Deck 9: The Wrath of Vulcan: Volcanic Eruptions

Question 1

Pahoehoe ____________.

A)forms when basaltic lava flows cease flowing and solidify simultaneously
B)has a smoother texture than aa
C)is easier to walk on than aa is
D)All of the above are correct.

Answer 1

D

Question 2

A fast-moving flow consisting of a mixture of water and volcaniclastic debris is termed a ____________.

A)lahar
B)glowing avalanche
C)flood basalt
D)stratovolcano

Answer 2

A

Question 3

Volcanic bombs are ____________.

A)pyroclastic blocks that acquire aerodynamic shapes during flight out of the volcanic vent
B)explosive bodies of lava with high volatile content
C)cinders that explode upon impact with the ground
D)used by geologists to set off small eruptions in volcanoes that are deemed potentially dangerous

Answer 3

A

Question 4

Ash,cinders,and blocks are all types of ____________.

A)volcaniclastic debris
B)lava flows
C)Pele's hair
D)volcanoes

Question 5

Most terrestrial volcanic glass ____________.

A)is highly silicic in composition
B)is coarse grained
C)consists of microscopic crystals
D)freezes from lavas with low viscosity

Question 6

Olympus Mons,the largest known volcano in the Universe,is found on ___________.

A)Earth
B)Mars
C)Neptune
D)Io,a moon of Jupiter

Question 7

Gases that are abundantly emitted by volcanoes include ____________.

A)water vapor,carbon dioxide,and sulfur dioxide
B)oxygen,ozone,and water vapor
C)oxygen,hydrogen,and neon
D)carbon dioxide,carbon monoxide,and oxygen

Question 8

Basaltic lavas ____________.

A)contain more iron and magnesium than rhyolitic lavas
B)contain more silica than rhyolitic lavas
C)are more viscous than rhyolitic lavas
D)contain a greater proportion of trapped volatiles than rhyolitic lavas

Question 9

Columnar jointing is a type of fracturing that occurs in andesitic and rhyolitic lava flows.

Question 10

In 79 C.E. ,the citizens of Pompeii in the Roman Empire were buried by pyroclastic debris derived from an eruption of ____________.

A)Mt.Olympus
B)Olympus Mons
C)Mt.Vesuvius
D)Mt.St.Helens

Question 11

Mafic magmas are distinguished by ____________.

A)light coloration
B)low viscosity
C)high viscosity
D)high silica content

Question 12

The characteristic "rotten egg" smell of many active volcanoes is derived from ____________.

A)iron and magnesium within lava
B)carbon dioxide gas
C)stale water within the magma chamber
D)hydrogen sulfide gas

Question 13

Basaltic lavas that solidify at the surface before flow ceases fracture irregularly,producing a sharp-surfaced lava rock named ____________.

A)pahoehoe
B)aa
C)pumice
D)hyaloclasite

Question 14

The smoky cloud that rises from the vent of an actively erupting volcano is composed of ____________.

A)smoke from wildfires inside the volcanic chimney
B)smoke from wildfires on the outer slopes of the volcano that funnel into the crater
C)fine volcaniclastic debris (ash)suspended in the air
D)a continuous fountain of dark,basaltic lava

Question 15

Rhyolitic lavas ____________.

A)do not flow as far from the vent as basaltic lavas do
B)cool much more slowly than basaltic lavas do
C)are associated with volcanoes that almost never emit pyroclastic debris
D)All of the above are correct.

Question 16

Pillow lavas are associated with ____________.

A)continental rhyolitic eruptions
B)continental basaltic eruptions
C)submarine rhyolitic eruptions
D)submarine basaltic eruptions

Question 17

The lithification of material from a pyroclastic flow forms a rock called ____________.

A)metabasalt
B)ignimbrite
C)migmatite
D)tuff

Question 18

Pele's hair ____________.

A)consists of thin strands of basaltic volcaniclastic debris
B)acquire aerodynamic torpedo-like shapes during flight out of the volcanic vent
C)forms only at the leading edge of basaltic lava flows
D)was instrumental in scoring the winning goal to defeat Uruguay in the 1958 World Cup finals

Question 19

The difference between tephra and tuff is that ____________.

A)tephra is created in ash falls,whereas tuff is created in pyroclastic flows
B)tephra is unlithified,whereas tuff is lithified
C)tephra is always silicic,whereas tuff is always basaltic
D)All of the above are correct.

Question 20

In 1902,a famous,deadly volcaniclastic flow killed thousands of people on the Caribbean island of ____________.

A)Puerto Rico
B)Martinique
C)Aruba
D)Jamaica

Question 21

Mt.Fuji in Japan is an example of a ____________.

A)stratovolcano
B)cinder cone
C)shield volcano

Question 22

Of the three primary forms of subaerial volcanoes,____________ consist of alternating layers of tephra and solidified lava.

A)stratovolcanoes
B)cinder cones
C)shield volcanoes

Question 23

Of the three primary forms of subaerial volcanoes,____________ have the most gently sloping sides,due to the low viscosity of the basaltic lavas that form them.

A)stratovolcanoes
B)cinder cones
C)shield volcanoes

Question 24

The Hawaiian island chain is an example of a(n)____________.

A)island volcanic arc
B)continental volcanic arc
C)hot-spot island chain
D)stratovolcanic assembly

Question 25

Olympus Mons,the largest known volcano in the Universe,is an example of a _____________.

A)stratovolcano
B)cinder cone
C)shield volcano

Question 26

Of the three primary forms of subaerial volcanoes,____________ are sometimes referred to as "composite volcanoes."

A)stratovolcanoes
B)cinder cones
C)shield volcanoes

Question 27

Of the three primary forms of subaerial volcanoes,____________ are the largest in area.

A)stratovolcanoes
B)cinder cones
C)shield volcanoes

Question 28

Iceland rises above the Atlantic Ocean as a result of ____________.

A)normal mid-ocean ridge activity
B)a submarine hot spot located within the interior of a plate
C)a submarine hot spot located along a mid-ocean ridge
D)subduction of an oceanic plate underneath the continental Eurasian Plate

Question 29

Which national park is home to a large volcanic caldera formed through a very large explosive eruption 640,000 years ago?

A)Acadia
B)Carlsbad Caverns
C)Great Smoky Mountains
D)Yellowstone

Question 30

Phreatomagmatic eruptions take place when ____________.

A)volatiles effervesce prior to lava flow
B)water enters the magma chamber and forms steam
C)basaltic lava clogs the chimney
D)lava or pyroclastic debris erupt by bursting through the sides of the volcano

Question 31

Explosive or voluminous eruptions may cause the volcano to collapse on the floor of the (now empty)magma chamber,producing a broad depression termed a ____________.

A)crater
B)lahar
C)caldera
D)fissure

Question 32

Hawaiian-style effusive eruptions are a greater threat to property than to human life.

Question 33

Phreatomagmatic eruptions are ____________.

A)explosive (pyroclastic)
B)effusive (dominated by lava flows)

Question 34

All volcanic eruptions pass through the crater at the volcanic summit.

Question 35

The Columbia River Plateau is an example of a ____________.

A)caldera
B)fissure
C)flood basalt
D)hot spot

Question 36

Nonviolent eruptions characterized by extensive flows of basaltic lava are termed ____________.

A)pyroclastic
B)effusive
C)explosive

Question 37

Whether an eruption will primarily produce lava flows or pyroclastic debris is influenced by the ____________.

A)viscosity of the lava
B)composition of the lava
C)proportion of volatiles within the lava
D)All of the above are correct.

Question 38

Hot-spot volcanoes ____________.

A)can arise from the ocean floor
B)can arise on continents
C)may arise in the interior of lithospheric plates
D)All of the above are correct.

Question 39

As compared to subaerial basaltic lavas,submarine basaltic lavas differ in that they ____________.

A)always produce violent pyroclastic debris flows
B)produce large crystals of pyroxene and plagioclase
C)form pillow-like mounds because they cannot flow as far from their source
D)All of the above are correct.

Question 40

Of the three primary forms of subaerial volcanoes,____________ consist of a simple,conical pile of tephra.

A)stratovolcanoes
B)cinder cones
C)shield volcanoes

Question 41

The eruption of Mt.St.Helens in 1980 was the greatest explosive eruption in the last 200 years of world data.

Question 42

The hot-spot track associated with the Hawaiian Islands and Emperor Seamounts ____________.

A)shows that the Pacific Plate has been stationary over the last 30 million years
B)occurs along a divergent plate boundary
C)occurs along a convergent plate boundary
D)shows that the Pacific Plate has been moving northwest for the last 30 million years

Question 43

What was unusual about the 1986 disaster around Lake Nyos in Cameroon?

A)a volcanic eruption involved a lateral blast of volcaniclastic debris that no one anticipated
B)pyroclastic flows buried surrounding villages,reminiscent of Pompeii 1,900 years earlier
C)volcanically derived carbon dioxide gas bubbled from the lake and suffocated people and animals nearby
D)a slurry of lava and lake water flowed rapidly outward from the lake and buried surrounding villages

Question 44

One of the reasons volcanic eruptions are so deadly is that there is no way to predict where an eruption will occur in the near future.

Question 45

Volcanoes are entirely detrimental to the planet and human civilization,offering no benefits to humankind.

Question 46

At continental rifts,vast bodies of basaltic lava flow forth from fissures,forming ____________.

A)flood basalts
B)pyroclastic flows
C)ash-fall tuffs

Question 47

rWhat signs do scientists look for when predicting volcanic eruptions?

A)changes in earthquake activity
B)increases in gas and steam emission
C)changes in shape
D)All of the above are correct.

Question 48

The greatest hazard to human life associated with volcanoes is ____________.

A)flowing lava
B)volcanic gas
C)falling ash
D)pyroclastic flows

Question 49

Large-scale volcanic eruptions can cause a drop in global temperatures.

Question 50

Mt.St.Helens killed a geologist studying the volcano because ____________.

A)the geologist disregarded orders to keep a safe distance from the vent
B)the eruption produced a greater volume of ash than anyone predicted
C)a landslide produced a lateral blast of volcaniclastic debris that no one anticipated
D)lahars swept down all sides of the volcano and buried all towns within 100 km