor, shield volcanoes erupt ________ lava.

A)rhyolitic
B)andesitic
C)porphyritic
D)basaltic

Question 9

With the exception of volcanoes associated with a subduction zone, most volcanic islands are ________ volcanoes.

A)cinder cone
B)shield
C)composite cone
D)caldera

Question 10

Which type of magma(s)will produce scoria?

A)Basaltic
B)Andesitic
C)Rhyolitic
D)Basaltic and andesitic
E)Andesitic and rhyolitic

Question 11

The ring of fire is a narrow zone of composite cone volcanoes rimming the ________ Ocean.

A)Pacific
B)Atlantic
C)Indian
D)Arctic

Question 12

What interpretations can be made about the maturity of a volcano where most eruptions occur from basal fissures and there are a number of parasitic cones along the volcano's flanks?

A)It is a mature volcano.
B)It is in the early stages of growth.

Question 13

What kind(s)of lava are most closely associated with composite cones?

A)Andesite
B)Rhyolite
C)Basalt
D)Rhyolite and basalt

Question 14

________ is pulverized rock, lava fragments, and ash erupted from a volcano.

A)Pahoehoe
B)Pyroclastic material
C)Basalt
D)Lapilli

Question 15

Which of the following choices best explains the difference between a crater and a caldera?

A)A crater is a very large circular depression over 1 km across; a caldera is a small funnel-shaped depression.
B)A crater is a small, funnel-shaped depression; a caldera is a large depression that has a diameter of over 1 km.
C)A crater is a fissure in the crust; a caldera is a collapsed summit.
D)A crater is a large circular depression over 1 km across; a caldera is a small, parasitic cone growing on the flank of the volcano.

Question 16

Define magma.

A)Dissolved gases in molten rock
B)A material's resistance to flowing
C)Molten rock that has been erupted
D)Molten rock found at depth that contains dissolved gases and some crystals

Question 17

In what year did Parícutin form in a Mexican cornfield?

A)1935
B)1939
C)1943
D)1952

Question 18

A ________ is a submarine volcano.

A)seamount
B)caldera
C)scoria cone
D)dome

Question 19

A ________ is a cone-shaped structure created by successive eruptions of volcanic materials such as lava or pyroclastic materials.

A)caldera
B)volcanic cone
C)crater
D)fumarole

Question 20

Using the choices below, select the statement that best explains how dissolved gases drive volcanic eruptions.

A)As the magma rises, gas bubbles contract, fragmenting the material and expelling it from the vent.
B)As the magma rises, gases reduce silicate mineral chains by breaking silicon-oxygen bonds; the result is an explosion.
C)Confining pressure decreases on a rising magma, allowing gas bubbles to expand and fracture the magma.This process further decreases pressure on the magma and will result in an explosive event.
D)Decreases in confining pressure result in decreasing viscosity of the magma, allowing the magma to ooze from the volcano.

Question 21

What kind of volcanic hazard can be triggered by the collapse of a lava dome?

A)Pyroclastic flow
B)Lava flow
C)Ash fall
D)Earthquake

Question 22

An example of a volcanic caldera that formed from the collapse of a magma chamber after large volumes of material were erupted is ________.

A)Parícutin
B)Yellowstone
C)Mount Fujiyama
D)Mount Rainier

Question 23

Which of the following eruptive materials can be associated with cinder cone volcanoes?

A)Ash
B)Lava flows
C)Scoria fragments
D)Lava flows and scoria fragments
E)Ash, lava flows, and scoria fragments

Question 24

What kind of volcano is most closely associated with pyroclastic flows?

A)Shield
B)Cinder cone
C)Composite cone
D)Caldera

Question 25

Which of the following is not a method of caldera formation?

A)Collapse of magma chamber after large volumes of material are erupted
B)Collapse of a composite cone summit following an explosive eruption
C)Collapse of the flank of a cinder cone volcano after an effusive lava flow
D)Collapse of summit of a shield volcano after draining of magma chamber

Question 26

Secondary vents on composite cones can generate ________ volcanoes.

A)shield
B)cinder cone
C)additional composite cone

Question 27

How is magma generated along subduction zones?

A)Decompression melting of the mantle from weight reduction.
B)Fluids are dehydrated out of the descending plate, which lowers the melting point of the surrounding mantle.
C)Friction from colliding plates melts mantle material.
D)Radioactive decay melts mantle material.

Question 28

What kind of viscosity would flood basalts have?

A)Low viscosity
B)Medium viscosity
C)High viscosity

Question 29

Along which tectonic boundary will chains of composite cone volcanoes be located?

A)Convergent boundary
B)Divergent boundary
C)Transform boundary
D)Mantle plumes

Question 30

What type of lava is produced at a divergent plate boundary?

A)Rhyolitic
B)Andesitic
C)Basaltic

Question 31

Pyroclastic materials are generally associated with which type of magma(s)?

A)Basaltic
B)Andesitic
C)Rhyolitic
D)Andesitic and rhyolitic
E)Basaltic and andesitic

Question 32

What kind(s)of lava generate a cinder cone?

A)Andesite
B)Andesite and rhyolite
C)Basalt
D)Basalt and andesite
E)Andesite, basalt, and rhyolite

Question 33

Which volcanic type(s)can have pyroclastic ejections during eruptions?

A)Shield volcanoes
B)Cinder cones
C)Composite cones
D)Cinder and composite cones
E)Shield volcanoes, cinder cones, and composite cones

Question 34

Which of the following statements about lava domes is true?

A)Lava domes can only collapse during eruptions.
B)Lava domes can collapse during eruptions or in quiet periods between eruptions.
C)Lava domes are most commonly associated with cinder cone volcanoes.
D)Lava domes are created by earthquakes.

Question 35

GPS units, satellites, and lasers are some of the tools used to monitor the ________ of the volcanic flanks, which indicates magma accumulating in the magma chamber.

A)gas content
B)temperature
C)inflation
D)mineral content

Question 36

What is the driving force behind pyroclastic flows?

A)Directed explosion
B)Gravity
C)Water
D)Earthquakes

Question 37

Which of the following eruptive materials can be described as basaltic, vesicular ejecta found around cinder cone volcanoes?

A)Tuff
B)Scoria
C)Lapilli
D)Pumice

Question 38

________ are small vents that emit volcanic gases.

A)Calderas
B)Domes
C)Fumaroles
D)Tuff

Question 39

Kilauea is a volcano created by ________.

A)intraplate volcanism
B)subduction
C)rifting
D)shear forces

Question 40

Which of the following changes are not evidence of migrating magma?

A)Changes in the pattern of earthquakes produced by moving magma
B)Molten rock flowing down the flank of a volcanic cone
C)Increase in ground temperature
D)Changes in the volcanic gases released from the volcano

Question 41

How is a volcanic neck different from a volcanic pipe?

A)Volcanic necks are longer and bring materials up from the mantle.
B)Volcanic pipes connect to shallow magma chambers.
C)Volcanic pipes are shorter.
D)Volcanic necks are shorter and connect to shallow magma chambers.

Question 42

Most cinder cones have eruptive phases that last for centuries.

Question 43

What substances are emitted from fumaroles?

A)Lava
B)Ash
C)Water
D)Volcanic gases

Question 44

Assume you live near Mount St.Helens and the volcano is going through an explosive eruption.Explain the effect pyroclastic materials would have on your home.

Question 45

Based on the eruptive materials, volcanic hazards, and violence of eruptions, which type of volcano would be the most dangerous to live near? Cite specific hazards and how they could affect nearby residents.

Question 46

How will the water vapor in magma reduce the viscosity of the magma?

Question 47

Along which tectonic boundary would the greatest amount of magma be generated every year? Why?

A)Transform boundaries: magma produced from friction
B)Convergent boundaries: magma produced by dehydration of plate water and partial melting
C)Divergent boundaries: magma produced by decompression melting

Question 48

Explain what will happen to the flanks of the volcano as magma moves into the magma chamber.

Question 49

What material makes up the flanks of cinder cones? Why does magma rising through the conduit of a cinder cone volcano often break through the side of the volcano and flow down the flank?

Question 50

Differentiate the three types of magma based on igneous composition and silica content.

Question 51

Kilauea, a volcano in Hawaii, generates fluid, extensive lava flows.Mount St.Helens, a volcano in Washington State, can produce lava flows that are short and thick, but that can also erupt violently and generate large volumes of ash.What might these differences indicate about each lava's silica content and temperature?

Question 52

What is the difference between a pyroclastic flow and a pyroclastic surge (aka surges)?

Question 53

When Eyjafjallajökull erupted in March 2010, ash plumes drifted southeast over Europe and, as a result, the controlled airspaces over many European countries were closed to air traffic, stranding thousands of people worldwide.Why would flying a commercial jet through a cloud of volcanic ash be dangerous?

A)Ash can impede visibility if thick enough.
B)Hot ash will cause the plane to catch fire.
C)Abrasion of windows and engine parts from ash.
D)Engines can be clogged by ash.
E)Ash impairs visibility, clogs engines, and abrades engine parts.

Question 54

What is the difference between a quiescent and an explosive eruption?

Question 55

Compare and contrast the three types of volcanoes (shield, cinder cones, and composite cones).Make sure to comment on the differences in size, shape, and slope angle.

Question 56

You are in charge of emergency planning in Electron, Washington, when it is brought to your attention that the entire town is built upon the remains of eruption materials from Mount Rainier, which is less than 30 miles away.Using the past volcanic hazard history of Mount Rainier, which volcanic hazard would most likely affect your town?

A)Pyroclastic flow
B)Lahar
C)Lava flow
D)Volcanic landslide
E)Earthquakes

Question 57

What is the importance of monitoring volcanic activity? Why should we pay attention to what volcanoes are doing?

Question 58

How do lava tubes form in basaltic lavas? How can the exterior solidify if the interior is still fluid?

Question 59

Composite cones are also known as stratovolcanoes.

Question 60

The more the silica in magma, the lower the viscosity.

Question 61

How does decompression melting generate magma at rift zones?

Question 62

Composite cones are famous for their conical shapes with steep summits, sloping flanks, and broad base.How might the composition of eruptive materials have changed for the volcano to transition from something with a broad base to something with a smaller base and steeper slopes?

Question 63

The volcanic islands visible here formed as a result of a mantle plume.Which volcanic island is the oldest and subsiding into the sea?

A)Volcano A
B)Volcano B
C)Volcano C

Question 64

The volcanic islands visible here formed as a result of a mantle plume.Researchers working on these volcanic islands have collected basalt samples for potassium-argon dating to determine when these islands formed Volcanic Island A has been dated to 7.6 million years ago.Volcanic Island C dates back to 3.4 million years ago and is 200 km away from A.Using the equation Rate = Distance/Time, calculate the rate of plate motion for this region.

A)4)2 km/million years
B)47.6 km/million years
C)102.3 km/million years
D)26.3 km/million years

Question 65

Volcanic island arcs and continental volcanic arcs are both associated with convergent plate boundaries.However, the lavas that their volcanoes erupt are different.Where does the lava come from for each type of volcanic arc?

Question 66

Based on the volcanic type and construction of the flanks, what assumptions can you make about the viscosity of the lava?

A)The lava is high viscosity.
B)The lava is low viscosity.

Question 67

Explain how sulfur dioxide gas erupted from a volcano can affect global climate.

Question 68

Provide three examples of how lahars can form.

Question 69

How is this chain of volcanic islands forming?

A)A tectonic plate is being subducted and partially melted, producing magma that rises to create a volcanic chain.
B)Two tectonic plates are pulling apart, creating magma through decompression melting.
C)A tectonic plate is moving over a mantle plume, which burns through the plate to create a chain of volcanoes.
D)Tectonic plates are sliding past each other, generating magma, which creates a volcano.

Question 70

Based on the volcanic type and construction of the flanks, what assumptions can you make about the type of lava?

A)The lava is basaltic.
B)The lava is andesitic.
C)The lava is rhyolitic.

Question 71

The volcanic islands visible here formed as a result of a mantle plume.Which volcanic island is still forming?

A)Volcano A
B)Volcano B
C)Volcano C

Question 72

Why are block lavas, such as an andesite lava, likely to create short, prominent flows rather than long, fluid flows?

Question 73

Explain why volcanic bombs take on a streamlined shape when they are flung through the air.

Question 74

Based on the information visible, what kind of volcano is this?

A)Shield volcano
B)Composite cone
C)Cinder cone

Question 75

What materials make up a pyroclastic flow?

Question 76

What kind of volcano is this?

A)Shield volcano
B)Composite cone
C)Cinder cone

Question 77

The volcanic islands visible here formed as a result of a mantle plume.Assuming the left side of the figure is west and the right side east, in which direction is the tectonic plate is moving?

A)North
B)South
C)East
D)West

Question 78

How do scientists use earthquakes to determine if a volcano may erupt soon?

Question 79

Pahoehoe and Aa can form in the same lava as it flows away from the eruptive vent.How does each form? What role does temperature play?

Question 80

How does a volcanic neck form? What happens to the rest of the volcano that originally surrounded it?