Question 1

Compare and contrast fissure eruptions and pyroclastic sheet deposits.

Accepted Answer

During both fissure eruptions and pyroclastic sheet deposits, eruptions issue from long cracks or fissures, cover vast areas, and volcanoes fail to develop. During fissure eruptions, the lava is so fluid (has such low viscosity)that it spreads out and covers vast areas. In contrast, it seems that pyroclastic sheet deposits originated as pyroclastic flows-hence the name. The pyroclastic materials of many of these flows were so hot that they fused together to form welded tuff. Geologists now think that major pyroclastic flows issue from fissures formed during the origin of calderas.

Question 2

Would you rather be chased by a pahoehoe flow or an aa flow? Explain.

Accepted Answer

I would rather be chased by an aa flow. Pahoehoe flows are hotter and less viscous and can move rapidly. Aa flows are cooler, more viscous, and move much more slowly.

Question 3

Lava domes form from ____.

Accepted Answer

A) mafic and intermediate magma 
B) intermediate magma 
C) viscous felsic and intermediate magma 
D) pyroclastic materials 
E) fissure eruptions 
A) mafic and intermediate magma 
B) intermediate magma 
C) viscous felsic and intermediate magma 
D) pyroclastic materials 
E) fissure eruptions C

Question 4

What are the criteria used by geologists to give a semiquantitative measure of the size of an eruption?

Accepted Answer

A) number of deaths caused by the eruption and the number of buildings destroyed 
B) volume of material erupted and height of the eruption plume 
C) size of the pre-erupted volcano and the type 
D) temperature and pressure during eruption 
E) sizes of pyroclastic materials ejected and the distances they travel from the volcano 
A) number of deaths caused by the eruption and the number of buildings destroyed 
B) volume of material erupted and height of the eruption plume 
C) size of the pre-erupted volcano and the type 
D) temperature and pressure during eruption 
E) sizes of pyroclastic materials ejected and the distances they travel from the volcano

Question 5

At convergent plate boundaries, more viscous magmas, usually of felsic composition, are emplaced as ____, thus accounting for the explosive eruptions that typically occur there.

Accepted Answer

A) supervolcanoes 
B) plutons 
C) fissures 
D) lava domes 
E) cinder cones 
A) supervolcanoes 
B) plutons 
C) fissures 
D) lava domes 
E) cinder cones

Question 6

Other than Earth, what planet is most likely to have active volcanoes?

Accepted Answer

A) Mercury 
B) Venus 
C) Mars 
D) Saturn 
E) Neptune 
A) Mercury 
B) Venus 
C) Mars 
D) Saturn 
E) Neptune

Question 7

What are lava domes? Provide one example. Explain under what circumstances they form and what type of magma is usually involved? Are their eruptions gentle or violent?

Accepted Answer

Lava domes , also known as volcanic dome

Question 8

Briefly describe cinder cones.

Accepted Answer

Cinder cones are small, steep-sided volc

Question 9

The particularly cold summer of 1816 was attributed to the huge eruption of Tambora in 1815 in Indonesia. In North America, 1816 was called ____________________.

Accepted Answer

"The Year Without a

Question 10

The type of volcano with the gentlest slope is the ____________________ volcano.

Accepted Answer

The answer of The type of volcano with the gentlest...

Question 11

Mafic magma is generated beneath spreading ridges, and intermediate or felsic magma forms where an oceanic plate is subducted beneath another plate. Therefore, we can conclude that most volcanism takes place at or near ____________________ and ____________________ plate boundaries.

Accepted Answer

divergent,

Question 12

Define volcanism.

Accepted Answer

Volcanism refers to all proces

Question 13

Cinder cones ____.

Accepted Answer

A) are large, gently sloped volcanoes 
B) often form on the flanks or within the calderas of larger volcanoes 
C) are often formed during the beginning stages of volcanic activity 
D) are also called stratovolcanoes 
E) result from the buildup of many layers of ancient lava flows 
A) are large, gently sloped volcanoes 
B) often form on the flanks or within the calderas of larger volcanoes 
C) are often formed during the beginning stages of volcanic activity 
D) are also called stratovolcanoes 
E) result from the buildup of many layers of ancient lava flows

Question 14

The three major types of volcanoes are ____.

Accepted Answer

A) shield volcanoes, cinder cones, and lava domes 
B) shield volcanoes, cinder cones, and composite volcanoes 
C) cinder cones, composite volcanoes, and lava domes 
D) composite volcanoes, stratovolcanoes, and lava domes 
E) shield volcanoes, composite volcanoes, and stratovolcanoes 
A) shield volcanoes, cinder cones, and lava domes 
B) shield volcanoes, cinder cones, and composite volcanoes 
C) cinder cones, composite volcanoes, and lava domes 
D) composite volcanoes, stratovolcanoes, and lava domes 
E) shield volcanoes, composite volcanoes, and stratovolcanoes

Question 15

Mount ____________________ erupted in 79 A.D. and buried the Italian city of Pompeii.

Accepted Answer

The answer of Mount ____________________ erupted in 79 A.D. and...

Question 16

Basalt plateaus erupt from ____.

Accepted Answer

A) supervolcanoes 
B) shield volcanoes 
C) fissures 
D) lava domes 
E) cinder cones 
A) supervolcanoes 
B) shield volcanoes 
C) fissures 
D) lava domes 
E) cinder cones

Question 17

Volcanic eruptions destroy buildings and productive land, and cause injuries and fatalities to life. Why, then, is volcanism considered a constructive process?

Accepted Answer

Volcanic emissions played an important r

Question 18

Geologists successfully gave timely warnings of impending eruptions of Mount St. Helens and Mount Pinatubo.

Accepted Answer

A) True 
 B)False

Question 19

Although it is difficult to get a precise number of active volcanoes, a common estimate is about ____.

Accepted Answer

A) 100 
B) 250 
C) 550 
D) 1100 
E) 2000 
A) 100 
B) 250 
C) 550 
D) 1100 
E) 2000

Question 20

Pyroclastic materials ____.

Accepted Answer

A) have low viscosity and a ropy texture 
B) are rare to absent at great depths in the ocean 
C) do not vary in size 
D) are always ejected very quickly from volcanoes 
E) can only be found at locations where intraplate volcanism occurs 
A) have low viscosity and a ropy texture 
B) are rare to absent at great depths in the ocean 
C) do not vary in size 
D) are always ejected very quickly from volcanoes 
E) can only be found at locations where intraplate volcanism occurs

Exam 5: Volcanoes and Volcanism

Compare and contrast fissure eruptions and pyroclastic sheet deposits.

Would you rather be chased by a pahoehoe flow or an aa flow? Explain.

Lava domes form from ____.

What are the criteria used by geologists to give a semiquantitative measure of the size of an eruption?

At convergent plate boundaries, more viscous magmas, usually of felsic composition, are emplaced as ____, thus accounting for the explosive eruptions that typically occur there.

Other than Earth, what planet is most likely to have active volcanoes?

What are lava domes? Provide one example. Explain under what circumstances they form and what type of magma is usually involved? Are their eruptions gentle or violent?

Briefly describe cinder cones.

The particularly cold summer of 1816 was attributed to the huge eruption of Tambora in 1815 in Indonesia. In North America, 1816 was called ____________________.

The type of volcano with the gentlest slope is the ____________________ volcano.

Mafic magma is generated beneath spreading ridges, and intermediate or felsic magma forms where an oceanic plate is subducted beneath another plate. Therefore, we can conclude that most volcanism takes place at or near ____________________ and ____________________ plate boundaries.

Define volcanism.

Cinder cones ____.

The three major types of volcanoes are ____.

Mount ____________________ erupted in 79 A.D. and buried the Italian city of Pompeii.

Basalt plateaus erupt from ____.

Volcanic eruptions destroy buildings and productive land, and cause injuries and fatalities to life. Why, then, is volcanism considered a constructive process?

Geologists successfully gave timely warnings of impending eruptions of Mount St. Helens and Mount Pinatubo.

Although it is difficult to get a precise number of active volcanoes, a common estimate is about ____.

Pyroclastic materials ____.

Understanding Earth: a Dynamic and Evolving Planet

Plate Tectonics: a Unifying Theory

Minerals: The Building Blocks of Rocks

Igneous Rocks and Plutons

Weathering, Erosion, and Soil

Sediment and Sedimentary Rocks

Metamorphism and Metamorphic Rocks

Earthquakes and Earthapos;s Interior

Deformation, Mountain Building, and Earthapos;s Crust

Mass Wasting

Running Water--Streams and Rivers

Groundwater

Glaciers and Glaciation

The Work of Wind and Deserts

Oceans, Shorelines, and Shoreline Processes

Geologic Time: Concepts and Principles

Organic Evolution--The Theory and Its Supporting Evidence

Precambrian Earth and Life History

Paleozoic Earth History

Paleozoic Life History

Mesozoic Earth and Life History

Cenozoic Earth and Life History

Filters

Mafic magma is generated beneath spreading ridges, and intermediate or felsic magma forms where an oceanic plate is subducted beneath another plate. Therefore, we can conclude that most volcanism takes place at or near and plate boundaries.