Deck 5: Volcanoes

Question 1

Mauna Loa in Hawaii is an example of which type of volcano?

A) Shield volcano
B) Composite cone
C) Lava dome
D) Cinder cone
E) Stratovolcano

Answer 1

A

Question 2

Where is the majority of lava extruded?

A) At subduction zones
B) At hotspots
C) At divergent plate boundaries
D) At transform plate boundaries
E) At convergent plate boundaries

Answer 2

C

Question 3

Which volcano type involves layers of pyroclastic debris and lava flows?

A) Shield volcano
B) Stratovolcano
C) Lava dome
D) Cinder cone

Answer 3

B

Question 4

Why are so many volcanoes found on the Ring of Fire around the margin of the Pacific Ocean?

A) Many hotspots occur there.
B) Many subduction zones occur there.
C) The Pacific Ocean is very hot, causing rock to melt.
D) The climate is hot there, favoring volcano formation.
E) The seafloor is spreading extremely fast there.

Question 5

Which of the following is FALSE about caldera eruptions?

A) Caldera eruptions are extremely violent in nature.
B) Caldera eruptions are very rare.
C) Caldera eruptions erupt enough ash to potentially alter global climate.
D) Caldera eruptions result in towering volcanic mountains.
E) Caldera eruptions have occurred in the United States in geologic history.

Question 6

Which type of magma typically results in the greatest explosive events?

A) Basaltic
B) Andesitic
C) Rhyolitic
D) Pahoehoe
E) Aa

Question 7

Which volcano type is composed mostly of pyroclastic debris?

A) Shield volcano
B) Stratovolcano
C) Lava dome
D) Cinder cone
E) Composite cone

Question 8

What are volatiles?

A) Large blocky projectiles fired from a volcano
B) Small abrasive particles such as volcanic ash that can make it difficult to breath
C) Thin fibers of lava that is extruded from a volcano
D) Silica tetrahedra in magma
E) Gases trapped in the magma

Question 9

What is the difference between magma and lava?

A) Magma is molten rock, lava is hot solid rock and water.
B) Magma is black, lava is red.
C) Magma is found below the Earth's surface, lava is found on the Earth's surface.
D) Magma is found on the ocean floor, lava is found on land surfaces.
E) There is no difference between lava and magma.

Question 10

In which of the following tectonic plate settings are volcanoes typically NOT found?

A) Mid-ocean ridge
B) Continental rift
C) Subduction zone
D) Transform fault
E) Hotspot

Question 11

A very large volcano with gentle slopes is a ________ , which is comprised of ________.

A) Shield volcano...lava flows
B) Shield volcano...pyroclastic debris
C) Stratovolcano...lava flows
D) Stratovolcano...lava flows and pyroclastic debris
E) Cinder cone volcano...pyroclastic debris

Question 12

Which of the following magma types will usually flow the fastest?

A) Basaltic
B) Andesitic
C) Rhyolitic
D) All magma flows at similar speeds.

Question 13

Which of the following is NOT a reason why stratovolcanoes are dangerous?

A) They are associated with higher viscosity magma.
B) They have dormant periods between eruptions, which can make people underestimate their hazard.
C) They erupt abundant pyroclastic debris.
D) They involve explosive eruptions.
E) They erupt fast-moving lava flows that kill many people.

Question 14

Mt. St. Helens in Washington is an example of which type of volcano?

A) Shield volcano
B) Stratovolcano
C) Caldera
D) Cinder cone

Question 15

Which of the following is FALSE about magma?

A) Most magmas come from melting of the asthenosphere.
B) Some magma comes from rocks melted through decompression.
C) Adding volatiles, such as water, to rock decreases its melting point and makes it easier to melt.
D) Some rocks are melted from magma that is rising from deep within the Earth.
E) Tectonic plates move around on an underground ocean of magma.

Question 16

Which of the following lists magma types in order of increasing viscosity (LEAST viscous first)?

A) Basaltic, andesitic, rhyolitic
B) Basaltic, rhyolitic, andesitic
C) Rhyolitic, basaltic, andesitic
D) Rhyolitic, andesitic, basaltic
E) Andesitic, rhyolitic, basaltic

Question 17

Why do cinder cone volcanoes have steep slopes?

A) They are made from lava flows that pile up steeply.
B) They are found near other volcanoes which crowds their ability to spread out.
C) They are made mostly from water and ash that hardens into steep cones.
D) They are made from pyroclastic materials that pile up near where they were erupted.
E) They are made from very thick magma that doesn't flow outward very much.

Question 18

At which plate boundary is more viscous lava found?

A) Oceanic hotspots
B) Oceanic subduction zones
C) Oceanic divergent plate boundaries
D) Continental rift zones
E) Shield volcanoes on the ocean floor

Question 19

What is the difference between a crater and a caldera?

A) Craters are only formed from asteroid impacts.
B) Craters are formed from explosions while calderas are formed from inward collapse of volcano tops.
C) Calderas are craters found on the moon.
D) Calderas are only formed from asteroid impacts.

Question 20

Where does tephra come from?

A) It is the volcanic rock and lava blasted into the air or carried by gases.
B) It is from the inner part of a gently erupted lava flow.
C) It represents broken pieces of the volcano and is produced by weathering and erosion.
D) It is mud associated with a mudflow that was triggered by a volcanic eruption.

Question 21

What is a pyroclastic flow?

A) A fast-moving avalanche of hot rock, ash and glass fragments
B) A slurry-like flow of hot ash, mud, and water
C) An avalanche of ash and water
D) A flow of volcanic rock pieces and molten lava
E) A flow of lava and water

Question 22

The disaster at Lake Nyos in Cameroon (Africa) is thought to have been caused by a

A) volcanic eruption that created a giant water wave, which flooded nearby areas.
B) volcanic eruption that created a landslide, which in turn created a giant water wave that flooded nearby areas.
C) volcanic eruption that destroyed a dam, which flooded nearby areas.
D) suffocating cloud of carbon dioxide gas.

Question 23

Which of the following environments has the most explosive volcanoes?

A) Hotspots in the ocean
B) Hotspots on land
C) Continental rift zones
D) Mid-ocean ridges
E) Subduction zones

Question 24

Which of the following is NOT a benefit of volcanoes to the Earth and its inhabitants?

A) Volcanic soils have minerals that grow certain types of plants.
B) Volcanic processes can create valuable deposits of metals and minerals that are useful for building.
C) Volcanoes are beautiful and provide areas for recreation.
D) Heat from volcanoes can be harnessed to produce energy.
E) Many of the world's major oil fields are in volcanic rock.

Question 25

Which of following effects might an area see even if a volcano does NOT actually erupt?

A) Lahars and pyroclastic flows
B) Lahars and ash falls
C) Landslides and poisonous gases
D) Landslides and pyroclastic flows
E) Lava flows and poisonous gases

Question 26

Where are the majority of the active volcanoes in the United States?

A) Washington, Oregon and California
B) Wyoming and Idaho
C) Hawaii
D) Alaska
E) There are NO active volcanoes in the United States.

Question 27

How can volcanoes contribute to climate change?

A) Volcanoes release hot air into the atmosphere, contributing to global warming.
B) Erupted lava from volcanoes heats up the air in the atmosphere, contributing to global warming.
C) Lava flows cool into black rock that increase sunlight absorption by the Earth, contributing to global warming.
D) Volcanoes can send large amounts of fine-grained ash and sulfuric acid aerosols into the atmosphere, potentially causing global cooling.

Question 28

What is the best reason why most lava flows aren't a threat to human life?

A) Most lava flows don't move into inhabited areas.
B) Lava flows usually don't flow very quickly, people can outrun them.
C) Lava stays in the volcano and generally doesn't flow.
D) Lava flows are not hot enough to kill people, just to burn them.

Question 29

Which of the following natural hazards is NOT caused by volcanoes?

A) Climate change
B) Landslides
C) Fire
D) Tsunami
E) Tornadoes

Question 30

Which is NOT a location where volcanoes are found?

A) Alaska
B) Central United States
C) Hawaii
D) Pacific Northwest United States
E) Yellowstone National Park

Question 31

Several communities around Mt. Rainier are built on enormous old lahar deposits. What might people in these areas expect in an eruption?

A) Their homes will probably be destroyed by a new lahar.
B) Their homes will be safe because new lahars will go elsewhere.
C) Their homes will probably be safe because homes are built to withstand lahars.
D) Their homes will probably have some water flooding damage.

Question 32

Which of the following volcanic hazards is responsible for the most deaths?

A) Lava flows
B) Ash falls
C) Poisonous gases
D) Pyroclastic flows

Question 33

Which of the following was NOT a hazard associated with the explosion of Mt. St. Helens?

A) Landslide
B) Mudslide
C) Ash fall
D) Lava flows that built up the north side of the volcano

Question 34

In which two environments are shield volcanoes found?

A) Hotspots in the ocean and subduction zones
B) Hotspots on land and divergent plate boundaries
C) Divergent plate boundaries and subduction zones
D) Hotspots on land and subduction zones
E) Hotspots in the ocean and divergent plate boundaries

Question 35

How might you escape from a lahar?

A) Swim to safety in the flow
B) Outrun the lahar because it is slow
C) Float in a boat in the lahar
D) Run up an embankment away from the flow
E) Walk on top of the flow because it is so thick

Question 36

Which of the following is NOT a reason why an ash fall can be hazardous?

A) Destroys crops and makes the ground unsuitable for planting
B) Contaminates water supplies
C) Accumulates on building roofs causing them to collapse
D) Gets into jet engines causing them to fail
E) Sets on fire everything it touches

Question 37

Do humans affect the frequency or size of volcanic eruptions?

A) Yes. Global warming is a direct cause of many volcanic eruptions.
B) Yes. More people living on volcanoes causes volcanoes to erupt.
C) Yes. More people in the area of volcanoes means less groundwater in those areas and that causes volcanoes to erupt.
D) Yes. Mitigation measures by humans keep many volcanoes from erupting.
E) No. People do not increase or decrease the volcanic hazard.

Question 38

What type of volcano is found in Iceland?

A) Shield
B) Stratovolcano
C) Cinder cone
D) Caldera
E) No volcanoes are found in Iceland.

Question 39

In the past 50 years, have there been any deaths attributed to a volcanic eruption?

A) Yes. Thousands of people have died as a result of an eruption.
B) Yes. A few unfortunate people have been killed due to volcanic eruptions.
C) No. All people were given enough warning and nobody has been killed in recent times.
D) No. Recent volcanic eruptions have been in remote areas where there were no deaths.
E) No. There have been no volcanic eruptions in recent times.

Question 40

Where is the best place to be during a pyroclastic flow?

A) In the water
B) In your house
C) On a hillside
D) In a valley
E) Nowhere is safe during a pyroclastic flow.

Question 41

Caldera eruptions can involve the largest volcanic eruptions on earth and they are the rarest.

Question 42

Which of the following is NOT a reason why people live near volcanoes?

A) They don't think that they will erupt.
B) They don't have anywhere else to go.
C) The soil is good for farming.
D) It is their home.
E) Local zoning laws require some people to live near volcanoes.

Question 43

Because of the alert systems and people's willingness to heed warnings, no one was killed in the 1980 Mt. St. Helens eruption.

Question 44

If a basaltic lava flow were coming toward you, you could probably outrun it.

Question 45

Why do scientists study earthquakes to predict a volcanic eruption?

A) When magma moves, it causes earthquakes.
B) Earthquakes break the earth apart and cause magma to appear at the surface.
C) All big earthquakes are caused by magma erupting.
D) Groundwater moves before an eruption, causing earthquakes.

Question 46

Magma with a higher silica content will also have a higher viscosity.

Question 47

Composite volcanoes can have a long dormant period in which people can forget that they were ever once active volcanoes.

Question 48

Volcanic ash is very lightweight and therefore is not much of a threat to buildings.

Question 49

The area around Mt. St. Helens is now safe because the volcano is finished erupting and will stay dormant for the next 200 years.

Question 50

Volcanoes associated with high viscosity magma are usually less dangerous than those with more freely flowing magma.

Question 51

There has never been a globally catastrophic volcanic eruption from Iceland's volcanoes because they only involve gentle lava flows.

Question 52

Most volcanoes are found near tectonic plate boundaries because that's where the magma is located.

Question 53

There have never been any caldera eruptions in the U.S. and probably won't be in the future.

Question 54

Shield volcanoes are the most dangerous volcanoes because they are so big.

Question 55

Mauna Loa in Hawaii is an example of a shield volcano built over a hotspot.

Question 56

Which of the following is NOT used to determine whether a volcanic eruption is expected?

A) Increase in earthquake activity
B) Changes in groundwater temperature
C) Decrease in atmospheric pressure
D) Change in shape of land surfaces around the volcano
E) Change in CO2 emissions

Question 57

If a volcanic eruption is predicted for your area, what is the best course of action?

A) Board up your windows and doors
B) Bring food and water into your basement and stay there
C) Build a firebreak around your home
D) Build a moat around your home
E) Evacuate

Question 58

The eruption of Mt. St. Helens was an isolated event and didn't have much impact outside the local area.

Question 59

Craters differ from calderas in that craters are created from an explosion and then collapse of the volcano top whereas calderas are simply the location where lava flows originate.

Question 60

Mudflows or lahars associated with volcanoes do not usually cause much damage in a volcanic eruption because they are constrained to river valleys.

Question 61

Explain the difference between magma formed at subduction zones and divergent plate boundaries.

Question 62

Scientists can use information about earthquakes to determine when a volcano is likely to erupt.

Question 63

Explain what viscosity is and how it affects the effects of a volcano. Give one example to illustrate your point.

Question 64

Unfortunately, volcanoes do not give any signs or indications of when they might erupt.

Question 65

Explain the difference between a lava flow, a lahar and a pyroclastic flow. Which would be the most dangerous in an eruption and why?

Question 66

Heat from volcanic areas can be used to generate electrical power.

Question 67

Tephra can come in many different sizes from dust size to large pieces called bombs.

Question 68

People have successfully diverted lava flows from populated areas.

Question 69

Describe the hazards associated with an ash fall.

Question 70

Seattle, Washington is near the active volcano, Mt. Rainier. If you were put in charge of education for the city of Seattle, what hazards would you alert people of about Mt. Rainier? In addition, what type of warning systems would you put in place and what would you tell people to do in case of a potential hazard?

Question 71

Volcanoes can cause tsunamis.

Question 72

Explain what viscosity is and how it affects the shape of a volcano. Give one example to illustrate your point.

Question 73

Hilo, Hawaii is near one of the largest volcanoes, Mauna Loa. If you were put in charge of education for the city of Hilo, what hazards would you alert people of about Mauna Loa? In addition, what type of warning systems would you put in place and what would you tell people to do in case of a potential hazard?

Question 74

What are the main activities involved in forecasting a volcano?

Question 75

Volcanic soils are usually too hot and dry to be of use for agriculture.

Question 76

The history of an area's rocks can give a timeline of past volcanic eruptions.

Question 77

Most volcanoes are around the Pacific Ocean's "Ring of Fire." Explain why they are there and what kind of volcanoes form there.

Question 78

An eruption of the Long Valley or Yellowstone volcano could have catastrophic consequences for the entire globe. Explain how an eruption might affect most of the United States and how it might affect the planet. Is it possible to prepare for an eruption of this magnitude? How? Why not?